Java tutorial
/** * Copyright (c) 2005-2013 by Appcelerator, Inc. All Rights Reserved. * Licensed under the terms of the Eclipse Public License (EPL). * Please see the license.txt included with this distribution for details. * Any modifications to this file must keep this entire header intact. */ /* * Author: atotic * Created: Jul 29, 2003 */ package org.brainwy.liclipsetext.shared_ui; import java.net.MalformedURLException; import java.net.URL; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import org.brainwy.liclipsetext.shared_core.log.Log; import org.brainwy.liclipsetext.shared_core.structure.Tuple3; import org.brainwy.liclipsetext.shared_core.structure.Tuple4; import org.eclipse.jface.resource.CompositeImageDescriptor; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Display; /** * Caches images, releases all on dispose */ public class ImageCache { /** * Helper to decorate an image. * * The only method that should be used is: drawDecoration */ private static final class ImageDecorator extends CompositeImageDescriptor { private Point size; private ImageData base; private ImageData decoration; private int ox; private int oy; @Override protected Point getSize() { return size; } @Override protected void drawCompositeImage(int width, int height) { this.drawImage(base, 0, 0); this.drawImage(decoration, ox, oy); } public final ImageData drawDecoration(ImageData base, ImageData decoration, int ox, int oy) { this.size = new Point(base.width, base.height); this.base = base; this.decoration = decoration; this.ox = ox; this.oy = oy; return getImageData(); } } // Access should be locked. private final Map<Object, Image> imageHash = new HashMap<Object, Image>(10); private Image getFromImageHash(Object key) { synchronized (lock) { Image ret = imageHash.get(key); if (ret != null && ret.isDisposed()) { imageHash.remove(key); ret = null; } return ret; } } private Image putOnImageHash(Object key, Image image) { synchronized (lock) { // Check if it wasn't created in the meanwhile... because // we only lock the actual put/get, not the image creation, we // might actually create an image twice. Ssshh, don't let the // external world know about it! Image createdInMeanwhile = imageHash.get(key); if (createdInMeanwhile != null && !createdInMeanwhile.isDisposed()) { image.dispose(); image = createdInMeanwhile; } else { imageHash.put(key, image); } return image; } } private final Map<Object, ImageDescriptor> descriptorHash = new HashMap<Object, ImageDescriptor>(10); private final ImageDecorator imageDecorator = new ImageDecorator(); private final URL baseURL; private volatile Image missing = null; private final Object lock = new Object(); private final Object descriptorLock = new Object(); public ImageCache(URL baseURL) { this.baseURL = baseURL; } public void dispose() { synchronized (lock) { Iterator<Image> e = imageHash.values().iterator(); while (e.hasNext()) { e.next().dispose(); } imageHash.clear(); Image m = missing; if (m != null) { m.dispose(); } missing = null; } } /** * @param key - relative path to the plugin directory * @return the image */ public Image get(String key) { Image image = getFromImageHash(key); if (image == null) { ImageDescriptor desc; try { // Don't lock for this creation (GTK has a global lock for the image // creation which is the same one for the main thread, so, if this // happens in a thread, the main thread could deadlock). // #PyDev-527: Deadlock in ImageCache rendering debug completions desc = getDescriptor(key); image = desc.createImage(); image = putOnImageHash(key, image); } catch (NoClassDefFoundError e) { //we're in tests... return null; } catch (UnsatisfiedLinkError e) { //we're in tests... return null; } catch (Exception e) { // If image is missing, create a default missing one Log.log("ERROR: Missing image: " + key); Image m = missing; if (m == null || m.isDisposed()) { desc = ImageDescriptor.getMissingImageDescriptor(); m = missing = desc.createImage(); } image = m; } } return image; } public Image getImageDecorated(String key, String decoration) { return getImageDecorated(key, decoration, DECORATION_LOCATION_TOP_RIGHT); } public final static int DECORATION_LOCATION_TOP_RIGHT = 0; public final static int DECORATION_LOCATION_BOTTOM_RIGHT = 1; public Image getImageDecorated(String key, String decoration, int decorationLocation) { return getImageDecorated(key, decoration, decorationLocation, null, -1); } /** * @param key the key of the image that should be decorated (relative path to the plugin directory) * @param decoration the key of the image that should be decorated (relative path to the plugin directory) */ @SuppressWarnings({ "rawtypes", "unchecked" }) public Image getImageDecorated(String key, String decoration, int decorationLocation, String secondDecoration, int secondDecorationLocation) { Display display = Display.getCurrent(); if (display == null) { Log.log("This method should only be called in a UI thread."); } Object cacheKey = new Tuple4(key, decoration, decorationLocation, "imageDecoration"); if (secondDecoration != null) { //Also add the second decoration to the cache key. cacheKey = new Tuple3(cacheKey, secondDecoration, secondDecorationLocation); } Image image = getFromImageHash(cacheKey); if (image == null) { //Note that changing the image data gotten here won't affect the original image. ImageData baseImageData = get(key).getImageData(); image = decorateImage(decoration, decorationLocation, display, baseImageData); if (secondDecoration != null) { image = decorateImage(secondDecoration, secondDecorationLocation, display, image.getImageData()); } image = putOnImageHash(cacheKey, image); } return image; } private Image decorateImage(String decoration, int decorationLocation, Display display, ImageData baseImageData) throws AssertionError { Image image; ImageData decorationImageData = get(decoration).getImageData(); ImageData imageData; switch (decorationLocation) { case DECORATION_LOCATION_TOP_RIGHT: imageData = imageDecorator.drawDecoration(baseImageData, decorationImageData, baseImageData.width - decorationImageData.width, 0); break; case DECORATION_LOCATION_BOTTOM_RIGHT: imageData = imageDecorator.drawDecoration(baseImageData, decorationImageData, baseImageData.width - decorationImageData.width, baseImageData.height - decorationImageData.height); break; default: throw new AssertionError("Decoration location not recognized: " + decorationLocation); } image = new Image(display, imageData); return image; } /** * @param key the key of the image that should be decorated (relative path to the plugin directory) * @param stringToAddToDecoration the string that should be drawn over the image */ public Image getStringDecorated(String key, String stringToAddToDecoration) { Display display = Display.getCurrent(); if (display == null) { Log.log("This method should only be called in a UI thread."); } Tuple3<String, String, String> cacheKey = new Tuple3<String, String, String>(key, stringToAddToDecoration, "stringDecoration"); Image image = getFromImageHash(cacheKey); if (image == null) { image = new Image(display, get(key), SWT.IMAGE_COPY); GC gc = new GC(image); // Color color = new Color(display, 0, 0, 0); // Color color2 = new Color(display, 255, 255, 255); // gc.setForeground(color2); // gc.setBackground(color2); // gc.setFillRule(SWT.FILL_WINDING); // gc.fillRoundRectangle(2, 1, base-1, base, 2, 2); // gc.setForeground(color); // gc.drawRoundRectangle(6, 0, base, base+1, 2, 2); // color2.dispose(); // color.dispose(); Color colorBackground = new Color(display, 255, 255, 255); Color colorForeground = new Color(display, 0, 83, 41); // get TextFont from preferences FontData fontData = FontUtils.getFontData(IFontUsage.IMAGECACHE, true); fontData.setStyle(SWT.BOLD); Font font = new Font(display, fontData); try { gc.setForeground(colorForeground); gc.setBackground(colorBackground); gc.setTextAntialias(SWT.ON); gc.setFont(font); gc.drawText(stringToAddToDecoration, 5, 0, true); } catch (Exception e) { Log.log(e); } finally { colorBackground.dispose(); colorForeground.dispose(); font.dispose(); gc.dispose(); } image = putOnImageHash(cacheKey, image); } return image; } /** * like get, but returns ImageDescription instead of image */ public ImageDescriptor getDescriptor(String key) { synchronized (descriptorLock) { if (!descriptorHash.containsKey(key)) { URL url; ImageDescriptor desc; try { url = new URL(baseURL, key); desc = ImageDescriptor.createFromURL(url); } catch (MalformedURLException e) { Log.log("ERROR: Missing image: " + key); desc = ImageDescriptor.getMissingImageDescriptor(); } descriptorHash.put(key, desc); return desc; } return descriptorHash.get(key); } } }