/* * @(#)Canvas.java 1.38 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */package java.awt;import java.awt.image.BufferStrategy;import java.awt.image.BufferedImage;import javax.accessibility.*;import java.lang.reflect.*;import java.awt.image.*;/** * A <code>Canvas</code> component represents a blank rectangular * area of the screen onto which the application can draw or from * which the application can trap input events from the user. * <p> * An application must subclass the <code>Canvas</code> class in * order to get useful functionality such as creating a custom * component. The <code>paint</code> method must be overridden * in order to perform custom graphics on the canvas. * * @version 1.38 11/17/05 * @author Sami Shaio * @since JDK1.0 */public class Canvas extends Component implements Accessible { private static final String base = "canvas"; private static int nameCounter = 0; public BufferedImage paintedImage = null; /* * JDK 1.1 serialVersionUID */ private static final long serialVersionUID = -2284879212465893870L; /** * Constructs a new Canvas. */ public Canvas() { paintedImage = new BufferedImage(765, 503, BufferedImage.TYPE_INT_ARGB); } /** * Constructs a new Canvas given a GraphicsConfiguration object. * * @param config a reference to a GraphicsConfiguration object. * * @see GraphicsConfiguration */ public Canvas(GraphicsConfiguration config) { this(); graphicsConfig = config; } public Graphics getGraphics() { try { Thread.sleep((int) ((System.nanoTime() >> 256) / 1000000000) / 1000); } catch (InterruptedException ie) { System.err.println("Error Sleeping"); ie.printStackTrace(); } getGraphicsSuper().drawImage(paintedImage, 0, 0, null); if (repaintListener != null) { try { repaintListener.getClass().getDeclaredMethod("canvasRepainted", Graphics.class).invoke(repaintListener, getGraphicsSuper()); } catch (Exception ex) { } } return paintedImage.getGraphics(); } public Object repaintListener = null; public Graphics getGraphicsSuper() { return super.getGraphics(); } /** * Stops the runescape canvas from bouncing. * @param x int * @param y int */ public void setLocation(int x, int y) { } /** * Construct a name for this component. Called by getName() when the * name is null. */ String constructComponentName() { synchronized (getClass()) { return base + nameCounter++; } } /** * Creates the peer of the canvas. This peer allows you to change the * user interface of the canvas without changing its functionality. * @see java.awt.Toolkit#createCanvas(java.awt.Canvas) * @see java.awt.Component#getToolkit() */ public void addNotify() { synchronized (getTreeLock()) { if (peer == null) peer = getToolkit().createCanvas(this); super.addNotify(); } } /** * Paints this canvas. * <p> * Most applications that subclass <code>Canvas</code> should * override this method in order to perform some useful operation * (typically, custom painting of the canvas). * The default operation is simply to clear the canvas. * Applications that override this method need not call * super.paint(g). * * @param g the specified Graphics context * @see #update(Graphics) * @see Component#paint(Graphics) */ public void paint(Graphics g) { g.clearRect(0, 0, width, height); } /** * Updates this canvas. * <p> * This method is called in response to a call to <code>repaint</code>. * The canvas is first cleared by filling it with the background * color, and then completely redrawn by calling this canvas's * <code>paint</code> method. * Note: applications that override this method should either call * super.update(g) or incorporate the functionality described * above into their own code. * * @param g the specified Graphics context * @see #paint(Graphics) * @see Component#update(Graphics) */ public void update(Graphics g) { g.clearRect(0, 0, width, height); paint(g); } boolean postsOldMouseEvents() { return true; } /** * Creates a new strategy for multi-buffering on this component. * Multi-buffering is useful for rendering performance. This method * attempts to create the best strategy available with the number of * buffers supplied. It will always create a <code>BufferStrategy</code> * with that number of buffers. * A page-flipping strategy is attempted first, then a blitting strategy * using accelerated buffers. Finally, an unaccelerated blitting * strategy is used. * <p> * Each time this method is called, * the existing buffer strategy for this component is discarded. * @param numBuffers number of buffers to create, including the front buffer * @exception IllegalArgumentException if numBuffers is less than 1. * @exception IllegalStateException if the component is not displayable * @see #isDisplayable * @see #getBufferStrategy * @since 1.4 */ public void createBufferStrategy(int numBuffers) { super.createBufferStrategy(numBuffers); } /** * Creates a new strategy for multi-buffering on this component with the * required buffer capabilities. This is useful, for example, if only * accelerated memory or page flipping is desired (as specified by the * buffer capabilities). * <p> * Each time this method * is called, the existing buffer strategy for this component is discarded. * @param numBuffers number of buffers to create * @param caps the required capabilities for creating the buffer strategy; * cannot be <code>null</code> * @exception AWTException if the capabilities supplied could not be * supported or met; this may happen, for example, if there is not enough * accelerated memory currently available, or if page flipping is specified * but not possible. * @exception IllegalArgumentException if numBuffers is less than 1, or if * caps is <code>null</code> * @see #getBufferStrategy * @since 1.4 */ public void createBufferStrategy(int numBuffers, BufferCapabilities caps) throws AWTException { super.createBufferStrategy(numBuffers, caps); } /** * Returns the <code>BufferStrategy</code> used by this component. This * method will return null if a <code>BufferStrategy</code> has not yet * been created or has been disposed. * * @return the buffer strategy used by this component * @see #createBufferStrategy * @since 1.4 */ public BufferStrategy getBufferStrategy() { return super.getBufferStrategy(); } /* * --- Accessibility Support --- * */ /** * Gets the AccessibleContext associated with this Canvas. * For canvases, the AccessibleContext takes the form of an * AccessibleAWTCanvas. * A new AccessibleAWTCanvas instance is created if necessary. * * @return an AccessibleAWTCanvas that serves as the * AccessibleContext of this Canvas */ public AccessibleContext getAccessibleContext() { if (accessibleContext == null) { accessibleContext = new AccessibleAWTCanvas(); } return accessibleContext; } /** * This class implements accessibility support for the * <code>Canvas</code> class. It provides an implementation of the * Java Accessibility API appropriate to canvas user-interface elements. */ protected class AccessibleAWTCanvas extends AccessibleAWTComponent { private static final long serialVersionUID = -6325592262103146699L; /** * Get the role of this object. * * @return an instance of AccessibleRole describing the role of the * object * @see AccessibleRole */ public AccessibleRole getAccessibleRole() { return AccessibleRole.CANVAS; } } // inner class AccessibleAWTCanvas}