/*
* =====================================================================
* DrawingPanel.java
* Simplified Java drawing window class
* to accompany Building Java Programs textbook and associated materials
*
* authors: Stuart Reges, University of Washington
* Marty Stepp
* version: 4.08, 2025/02/07 (BJP 6th edition)
* (make sure to also update version string in Javadoc header below!)
* =====================================================================
*
* COMPATIBILITY NOTE: This version of DrawingPanel requires Java 8 or higher.
* If you need a version that works on Java 7 or lower, please see our
* web site at http://www.buildingjavaprograms.com/ .
* To make this file work on Java 7 and lower, you must make two small
* modifications to its source code.
* Search for the two occurrences of the annotation @FunctionalInterface
* and comment them out or remove those lines.
* Then the file should compile and run properly on older versions of Java.
*
* =====================================================================
*
* The DrawingPanel class provides a simple interface for drawing persistent
* images using a Graphics object. An internal BufferedImage object is used
* to keep track of what has been drawn. A client of the class simply
* constructs a DrawingPanel of a particular size and then draws on it with
* the Graphics object, setting the background color if they so choose.
* See JavaDoc comments below for more information.
*/
import java.awt.FontMetrics;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.image.ImageObserver;
import java.text.AttributedCharacterIterator;
import java.util.Collections;
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.awt.image.BufferedImage;
import java.awt.image.PixelGrabber;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.lang.Exception;
import java.lang.Integer;
import java.lang.InterruptedException;
import java.lang.Math;
import java.lang.Object;
import java.lang.OutOfMemoryError;
import java.lang.SecurityException;
import java.lang.String;
import java.lang.System;
import java.lang.Thread;
import java.net.URL;
import java.net.NoRouteToHostException;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;
import java.util.Vector;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JColorChooser;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.KeyStroke;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.MouseInputAdapter;
import javax.swing.event.MouseInputListener;
import javax.swing.filechooser.FileFilter;
/**
*
* DrawingPanel is a simplified Java drawing window class to accompany
* Building Java Programs textbook and associated materials.
*
*
* Authors: Stuart Reges (University of Washington) and Marty Stepp.
*
*
* Version: 4.08, 2025/02/07 (to accompany BJP 6th edition).
*
*
* You can always download the latest {@code DrawingPanel} from
*
* http://www.buildingjavaprograms.com/drawingpanel/DrawingPanel.java .
*
*
* For more information and related materials, please visit
*
* www.buildingjavaprograms.com .
*
*
* COMPATIBILITY NOTE: This version of DrawingPanel requires Java 8 or higher.
* To make this file work on Java 7 and lower, you must make two small
* modifications to its source code.
* Search for the two occurrences of the annotation @FunctionalInterface
* and comment them out or remove those lines.
* Then the file should compile and run properly on older versions of Java.
*
*
Description:
*
*
* The {@code DrawingPanel} class provides a simple interface for drawing persistent
* images using a {@code Graphics} object. An internal {@code BufferedImage} object is used
* to keep track of what has been drawn. A client of the class simply
* constructs a {@code DrawingPanel} of a particular size and then draws on it with
* the {@code Graphics} object, setting the background color if they so choose.
*
*
*
* The intention is that this custom library will mostly "stay out of the way"
* so that the client mostly interacts with a standard Java {@code java.awt.Graphics}
* object, and therefore most of the experience gained while using this library
* will transfer to Java graphics programming in other contexts.
* {@code DrawingPanel} is not intended to be a full rich graphical library for things
* like object-oriented drawing of shapes, animations, creating games, etc.
*
*
* Example basic usage:
*
*
* Here is a canonical example of creating a {@code DrawingPanel} of a given size and
* using it to draw a few shapes.
*
*
*
* // basic usage example
* DrawingPanel panel = new DrawingPanel(600, 400);
* Graphics g = panel.getGraphics();
* g.setColor(Color.RED);
* g.fillRect(17, 45, 139, 241);
* g.drawOval(234, 77, 100, 100);
* ...
*
*
*
* To ensure that the image is always displayed, a timer calls repaint at
* regular intervals.
*
*
* Pixel processing (new in BJP 4th edition):
*
*
* This version of {@code DrawingPanel} allows you to loop over the pixels of an image.
* You can process each pixel as a {@code Color} object (easier OO interface, but takes
* more CPU and memory to run) or as a 32-bit RGB integer (clunkier to use, but
* much more efficient in runtime and memory usage).
* Look at the methods get/setPixel(s) to get a better idea.
*
*
* // example of horizontally flipping an image
* public static void flipHorizontal(DrawingPanel panel) {
* int width = panel.getWidth();
* int height = panel.getHeight();
* int[][] pixels = panel.getPixelsRGB();
* for (int row = 0; row < height; row++) {
* for (int col = 0; col < width / 2; col++) {
* // swap this pixel with the one opposite it
* int col2 = width - 1 - col;
* int temp = pixels[row][col];
* pixels[row][col] = pixels[row][col2];
* pixels[row][col2] = temp;
* }
* }
* panel.setPixels(pixels);
* }
*
*
* Event listeners and lambdas (new in BJP 4th edition):
*
*
* With Java 8, you can now attach event handlers to listen to keyboard and mouse
* events that occur in a {@code DrawingPanel} using a lambda function. For example:
*
*
* // example of attaching a mouse click handler using Java 8
* panel.onClick( (x, y) -> System.out.println(x + " " + y) );
*
* Debugging facilities (new in BJP 4th edition):
*
*
* This version now includes an inner class named {@code DebuggingGraphics}
* that keeps track of how many times various drawing methods are called.
* It includes a {@code showCounts} method for the {@code DrawingPanel} itself
* that allows a client to examine this. The panel will record basic drawing
* methods performed by a version of the {@code Graphics} class obtained by
* calling {@code getDebuggingGraphics} :
*
*
* // example of debugging counts of graphics method calls
* Graphics g = panel.getDebuggingGraphics();
*
*
*
* Novices will be encouraged to simply print it at the end of {@code main}, as in:
*
*
* System.out.println(panel.getCounts());
*
*
* History and recent changes:
*
* 2025/02/07
* - Minor update to fix a bug in headless mode.
*
*
* 2022/04/07
* - Minor update to remove a security manager-related compiler warning in JDK 17+.
*
*
* 2016/07/25
* - Added and cleaned up BJP4 features, static anti-alias settings, bug fixes.
*
*
* 2016/03/07
* - Code cleanup and improvements to JavaDoc comments for BJP4 release.
*
*
* 2015/09/04
* - Now includes methods for get/setting individual pixels and all pixels on the
* drawing panel. This helps facilitate 2D array-based pixel-processing
* exercises and problems for Building Java Programs, 4th edition.
* - Code cleanup and reorganization.
* Now better alphabetization/formatting of members and encapsulation.
* Commenting also augmented throughout code.
*
*
* 2015/04/09
* - Now includes a DebuggingGraphics inner class that keeps track of how many
* times various drawing methods are called.
* All additions are commented (search for "DebuggingGraphics")
*
*
* 2011/10/25
* - save zoomed images (2011/10/25)
*
*
* 2011/10/21
* - window no longer moves when zoom changes
* - grid lines
*
* @author Stuart Reges (University of Washington) and Marty Stepp
* @version 4.08, 2025/02/07 (BJP 5th edition)
*/
public final class DrawingPanel implements ImageObserver {
// class constants
private static final Color GRID_LINE_COLOR = new Color(64, 64, 64, 128); // color of grid lines on panel
private static final Object LOCK = new Object(); // object used for concurrency locking
private static final boolean SAVE_SCALED_IMAGES = true; // if true, when panel is zoomed, saves images at that zoom factor
private static final int DELAY = 100; // delay between repaints in millis
private static final int MAX_FRAMES = 100; // max animation frames
private static final int MAX_SIZE = 10000; // max width/height
private static final int GRID_LINES_PX_GAP_DEFAULT = 10; // default px between grid lines
private static final String VERSION = "4.08 (2025/02/07)";
private static final String ABOUT_MESSAGE = "DrawingPanel\n"
+ "Graphical library class to support Building Java Programs textbook\n"
+ "written by Stuart Reges, University of Washington\n"
+ "and Marty Stepp\n\n"
+ "Version: " + VERSION + "\n\n"
+ "please visit our web site at:\n"
+ "http://www.buildingjavaprograms.com/";
private static final String ABOUT_MESSAGE_TITLE = "About DrawingPanel";
private static final String COURSE_WEB_SITE = "https://courses.cs.washington.edu/courses/cse142/CurrentQtr/drawingpanel.txt";
private static final String TITLE = "Drawing Panel";
/** An RGB integer representing alpha at 100% opacity (0xff000000). */
public static final int PIXEL_ALPHA = 0xff000000; // rgb integer for alpha 100% opacity
/** An RGB integer representing 100% blue (0x000000ff). */
public static final int PIXEL_BLUE = 0x000000ff; // rgb integer for 100% blue
/** An RGB integer representing 100% green (0x0000ff00). */
public static final int PIXEL_GREEN = 0x0000ff00; // rgb integer for 100% green
/** An RGB integer representing 100% red (0x00ff0000). */
public static final int PIXEL_RED = 0x00ff0000; // rgb integer for 100% red
/**
* The default width of a DrawingPanel in pixels, if none is supplied at construction (500 pixels).
*/
public static final int DEFAULT_WIDTH = 500;
/**
* The default height of a DrawingPanel in pixels, if none is supplied at construction (400 pixels).
*/
public static final int DEFAULT_HEIGHT = 400;
/** An internal constant for setting system properties; clients should not use this. */
public static final String ANIMATED_PROPERTY = "drawingpanel.animated";
/** An internal constant for setting system properties; clients should not use this. */
public static final String ANIMATION_FILE_NAME = "_drawingpanel_animation_save.txt";
/** An internal constant for setting system properties; clients should not use this. */
public static final String ANTIALIAS_PROPERTY = "drawingpanel.antialias";
/** An internal constant for setting system properties; clients should not use this. */
public static final String AUTO_ENABLE_ANIMATION_ON_SLEEP_PROPERTY = "drawingpanel.animateonsleep";
/** An internal constant for setting system properties; clients should not use this. */
public static final String DIFF_PROPERTY = "drawingpanel.diff";
/** An internal constant for setting system properties; clients should not use this. */
public static final String HEADLESS_PROPERTY = "drawingpanel.headless";
private static final String AWT_HEADLESS_PROPERTY = "java.awt.headless";
/** An internal constant for setting system properties; clients should not use this. */
public static final String MULTIPLE_PROPERTY = "drawingpanel.multiple";
/** An internal constant for setting system properties; clients should not use this. */
public static final String SAVE_PROPERTY = "drawingpanel.save";
/* a list of all DrawingPanel instances ever created; used for saving graphical output */
private static final List INSTANCES = new ArrayList();
// static variables
private static boolean DEBUG = false;
private static int instances = 0;
private static String saveFileName = null;
private static Boolean headless = null;
private static Boolean antiAliasDefault = true;
private static Thread shutdownThread = null;
// static class initializer - sets up thread to close program if
// last DrawingPanel is closed
static {
try {
String debugProp = String.valueOf(System.getProperty("drawingpanel.debug")).toLowerCase();
DEBUG = DEBUG || "true".equalsIgnoreCase(debugProp)
|| "on".equalsIgnoreCase(debugProp)
|| "yes".equalsIgnoreCase(debugProp)
|| "1".equals(debugProp);
} catch (Throwable t) {
// empty
}
}
/*
* Called when DrawingPanel class loads up.
* Checks whether the user wants to save an animation to a file.
*/
private static void checkAnimationSettings() {
try {
File settingsFile = new File(ANIMATION_FILE_NAME);
if (settingsFile.exists()) {
Scanner input = new Scanner(settingsFile);
String animationSaveFileName = input.nextLine();
input.close();
System.out.println("***");
System.out.println("*** DrawingPanel saving animated GIF: " +
new File(animationSaveFileName).getName());
System.out.println("***");
settingsFile.delete();
System.setProperty(ANIMATED_PROPERTY, "1");
System.setProperty(SAVE_PROPERTY, animationSaveFileName);
}
} catch (Exception e) {
if (DEBUG) {
System.out.println("error checking animation settings: " + e);
}
}
}
/*
* Helper that throws an IllegalArgumentException if the given integer
* is not between the given min-max inclusive
*/
private static void ensureInRange(String name, int value, int min, int max) {
if (value < min || value > max) {
throw new IllegalArgumentException(name + " must be between " + min
+ " and " + max + ", but saw " + value);
}
}
/*
* Helper that throws a NullPointerException if the given value is null
*/
private static void ensureNotNull(String name, Object value) {
if (value == null) {
throw new NullPointerException("null value was passed for " + name);
}
}
/**
* Returns the alpha (opacity) component of the given RGB pixel from 0-255.
* Often used in conjunction with the methods getPixelRGB, setPixelRGB, etc.
* @param rgb RGB integer with alpha in bits 0-7, red in bits 8-15, green in
* bits 16-23, and blue in bits 24-31
* @return alpha component from 0-255
*/
public static int getAlpha(int rgb) {
return (rgb & 0xff000000) >> 24;
}
/**
* Returns the blue component of the given RGB pixel from 0-255.
* Often used in conjunction with the methods getPixelRGB, setPixelRGB, etc.
* @param rgb RGB integer with alpha in bits 0-7, red in bits 8-15, green in
* bits 16-23, and blue in bits 24-31
* @return blue component from 0-255
*/
public static int getBlue(int rgb) {
return (rgb & 0x000000ff);
}
/**
* Returns the green component of the given RGB pixel from 0-255.
* Often used in conjunction with the methods getPixelRGB, setPixelRGB, etc.
* @param rgb RGB integer with alpha in bits 0-7, red in bits 8-15, green in
* bits 16-23, and blue in bits 24-31
* @return green component from 0-255
*/
public static int getGreen(int rgb) {
return (rgb & 0x0000ff00) >> 8;
}
/**
* Returns the red component of the given RGB pixel from 0-255.
* Often used in conjunction with the methods getPixelRGB, setPixelRGB, etc.
* @param rgb RGB integer with alpha in bits 0-7, red in bits 8-15, green in
* bits 16-23, and blue in bits 24-31
* @return red component from 0-255
*/
public static int getRed(int rgb) {
return (rgb & 0x00ff0000) >> 16;
}
/*
* Returns the given Java system property as a Boolean.
* Note uppercase-B meaning that if the property isn't set, this will return null.
* That also means that if you call it and try to store as lowercase-B boolean and
* it's null, you will crash the program. You have been warned.
*/
private static Boolean getPropertyBoolean(String name) {
try {
String prop = System.getProperty(name);
if (prop == null) {
return null;
} else {
return prop.equalsIgnoreCase("true")
|| prop.equals("1")
|| prop.equalsIgnoreCase("on")
|| prop.equalsIgnoreCase("yes");
}
} catch (SecurityException e) {
if (DEBUG) System.out.println("Security exception when trying to read " + name);
return null;
}
}
/**
* Returns the file name used for saving all DrawingPanel instances.
* By default this is null, but it can be set using setSaveFileName
* or by setting the SAVE_PROPERTY env variable.
* @return the shared save file name
*/
public static String getSaveFileName() {
if (saveFileName == null) {
try {
saveFileName = System.getProperty(SAVE_PROPERTY);
} catch (SecurityException e) {
// empty
}
}
return saveFileName;
}
/*
* Returns whether the given Java system property has been set.
*/
private static boolean hasProperty(String name) {
try {
return System.getProperty(name) != null;
} catch (SecurityException e) {
if (DEBUG) System.out.println("Security exception when trying to read " + name);
return false;
}
}
/**
* Returns true if DrawingPanel instances should anti-alias (smooth) their graphics.
* By default this is true, but it can be set to false using the ANTIALIAS_PROPERTY.
* @return true if anti-aliasing is enabled (default true)
*/
public static boolean isAntiAliasDefault() {
if (antiAliasDefault != null) {
return antiAliasDefault;
} else if (hasProperty(ANTIALIAS_PROPERTY)) {
return getPropertyBoolean(ANTIALIAS_PROPERTY);
} else {
return true; // default
}
}
/**
* Returns true if the class is in "headless" mode, meaning that it is running on
* a server without a graphical user interface.
* @return true if we are in headless mode (default false)
*/
public static boolean isHeadless() {
if (headless != null) {
return headless;
} else {
return hasProperty(HEADLESS_PROPERTY) && getPropertyBoolean(HEADLESS_PROPERTY);
}
}
/**
* Internal method; returns whether the 'main' thread is still running.
* Used to determine whether to exit the program when the drawing panel
* is closed by the user.
* This is an internal method not meant to be called by clients.
* @return true if main thread is still running
*/
public static boolean mainIsActive() {
ThreadGroup group = Thread.currentThread().getThreadGroup();
int activeCount = group.activeCount();
// look for the main thread in the current thread group
Thread[] threads = new Thread[activeCount];
group.enumerate(threads);
for (int i = 0; i < threads.length; i++) {
Thread thread = threads[i];
String name = String.valueOf(thread.getName()).toLowerCase();
if (DEBUG) System.out.println(" DrawingPanel.mainIsActive(): " + thread.getName() + ", priority=" + thread.getPriority() + ", alive=" + thread.isAlive() + ", stack=" + java.util.Arrays.toString(thread.getStackTrace()));
if (name.indexOf("main") >= 0 ||
name.indexOf("testrunner-assignmentrunner") >= 0) {
// found main thread!
// (TestRunnerApplet's main runner also counts as "main" thread)
return thread.isAlive();
}
}
// didn't find a running main thread; guess that main is done running
return false;
}
/*
* Returns whether the given Java system property has been set to a
* "truthy" value such as "yes" or "true" or "1".
*/
private static boolean propertyIsTrue(String name) {
try {
String prop = System.getProperty(name);
return prop != null && (prop.equalsIgnoreCase("true")
|| prop.equalsIgnoreCase("yes")
|| prop.equalsIgnoreCase("1"));
} catch (SecurityException e) {
if (DEBUG) System.out.println("Security exception when trying to read " + name);
return false;
}
}
/**
* Saves every DrawingPanel instance that is active.
* @throws IOException if unable to save any of the files.
*/
public static void saveAll() throws IOException {
for (DrawingPanel panel : INSTANCES) {
if (!panel.hasBeenSaved) {
panel.save(getSaveFileName());
}
}
}
/**
* Sets whether DrawingPanel instances should anti-alias (smooth) their pixels by default.
* Default true. You can set this on a given DrawingPanel instance with setAntialias(boolean).
* @param value whether to enable anti-aliasing (default true)
*/
public static void setAntiAliasDefault(Boolean value) {
antiAliasDefault = value;
}
/**
* Sets the class to run in "headless" mode, with no graphical output on screen.
* @param value whether to enable headless mode (default false)
*/
public static void setHeadless(Boolean value) {
headless = value;
if (headless != null) {
if (headless) {
// Set up Java AWT graphics configuration so that it can draw in 'headless' mode
// (without popping up actual graphical windows on the server's monitor)
// creating the buffered image below will prep the classloader so that Image
// classes are available later to the JVM
System.setProperty(AWT_HEADLESS_PROPERTY, "true");
System.setProperty(HEADLESS_PROPERTY, "true");
java.awt.image.BufferedImage img = new java.awt.image.BufferedImage(100, 100, java.awt.image.BufferedImage.TYPE_INT_RGB);
img.getGraphics().drawRect(10, 20, 30, 40);
} else {
System.setProperty(AWT_HEADLESS_PROPERTY, "false");
System.setProperty(HEADLESS_PROPERTY, "false");
}
}
}
/**
* Sets the file to be used when saving graphical output for all DrawingPanels.
* @param file the file to use as default save file
*/
public static void setSaveFile(File file) {
setSaveFileName(file.toString());
}
/**
* Sets the filename to be used when saving graphical output for all DrawingPanels.
* @param filename the name/path of the file to use as default save file
*/
public static void setSaveFileName(String filename) {
try {
System.setProperty(SAVE_PROPERTY, filename);
} catch (SecurityException e) {
// empty
}
saveFileName = filename;
}
/**
* Returns an RGB integer made from the given red, green, and blue components
* from 0-255. The returned integer is suitable for use with various RGB
* integer methods in this class such as setPixel.
* @param r red component from 0-255 (bits 8-15)
* @param g green component from 0-255 (bits 16-23)
* @param b blue component from 0-255 (bits 24-31)
* @return RGB integer with full 255 for alpha and r-g-b in bits 8-31
* @throws IllegalArgumentException if r, g, or b is not in 0-255 range
*/
public static int toRgbInteger(int r, int g, int b) {
return toRgbInteger(/* alpha */ 255, r, g, b);
}
/**
* Returns an RGB integer made from the given alpha, red, green, and blue components
* from 0-255. The returned integer is suitable for use with various RGB
* integer methods in this class such as setPixel.
* @param alpha alpha (transparency) component from 0-255 (bits 0-7)
* @param r red component from 0-255 (bits 8-15)
* @param g green component from 0-255 (bits 16-23)
* @param b blue component from 0-255 (bits 24-31)
* @return RGB integer with the given four components
* @throws IllegalArgumentException if alpha, r, g, or b is not in 0-255 range
*/
public static int toRgbInteger(int alpha, int r, int g, int b) {
ensureInRange("alpha", alpha, 0, 255);
ensureInRange("red", r, 0, 255);
ensureInRange("green", g, 0, 255);
ensureInRange("blue", b, 0, 255);
return ((alpha & 0x000000ff) << 24)
| ((r & 0x000000ff) << 16)
| ((g & 0x000000ff) << 8)
| ((b & 0x000000ff));
}
/*
* Returns whether the current program is running in the DrJava editor.
* This was needed in the past because DrJava messed with some settings.
*/
private static boolean usingDrJava() {
try {
return System.getProperty("drjava.debug.port") != null ||
System.getProperty("java.class.path").toLowerCase().indexOf("drjava") >= 0;
} catch (SecurityException e) {
// running as an applet, or something
return false;
}
}
// fields
private ActionListener actionListener;
private List frames; // stores frames of animation to save
private boolean animated = false; // changes to true if sleep() is called
private boolean antialias = isAntiAliasDefault(); // true to smooth corners of shapes
private boolean gridLines = false; // grid lines every 10px on screen
private boolean hasBeenSaved = false; // set true once saved to file (to avoid re-saving same panel)
private BufferedImage image; // remembers drawing commands
private Color backgroundColor = Color.WHITE;
private Gif89Encoder encoder; // for saving animations
private Graphics g3; // new field to support DebuggingGraphics
private Graphics2D g2; // graphics context for painting
private ImagePanel imagePanel; // real drawing surface
private int currentZoom = 1; // panel's zoom factor for drawing
private int gridLinesPxGap = GRID_LINES_PX_GAP_DEFAULT; // px between grid lines
private int initialPixel; // initial value in each pixel, for clear()
private int instanceNumber; // every DPanel has a unique number
private int width; // dimensions of window frame
private int height; // dimensions of window frame
private JFileChooser chooser; // file chooser to save files
private JFrame frame; // overall window frame
private JLabel statusBar; // status bar showing mouse position
private JPanel panel; // overall drawing surface
private long createTime; // time at which DrawingPanel was constructed
private Map counts; // new field to support DebuggingGraphics
private MouseInputListener mouseListener;
private String callingClassName; // name of class that constructed this panel
private Timer timer; // animation timer
private WindowListener windowListener;
/**
* Constructs a drawing panel with a default width and height enclosed in a window.
* Uses DEFAULT_WIDTH and DEFAULT_HEIGHT for the panel's size.
*/
public DrawingPanel() {
this(DEFAULT_WIDTH, DEFAULT_HEIGHT);
}
/**
* Constructs a drawing panel of given width and height enclosed in a window.
* @param width panel's width in pixels
* @param height panel's height in pixels
*/
public DrawingPanel(int width, int height) {
ensureInRange("width", width, 0, MAX_SIZE);
ensureInRange("height", height, 0, MAX_SIZE);
checkAnimationSettings();
if (DEBUG) System.out.println("DrawingPanel(): going to grab lock");
synchronized (LOCK) {
instances++;
instanceNumber = instances; // each DrawingPanel stores its own int number
INSTANCES.add(this);
if (shutdownThread == null && !usingDrJava()) {
if (DEBUG) System.out.println("DrawingPanel(): starting idle thread");
shutdownThread = new Thread(new Runnable() {
// Runnable implementation; used for shutdown thread.
public void run() {
boolean save = shouldSave();
try {
while (true) {
// maybe shut down the program, if no more DrawingPanels are onscreen
// and main has finished executing
save |= shouldSave();
if (DEBUG) System.out.println("DrawingPanel idle thread: instances=" + instances + ", save=" + save + ", main active=" + mainIsActive());
if ((instances == 0 || save) && !mainIsActive()) {
try {
System.exit(0);
} catch (SecurityException sex) {
if (DEBUG) System.out.println("DrawingPanel idle thread: unable to exit program: " + sex);
}
}
Thread.sleep(250);
}
} catch (Exception e) {
if (DEBUG) System.out.println("DrawingPanel idle thread: exception caught: " + e);
}
}
});
// shutdownThread.setPriority(Thread.MIN_PRIORITY);
shutdownThread.setName("DrawingPanel-shutdown");
shutdownThread.start();
}
}
this.width = width;
this.height = height;
if (DEBUG) System.out.println("DrawingPanel(w=" + width + ",h=" + height + ",anim=" + isAnimated() + ",graph=" + isGraphical() + ",save=" + shouldSave());
if (isAnimated() && shouldSave()) {
// image must be no more than 256 colors
image = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_INDEXED);
// image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
antialias = false; // turn off anti-aliasing to save palette colors
// initially fill the entire frame with the background color,
// because it won't show through via transparency like with a full ARGB image
Graphics g = image.getGraphics();
g.setColor(backgroundColor);
g.fillRect(0, 0, width + 1, height + 1);
} else {
image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
}
initialPixel = image.getRGB(0, 0);
g2 = (Graphics2D) image.getGraphics();
// new field assignments for DebuggingGraphics
g3 = new DebuggingGraphics();
counts = new TreeMap();
g2.setColor(Color.BLACK);
if (antialias) {
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
if (isAnimated()) {
initializeAnimation();
}
if (isGraphical()) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
// empty
}
statusBar = new JLabel(" ");
statusBar.setBorder(BorderFactory.createLineBorder(Color.BLACK));
panel = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
panel.setBackground(backgroundColor);
panel.setPreferredSize(new Dimension(width, height));
imagePanel = new ImagePanel(image);
imagePanel.setBackground(backgroundColor);
panel.add(imagePanel);
// listen to mouse movement
mouseListener = new DPMouseListener();
panel.addMouseMotionListener(mouseListener);
// main window frame
frame = new JFrame(TITLE);
// frame.setResizable(false);
windowListener = new DPWindowListener();
frame.addWindowListener(windowListener);
// JPanel center = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 0));
JScrollPane center = new JScrollPane(panel);
// center.add(panel);
frame.getContentPane().add(center);
frame.getContentPane().add(statusBar, "South");
frame.setBackground(Color.DARK_GRAY);
// menu bar
actionListener = new DPActionListener();
setupMenuBar();
frame.pack();
center(frame);
frame.setVisible(true);
if (!shouldSave()) {
toFront(frame);
}
// repaint timer so that the screen will update
createTime = System.currentTimeMillis();
timer = new Timer(DELAY, actionListener);
timer.start();
} else if (shouldSave()) {
// headless mode; just set a hook on shutdown to save the image
callingClassName = getCallingClassName();
try {
Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
// run on shutdown to save the image
public void run() {
if (DEBUG) System.out.println("DrawingPanel.run(): Running shutdown hook");
if (DEBUG) System.out.println("DrawingPanel shutdown hook: instances=" + instances);
try {
String filename = System.getProperty(SAVE_PROPERTY);
if (filename == null) {
filename = callingClassName + ".png";
}
if (isAnimated()) {
saveAnimated(filename);
} else {
save(filename);
}
} catch (SecurityException e) {
System.err.println("Security error while saving image: " + e);
} catch (IOException e) {
System.err.println("Error saving image: " + e);
}
}
}));
} catch (Exception e) {
if (DEBUG) System.out.println("DrawingPanel(): unable to add shutdown hook: " + e);
}
}
}
/**
* Constructs a drawing panel that displays the image from the given file enclosed in a window.
* The panel will be sized exactly to fit the image inside it.
* @param imageFile the image file to load
* @throws RuntimeException if the image file is not found
*/
public DrawingPanel(File imageFile) {
this(imageFile.toString());
}
/**
* Constructs a drawing panel that displays the image from the given file name enclosed in a window.
* The panel will be sized exactly to fit the image inside it.
* @param imageFileName the file name/path of the image file to load
* @throws RuntimeException if the image file is not found
*/
public DrawingPanel(String imageFileName) {
this();
Image image = loadImage(imageFileName);
setSize(image.getWidth(this), image.getHeight(this));
getGraphics().drawImage(image, 0, 0, this);
}
/**
* Adds the given event listener to respond to key events on this panel.
* @param listener the key event listener to attach
*/
public void addKeyListener(KeyListener listener) {
ensureNotNull("listener", listener);
frame.addKeyListener(listener);
panel.setFocusable(false);
frame.requestFocusInWindow();
frame.requestFocus();
}
/**
* Adds the given event listener to respond to mouse events on this panel.
* @param listener the mouse event listener to attach
*/
public void addMouseListener(MouseListener listener) {
ensureNotNull("listener", listener);
panel.addMouseListener(listener);
if (listener instanceof MouseMotionListener) {
panel.addMouseMotionListener((MouseMotionListener) listener);
}
}
/**
* Adds the given event listener to respond to mouse events on this panel.
*/
// public void addMouseListener(MouseMotionListener listener) {
// panel.addMouseMotionListener(listener);
// if (listener instanceof MouseListener) {
// panel.addMouseListener((MouseListener) listener);
// }
// }
// /**
// * Adds the given event listener to respond to mouse events on this panel.
// */
// public void addMouseListener(MouseInputListener listener) {
// addMouseListener((MouseListener) listener);
// }
/*
* Whether the panel should automatically switch to animated mode
* if it calls the sleep method.
*/
private boolean autoEnableAnimationOnSleep() {
return propertyIsTrue(AUTO_ENABLE_ANIMATION_ON_SLEEP_PROPERTY);
}
/*
* Moves the given JFrame to the center of the screen.
*/
private void center(Window frame) {
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension screen = tk.getScreenSize();
int x = Math.max(0, (screen.width - frame.getWidth()) / 2);
int y = Math.max(0, (screen.height - frame.getHeight()) / 2);
frame.setLocation(x, y);
}
/*
* Constructs and initializes our JFileChooser field if necessary.
*/
private void checkChooser() {
if (chooser == null) {
chooser = new JFileChooser();
try {
chooser.setCurrentDirectory(new File(System.getProperty("user.dir")));
} catch (Exception e) {
// empty
}
chooser.setMultiSelectionEnabled(false);
chooser.setFileFilter(new DPFileFilter());
}
}
/**
* Erases all drawn shapes/lines/colors from the panel.
*/
public void clear() {
int[] pixels = new int[width * height];
for (int i = 0; i < pixels.length; i++) {
pixels[i] = initialPixel;
}
image.setRGB(0, 0, width, height, pixels, 0, 1);
}
/*
* Compares the current DrawingPanel image to an image file on disk.
*/
private void compareToFile() {
// save current image to a temp file
try {
String tempFile = saveToTempFile();
// use file chooser dialog to find image to compare against
checkChooser();
if (chooser.showOpenDialog(frame) != JFileChooser.APPROVE_OPTION) {
return;
}
// user chose a file; let's diff it
new DiffImage(chooser.getSelectedFile().toString(), tempFile);
} catch (IOException ioe) {
JOptionPane.showMessageDialog(frame,
"Unable to compare images: \n" + ioe);
}
}
/*
* Compares the current DrawingPanel image to an image file on the web.
*/
private void compareToURL() {
// save current image to a temp file
try {
String tempFile = saveToTempFile();
// get list of images to compare against from web site
URL url = new URL(COURSE_WEB_SITE);
Scanner input = new Scanner(url.openStream());
List lines = new ArrayList();
List filenames = new ArrayList();
while (input.hasNextLine()) {
String line = input.nextLine().trim();
if (line.length() == 0) { continue; }
if (line.startsWith("#")) {
// a comment
if (line.endsWith(":")) {
// category label
lines.add(line);
line = line.replaceAll("#\\s*", "");
filenames.add(line);
}
} else {
lines.add(line);
// get filename
int lastSlash = line.lastIndexOf('/');
if (lastSlash >= 0) {
line = line.substring(lastSlash + 1);
}
// remove extension
int dot = line.lastIndexOf('.');
if (dot >= 0) {
line = line.substring(0, dot);
}
filenames.add(line);
}
}
input.close();
if (filenames.isEmpty()) {
JOptionPane.showMessageDialog(frame,
"No valid web files found to compare against.",
"Error: no web files found",
JOptionPane.ERROR_MESSAGE);
return;
} else {
String fileURL = null;
if (filenames.size() == 1) {
// only one choice; take it
fileURL = lines.get(0);
} else {
// user chooses file to compare against
int choice = showOptionDialog(frame, "File to compare against?",
"Choose File", filenames.toArray(new String[0]));
if (choice < 0) {
return;
}
// user chose a file; let's diff it
fileURL = lines.get(choice);
}
new DiffImage(fileURL, tempFile);
}
} catch (NoRouteToHostException nrthe) {
JOptionPane.showMessageDialog(frame, "You do not appear to have a working internet connection.\nPlease check your internet settings and try again.\n\n" + nrthe);
} catch (UnknownHostException uhe) {
JOptionPane.showMessageDialog(frame, "Internet connection error: \n" + uhe);
} catch (SocketException se) {
JOptionPane.showMessageDialog(frame, "Internet connection error: \n" + se);
} catch (IOException ioe) {
JOptionPane.showMessageDialog(frame, "Unable to compare images: \n" + ioe);
}
}
/*
* Closes the DrawingPanel and exits the program.
*/
private void exit() {
if (isGraphical()) {
frame.setVisible(false);
frame.dispose();
}
try {
System.exit(0);
} catch (SecurityException e) {
// if we're running in an applet or something, can't do System.exit
}
}
/*
* Returns a best guess about the name of the class that constructed this panel.
*/
private String getCallingClassName() {
StackTraceElement[] stack = new RuntimeException().getStackTrace();
String className = this.getClass().getName();
for (StackTraceElement element : stack) {
String cl = element.getClassName();
if (!className.equals(cl)) {
className = cl;
break;
}
}
return className;
}
/**
* Returns a map of counts of occurrences of calls of various drawing methods.
* You can print this map to see how many times your graphics methods have
* been called to aid in debugging.
* @return map of {method name, count} pairs
*/
public Map getCounts() {
return Collections.unmodifiableMap(counts);
}
/**
* A variation of getGraphics that returns an object that records
* a count for various drawing methods.
* See also: getCounts
* @return debug Graphics object
*/
public Graphics getDebuggingGraphics() {
if (g3 == null) {
g3 = new DebuggingGraphics();
}
return g3;
}
/**
* Obtain the Graphics object to draw on the panel.
* @return panel's Graphics object
*/
public Graphics2D getGraphics() {
return g2;
}
/*
* Creates the buffered image for drawing on this panel.
*/
private BufferedImage getImage() {
// create second image so we get the background color
BufferedImage image2;
if (isAnimated()) {
image2 = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_INDEXED);
} else {
image2 = new BufferedImage(width, height, image.getType());
}
Graphics g = image2.getGraphics();
// if (DEBUG) System.out.println("DrawingPanel getImage setting background to " + backgroundColor);
g.setColor(backgroundColor);
g.fillRect(0, 0, width, height);
g.drawImage(image, 0, 0, panel);
return image2;
}
/**
* Returns the drawing panel's height in pixels.
* @return drawing panel's height in pixels
*/
public int getHeight() {
return height;
}
/**
* Returns the color of the pixel at the given x/y coordinate as a Color object.
* If nothing has been explicitly drawn on this particular pixel, the panel's
* background color is returned.
* @param x x-coordinate of pixel to retrieve
* @param y y-coordinate of pixel to retrieve
* @return pixel (x, y) color as a Color object
* @throws IllegalArgumentException if (x, y) is out of range
*/
public Color getPixel(int x, int y) {
int rgb = getPixelRGB(x, y);
if (getAlpha(rgb) == 0) {
return backgroundColor;
} else {
return new Color(rgb, /* hasAlpha */ true);
}
}
/**
* Returns the color of the pixel at the given x/y coordinate as an RGB integer.
* The individual red, green, and blue components of the RGB integer can be
* extracted from this by calling DrawingPanel.getRed, getGreen, and getBlue.
* If nothing has been explicitly drawn on this particular pixel, the panel's
* background color is returned.
* See also: getPixel.
* @param x x-coordinate of pixel to retrieve
* @param y y-coordinate of pixel to retrieve
* @return pixel (x, y) color as an RGB integer
* @throws IllegalArgumentException if (x, y) is out of range
*/
public int getPixelRGB(int x, int y) {
ensureInRange("x", x, 0, getWidth() - 1);
ensureInRange("y", y, 0, getHeight() - 1);
int rgb = image.getRGB(x, y);
if (getAlpha(rgb) == 0) {
return backgroundColor.getRGB();
} else {
return rgb;
}
}
/**
* Returns the colors of all pixels in this DrawingPanel as a 2-D array
* of Color objects.
* The first index of the array is the y-coordinate, and the second index
* is the x-coordinate. So, for example, index [r][c] represents the RGB
* pixel data for the pixel at position (x=c, y=r).
* @return 2D array of colors (row-major)
*/
public Color[][] getPixels() {
Color[][] pixels = new Color[getHeight()][getWidth()];
for (int row = 0; row < pixels.length; row++) {
for (int col = 0; col < pixels[0].length; col++) {
// note axis inversion; x/y => col/row
pixels[row][col] = getPixel(col, row);
}
}
return pixels;
}
/**
* Returns the colors of all pixels in this DrawingPanel as a 2-D array
* of RGB integers.
* The first index of the array is the y-coordinate, and the second index
* is the x-coordinate. So, for example, index [r][c] represents the RGB
* pixel data for the pixel at position (x=c, y=r).
* The individual red, green, and blue components of each RGB integer can be
* extracted from this by calling DrawingPanel.getRed, getGreen, and getBlue.
* @return 2D array of RGB integers (row-major)
*/
public int[][] getPixelsRGB() {
int[][] pixels = new int[getHeight()][getWidth()];
int backgroundRGB = backgroundColor.getRGB();
for (int row = 0; row < pixels.length; row++) {
for (int col = 0; col < pixels[0].length; col++) {
// note axis inversion; x/y => col/row
int px = image.getRGB(col, row);
if (getAlpha(px) == 0) {
pixels[row][col] = backgroundRGB;
} else {
pixels[row][col] = px;
}
}
}
return pixels;
}
/**
* Returns the drawing panel's pixel size (width, height) as a Dimension object.
* @return panel's size
*/
public Dimension getSize() {
return new Dimension(width, height);
}
/**
* Returns the drawing panel's width in pixels.
* @return panel's width
*/
public int getWidth() {
return width;
}
/**
* Returns the drawing panel's x-coordinate on the screen.
* @return panel's x-coordinate
*/
public int getX() {
if (isGraphical()) {
return frame.getX();
} else {
return 0;
}
}
/**
* Returns the drawing panel's y-coordinate on the screen.
* @return panel's y-coordinate
*/
public int getY() {
if (isGraphical()) {
return frame.getY();
} else {
return 0;
}
}
/**
* Returns the drawing panel's current zoom factor.
* Initially this is 1 to indicate 100% zoom, the original size.
* A factor of 2 would indicate 200% zoom, and so on.
* @return zoom factor (default 1)
*/
public int getZoom() {
return currentZoom;
}
/**
* Internal method;
* notifies the panel when images are loaded and updated.
* This is a required method of ImageObserver interface.
* This is an internal method not meant to be called by clients.
* @param img internal method; do not call
* @param infoflags internal method; do not call
* @param x internal method; do not call
* @param y internal method; do not call
* @param width internal method; do not call
* @param height internal method; do not call
*/
@Override
public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height) {
if (imagePanel != null) {
imagePanel.imageUpdate(img, infoflags, x, y, width, height);
}
return false;
}
/*
* Sets up state for drawing and saving frames of animation to a GIF image.
*/
private void initializeAnimation() {
frames = new ArrayList();
encoder = new Gif89Encoder();
/*
try {
if (hasProperty(SAVE_PROPERTY)) {
stream = new FileOutputStream(System.getProperty(SAVE_PROPERTY));
}
// encoder.startEncoding(stream);
} catch (IOException e) {
System.out.println(e);
}
*/
}
/*
* Returns whether this drawing panel is in animation mode.
*/
private boolean isAnimated() {
return animated || propertyIsTrue(ANIMATED_PROPERTY);
}
/*
* Returns whether this drawing panel is going to be displayed on screen.
* This is almost always true except in some server environments where
* the DrawingPanel is run 'headless' without a GUI, often for scripting
* and automation purposes.
*/
private boolean isGraphical() {
return !hasProperty(SAVE_PROPERTY) && !isHeadless();
}
/*
* Returns true if the drawing panel class is in multiple mode.
* This would be true if the current program pops up several drawing panels
* and we want to save the state of each of them to a different file.
*/
private boolean isMultiple() {
return propertyIsTrue(MULTIPLE_PROPERTY);
}
/**
* Loads an image from the given file on disk and returns it
* as an Image object.
* @param file the file to load
* @return loaded image object
* @throws NullPointerException if filename is null
* @throws RuntimeException if the given file is not found
*/
public Image loadImage(File file) {
ensureNotNull("file", file);
return loadImage(file.toString());
}
/**
* Loads an image from the given file on disk and returns it
* as an Image object.
* @param filename name/path of the file to load
* @return loaded image object
* @throws NullPointerException if filename is null
* @throws RuntimeException if the given file is not found
*/
public Image loadImage(String filename) {
ensureNotNull("filename", filename);
if (!(new File(filename)).exists()) {
throw new RuntimeException("DrawingPanel.loadImage: File not found: " + filename);
}
Image img = Toolkit.getDefaultToolkit().getImage(filename);
MediaTracker mt = new MediaTracker(imagePanel == null ? new JPanel() : imagePanel);
mt.addImage(img, 0);
try {
mt.waitForID(0);
} catch (InterruptedException ie) {
// empty
}
return img;
}
/**
* Adds an event handler for mouse clicks.
* You can pass a lambda function here to be called when a mouse click event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onClick(DPMouseEventHandler e) {
onMouseClick(e);
}
/**
* Adds an event handler for mouse drags.
* You can pass a lambda function here to be called when a mouse drag event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onDrag(DPMouseEventHandler e) {
onMouseDrag(e);
}
/**
* Adds an event handler for mouse enters.
* You can pass a lambda function here to be called when a mouse enter event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onEnter(DPMouseEventHandler e) {
onMouseEnter(e);
}
/**
* Adds an event handler for mouse exits.
* You can pass a lambda function here to be called when a mouse exit event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onExit(DPMouseEventHandler e) {
onMouseExit(e);
}
/**
* Adds an event handler for key presses.
* You can pass a lambda function here to be called when a key press event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onKeyDown(DPKeyEventHandler e) {
ensureNotNull("event handler", e);
DPKeyEventHandlerAdapter adapter = new DPKeyEventHandlerAdapter(e, "press");
addKeyListener(adapter);
}
/**
* Adds an event handler for key releases.
* You can pass a lambda function here to be called when a key release event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onKeyUp(DPKeyEventHandler e) {
ensureNotNull("event handler", e);
DPKeyEventHandlerAdapter adapter = new DPKeyEventHandlerAdapter(e, "release");
addKeyListener(adapter);
}
/**
* Adds an event handler for mouse clicks.
* You can pass a lambda function here to be called when a mouse click event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseClick(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "click");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse button down events.
* You can pass a lambda function here to be called when a mouse button down event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseDown(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "press");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse drags.
* You can pass a lambda function here to be called when a mouse drag event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseDrag(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "drag");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse enters.
* You can pass a lambda function here to be called when a mouse enter event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseEnter(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "enter");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse exits.
* You can pass a lambda function here to be called when a mouse exit event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseExit(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "exit");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse movement.
* You can pass a lambda function here to be called when a mouse move event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseMove(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "move");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse button up events.
* You can pass a lambda function here to be called when a mouse button up event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMouseUp(DPMouseEventHandler e) {
ensureNotNull("event handler", e);
DPMouseEventHandlerAdapter adapter = new DPMouseEventHandlerAdapter(e, "release");
addMouseListener((MouseListener) adapter);
}
/**
* Adds an event handler for mouse movement.
* You can pass a lambda function here to be called when a mouse move event occurs.
* @param e event handler function to call
* @throws NullPointerException if event handler is null
*/
public void onMove(DPMouseEventHandler e) {
onMouseMove(e);
}
/*
* Returns whether the drawing panel should be closed and the program
* should be shut down.
*/
private boolean readyToClose() {
/*
if (isAnimated()) {
// wait a little longer, in case animation is sleeping
return System.currentTimeMillis() > createTime + 5 * DELAY;
} else {
return System.currentTimeMillis() > createTime + 4 * DELAY;
}
*/
return (instances == 0 || shouldSave()) && !mainIsActive();
}
/*
* Replaces all occurrences of the given old color with the given new color.
*/
private void replaceColor(BufferedImage image, Color oldColor, Color newColor) {
int oldRGB = oldColor.getRGB();
int newRGB = newColor.getRGB();
for (int y = 0; y < image.getHeight(); y++) {
for (int x = 0; x < image.getWidth(); x++) {
if (image.getRGB(x, y) == oldRGB) {
image.setRGB(x, y, newRGB);
}
}
}
}
/**
* Takes the current contents of the drawing panel and writes them to
* the given file.
* @param file the file to save
* @throws NullPointerException if filename is null
* @throws IOException if the given file cannot be written
*/
public void save(File file) throws IOException {
ensureNotNull("file", file);
save(file.toString());
}
/**
* Takes the current contents of the drawing panel and writes them to
* the given file.
* @param filename name/path of the file to save
* @throws NullPointerException if filename is null
* @throws IOException if the given file cannot be written
*/
public void save(String filename) throws IOException {
ensureNotNull("filename", filename);
BufferedImage image2 = getImage();
// if zoomed, scale image before saving it
if (SAVE_SCALED_IMAGES && currentZoom != 1) {
BufferedImage zoomedImage = new BufferedImage(width * currentZoom, height * currentZoom, image.getType());
Graphics2D g = (Graphics2D) zoomedImage.getGraphics();
g.setColor(Color.BLACK);
if (antialias) {
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
g.scale(currentZoom, currentZoom);
g.drawImage(image2, 0, 0, imagePanel);
image2 = zoomedImage;
}
// if saving multiple panels, append number
// (e.g. output_*.png becomes output_1.png, output_2.png, etc.)
if (isMultiple()) {
filename = filename.replaceAll("\\*", String.valueOf(instanceNumber));
}
int lastDot = filename.lastIndexOf(".");
String extension = filename.substring(lastDot + 1);
// write file
// (for some reason, NPEs throw sometimes for no reason; just squish them)
try {
ImageIO.write(image2, extension, new File(filename));
} catch (NullPointerException npe) {
// empty
} catch (FileNotFoundException fnfe) {
// this is a dumb file overwrite issue related to file locking; ignore
}
hasBeenSaved = true;
}
/**
* Takes the current contents of the drawing panel and writes them to
* the given file.
* @param file the file to save
* @throws NullPointerException if filename is null
* @throws IOException if the given file cannot be written
*/
public void saveAnimated(File file) throws IOException {
ensureNotNull("file", file);
saveAnimated(file.toString());
}
/**
* Takes the current contents of the drawing panel and writes them to
* the given file.
* @param filename name/path of the file to save
* @throws NullPointerException if filename is null
* @throws IOException if the given file cannot be written
*/
public void saveAnimated(String filename) throws IOException {
ensureNotNull("filename", filename);
// add one more final frame
if (DEBUG) System.out.println("DrawingPanel.saveAnimated(" + filename + ")");
frames.add(new ImageFrame(getImage(), 5000));
// encoder.continueEncoding(stream, getImage(), 5000);
// Gif89Encoder gifenc = new Gif89Encoder();
// add each frame of animation to the encoder
try {
for (int i = 0; i < frames.size(); i++) {
ImageFrame imageFrame = frames.get(i);
encoder.addFrame(imageFrame.image);
encoder.getFrameAt(i).setDelay(imageFrame.delay);
imageFrame.image.flush();
frames.set(i, null);
}
} catch (OutOfMemoryError e) {
System.out.println("Out of memory when saving");
}
// gifenc.setComments(annotation);
// gifenc.setUniformDelay((int) Math.round(100 / frames_per_second));
// gifenc.setUniformDelay(DELAY);
// encoder.setBackground(backgroundColor);
encoder.setLoopCount(0);
encoder.encode(new FileOutputStream(filename));
}
/*
* Called when the user presses the "Save As" menu item.
* Pops up a file chooser prompting the user to save their panel to an image.
*/
private void saveAs() {
String filename = saveAsHelper("png");
if (filename != null) {
try {
save(filename); // save the file
} catch (IOException ex) {
JOptionPane.showMessageDialog(frame, "Unable to save image:\n" + ex);
}
}
}
/*
* Called when the user presses the "Save As" menu item on an animated panel.
* Pops up a file chooser prompting the user to save their panel to an image.
*/
private void saveAsAnimated() {
String filename = saveAsHelper("gif");
if (filename != null) {
try {
// record that the file should be saved next time
PrintStream out = new PrintStream(new File(ANIMATION_FILE_NAME));
out.println(filename);
out.close();
JOptionPane.showMessageDialog(frame,
"Due to constraints about how DrawingPanel works, you'll need to\n" +
"re-run your program. When you run it the next time, DrawingPanel will \n" +
"automatically save your animated image as: " + new File(filename).getName()
);
} catch (IOException ex) {
JOptionPane.showMessageDialog(frame, "Unable to store animation settings:\n" + ex);
}
}
}
/*
* A helper method to facilitate the Save As action for both animated
* and non-animated images.
*/
private String saveAsHelper(String extension) {
// use file chooser dialog to get filename to save into
checkChooser();
if (chooser.showSaveDialog(frame) != JFileChooser.APPROVE_OPTION) {
return null;
}
File selectedFile = chooser.getSelectedFile();
String filename = selectedFile.toString();
if (!filename.toLowerCase().endsWith(extension)) {
// Windows is dumb about extensions with file choosers
filename += "." + extension;
}
// confirm overwrite of file
if (new File(filename).exists() && JOptionPane.showConfirmDialog(
frame, "File exists. Overwrite?", "Overwrite?",
JOptionPane.YES_NO_OPTION) != JOptionPane.YES_OPTION) {
return null;
}
return filename;
}
/*
* Saves the drawing panel's image to a temporary file and returns
* that file's name.
*/
private String saveToTempFile() throws IOException {
File currentImageFile = File.createTempFile("current_image", ".png");
save(currentImageFile.toString());
return currentImageFile.toString();
}
/**
* Sets whether the panel will always cover other windows (default false).
* @param alwaysOnTop true if the panel should always cover other windows
*/
public void setAlwaysOnTop(boolean alwaysOnTop) {
if (frame != null) {
frame.setAlwaysOnTop(alwaysOnTop);
}
}
/**
* Sets whether the panel should use anti-aliased / smoothed graphics (default true).
* @param antiAlias true if the panel should be smoothed
*/
public void setAntiAlias(boolean antiAlias) {
this.antialias = antiAlias;
Object value = antiAlias ? RenderingHints.VALUE_ANTIALIAS_ON : RenderingHints.VALUE_ANTIALIAS_OFF;
if (g2 != null) {
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, value);
}
if (imagePanel != null) {
imagePanel.repaint();
}
}
/**
* Sets the background color of the drawing panel to be the given color.
* @param c color to use as background
* @throws NullPointerException if color is null
*/
public void setBackground(Color c) {
ensureNotNull("color", c);
Color oldBackgroundColor = backgroundColor;
backgroundColor = c;
if (isGraphical()) {
panel.setBackground(c);
imagePanel.setBackground(c);
}
// with animated images, need to palette-swap the old bg color for the new
// because there's no notion of transparency in a palettized 8-bit image
if (isAnimated()) {
replaceColor(image, oldBackgroundColor, c);
}
}
/**
* Sets the background color of the drawing panel to be the color
* represented by the given RGB integer.
* @param rgb RGB integer to use as background color (full alpha assumed/applied)
*/
public void setBackground(int rgb) {
setBackground(new Color(rgb & 0xff000000, /* hasAlpha */ true));
}
/**
* Enables or disables the drawing of grid lines on top of the image to help
* with debugging sizes and coordinates.
* By default the grid lines will be shown every 10 pixels in each dimension.
* @param gridLines whether to show grid lines (true) or not (false)
*/
public void setGridLines(boolean gridLines) {
setGridLines(gridLines, GRID_LINES_PX_GAP_DEFAULT);
}
/**
* Enables or disables the drawing of grid lines on top of the image to help
* with debugging sizes and coordinates.
* The grid lines will be shown every pxGap pixels in each dimension.
* @param gridLines whether to show grid lines (true) or not (false)
* @param pxGap number of pixels between grid lines
*/
public void setGridLines(boolean gridLines, int pxGap) {
this.gridLines = gridLines;
this.gridLinesPxGap = pxGap;
if (imagePanel != null) {
imagePanel.repaint();
}
}
/**
* Sets the drawing panel's height in pixels to the given value.
* After calling this method, the client must call getGraphics() again
* to get the new graphics context of the newly enlarged image buffer.
* @param height height, in pixels
* @throws IllegalArgumentException if height is negative or exceeds MAX_SIZE
*/
public void setHeight(int height) {
setSize(getWidth(), height);
}
/**
* Sets the color of the pixel at the given x/y coordinate to be the given color.
* If the color is null, the call has no effect.
* @param x x-coordinate of pixel to set
* @param y y-coordinate of pixel to set
* @param color Color to set the pixel to use
* @throws IllegalArgumentException if x or y is out of bounds
* @throws NullPointerException if color is null
*/
public void setPixel(int x, int y, Color color) {
ensureInRange("x", x, 0, getWidth() - 1);
ensureInRange("y", y, 0, getHeight() - 1);
ensureNotNull("color", color);
image.setRGB(x, y, color.getRGB());
}
/**
* Sets the color of the pixel at the given x/y coordinate to be the color
* represented by the given RGB integer.
* The passed RGB integer's alpha value is ignored and a full alpha of 255
* is always used here, to avoid common bugs with using a 0 value for alpha.
* See also: setPixel.
* See also: setPixelRGB.
* @param x x-coordinate of pixel to set
* @param y y-coordinate of pixel to set
* @param rgb RGB integer representing the color to set the pixel to use
* @throws IllegalArgumentException if x or y is out of bounds
*/
public void setPixel(int x, int y, int rgb) {
setPixelRGB(x, y, rgb);
}
/**
* Sets the color of the pixel at the given x/y coordinate to be the color
* represented by the given RGB integer.
* The passed RGB integer's alpha value is ignored and a full alpha of 255
* is always used here, to avoid common bugs with using a 0 value for alpha.
* See also: setPixel.
* @param x x-coordinate of pixel to set
* @param y y-coordinate of pixel to set
* @param rgb RGB integer representing the color to set the pixel to use
* @throws IllegalArgumentException if x or y is out of bounds
*/
public void setPixelRGB(int x, int y, int rgb) {
ensureInRange("x", x, 0, getWidth() - 1);
ensureInRange("y", y, 0, getHeight() - 1);
image.setRGB(x, y, rgb | PIXEL_ALPHA);
}
/**
* Sets the colors of all pixels in this DrawingPanel to the colors
* in the given 2-D array of Color objects.
* The first index of the array is the y-coordinate, and the second index
* is the x-coordinate. So, for example, index [r][c] represents the RGB
* pixel data for the pixel at position (x=c, y=r).
* If the given array's dimensions do not match the width/height of the
* drawing panel, the panel is resized to match the array.
* If the pixel array is null or size 0, the call has no effect.
* If any rows or colors in the array are null, those pixels will be ignored.
* The 2-D array passed is assumed to be rectangular in length (not jagged).
* @param pixels 2D array of pixels (row-major)
* @throws NullPointerException if pixels array is null
*/
public void setPixels(Color[][] pixels) {
ensureNotNull("pixels", pixels);
if (pixels != null && pixels.length > 0 && pixels[0] != null) {
if (width != pixels[0].length || height != pixels.length) {
setSize(pixels[0].length, pixels.length);
}
for (int row = 0; row < height; row++) {
if (pixels[row] != null) {
for (int col = 0; col < width; col++) {
if (pixels[row][col] != null) {
int rgb = pixels[row][col].getRGB();
image.setRGB(col, row, rgb);
}
}
}
}
}
}
/**
* Sets the colors of all pixels in this DrawingPanel to the colors
* represented by the given 2-D array of RGB integers.
* The first index of the array is the y-coordinate, and the second index
* is the x-coordinate. So, for example, index [r][c] represents the RGB
* pixel data for the pixel at position (x=c, y=r).
* If the given array's dimensions do not match the width/height of the
* drawing panel, the panel is resized to match the array.
* If the pixel array is null or size 0, the call has no effect.
* The 2-D array passed is assumed to be rectangular in length (not jagged).
* @param pixels 2D array of pixels (row-major)
* @throws NullPointerException if pixels array is null
*/
public void setPixels(int[][] pixels) {
setPixelsRGB(pixels);
}
/**
* Sets the colors of all pixels in this DrawingPanel to the colors
* represented by the given 2-D array of RGB integers.
* The first index of the array is the y-coordinate, and the second index
* is the x-coordinate. So, for example, index [r][c] represents the RGB
* pixel data for the pixel at position (x=c, y=r).
* If the given array's dimensions do not match the width/height of the
* drawing panel, the panel is resized to match the array.
* If the pixel array is null or size 0, the call has no effect.
* The 2-D array passed is assumed to be rectangular in length (not jagged).
* @param pixels 2D array of pixels (row-major)
* @throws NullPointerException if pixels array is null
*/
public void setPixelsRGB(int[][] pixels) {
ensureNotNull("pixels", pixels);
if (pixels != null && pixels.length > 0 && pixels[0] != null) {
if (width != pixels[0].length || height != pixels.length) {
setSize(pixels[0].length, pixels.length);
}
for (int row = 0; row < height; row++) {
if (pixels[row] != null) {
for (int col = 0; col < width; col++) {
// note axis inversion, row/col => y/x
image.setRGB(col, row, pixels[row][col] | PIXEL_ALPHA);
}
}
}
}
}
/**
* Sets the drawing panel's pixel size (width, height) to the given values.
* After calling this method, the client must call getGraphics() again
* to get the new graphics context of the newly enlarged image buffer.
* @param width width, in pixels
* @param height height, in pixels
* @throws IllegalArgumentException if width/height is negative or exceeds MAX_SIZE
*/
public void setSize(int width, int height) {
ensureInRange("width", width, 0, MAX_SIZE);
ensureInRange("height", height, 0, MAX_SIZE);
// replace the image buffer for drawing
BufferedImage newImage = new BufferedImage(width, height, image.getType());
if (imagePanel != null) {
imagePanel.setImage(newImage);
}
newImage.getGraphics().drawImage(image, 0, 0, imagePanel == null ? new JPanel() : imagePanel);
this.width = width;
this.height = height;
image = newImage;
g2 = (Graphics2D) newImage.getGraphics();
g2.setColor(Color.BLACK);
if (antialias) {
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
zoom(currentZoom);
if (isGraphical()) {
frame.pack();
}
}
/*
* Sets the text that will appear in the drawing panel's bottom status bar.
*/
private void setStatusBarText(String text) {
if (currentZoom != 1) {
text += " (current zoom: " + currentZoom + "x" + ")";
}
statusBar.setText(text);
}
/*
* Initializes the drawing panel's menu bar items.
*/
private void setupMenuBar() {
// abort compare if we're running as an applet or in a secure environment
// boolean secure = (System.getSecurityManager() != null);
// for now, assume non-secure mode since DrawingPanel applet usage is minimal
final boolean secure = false;
JMenuItem saveAs = new JMenuItem("Save As...", 'A');
saveAs.addActionListener(actionListener);
saveAs.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));
saveAs.setEnabled(!secure);
JMenuItem saveAnimated = new JMenuItem("Save Animated GIF...", 'G');
saveAnimated.addActionListener(actionListener);
saveAnimated.setAccelerator(KeyStroke.getKeyStroke("ctrl A"));
saveAnimated.setEnabled(!secure);
JMenuItem compare = new JMenuItem("Compare to File...", 'C');
compare.addActionListener(actionListener);
compare.setEnabled(!secure);
JMenuItem compareURL = new JMenuItem("Compare to Web File...", 'U');
compareURL.addActionListener(actionListener);
compareURL.setAccelerator(KeyStroke.getKeyStroke("ctrl U"));
compareURL.setEnabled(!secure);
JMenuItem zoomIn = new JMenuItem("Zoom In", 'I');
zoomIn.addActionListener(actionListener);
zoomIn.setAccelerator(KeyStroke.getKeyStroke("ctrl EQUALS"));
JMenuItem zoomOut = new JMenuItem("Zoom Out", 'O');
zoomOut.addActionListener(actionListener);
zoomOut.setAccelerator(KeyStroke.getKeyStroke("ctrl MINUS"));
JMenuItem zoomNormal = new JMenuItem("Zoom Normal (100%)", 'N');
zoomNormal.addActionListener(actionListener);
zoomNormal.setAccelerator(KeyStroke.getKeyStroke("ctrl 0"));
JCheckBoxMenuItem gridLinesItem = new JCheckBoxMenuItem("Grid Lines");
gridLinesItem.setMnemonic('G');
gridLinesItem.setSelected(gridLines);
gridLinesItem.addActionListener(actionListener);
gridLinesItem.setAccelerator(KeyStroke.getKeyStroke("ctrl G"));
JMenuItem exit = new JMenuItem("Exit", 'x');
exit.addActionListener(actionListener);
JMenuItem about = new JMenuItem("About...", 'A');
about.addActionListener(actionListener);
JMenu file = new JMenu("File");
file.setMnemonic('F');
file.add(compareURL);
file.add(compare);
file.addSeparator();
file.add(saveAs);
file.add(saveAnimated);
file.addSeparator();
file.add(exit);
JMenu view = new JMenu("View");
view.setMnemonic('V');
view.add(zoomIn);
view.add(zoomOut);
view.add(zoomNormal);
view.addSeparator();
view.add(gridLinesItem);
JMenu help = new JMenu("Help");
help.setMnemonic('H');
help.add(about);
JMenuBar bar = new JMenuBar();
bar.add(file);
bar.add(view);
bar.add(help);
frame.setJMenuBar(bar);
}
/**
* Show or hide the drawing panel on the screen.
* @param visible true to show, false to hide
*/
public void setVisible(boolean visible) {
if (isGraphical()) {
frame.setVisible(visible);
}
}
/**
* Sets the drawing panel's width in pixels to the given value.
* After calling this method, the client must call getGraphics() again
* to get the new graphics context of the newly enlarged image buffer.
* @param width width, in pixels
* @throws IllegalArgumentException if height is negative or exceeds MAX_SIZE
*/
public void setWidth(int width) {
ensureInRange("width", width, 0, MAX_SIZE);
setSize(width, getHeight());
}
/*
* Returns whether the user wants to perform a 'diff' comparison of their
* drawing panel with a given expected output image.
*/
private boolean shouldDiff() {
return hasProperty(DIFF_PROPERTY);
}
/*
* Returns whether the user wants to save the drawing panel contents to
* a file automatically.
*/
private boolean shouldSave() {
return hasProperty(SAVE_PROPERTY);
}
/*
* Shows a dialog box with the given choices;
* returns the index chosen (-1 == canceled).
*/
private int showOptionDialog(Frame parent, String title,
String message, final String[] names) {
final JDialog dialog = new JDialog(parent, title, true);
JPanel center = new JPanel(new GridLayout(0, 1));
// just a hack to make the return value a mutable reference to an int
final int[] hack = {-1};
for (int i = 0; i < names.length; i++) {
if (names[i].endsWith(":")) {
center.add(new JLabel("" + names[i] + ""));
} else {
final JButton button = new JButton(names[i]);
button.setActionCommand(String.valueOf(i));
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
hack[0] = Integer.parseInt(button.getActionCommand());
dialog.setVisible(false);
}
});
center.add(button);
}
}
JPanel south = new JPanel();
JButton cancel = new JButton("Cancel");
cancel.setMnemonic('C');
cancel.requestFocus();
cancel.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
dialog.setVisible(false);
}
});
south.add(cancel);
dialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
dialog.getContentPane().setLayout(new BorderLayout(10, 5));
if (message != null) {
JLabel messageLabel = new JLabel(message);
dialog.add(messageLabel, BorderLayout.NORTH);
}
dialog.add(center);
dialog.add(south, BorderLayout.SOUTH);
dialog.pack();
dialog.setResizable(false);
center(dialog);
cancel.requestFocus();
dialog.setVisible(true);
cancel.requestFocus();
return hack[0];
}
/**
* Causes the program to pause for the given amount of time in milliseconds.
* This allows for animation by calling pause in a loop.
* If the DrawingPanel is not showing on the screen, has no effect.
* @param millis number of milliseconds to sleep
* @throws IllegalArgumentException if a negative number of ms is passed
*/
public void sleep(int millis) {
ensureInRange("millis", millis, 0, Integer.MAX_VALUE);
if (isGraphical() && frame.isVisible()) {
// if not even displaying, we don't actually need to sleep
if (millis > 0) {
try {
Thread.sleep(millis);
panel.repaint();
// toFront(frame);
} catch (Exception e) {
// empty
}
}
}
// manually enable animation if necessary
if (!isAnimated() && !isMultiple() && autoEnableAnimationOnSleep()) {
animated = true;
initializeAnimation();
}
// capture a frame of animation
if (isAnimated() && shouldSave() && !isMultiple()) {
try {
if (frames.size() < MAX_FRAMES) {
frames.add(new ImageFrame(getImage(), millis));
}
// reset creation timer so that we won't save/close just yet
createTime = System.currentTimeMillis();
} catch (OutOfMemoryError e) {
System.out.println("Out of memory after capturing " + frames.size() + " frames");
}
}
}
/**
* Moves the drawing panel window on top of other windows so it can be seen.
*/
public void toFront() {
toFront(frame);
}
/*
* Brings the given window to the front of the Z-ordering.
*/
private void toFront(final Window window) {
// TODO: remove anonymous inner class
EventQueue.invokeLater(new Runnable() {
public void run() {
if (window != null) {
window.toFront();
window.repaint();
}
}
});
}
/**
* Zooms the drawing panel in/out to the given factor.
* A zoom factor of 1, the default, indicates normal size.
* A zoom factor of 2 would indicate 200% size, and so on.
* The factor value passed should be at least 1; if not, 1 will be used.
* @param zoomFactor the zoom factor to use (1 or greater)
*/
public void zoom(int zoomFactor) {
currentZoom = Math.max(1, zoomFactor);
if (isGraphical()) {
Dimension size = new Dimension(width * currentZoom, height * currentZoom);
imagePanel.setPreferredSize(size);
panel.setPreferredSize(size);
imagePanel.validate();
imagePanel.revalidate();
panel.validate();
panel.revalidate();
// imagePanel.setSize(size);
frame.getContentPane().validate();
imagePanel.repaint();
setStatusBarText(" ");
// resize frame if any more space for it exists or it's the wrong size
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
if (size.width <= screen.width || size.height <= screen.height) {
frame.pack();
}
if (currentZoom != 1) {
frame.setTitle(TITLE + " (" + currentZoom + "x zoom)");
} else {
frame.setTitle(TITLE);
}
}
}
// INNER/NESTED CLASSES
/*
* Internal action listener for handling events on buttons and GUI components.
*/
private class DPActionListener implements ActionListener {
// used for an internal timer that keeps repainting
public void actionPerformed(ActionEvent e) {
if (e.getSource() instanceof Timer) {
// redraw the screen at regular intervals to catch all paint operations
panel.repaint();
if (shouldDiff() &&
System.currentTimeMillis() > createTime + 4 * DELAY) {
String expected = System.getProperty(DIFF_PROPERTY);
try {
String actual = saveToTempFile();
DiffImage diff = new DiffImage(expected, actual);
diff.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
} catch (IOException ioe) {
System.err.println("Error diffing image: " + ioe);
}
timer.stop();
} else if (shouldSave() && readyToClose()) {
// auto-save-and-close if desired
try {
if (isAnimated()) {
saveAnimated(System.getProperty(SAVE_PROPERTY));
} else {
save(System.getProperty(SAVE_PROPERTY));
}
} catch (IOException ioe) {
System.err.println("Error saving image: " + ioe);
}
exit();
}
} else if (e.getActionCommand().equals("Exit")) {
exit();
} else if (e.getActionCommand().equals("Compare to File...")) {
compareToFile();
} else if (e.getActionCommand().equals("Compare to Web File...")) {
new Thread(new Runnable() {
public void run() {
compareToURL();
}
}).start();
} else if (e.getActionCommand().equals("Save As...")) {
saveAs();
} else if (e.getActionCommand().equals("Save Animated GIF...")) {
saveAsAnimated();
} else if (e.getActionCommand().equals("Zoom In")) {
zoom(currentZoom + 1);
} else if (e.getActionCommand().equals("Zoom Out")) {
zoom(currentZoom - 1);
} else if (e.getActionCommand().equals("Zoom Normal (100%)")) {
zoom(1);
} else if (e.getActionCommand().equals("Grid Lines")) {
setGridLines(((JCheckBoxMenuItem) e.getSource()).isSelected());
} else if (e.getActionCommand().equals("About...")) {
JOptionPane.showMessageDialog(frame,
ABOUT_MESSAGE,
ABOUT_MESSAGE_TITLE,
JOptionPane.INFORMATION_MESSAGE);
}
}
}
/*
* Internal file filter class for showing image files in JFileChooser.
*/
private class DPFileFilter extends FileFilter {
public boolean accept(File file) {
return file.isDirectory() ||
(file.getName().toLowerCase().endsWith(".png") ||
file.getName().toLowerCase().endsWith(".gif"));
}
public String getDescription() {
return "Image files (*.png; *.gif)";
}
}
// BEGIN EVENT ADAPTER CODE FOR JAVA 8 FUNCTIONAL INTERFACE CLIENTS
// EXAMPLE:
// panel.onClick( (x, y) -> System.out.println(x + " " + y) );
/**
* This functional interface is provided to allow Java 8 clients to write
* lambda functions to handle mouse events that occur in a DrawingPanel.
*/
@FunctionalInterface
public static interface DPMouseEventHandler {
/**
* Called when a mouse event occurs at the given (x, y) position
* in the drawing panel window.
* @param x x-coordinate at which the event occurred
* @param y y-coordinate at which the event occurred
*/
public void onMouseEvent(int x, int y);
}
/**
* This functional interface is provided to allow Java 8 clients to write
* lambda functions to handle key events that occur in a DrawingPanel.
*/
@FunctionalInterface
public static interface DPKeyEventHandler {
/**
* Called when a key event occurs involving the given key character
* in the drawing panel window.
* @param keyCode char value that was typed
*/
public void onKeyEvent(char keyCode);
}
// internal class to implement DPKeyEventHandler behavior.
private class DPKeyEventHandlerAdapter implements KeyListener {
private DPKeyEventHandler handler;
private String eventType;
/**
* Constructs a new key handler adapter.
* @param handler event handler function
* @param eventType type of event to print
*/
public DPKeyEventHandlerAdapter(DPKeyEventHandler handler, String eventType) {
this.handler = handler;
this.eventType = eventType.intern();
}
/**
* Called when a key press occurs.
* @param e event that occurred
*/
@Override
public void keyPressed(KeyEvent e) {
// empty; see keyTyped
}
/**
* Called when a key release occurs.
* @param e event that occurred
*/
@Override
public void keyReleased(KeyEvent e) {
if (eventType == "release") {
int keyCode = e.getKeyCode();
if (keyCode < ' ') {
return;
}
handler.onKeyEvent(e.getKeyChar());
}
}
/**
* Called when a key type event occurs.
* @param e event that occurred
*/
@Override
public void keyTyped(KeyEvent e) {
if (eventType == "press") {
handler.onKeyEvent(e.getKeyChar());
}
}
}
// internal class to implement DPMouseEventHandler behavior.
private class DPMouseEventHandlerAdapter implements MouseInputListener {
private DPMouseEventHandler handler;
private String eventType;
/**
* Constructs a new mouse handler adapter.
* @param handler event handler function
* @param eventType type of event to print
*/
public DPMouseEventHandlerAdapter(DPMouseEventHandler handler, String eventType) {
this.handler = handler;
this.eventType = eventType.intern();
}
/**
* Called when a mouse press occurs.
* @param e event that occurred
*/
@Override
public void mousePressed(MouseEvent e) {
if (eventType == "press") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse release occurs.
* @param e event that occurred
*/
@Override
public void mouseReleased(MouseEvent e) {
if (eventType == "release") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse click occurs.
* @param e event that occurred
*/
@Override
public void mouseClicked(MouseEvent e) {
if (eventType == "click") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse enter occurs.
* @param e event that occurred
*/
@Override
public void mouseEntered(MouseEvent e) {
if (eventType == "enter") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse exit occurs.
* @param e event that occurred
*/
@Override
public void mouseExited(MouseEvent e) {
if (eventType == "exit") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse movement occurs.
* @param e event that occurred
*/
@Override
public void mouseMoved(MouseEvent e) {
if (eventType == "move") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
/**
* Called when a mouse drag occurs.
* @param e event that occurred
*/
@Override
public void mouseDragged(MouseEvent e) {
if (eventType == "drag") {
handler.onMouseEvent(e.getX(), e.getY());
}
}
}
// END EVENT ADAPTER CODE FOR JAVA 8 FUNCTIONAL INTERFACE CLIENTS
// Internal MouseListener class for handling mouse events in the panel.
private class DPMouseListener extends MouseInputAdapter {
// listens to mouse movement
public void mouseMoved(MouseEvent e) {
int x = e.getX() / currentZoom;
int y = e.getY() / currentZoom;
String status = "(x=" + x + ", y=" + y + ")";
if (x >= 0 && x < width && y >= 0 && y < height) {
int rgb = getPixelRGB(x, y);
int r = getRed(rgb);
int g = getGreen(rgb);
int b = getBlue(rgb);
status += ", r=" + r + " g=" + g + " b=" + b;
}
setStatusBarText(status);
}
}
// Internal WindowListener class for handling window events in the panel.
private class DPWindowListener extends WindowAdapter {
// called when DrawingPanel closes, to potentially exit the program
public void windowClosing(WindowEvent event) {
frame.setVisible(false);
synchronized (LOCK) {
instances--;
}
frame.dispose();
}
}
/*
* This inner class passes through calls to the panel's Graphics object g2
* but also records a count of how many times various basic drawing methods
* are called. This is used for debugging purposes, so that a client can
* compare their counts of various graphical method calls to those from an
* expected output as a "sanity check" on their program's behavior.
* Notice that it extends Graphics and not Graphics2D, so it is more limited
* than g2.
* @author Stuart Reges
*/
private class DebuggingGraphics extends Graphics {
public Graphics create() {
return g2.create();
}
public void translate(int x, int y) {
g2.translate(x, y);
}
public Color getColor() {
return g2.getColor();
}
public void setPaintMode() {
g2.setPaintMode();
}
public void setXORMode(Color c1) {
g2.setXORMode(c1);
}
public Font getFont() {
return g2.getFont();
}
public void setFont(Font font) {
g2.setFont(font);
}
public FontMetrics getFontMetrics(Font f) {
return g2.getFontMetrics();
}
public Rectangle getClipBounds() {
return g2.getClipBounds();
}
public void clipRect(int x, int y, int width, int height) {
g2.clipRect(x, y, width, height);
}
public void setClip(int x, int y, int width, int height) {
g2.setClip(x, y, width, height);
}
public Shape getClip() {
return g2.getClip();
}
public void setClip(Shape clip) {
g2.setClip(clip);
}
public void copyArea(int x, int y, int width, int height, int dx, int dy) {
g2.copyArea(x, y, width, height, dx, dy);
}
public void clearRect(int x, int y, int width, int height) {
g2.clearRect(x, y, width, height);
}
public void drawRoundRect(int x, int y, int width, int height,
int arcWidth, int arcHeight) {
g2.drawRoundRect(x, y, width, height, arcWidth, arcHeight);
}
public void fillRoundRect(int x, int y, int width, int height,
int arcWidth, int arcHeight) {
g2.fillRoundRect(x, y, width, height, arcWidth, arcHeight);
}
public void drawArc(int x, int y, int width, int height,
int startAngle, int arcAngle) {
g2.drawArc(x, y, width, height, startAngle, arcAngle);
}
public void fillArc(int x, int y, int width, int height,
int startAngle, int arcAngle) {
g2.fillArc(x, y, width, height, startAngle, arcAngle);
}
public void drawPolyline(int xPoints[], int yPoints[], int nPoints) {
g2.drawPolyline(xPoints, yPoints, nPoints);
}
public void drawPolygon(int xPoints[], int yPoints[], int nPoints) {
g2.drawPolygon(xPoints, yPoints, nPoints);
}
public void fillPolygon(int xPoints[], int yPoints[], int nPoints) {
g2.fillPolygon(xPoints, yPoints, nPoints);
}
public void drawString(AttributedCharacterIterator iterator, int x,
int y) {
g2.drawString(iterator, x, y);
}
public boolean drawImage(Image img, int x, int y, ImageObserver observer) {
return g2.drawImage(img, x, y, observer);
};
public boolean drawImage(Image img, int x, int y, int width,
int height, ImageObserver observer) {
return g2.drawImage(img, x, y, width, height, observer);
};
public boolean drawImage(Image img, int x, int y, Color bgcolor,
ImageObserver observer) {
return g2.drawImage(img, x, y, bgcolor, observer);
};
public boolean drawImage(Image img, int x, int y, int width,
int height, Color bgcolor, ImageObserver observer) {
return g2.drawImage(img, x, y, width, height, bgcolor, observer);
}
public boolean drawImage(Image img, int dx1, int dy1, int dx2, int dy2,
int sx1, int sy1, int sx2, int sy2, ImageObserver observer) {
return g2.drawImage(img, dx1, dy1, dx2, dy2, sx1, dy1, dx2, sy2,
observer);
}
public boolean drawImage(Image img, int dx1, int dy1, int dx2, int dy2,
int sx1, int sy1, int sx2, int sy2, Color bgcolor,
ImageObserver observer) {
return g2.drawImage(img, dx1, dy1, dx2, dy2, sx1, dy1, sx2, sy2,
bgcolor, observer);
}
public void dispose() {
g2.dispose();
}
public void drawOval(int x, int y, int width, int height) {
g2.drawOval(x, y, width, height);
recordString("drawOval");
}
public void fillOval(int x, int y, int width, int height) {
g2.fillOval(x, y, width, height);
recordString("fillOval");
}
public void drawString(String str, int x, int y) {
g2.drawString(str, x, y);
recordString("drawString");
}
public void drawLine(int x1, int y1, int x2, int y2) {
g2.drawLine(x1, y1, x2, y2);
recordString("drawLine");
}
public void fillRect(int x, int y, int width, int height) {
g2.fillRect(x, y, width, height);
recordString("fillRect");
}
public void drawRect(int x, int y, int width, int height) {
g2.drawRect(x, y, width, height);
recordString("drawRect");
}
public void setColor(Color c) {
g2.setColor(c);
// recordString("setColor");
}
public void recordString(String s) {
if (!counts.containsKey(s)) {
counts.put(s, 1);
} else {
counts.put(s, counts.get(s) + 1);
}
}
} // end class DebuggingGraphics
/*
* This internal class represents a graphical panel that can pop up on the
* screen to report the differences between two images.
* It is used to allow the client to compare their program's output against
* a known correct output and view which pixels differ between the two.
*/
private class DiffImage extends JPanel
implements ActionListener, ChangeListener {
private static final long serialVersionUID = 0;
private BufferedImage image1;
private BufferedImage image2;
private String image1name;
private int numDiffPixels;
private int opacity = 50;
private String label1Text = "Expected";
private String label2Text = "Actual";
private boolean highlightDiffs = false;
private Color highlightColor = new Color(224, 0, 224);
private JLabel image1Label;
private JLabel image2Label;
private JLabel diffPixelsLabel;
private JSlider slider;
private JCheckBox box;
private JMenuItem saveAsItem;
private JMenuItem setImage1Item;
private JMenuItem setImage2Item;
private JFrame frame;
private JButton colorButton;
public DiffImage(String file1, String file2) throws IOException {
setImage1(file1);
setImage2(file2);
display();
}
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == box) {
highlightDiffs = box.isSelected();
repaint();
} else if (source == colorButton) {
Color color = JColorChooser.showDialog(frame,
"Choose highlight color", highlightColor);
if (color != null) {
highlightColor = color;
colorButton.setBackground(color);
colorButton.setForeground(color);
repaint();
}
} else if (source == saveAsItem) {
saveAs();
} else if (source == setImage1Item) {
setImage1();
} else if (source == setImage2Item) {
setImage2();
}
}
// Counts number of pixels that differ between the two images.
public void countDiffPixels() {
if (image1 == null || image2 == null) {
return;
}
int w1 = image1.getWidth();
int h1 = image1.getHeight();
int w2 = image2.getWidth();
int h2 = image2.getHeight();
int wmax = Math.max(w1, w2);
int hmax = Math.max(h1, h2);
// check each pair of pixels
numDiffPixels = 0;
for (int y = 0; y < hmax; y++) {
for (int x = 0; x < wmax; x++) {
int pixel1 = (x < w1 && y < h1) ? image1.getRGB(x, y) : 0;
int pixel2 = (x < w2 && y < h2) ? image2.getRGB(x, y) : 0;
if (pixel1 != pixel2) {
numDiffPixels++;
}
}
}
}
// initializes diffimage panel
public void display() {
countDiffPixels();
setupComponents();
setupEvents();
setupLayout();
frame.pack();
center(frame);
frame.setVisible(true);
toFront(frame);
}
// draws the given image onto the given graphics context
public void drawImageFull(Graphics2D g2, BufferedImage image) {
int iw = image.getWidth();
int ih = image.getHeight();
int w = getWidth();
int h = getHeight();
int dw = w - iw;
int dh = h - ih;
if (dw > 0) {
g2.fillRect(iw, 0, dw, ih);
}
if (dh > 0) {
g2.fillRect(0, ih, iw, dh);
}
if (dw > 0 && dh > 0) {
g2.fillRect(iw, ih, dw, dh);
}
g2.drawImage(image, 0, 0, this);
}
// paints the DiffImage panel
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
// draw the expected output (image 1)
if (image1 != null) {
drawImageFull(g2, image1);
}
// draw the actual output (image 2)
if (image2 != null) {
Composite oldComposite = g2.getComposite();
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ((float) opacity) / 100));
drawImageFull(g2, image2);
g2.setComposite(oldComposite);
}
g2.setColor(Color.BLACK);
// draw the highlighted diffs (if so desired)
if (highlightDiffs && image1 != null && image2 != null) {
int w1 = image1.getWidth();
int h1 = image1.getHeight();
int w2 = image2.getWidth();
int h2 = image2.getHeight();
int wmax = Math.max(w1, w2);
int hmax = Math.max(h1, h2);
// check each pair of pixels
g2.setColor(highlightColor);
for (int y = 0; y < hmax; y++) {
for (int x = 0; x < wmax; x++) {
int pixel1 = (x < w1 && y < h1) ? image1.getRGB(x, y) : 0;
int pixel2 = (x < w2 && y < h2) ? image2.getRGB(x, y) : 0;
if (pixel1 != pixel2) {
g2.fillRect(x, y, 1, 1);
}
}
}
}
}
public void save(File file) throws IOException {
// String extension = filename.substring(filename.lastIndexOf(".") + 1);
// ImageIO.write(diffImage, extension, new File(filename));
String filename = file.getName();
String extension = filename.substring(filename.lastIndexOf(".") + 1);
BufferedImage img = new BufferedImage(getPreferredSize().width, getPreferredSize().height, BufferedImage.TYPE_INT_ARGB);
img.getGraphics().setColor(getBackground());
img.getGraphics().fillRect(0, 0, img.getWidth(), img.getHeight());
paintComponent(img.getGraphics());
ImageIO.write(img, extension, file);
}
public void save(String filename) throws IOException {
save(new File(filename));
}
// Called when "Save As" menu item is clicked
public void saveAs() {
checkChooser();
if (chooser.showSaveDialog(frame) != JFileChooser.APPROVE_OPTION) {
return;
}
File selectedFile = chooser.getSelectedFile();
try {
save(selectedFile.toString());
} catch (IOException ex) {
JOptionPane.showMessageDialog(frame, "Unable to save image:\n" + ex);
}
}
// called when "Set Image 1" menu item is clicked
public void setImage1() {
checkChooser();
if (chooser.showSaveDialog(frame) != JFileChooser.APPROVE_OPTION) {
return;
}
File selectedFile = chooser.getSelectedFile();
try {
setImage1(selectedFile.toString());
countDiffPixels();
diffPixelsLabel.setText("(" + numDiffPixels + " pixels differ)");
image1Label.setText(selectedFile.getName());
frame.pack();
} catch (IOException ex) {
JOptionPane.showMessageDialog(frame, "Unable to set image 1:\n" + ex);
}
}
// sets image 1 to be the given image
public void setImage1(BufferedImage image) {
if (image == null) {
throw new NullPointerException();
}
image1 = image;
setPreferredSize(new Dimension(
Math.max(getPreferredSize().width, image.getWidth()),
Math.max(getPreferredSize().height, image.getHeight()))
);
if (frame != null) {
frame.pack();
}
repaint();
}
// loads image 1 from the given filename or URL
public void setImage1(String filename) throws IOException {
image1name = new File(filename).getName();
if (filename.startsWith("http")) {
setImage1(ImageIO.read(new URL(filename)));
} else {
setImage1(ImageIO.read(new File(filename)));
}
}
// called when "Set Image 2" menu item is clicked
public void setImage2() {
checkChooser();
if (chooser.showSaveDialog(frame) != JFileChooser.APPROVE_OPTION) {
return;
}
File selectedFile = chooser.getSelectedFile();
try {
setImage2(selectedFile.toString());
countDiffPixels();
diffPixelsLabel.setText("(" + numDiffPixels + " pixels differ)");
image2Label.setText(selectedFile.getName());
frame.pack();
} catch (IOException ex) {
JOptionPane.showMessageDialog(frame, "Unable to set image 2:\n" + ex);
}
}
// sets image 2 to be the given image
public void setImage2(BufferedImage image) {
if (image == null) {
throw new NullPointerException();
}
image2 = image;
setPreferredSize(new Dimension(
Math.max(getPreferredSize().width, image.getWidth()),
Math.max(getPreferredSize().height, image.getHeight()))
);
if (frame != null) {
frame.pack();
}
repaint();
}
// loads image 2 from the given filename
public void setImage2(String filename) throws IOException {
if (filename.startsWith("http")) {
setImage2(ImageIO.read(new URL(filename)));
} else {
setImage2(ImageIO.read(new File(filename)));
}
}
private void setupComponents() {
String title = "DiffImage";
if (image1name != null) {
title = "Compare to " + image1name;
}
frame = new JFrame(title);
frame.setResizable(false);
// frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
slider = new JSlider();
slider.setPaintLabels(false);
slider.setPaintTicks(true);
slider.setSnapToTicks(true);
slider.setMajorTickSpacing(25);
slider.setMinorTickSpacing(5);
box = new JCheckBox("Highlight diffs in color: ", highlightDiffs);
colorButton = new JButton();
colorButton.setBackground(highlightColor);
colorButton.setForeground(highlightColor);
colorButton.setPreferredSize(new Dimension(24, 24));
diffPixelsLabel = new JLabel("(" + numDiffPixels + " pixels differ)");
diffPixelsLabel.setFont(diffPixelsLabel.getFont().deriveFont(Font.BOLD));
image1Label = new JLabel(label1Text);
image2Label = new JLabel(label2Text);
setupMenuBar();
}
// initializes layout of components
private void setupLayout() {
JPanel southPanel1 = new JPanel();
southPanel1.setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY));
southPanel1.add(image1Label);
southPanel1.add(slider);
southPanel1.add(image2Label);
southPanel1.add(Box.createHorizontalStrut(20));
JPanel southPanel2 = new JPanel();
southPanel2.setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY));
southPanel2.add(diffPixelsLabel);
southPanel2.add(Box.createHorizontalStrut(20));
southPanel2.add(box);
southPanel2.add(colorButton);
Container southPanel = javax.swing.Box.createVerticalBox();
southPanel.add(southPanel1);
southPanel.add(southPanel2);
frame.add(this, BorderLayout.CENTER);
frame.add(southPanel, BorderLayout.SOUTH);
}
// initializes main menu bar
private void setupMenuBar() {
saveAsItem = new JMenuItem("Save As...", 'A');
saveAsItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));
setImage1Item = new JMenuItem("Set Image 1...", '1');
setImage1Item.setAccelerator(KeyStroke.getKeyStroke("ctrl 1"));
setImage2Item = new JMenuItem("Set Image 2...", '2');
setImage2Item.setAccelerator(KeyStroke.getKeyStroke("ctrl 2"));
JMenu file = new JMenu("File");
file.setMnemonic('F');
file.add(setImage1Item);
file.add(setImage2Item);
file.addSeparator();
file.add(saveAsItem);
JMenuBar bar = new JMenuBar();
bar.add(file);
// disabling menu bar to simplify code
// frame.setJMenuBar(bar);
}
// method of ChangeListener interface
public void stateChanged(ChangeEvent e) {
opacity = slider.getValue();
repaint();
}
// adds event listeners to various components
private void setupEvents() {
slider.addChangeListener(this);
box.addActionListener(this);
colorButton.addActionListener(this);
saveAsItem.addActionListener(this);
this.setImage1Item.addActionListener(this);
this.setImage2Item.addActionListener(this);
}
}
// inner class to represent one frame of an animated GIF
private static class ImageFrame {
public Image image;
public int delay;
public ImageFrame(Image image, int delay) {
this.image = image;
this.delay = delay / 10; // strangely, gif stores delay as sec/100
}
}
// inner class to do the actual drawing onto the DrawingPanel
private class ImagePanel extends JPanel {
private static final long serialVersionUID = 0;
private Image image;
// constructs the image panel
public ImagePanel(Image image) {
super(/* isDoubleBuffered */ true);
setImage(image);
setBackground(Color.WHITE);
setPreferredSize(new Dimension(image.getWidth(this), image.getHeight(this)));
setAlignmentX(0.0f);
}
// draws everything onto the panel
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
if (currentZoom != 1) {
g2.scale(currentZoom, currentZoom);
}
g2.drawImage(image, 0, 0, this);
// possibly draw grid lines for debugging
if (gridLines) {
g2.setPaint(GRID_LINE_COLOR);
for (int row = 1; row <= getHeight() / gridLinesPxGap; row++) {
g2.drawLine(0, row * gridLinesPxGap, getWidth(), row * gridLinesPxGap);
}
for (int col = 1; col <= getWidth() / gridLinesPxGap; col++) {
g2.drawLine(col * gridLinesPxGap, 0, col * gridLinesPxGap, getHeight());
}
}
}
public void setImage(Image image) {
this.image = image;
repaint();
}
}
// BEGIN GIF ENCODING CLASSES
//******************************************************************************
// DirectGif89Frame.java
//******************************************************************************
// ==============================================================================
/**
* Instances of this Gif89Frame subclass are constructed from RGB image
* info, either in the form of an Image object or a pixel array.
*
* There is an important restriction to note. It is only permissible to add
* DirectGif89Frame objects to a Gif89Encoder constructed without an
* explicit color map. The GIF color table will be automatically generated
* from pixel information.
*
* @version 0.90 beta (15-Jul-2000)
* @author J. M. G. Elliott (tep@jmge.net)
* @see Gif89Encoder
* @see Gif89Frame
* @see IndexGif89Frame
*/
class DirectGif89Frame extends Gif89Frame {
private int[] argbPixels;
// ----------------------------------------------------------------------------
/**
* Construct an DirectGif89Frame from a Java image.
*
* @param img
* A java.awt.Image object that supports pixel-grabbing.
* @exception IOException
* If the image is unencodable due to failure of
* pixel-grabbing.
*/
public DirectGif89Frame(Image img) throws IOException {
PixelGrabber pg = new PixelGrabber(img, 0, 0, -1, -1, true);
String errmsg = null;
try {
if (!pg.grabPixels())
errmsg = "can't grab pixels from image";
} catch (InterruptedException e) {
errmsg = "interrupted grabbing pixels from image";
}
if (errmsg != null)
throw new IOException(errmsg + " (" + getClass().getName()
+ ")");
theWidth = pg.getWidth();
theHeight = pg.getHeight();
argbPixels = (int[]) pg.getPixels();
ciPixels = new byte[argbPixels.length];
// flush to conserve resources
img.flush();
}
// ----------------------------------------------------------------------------
/**
* Construct an DirectGif89Frame from ARGB pixel data.
*
* @param width
* Width of the bitmap.
* @param height
* Height of the bitmap.
* @param argb_pixels
* Array containing at least width*height pixels in the
* format returned by java.awt.Color.getRGB().
*/
public DirectGif89Frame(int width, int height, int argb_pixels[]) {
theWidth = width;
theHeight = height;
argbPixels = new int[theWidth * theHeight];
System.arraycopy(argb_pixels, 0, argbPixels, 0, argbPixels.length);
ciPixels = new byte[argbPixels.length];
}
// ----------------------------------------------------------------------------
Object getPixelSource() {
return argbPixels;
}
}
// ******************************************************************************
// Gif89Encoder.java
// ******************************************************************************
// ==============================================================================
/**
* This is the central class of a JDK 1.1 compatible GIF encoder that,
* AFAIK, supports more features of the extended GIF spec than any other
* Java open source encoder. Some sections of the source are lifted or
* adapted from Jef Poskanzer's Acme GifEncoder (so please see
* the readme containing his notice), but much
* of it, including nearly all of the present class, is original code. My
* main motivation for writing a new encoder was to support animated GIFs,
* but the package also adds support for embedded textual comments.
*
* There are still some limitations. For instance, animations are limited to
* a single global color table. But that is usually what you want anyway, so
* as to avoid irregularities on some displays. (So this is not really a
* limitation, but a "disciplinary feature" :) Another rather more serious
* restriction is that the total number of RGB colors in a given input-batch
* mustn't exceed 256. Obviously, there is an opening here for someone who
* would like to add a color-reducing preprocessor.
*
* The encoder, though very usable in its present form, is at bottom only a
* partial implementation skewed toward my own particular needs. Hence a
* couple of caveats are in order. (1) During development it was in the back
* of my mind that an encoder object should be reusable - i.e., you should
* be able to make multiple calls to encode() on the same object, with or
* without intervening frame additions or changes to options. But I haven't
* reviewed the code with such usage in mind, much less tested it, so it's
* likely I overlooked something. (2) The encoder classes aren't thread
* safe, so use caution in a context where access is shared by multiple
* threads. (Better yet, finish the library and re-release it :)
*
* There follow a couple of simple examples illustrating the most common way
* to use the encoder, i.e., to encode AWT Image objects created elsewhere
* in the program. Use of some of the most popular format options is also
* shown, though you will want to peruse the API for additional features.
*
*
* Animated GIF Example
*
*
* import net.jmge.gif.Gif89Encoder;
* // ...
* void writeAnimatedGIF(Image[] still_images,
* String annotation,
* boolean looped,
* double frames_per_second,
* OutputStream out) throws IOException
* {
* Gif89Encoder gifenc = new Gif89Encoder();
* for (int i = 0; i < still_images.length; ++i)
* gifenc.addFrame(still_images[i]);
* gifenc.setComments(annotation);
* gifenc.setLoopCount(looped ? 0 : 1);
* gifenc.setUniformDelay((int) Math.round(100 / frames_per_second));
* gifenc.encode(out);
* }
*
*
* Static GIF Example
*
*
* import net.jmge.gif.Gif89Encoder;
* // ...
* void writeNormalGIF(Image img,
* String annotation,
* int transparent_index, // pass -1 for none
* boolean interlaced,
* OutputStream out) throws IOException
* {
* Gif89Encoder gifenc = new Gif89Encoder(img);
* gifenc.setComments(annotation);
* gifenc.setTransparentIndex(transparent_index);
* gifenc.getFrameAt(0).setInterlaced(interlaced);
* gifenc.encode(out);
* }
*
*
* @version 0.90 beta (15-Jul-2000)
* @author J. M. G. Elliott (tep@jmge.net)
* @see Gif89Frame
* @see DirectGif89Frame
* @see IndexGif89Frame
*/
class Gif89Encoder {
private static final boolean DEBUG = false;
private Dimension dispDim = new Dimension(0, 0);
private GifColorTable colorTable;
private int bgIndex = 0;
private int loopCount = 1;
private String theComments;
private Vector vFrames = new Vector();
// ----------------------------------------------------------------------------
/**
* Use this default constructor if you'll be adding multiple frames
* constructed from RGB data (i.e., AWT Image objects or ARGB-pixel
* arrays).
*/
public Gif89Encoder() {
// empty color table puts us into "palette autodetect" mode
colorTable = new GifColorTable();
}
// ----------------------------------------------------------------------------
/**
* Like the default except that it also adds a single frame, for
* conveniently encoding a static GIF from an image.
*
* @param static_image
* Any Image object that supports pixel-grabbing.
* @exception IOException
* See the addFrame() methods.
*/
public Gif89Encoder(Image static_image) throws IOException {
this();
addFrame(static_image);
}
// ----------------------------------------------------------------------------
/**
* This constructor installs a user color table, overriding the
* detection of of a palette from ARBG pixels.
*
* Use of this constructor imposes a couple of restrictions: (1) Frame
* objects can't be of type DirectGif89Frame (2) Transparency, if
* desired, must be set explicitly.
*
* @param colors
* Array of color values; no more than 256 colors will be
* read, since that's the limit for a GIF.
*/
public Gif89Encoder(Color[] colors) {
colorTable = new GifColorTable(colors);
}
// ----------------------------------------------------------------------------
/**
* Convenience constructor for encoding a static GIF from index-model
* data. Adds a single frame as specified.
*
* @param colors
* Array of color values; no more than 256 colors will be
* read, since that's the limit for a GIF.
* @param width
* Width of the GIF bitmap.
* @param height
* Height of same.
* @param ci_pixels
* Array of color-index pixels no less than width * height in
* length.
* @exception IOException
* See the addFrame() methods.
*/
public Gif89Encoder(Color[] colors, int width, int height,
byte ci_pixels[]) throws IOException {
this(colors);
addFrame(width, height, ci_pixels);
}
// ----------------------------------------------------------------------------
/**
* Get the number of frames that have been added so far.
*
* @return Number of frame items.
*/
public int getFrameCount() {
return vFrames.size();
}
// ----------------------------------------------------------------------------
/**
* Get a reference back to a Gif89Frame object by position.
*
* @param index
* Zero-based index of the frame in the sequence.
* @return Gif89Frame object at the specified position (or null if no
* such frame).
*/
public Gif89Frame getFrameAt(int index) {
return isOk(index) ? vFrames.elementAt(index) : null;
}
// ----------------------------------------------------------------------------
/**
* Add a Gif89Frame frame to the end of the internal sequence. Note that
* there are restrictions on the Gif89Frame type: if the encoder object
* was constructed with an explicit color table, an attempt to add a
* DirectGif89Frame will throw an exception.
*
* @param gf
* An externally constructed Gif89Frame.
* @exception IOException
* If Gif89Frame can't be accommodated. This could happen
* if either (1) the aggregate cross-frame RGB color
* count exceeds 256, or (2) the Gif89Frame subclass is
* incompatible with the present encoder object.
*/
public void addFrame(Gif89Frame gf) throws IOException {
accommodateFrame(gf);
vFrames.addElement(gf);
}
// ----------------------------------------------------------------------------
/**
* Convenience version of addFrame() that takes a Java Image, internally
* constructing the requisite DirectGif89Frame.
*
* @param image
* Any Image object that supports pixel-grabbing.
* @exception IOException
* If either (1) pixel-grabbing fails, (2) the aggregate
* cross-frame RGB color count exceeds 256, or (3) this
* encoder object was constructed with an explicit color
* table.
*/
public void addFrame(Image image) throws IOException {
DirectGif89Frame frame = new DirectGif89Frame(image);
addFrame(frame);
}
// ----------------------------------------------------------------------------
/**
* The index-model convenience version of addFrame().
*
* @param width
* Width of the GIF bitmap.
* @param height
* Height of same.
* @param ci_pixels
* Array of color-index pixels no less than width * height in
* length.
* @exception IOException
* Actually, in the present implementation, there aren't
* any unchecked exceptions that can be thrown when
* adding an IndexGif89Frame per se. But I might
* add some pedantic check later, to justify the
* generality :)
*/
public void addFrame(int width, int height, byte ci_pixels[])
throws IOException {
addFrame(new IndexGif89Frame(width, height, ci_pixels));
}
// ----------------------------------------------------------------------------
/**
* Like addFrame() except that the frame is inserted at a specific point
* in the sequence rather than appended.
*
* @param index
* Zero-based index at which to insert frame.
* @param gf
* An externally constructed Gif89Frame.
* @exception IOException
* If Gif89Frame can't be accommodated. This could happen
* if either (1) the aggregate cross-frame RGB color
* count exceeds 256, or (2) the Gif89Frame subclass is
* incompatible with the present encoder object.
*/
public void insertFrame(int index, Gif89Frame gf) throws IOException {
accommodateFrame(gf);
vFrames.insertElementAt(gf, index);
}
// ----------------------------------------------------------------------------
/**
* Set the color table index for the transparent color, if any.
*
* @param index
* Index of the color that should be rendered as transparent,
* if any. A value of -1 turns off transparency. (Default:
* -1)
*/
public void setTransparentIndex(int index) {
colorTable.setTransparent(index);
}
// ----------------------------------------------------------------------------
/**
* Sets attributes of the multi-image display area, if applicable.
*
* @param dim
* Width/height of display. (Default: largest detected frame
* size)
* @param background
* Color table index of background color. (Default: 0)
* @see Gif89Frame#setPosition
*/
public void setLogicalDisplay(Dimension dim, int background) {
dispDim = new Dimension(dim);
bgIndex = background;
}
// ----------------------------------------------------------------------------
/**
* Set animation looping parameter, if applicable.
*
* @param count
* Number of times to play sequence. Special value of 0
* specifies indefinite looping. (Default: 1)
*/
public void setLoopCount(int count) {
loopCount = count;
}
// ----------------------------------------------------------------------------
/**
* Specify some textual comments to be embedded in GIF.
*
* @param comments
* String containing ASCII comments.
*/
public void setComments(String comments) {
theComments = comments;
}
// ----------------------------------------------------------------------------
/**
* A convenience method for setting the "animation speed". It simply
* sets the delay parameter for each frame in the sequence to the
* supplied value. Since this is actually frame-level rather than
* animation-level data, take care to add your frames before calling
* this method.
*
* @param interval
* Interframe interval in centiseconds.
*/
public void setUniformDelay(int interval) {
for (int i = 0; i < vFrames.size(); ++i)
vFrames.elementAt(i).setDelay(interval);
}
// ----------------------------------------------------------------------------
/**
* After adding your frame(s) and setting your options, simply call this
* method to write the GIF to the passed stream. Multiple calls are
* permissible if for some reason that is useful to your application.
* (The method simply encodes the current state of the object with no
* thought to previous calls.)
*
* @param out
* The stream you want the GIF written to.
* @exception IOException
* If a write error is encountered.
*/
public void encode(OutputStream out) throws IOException {
int nframes = getFrameCount();
boolean is_sequence = nframes > 1;
// N.B. must be called before writing screen descriptor
colorTable.closePixelProcessing();
// write GIF HEADER
putAscii("GIF89a", out);
// write global blocks
writeLogicalScreenDescriptor(out);
colorTable.encode(out);
if (is_sequence && loopCount != 1)
writeNetscapeExtension(out);
if (theComments != null && theComments.length() > 0)
writeCommentExtension(out);
// write out the control and rendering data for each frame
for (int i = 0; i < nframes; ++i) {
DirectGif89Frame frame = (DirectGif89Frame) vFrames
.elementAt(i);
frame.encode(out, is_sequence, colorTable.getDepth(),
colorTable.getTransparent());
vFrames.set(i, null); // for GC's sake
System.gc();
}
// write GIF TRAILER
out.write((int) ';');
out.flush();
}
public boolean hasStarted = false;
// ----------------------------------------------------------------------------
/**
* After adding your frame(s) and setting your options, simply call this
* method to write the GIF to the passed stream. Multiple calls are
* permissible if for some reason that is useful to your application.
* (The method simply encodes the current state of the object with no
* thought to previous calls.)
*
* @param out
* The stream you want the GIF written to.
* @exception IOException
* If a write error is encountered.
*/
public void startEncoding(OutputStream out, Image image, int delay)
throws IOException {
hasStarted = true;
boolean is_sequence = true;
Gif89Frame gf = new DirectGif89Frame(image);
accommodateFrame(gf);
// N.B. must be called before writing screen descriptor
colorTable.closePixelProcessing();
// write GIF HEADER
putAscii("GIF89a", out);
// write global blocks
writeLogicalScreenDescriptor(out);
colorTable.encode(out);
if (is_sequence && loopCount != 1)
writeNetscapeExtension(out);
if (theComments != null && theComments.length() > 0)
writeCommentExtension(out);
}
public void continueEncoding(OutputStream out, Image image, int delay)
throws IOException {
// write out the control and rendering data for each frame
Gif89Frame gf = new DirectGif89Frame(image);
accommodateFrame(gf);
gf.encode(out, true, colorTable.getDepth(),
colorTable.getTransparent());
out.flush();
image.flush();
}
public void endEncoding(OutputStream out) throws IOException {
// write GIF TRAILER
out.write((int) ';');
out.flush();
}
public void setBackground(Color color) {
bgIndex = colorTable.indexOf(color);
if (bgIndex < 0) {
try {
BufferedImage img = new BufferedImage(1, 1,
BufferedImage.TYPE_BYTE_INDEXED);
Graphics g = img.getGraphics();
g.setColor(color);
g.fillRect(0, 0, 2, 2);
DirectGif89Frame frame = new DirectGif89Frame(img);
accommodateFrame(frame);
bgIndex = colorTable.indexOf(color);
} catch (IOException e) {
if (DEBUG)
System.out
.println("Error while setting background color: "
+ e);
}
}
if (DEBUG)
System.out.println("Setting bg index to " + bgIndex);
}
// ----------------------------------------------------------------------------
private void accommodateFrame(Gif89Frame gf) throws IOException {
dispDim.width = Math.max(dispDim.width, gf.getWidth());
dispDim.height = Math.max(dispDim.height, gf.getHeight());
colorTable.processPixels(gf);
}
// ----------------------------------------------------------------------------
private void writeLogicalScreenDescriptor(OutputStream os)
throws IOException {
putShort(dispDim.width, os);
putShort(dispDim.height, os);
// write 4 fields, packed into a byte (bitfieldsize:value)
// global color map present? (1:1)
// bits per primary color less 1 (3:7)
// sorted color table? (1:0)
// bits per pixel less 1 (3:varies)
os.write(0xf0 | colorTable.getDepth() - 1);
// write background color index
os.write(bgIndex);
// Jef Poskanzer's notes on the next field, for our possible
// edification:
// Pixel aspect ratio - 1:1.
// Putbyte( (byte) 49, outs );
// Java's GIF reader currently has a bug, if the aspect ratio byte
// is
// not zero it throws an ImageFormatException. It doesn't know that
// 49 means a 1:1 aspect ratio. Well, whatever, zero works with all
// the other decoders I've tried so it probably doesn't hurt.
// OK, if it's good enough for Jef, it's definitely good enough for
// us:
os.write(0);
}
// ----------------------------------------------------------------------------
private void writeNetscapeExtension(OutputStream os) throws IOException {
// n.b. most software seems to interpret the count as a repeat count
// (i.e., interations beyond 1) rather than as an iteration count
// (thus, to avoid repeating we have to omit the whole extension)
os.write((int) '!'); // GIF Extension Introducer
os.write(0xff); // Application Extension Label
os.write(11); // application ID block size
putAscii("NETSCAPE2.0", os); // application ID data
os.write(3); // data sub-block size
os.write(1); // a looping flag? dunno
// we finally write the relevent data
putShort(loopCount > 1 ? loopCount - 1 : 0, os);
os.write(0); // block terminator
}
// ----------------------------------------------------------------------------
private void writeCommentExtension(OutputStream os) throws IOException {
os.write((int) '!'); // GIF Extension Introducer
os.write(0xfe); // Comment Extension Label
int remainder = theComments.length() % 255;
int nsubblocks_full = theComments.length() / 255;
int nsubblocks = nsubblocks_full + (remainder > 0 ? 1 : 0);
int ibyte = 0;
for (int isb = 0; isb < nsubblocks; ++isb) {
int size = isb < nsubblocks_full ? 255 : remainder;
os.write(size);
putAscii(theComments.substring(ibyte, ibyte + size), os);
ibyte += size;
}
os.write(0); // block terminator
}
// ----------------------------------------------------------------------------
private boolean isOk(int frame_index) {
return frame_index >= 0 && frame_index < vFrames.size();
}
}
// ==============================================================================
class GifColorTable {
// the palette of ARGB colors, packed as returned by Color.getRGB()
private int[] theColors = new int[256];
// other basic attributes
private int colorDepth;
private int transparentIndex = -1;
// these fields track color-index info across frames
private int ciCount = 0; // count of distinct color indices
private ReverseColorMap ciLookup; // cumulative rgb-to-ci lookup table
// ----------------------------------------------------------------------------
GifColorTable() {
ciLookup = new ReverseColorMap(); // puts us into "auto-detect mode"
}
// ----------------------------------------------------------------------------
GifColorTable(Color[] colors) {
int n2copy = Math.min(theColors.length, colors.length);
for (int i = 0; i < n2copy; ++i)
theColors[i] = colors[i].getRGB();
}
int indexOf(Color color) {
int rgb = color.getRGB();
for (int i = 0; i < theColors.length; i++) {
if (rgb == theColors[i]) {
return i;
}
}
return -1;
}
// ----------------------------------------------------------------------------
int getDepth() {
return colorDepth;
}
// ----------------------------------------------------------------------------
int getTransparent() {
return transparentIndex;
}
// ----------------------------------------------------------------------------
// default: -1 (no transparency)
void setTransparent(int color_index) {
transparentIndex = color_index;
}
// ----------------------------------------------------------------------------
void processPixels(Gif89Frame gf) throws IOException {
if (gf instanceof DirectGif89Frame)
filterPixels((DirectGif89Frame) gf);
else
trackPixelUsage((IndexGif89Frame) gf);
}
// ----------------------------------------------------------------------------
void closePixelProcessing() // must be called before encode()
{
colorDepth = computeColorDepth(ciCount);
}
// ----------------------------------------------------------------------------
void encode(OutputStream os) throws IOException {
// size of palette written is the smallest power of 2 that can
// accomdate
// the number of RGB colors detected (or largest color index, in
// case of
// index pixels)
int palette_size = 1 << colorDepth;
for (int i = 0; i < palette_size; ++i) {
os.write(theColors[i] >> 16 & 0xff);
os.write(theColors[i] >> 8 & 0xff);
os.write(theColors[i] & 0xff);
}
}
// ----------------------------------------------------------------------------
// This method accomplishes three things:
// (1) converts the passed rgb pixels to indexes into our rgb lookup
// table
// (2) fills the rgb table as new colors are encountered
// (3) looks for transparent pixels so as to set the transparent index
// The information is cumulative across multiple calls.
//
// (Note: some of the logic is borrowed from Jef Poskanzer's code.)
// ----------------------------------------------------------------------------
private void filterPixels(DirectGif89Frame dgf) throws IOException {
if (ciLookup == null)
throw new IOException(
"RGB frames require palette autodetection");
int[] argb_pixels = (int[]) dgf.getPixelSource();
byte[] ci_pixels = dgf.getPixelSink();
int npixels = argb_pixels.length;
for (int i = 0; i < npixels; ++i) {
int argb = argb_pixels[i];
// handle transparency
if ((argb >>> 24) < 0x80) // transparent pixel?
if (transparentIndex == -1) // first transparent color
// encountered?
transparentIndex = ciCount; // record its index
else if (argb != theColors[transparentIndex]) // different
// pixel
// value?
{
// collapse all transparent pixels into one color index
ci_pixels[i] = (byte) transparentIndex;
continue; // CONTINUE - index already in table
}
// try to look up the index in our "reverse" color table
int color_index = ciLookup.getPaletteIndex(argb & 0xffffff);
if (color_index == -1) // if it isn't in there yet
{
if (ciCount == 256)
throw new IOException(
"can't encode as GIF (> 256 colors)");
// store color in our accumulating palette
theColors[ciCount] = argb;
// store index in reverse color table
ciLookup.put(argb & 0xffffff, ciCount);
// send color index to our output array
ci_pixels[i] = (byte) ciCount;
// increment count of distinct color indices
++ciCount;
} else
// we've already snagged color into our palette
ci_pixels[i] = (byte) color_index; // just send filtered
// pixel
}
}
// ----------------------------------------------------------------------------
private void trackPixelUsage(IndexGif89Frame igf) throws IOException {
byte[] ci_pixels = (byte[]) igf.getPixelSource();
int npixels = ci_pixels.length;
for (int i = 0; i < npixels; ++i)
if (ci_pixels[i] >= ciCount)
ciCount = ci_pixels[i] + 1;
}
// ----------------------------------------------------------------------------
private int computeColorDepth(int colorcount) {
// color depth = log-base-2 of maximum number of simultaneous
// colors, i.e.
// bits per color-index pixel
if (colorcount <= 2)
return 1;
if (colorcount <= 4)
return 2;
if (colorcount <= 16)
return 4;
return 8;
}
}
// ==============================================================================
// We're doing a very simple linear hashing thing here, which seems
// sufficient
// for our needs. I make no claims for this approach other than that it
// seems
// an improvement over doing a brute linear search for each pixel on the one
// hand, and creating a Java object for each pixel (if we were to use a Java
// Hashtable) on the other. Doubtless my little hash could be improved by
// tuning the capacity (at the very least). Suggestions are welcome.
// ==============================================================================
class ReverseColorMap {
private class ColorRecord {
int rgb;
int ipalette;
ColorRecord(int rgb, int ipalette) {
this.rgb = rgb;
this.ipalette = ipalette;
}
}
// I wouldn't really know what a good hashing capacity is, having missed
// out
// on data structures and algorithms class :) Alls I know is, we've got
// a lot
// more space than we have time. So let's try a sparse table with a
// maximum
// load of about 1/8 capacity.
private static final int HCAPACITY = 2053; // a nice prime number
// our hash table proper
private ColorRecord[] hTable = new ColorRecord[HCAPACITY];
// ----------------------------------------------------------------------------
// Assert: rgb is not negative (which is the same as saying, be sure the
// alpha transparency byte - i.e., the high byte - has been masked out).
// ----------------------------------------------------------------------------
int getPaletteIndex(int rgb) {
ColorRecord rec;
for (int itable = rgb % hTable.length; (rec = hTable[itable]) != null
&& rec.rgb != rgb; itable = ++itable % hTable.length)
;
if (rec != null)
return rec.ipalette;
return -1;
}
// ----------------------------------------------------------------------------
// Assert: (1) same as above; (2) rgb key not already present
// ----------------------------------------------------------------------------
void put(int rgb, int ipalette) {
int itable;
for (itable = rgb % hTable.length; hTable[itable] != null; itable = ++itable
% hTable.length)
;
hTable[itable] = new ColorRecord(rgb, ipalette);
}
}
// ******************************************************************************
// Gif89Frame.java
// ******************************************************************************
// ==============================================================================
/**
* First off, just to dispel any doubt, this class and its subclasses have
* nothing to do with GUI "frames" such as java.awt.Frame. We merely use the
* term in its very common sense of a still picture in an animation
* sequence. It's hoped that the restricted context will prevent any
* confusion.
*
* An instance of this class is used in conjunction with a Gif89Encoder
* object to represent and encode a single static image and its associated
* "control" data. A Gif89Frame doesn't know or care whether it is encoding
* one of the many animation frames in a GIF movie, or the single bitmap in
* a "normal" GIF. (FYI, this design mirrors the encoded GIF structure.)
*
* Since Gif89Frame is an abstract class we don't instantiate it directly,
* but instead create instances of its concrete subclasses, IndexGif89Frame
* and DirectGif89Frame. From the API standpoint, these subclasses differ
* only in the sort of data their instances are constructed from. Most folks
* will probably work with DirectGif89Frame, since it can be constructed
* from a java.awt.Image object, but the lower-level IndexGif89Frame class
* offers advantages in specialized circumstances. (Of course, in routine
* situations you might not explicitly instantiate any frames at all,
* instead letting Gif89Encoder's convenience methods do the honors.)
*
* As far as the public API is concerned, objects in the Gif89Frame
* hierarchy interact with a Gif89Encoder only via the latter's methods for
* adding and querying frames. (As a side note, you should know that while
* Gif89Encoder objects are permanently modified by the addition of
* Gif89Frames, the reverse is NOT true. That is, even though the ultimate
* encoding of a Gif89Frame may be affected by the context its parent
* encoder object provides, it retains its original condition and can be
* reused in a different context.)
*
* The core pixel-encoding code in this class was essentially lifted from
* Jef Poskanzer's well-known Acme GifEncoder, so please see
* the readme containing his notice.
*
* @version 0.90 beta (15-Jul-2000)
* @author J. M. G. Elliott (tep@jmge.net)
* @see Gif89Encoder
* @see DirectGif89Frame
* @see IndexGif89Frame
*/
abstract class Gif89Frame {
// // Public "Disposal Mode" constants ////
/**
* The animated GIF renderer shall decide how to dispose of this
* Gif89Frame's display area.
*
* @see Gif89Frame#setDisposalMode
*/
public static final int DM_UNDEFINED = 0;
/**
* The animated GIF renderer shall take no display-disposal action.
*
* @see Gif89Frame#setDisposalMode
*/
public static final int DM_LEAVE = 1;
/**
* The animated GIF renderer shall replace this Gif89Frame's area with
* the background color.
*
* @see Gif89Frame#setDisposalMode
*/
public static final int DM_BGCOLOR = 2;
/**
* The animated GIF renderer shall replace this Gif89Frame's area with
* the previous frame's bitmap.
*
* @see Gif89Frame#setDisposalMode
*/
public static final int DM_REVERT = 3;
// // Bitmap variables set in package subclass constructors ////
int theWidth = -1;
int theHeight = -1;
byte[] ciPixels;
// // GIF graphic frame control options ////
private Point thePosition = new Point(0, 0);
private boolean isInterlaced;
private int csecsDelay;
private int disposalCode = DM_LEAVE;
// ----------------------------------------------------------------------------
/**
* Set the position of this frame within a larger animation display
* space.
*
* @param p
* Coordinates of the frame's upper left corner in the
* display space. (Default: The logical display's origin [0,
* 0])
* @see Gif89Encoder#setLogicalDisplay
*/
public void setPosition(Point p) {
thePosition = new Point(p);
}
// ----------------------------------------------------------------------------
/**
* Set or clear the interlace flag.
*
* @param b
* true if you want interlacing. (Default: false)
*/
public void setInterlaced(boolean b) {
isInterlaced = b;
}
// ----------------------------------------------------------------------------
/**
* Set the between-frame interval.
*
* @param interval
* Centiseconds to wait before displaying the subsequent
* frame. (Default: 0)
*/
public void setDelay(int interval) {
csecsDelay = interval;
}
// ----------------------------------------------------------------------------
/**
* Setting this option determines (in a cooperative GIF-viewer) what
* will be done with this frame's display area before the subsequent
* frame is displayed. For instance, a setting of DM_BGCOLOR can be used
* for erasure when redrawing with displacement.
*
* @param code
* One of the four int constants of the Gif89Frame.DM_*
* series. (Default: DM_LEAVE)
*/
public void setDisposalMode(int code) {
disposalCode = code;
}
// ----------------------------------------------------------------------------
Gif89Frame() {
} // package-visible default constructor
// ----------------------------------------------------------------------------
abstract Object getPixelSource();
// ----------------------------------------------------------------------------
int getWidth() {
return theWidth;
}
// ----------------------------------------------------------------------------
int getHeight() {
return theHeight;
}
// ----------------------------------------------------------------------------
byte[] getPixelSink() {
return ciPixels;
}
// ----------------------------------------------------------------------------
void encode(OutputStream os, boolean epluribus, int color_depth,
int transparent_index) throws IOException {
writeGraphicControlExtension(os, epluribus, transparent_index);
writeImageDescriptor(os);
new GifPixelsEncoder(theWidth, theHeight, ciPixels, isInterlaced,
color_depth).encode(os);
}
// ----------------------------------------------------------------------------
private void writeGraphicControlExtension(OutputStream os,
boolean epluribus, int itransparent) throws IOException {
int transflag = itransparent == -1 ? 0 : 1;
if (transflag == 1 || epluribus) // using transparency or animating
// ?
{
os.write((int) '!'); // GIF Extension Introducer
os.write(0xf9); // Graphic Control Label
os.write(4); // subsequent data block size
os.write((disposalCode << 2) | transflag); // packed fields (1
// byte)
putShort(csecsDelay, os); // delay field (2 bytes)
os.write(itransparent); // transparent index field
os.write(0); // block terminator
}
}
// ----------------------------------------------------------------------------
private void writeImageDescriptor(OutputStream os) throws IOException {
os.write((int) ','); // Image Separator
putShort(thePosition.x, os);
putShort(thePosition.y, os);
putShort(theWidth, os);
putShort(theHeight, os);
os.write(isInterlaced ? 0x40 : 0); // packed fields (1 byte)
}
}
// ==============================================================================
class GifPixelsEncoder {
private static final int EOF = -1;
private int imgW, imgH;
private byte[] pixAry;
private boolean wantInterlaced;
private int initCodeSize;
// raster data navigators
private int countDown;
private int xCur, yCur;
private int curPass;
// ----------------------------------------------------------------------------
GifPixelsEncoder(int width, int height, byte[] pixels,
boolean interlaced, int color_depth) {
imgW = width;
imgH = height;
pixAry = pixels;
wantInterlaced = interlaced;
initCodeSize = Math.max(2, color_depth);
}
// ----------------------------------------------------------------------------
void encode(OutputStream os) throws IOException {
os.write(initCodeSize); // write "initial code size" byte
countDown = imgW * imgH; // reset navigation variables
xCur = yCur = curPass = 0;
compress(initCodeSize + 1, os); // compress and write the pixel data
os.write(0); // write block terminator
}
// ****************************************************************************
// (J.E.) The logic of the next two methods is largely intact from
// Jef Poskanzer. Some stylistic changes were made for consistency sake,
// plus the second method accesses the pixel value from a prefiltered
// linear
// array. That's about it.
// ****************************************************************************
// ----------------------------------------------------------------------------
// Bump the 'xCur' and 'yCur' to point to the next pixel.
// ----------------------------------------------------------------------------
private void bumpPosition() {
// Bump the current X position
++xCur;
// If we are at the end of a scan line, set xCur back to the
// beginning
// If we are interlaced, bump the yCur to the appropriate spot,
// otherwise, just increment it.
if (xCur == imgW) {
xCur = 0;
if (!wantInterlaced)
++yCur;
else
switch (curPass) {
case 0:
yCur += 8;
if (yCur >= imgH) {
++curPass;
yCur = 4;
}
break;
case 1:
yCur += 8;
if (yCur >= imgH) {
++curPass;
yCur = 2;
}
break;
case 2:
yCur += 4;
if (yCur >= imgH) {
++curPass;
yCur = 1;
}
break;
case 3:
yCur += 2;
break;
}
}
}
// ----------------------------------------------------------------------------
// Return the next pixel from the image
// ----------------------------------------------------------------------------
private int nextPixel() {
if (countDown == 0)
return EOF;
--countDown;
byte pix = pixAry[yCur * imgW + xCur];
bumpPosition();
return pix & 0xff;
}
// ****************************************************************************
// (J.E.) I didn't touch Jef Poskanzer's code from this point on. (Well,
// OK,
// I changed the name of the sole outside method it accesses.) I figure
// if I have no idea how something works, I shouldn't play with it :)
//
// Despite its unencapsulated structure, this section is actually highly
// self-contained. The calling code merely calls compress(), and the
// present
// code calls nextPixel() in the caller. That's the sum total of their
// communication. I could have dumped it in a separate class with a
// callback
// via an interface, but it didn't seem worth messing with.
// ****************************************************************************
// GIFCOMPR.C - GIF Image compression routines
//
// Lempel-Ziv compression based on 'compress'. GIF modifications by
// David Rowley (mgardi@watdcsu.waterloo.edu)
// General DEFINEs
static final int BITS = 12;
static final int HSIZE = 5003; // 80% occupancy
// GIF Image compression - modified 'compress'
//
// Based on: compress.c - File compression ala IEEE Computer, June 1984.
//
// By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
// Jim McKie (decvax!mcvax!jim)
// Steve Davies (decvax!vax135!petsd!peora!srd)
// Ken Turkowski (decvax!decwrl!turtlevax!ken)
// James A. Woods (decvax!ihnp4!ames!jaw)
// Joe Orost (decvax!vax135!petsd!joe)
int n_bits; // number of bits/code
int maxbits = BITS; // user settable max # bits/code
int maxcode; // maximum code, given n_bits
int maxmaxcode = 1 << BITS; // should NEVER generate this code
final int MAXCODE(int n_bits) {
return (1 << n_bits) - 1;
}
int[] htab = new int[HSIZE];
int[] codetab = new int[HSIZE];
int hsize = HSIZE; // for dynamic table sizing
int free_ent = 0; // first unused entry
// block compression parameters -- after all codes are used up,
// and compression rate changes, start over.
boolean clear_flg = false;
// Algorithm: use open addressing double hashing (no chaining) on the
// prefix code / next character combination. We do a variant of Knuth's
// algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
// secondary probe. Here, the modular division first probe is gives way
// to a faster exclusive-or manipulation. Also do block compression with
// an adaptive reset, whereby the code table is cleared when the
// compression
// ratio decreases, but after the table fills. The variable-length
// output
// codes are re-sized at this point, and a special CLEAR code is
// generated
// for the decompressor. Late addition: construct the table according to
// file size for noticeable speed improvement on small files. Please
// direct
// questions about this implementation to ames!jaw.
int g_init_bits;
int ClearCode;
int EOFCode;
void compress(int init_bits, OutputStream outs) throws IOException {
int fcode;
int i /* = 0 */;
int c;
int ent;
int disp;
int hsize_reg;
int hshift;
// Set up the globals: g_init_bits - initial number of bits
g_init_bits = init_bits;
// Set up the necessary values
clear_flg = false;
n_bits = g_init_bits;
maxcode = MAXCODE(n_bits);
ClearCode = 1 << (init_bits - 1);
EOFCode = ClearCode + 1;
free_ent = ClearCode + 2;
char_init();
ent = nextPixel();
hshift = 0;
for (fcode = hsize; fcode < 65536; fcode *= 2)
++hshift;
hshift = 8 - hshift; // set hash code range bound
hsize_reg = hsize;
cl_hash(hsize_reg); // clear hash table
output(ClearCode, outs);
outer_loop: while ((c = nextPixel()) != EOF) {
fcode = (c << maxbits) + ent;
i = (c << hshift) ^ ent; // xor hashing
if (htab[i] == fcode) {
ent = codetab[i];
continue;
} else if (htab[i] >= 0) // non-empty slot
{
disp = hsize_reg - i; // secondary hash (after G. Knott)
if (i == 0)
disp = 1;
do {
if ((i -= disp) < 0)
i += hsize_reg;
if (htab[i] == fcode) {
ent = codetab[i];
continue outer_loop;
}
} while (htab[i] >= 0);
}
output(ent, outs);
ent = c;
if (free_ent < maxmaxcode) {
codetab[i] = free_ent++; // code -> hashtable
htab[i] = fcode;
} else
cl_block(outs);
}
// Put out the final code.
output(ent, outs);
output(EOFCode, outs);
}
// output
//
// Output the given code.
// Inputs:
// code: A n_bits-bit integer. If == -1, then EOF. This assumes
// that n_bits =< wordsize - 1.
// Outputs:
// Outputs code to the file.
// Assumptions:
// Chars are 8 bits long.
// Algorithm:
// Maintain a BITS character long buffer (so that 8 codes will
// fit in it exactly). Use the VAX insv instruction to insert each
// code in turn. When the buffer fills up empty it and start over.
int cur_accum = 0;
int cur_bits = 0;
int masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F,
0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF,
0x7FFF, 0xFFFF };
void output(int code, OutputStream outs) throws IOException {
cur_accum &= masks[cur_bits];
if (cur_bits > 0)
cur_accum |= (code << cur_bits);
else
cur_accum = code;
cur_bits += n_bits;
while (cur_bits >= 8) {
char_out((byte) (cur_accum & 0xff), outs);
cur_accum >>= 8;
cur_bits -= 8;
}
// If the next entry is going to be too big for the code size,
// then increase it, if possible.
if (free_ent > maxcode || clear_flg) {
if (clear_flg) {
maxcode = MAXCODE(n_bits = g_init_bits);
clear_flg = false;
} else {
++n_bits;
if (n_bits == maxbits)
maxcode = maxmaxcode;
else
maxcode = MAXCODE(n_bits);
}
}
if (code == EOFCode) {
// At EOF, write the rest of the buffer.
while (cur_bits > 0) {
char_out((byte) (cur_accum & 0xff), outs);
cur_accum >>= 8;
cur_bits -= 8;
}
flush_char(outs);
}
}
// Clear out the hash table
// table clear for block compress
void cl_block(OutputStream outs) throws IOException {
cl_hash(hsize);
free_ent = ClearCode + 2;
clear_flg = true;
output(ClearCode, outs);
}
// reset code table
void cl_hash(int hsize) {
for (int i = 0; i < hsize; ++i)
htab[i] = -1;
}
// GIF Specific routines
// Number of characters so far in this 'packet'
int a_count;
// Set up the 'byte output' routine
void char_init() {
a_count = 0;
}
// Define the storage for the packet accumulator
byte[] accum = new byte[256];
// Add a character to the end of the current packet, and if it is 254
// characters, flush the packet to disk.
void char_out(byte c, OutputStream outs) throws IOException {
accum[a_count++] = c;
if (a_count >= 254)
flush_char(outs);
}
// Flush the packet to disk, and reset the accumulator
void flush_char(OutputStream outs) throws IOException {
if (a_count > 0) {
outs.write(a_count);
outs.write(accum, 0, a_count);
a_count = 0;
}
}
}
// ******************************************************************************
// IndexGif89Frame.java
// ******************************************************************************
// ==============================================================================
/**
* Instances of this Gif89Frame subclass are constructed from bitmaps in the
* form of color-index pixels, which accords with a GIF's native palettized
* color model. The class is useful when complete control over a GIF's color
* palette is desired. It is also much more efficient when one is using an
* algorithmic frame generator that isn't interested in RGB values (such as
* a cellular automaton).
*
* Objects of this class are normally added to a Gif89Encoder object that
* has been provided with an explicit color table at construction. While you
* may also add them to "auto-map" encoders without an exception being
* thrown, there obviously must be at least one DirectGif89Frame object in
* the sequence so that a color table may be detected.
*
* @version 0.90 beta (15-Jul-2000)
* @author J. M. G. Elliott (tep@jmge.net)
* @see Gif89Encoder
* @see Gif89Frame
* @see DirectGif89Frame
*/
class IndexGif89Frame extends Gif89Frame {
// ----------------------------------------------------------------------------
/**
* Construct a IndexGif89Frame from color-index pixel data.
*
* @param width
* Width of the bitmap.
* @param height
* Height of the bitmap.
* @param ci_pixels
* Array containing at least width*height color-index pixels.
*/
public IndexGif89Frame(int width, int height, byte ci_pixels[]) {
theWidth = width;
theHeight = height;
ciPixels = new byte[theWidth * theHeight];
System.arraycopy(ci_pixels, 0, ciPixels, 0, ciPixels.length);
}
// ----------------------------------------------------------------------------
Object getPixelSource() {
return ciPixels;
}
}
// ----------------------------------------------------------------------------
/**
* Internal method;
* write just the low bytes of a String. (This sucks, but the concept of an
* encoding seems inapplicable to a binary file ID string. I would think
* flexibility is just what we don't want - but then again, maybe I'm slow.)
* This is an internal method not meant to be called by clients.
*/
private static void putAscii(String s, OutputStream os) throws IOException {
byte[] bytes = new byte[s.length()];
for (int i = 0; i < bytes.length; ++i) {
bytes[i] = (byte) s.charAt(i); // discard the high byte
}
os.write(bytes);
}
// ----------------------------------------------------------------------------
/**
* Internal method;
* write a 16-bit integer in little endian byte order.
* This is an internal method not meant to be called by clients.
*/
private static void putShort(int i16, OutputStream os) throws IOException {
os.write(i16 & 0xff);
os.write(i16 >> 8 & 0xff);
}
}