Java tutorial
/******************************************************************************* * Copyright (c) 2004, 2010 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.wst.xml.ui.internal.tabletree; import java.util.HashMap; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.resource.ImageRegistry; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.widgets.Display; import org.eclipse.ui.plugin.AbstractUIPlugin; import org.eclipse.wst.xml.ui.internal.XMLUIPlugin; /** * Helper class to handle images provided by this plug-in. * * NOTE: For internal use only. For images used externally, please use the * Shared***ImageHelper class instead. * * @author amywu */ public class XMLEditorPluginImageHelper { private final String PLUGINID = XMLUIPlugin.ID; private static XMLEditorPluginImageHelper instance = null; public static final String EDITOR_MENU = "editor.xml_tabletree.menu"; //$NON-NLS-1$ // save a descriptor for each image private static HashMap fImageDescRegistry = null; /** * Gets the instance. * * @return Returns a XMLEditorPluginImageHelper */ public synchronized static XMLEditorPluginImageHelper getInstance() { if (instance == null) { instance = new XMLEditorPluginImageHelper(); initializeRegistry(); } return instance; } private static void initializeRegistry() { // Taken from org.eclipse.ui.internal.WorkbenchImages Display d = Display.getCurrent(); Image viewMenu = new Image(d, 11, 16); Image viewMenuMask = new Image(d, 11, 16); GC gc = new GC(viewMenu); GC maskgc = new GC(viewMenuMask); drawViewMenu(gc, maskgc); gc.dispose(); maskgc.dispose(); ImageData data = viewMenu.getImageData(); data.transparentPixel = data.getPixel(0, 0); Image vm2 = new Image(d, viewMenu.getImageData(), viewMenuMask.getImageData()); viewMenu.dispose(); viewMenuMask.dispose(); getImageRegistry().put(EDITOR_MENU, vm2); getImageDescriptorRegistry().put(EDITOR_MENU, ImageDescriptor.createFromImage(vm2)); } private static void drawViewMenu(GC gc, GC maskgc) { Display display = Display.getCurrent(); gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW)); gc.setBackground(display.getSystemColor(SWT.COLOR_LIST_BACKGROUND)); int[] shapeArray = new int[] { 1, 1, 10, 1, 6, 5, 5, 5 }; gc.fillPolygon(shapeArray); gc.drawPolygon(shapeArray); Color black = display.getSystemColor(SWT.COLOR_BLACK); Color white = display.getSystemColor(SWT.COLOR_WHITE); maskgc.setBackground(black); maskgc.fillRectangle(0, 0, 12, 16); maskgc.setBackground(white); maskgc.setForeground(white); maskgc.fillPolygon(shapeArray); maskgc.drawPolygon(shapeArray); } /** * Retrieves the image associated with resource from the image registry. * If the image cannot be retrieved, attempt to find and load the image at * the location specified in resource. * * @param resource * the image to retrieve * @return Image the image associated with resource or null if one could * not be found */ public Image getImage(String resource) { Image image = getImageRegistry().get(resource); if (image == null) { // create an image image = createImage(resource); } return image; } /** * Retrieves the image descriptor associated with resource from the image * descriptor registry. If the image descriptor cannot be retrieved, * attempt to find and load the image descriptor at the location specified * in resource. * * @param resource * the image descriptor to retrieve * @return ImageDescriptor the image descriptor assocated with resource or * the default "missing" image descriptor if one could not be * found */ public ImageDescriptor getImageDescriptor(String resource) { ImageDescriptor imageDescriptor = null; Object o = getImageDescriptorRegistry().get(resource); if (o == null) { // create a descriptor imageDescriptor = createImageDescriptor(resource); } else { imageDescriptor = (ImageDescriptor) o; } return imageDescriptor; } /** * Returns the image descriptor registry for this plugin. * * @return HashMap - image descriptor registry for this plugin */ private static HashMap getImageDescriptorRegistry() { if (fImageDescRegistry == null) { fImageDescRegistry = new HashMap(); } return fImageDescRegistry; } /** * Returns the image registry for this plugin. * * @return ImageRegistry - image registry for this plugin */ private static ImageRegistry getImageRegistry() { return JFaceResources.getImageRegistry(); } /** * Creates an image from the given resource and adds the image to the * image registry. * * @param resource * @return Image */ private Image createImage(String resource) { ImageDescriptor desc = getImageDescriptor(resource); Image image = null; if (desc != null) { image = desc.createImage(); // dont add the missing image descriptor image to the image // registry if (!desc.equals(ImageDescriptor.getMissingImageDescriptor())) { getImageRegistry().put(resource, image); } } return image; } /** * Creates an image descriptor from the given imageFilePath and adds the * image descriptor to the image descriptor registry. If an image * descriptor could not be created, the default "missing" image descriptor * is returned but not added to the image descriptor registry. * * @param imageFilePath * @return ImageDescriptor image descriptor for imageFilePath or default * "missing" image descriptor if resource could not be found */ private ImageDescriptor createImageDescriptor(String imageFilePath) { ImageDescriptor imageDescriptor = AbstractUIPlugin.imageDescriptorFromPlugin(PLUGINID, imageFilePath); if (imageDescriptor != null) { getImageDescriptorRegistry().put(imageFilePath, imageDescriptor); } else { imageDescriptor = ImageDescriptor.getMissingImageDescriptor(); } return imageDescriptor; } }