Java tutorial
/* * Copyright (c) 2012 Diamond Light Source Ltd. * * 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 */ package org.dawnsci.internal.intro.universal.util; import java.net.URL; import org.dawnsci.internal.intro.universal.IUniversalIntroConstants; import org.dawnsci.internal.intro.universal.UniversalIntroPlugin; import org.eclipse.core.runtime.FileLocator; import org.eclipse.core.runtime.IPath; import org.eclipse.core.runtime.Path; import org.eclipse.core.runtime.Platform; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.resource.ImageRegistry; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Display; import org.eclipse.ui.PlatformUI; import org.osgi.framework.Bundle; /** * Convenience class for Images. */ public final class ImageUtil { /** * Image keys, to be used by plugin (intro) registry. */ // Default images public static final String DEFAULT_ROOT_LINK = "rootLink"; //$NON-NLS-1$ public static final String DEFAULT_SMALL_ROOT_LINK = "rootLinkSmall"; //$NON-NLS-1$ public static final String DEFAULT_FORM_BG = "formBg"; //$NON-NLS-1$ public static final String DEFAULT_LINK = "link"; //$NON-NLS-1$ // Standby images public static final String BACK = "back"; //$NON-NLS-1$ public static final String HELP_TOPIC = "helpTopic"; //$NON-NLS-1$ // Launch bar image public static final String RESTORE_WELCOME = "restoreWelcome"; //$NON-NLS-1$ // Viewer images public static final String INTRO_MODEL_LEAF = "leaf"; //$NON-NLS-1$ public static final String INTRO_MODEL_CONTAINER = "container"; //$NON-NLS-1$ public static final String OPEN_ITNRO_VIEW = "introView"; //$NON-NLS-1$ public static final String CONFIG_EXTENSION = "configExtension";//$NON-NLS-1$ // Image location public static final String ICONS_PATH = "$nl$/icons/"; //$NON-NLS-1$ /** * Convenience method to create an image descriptor from the Intro plugin. * * Method assumes that images are under the "icons" directory, so don't * append that directory name for "imageName". */ public static ImageDescriptor createImageDescriptor(String imageName) { return createImageDescriptor(Platform.getBundle(IUniversalIntroConstants.PLUGIN_ID), ICONS_PATH + imageName); } /** * Convenience method to create an image descriptor. * */ public static ImageDescriptor createImageDescriptor(Bundle bundle, String imageName) { try { URL imageUrl = FileLocator.find(bundle, new Path(imageName), null); if (imageUrl != null) { ImageDescriptor desc = ImageDescriptor.createFromURL(imageUrl); return desc; } } catch (Exception e) { // Should never be here. Log.error("could not create Image Descriptor", e); //$NON-NLS-1$ } Log.warning("could not create Image Descriptor for: " + imageName //$NON-NLS-1$ + " in bundle: " + bundle.getSymbolicName()); //$NON-NLS-1$ return ImageDescriptor.getMissingImageDescriptor(); } /** * Convenience method to create an image descriptor. * */ public static ImageDescriptor createImageDescriptor(IPath base, String imageName) { try { URL imageUrl = new URL(base.append(imageName).toOSString()); if (imageUrl != null) { ImageDescriptor desc = ImageDescriptor.createFromURL(imageUrl); return desc; } } catch (Exception e) { // Should never be here. Log.error("could not create Image Descriptor", e); //$NON-NLS-1$ } Log.warning("could not create Image Descriptor for: " + imageName); //$NON-NLS-1$ return ImageDescriptor.getMissingImageDescriptor(); } /** * Convenience method to create an image from the Intro plugin. * * Method assumes that images are under the "icons" directory, so don't * append that directory name for "imageName". */ public static Image createImage(String imageName) { try { ImageDescriptor imageDsc = createImageDescriptor(imageName); return imageDsc.createImage(); } catch (Exception e) { // Should never be here. Log.error("could not create Image", e); //$NON-NLS-1$ return ImageDescriptor.getMissingImageDescriptor().createImage(); } } /** * Util method for image re-use in Intro Plugin. * * @param key * @return */ public static Image getImage(String key) { // INTRO: Image registry should not have the same life span // as the intro plug-in. It should be disposed when // presentation is disposed, otherwise images will // stay around once Inro has been loaded. return UniversalIntroPlugin.getDefault().getVolatileImageRegistry().get(key); } public static boolean hasImage(String key) { ImageRegistry registry = UniversalIntroPlugin.getDefault().getVolatileImageRegistry(); return (registry.getDescriptor(key) != null); } /** * Register an image descriptor in the Intro Plugin image registry. Has no * effect if the key has already been registered. * * @param key * @param imageName */ public static void registerImage(String key, String imageName) { ImageRegistry registry = UniversalIntroPlugin.getDefault().getVolatileImageRegistry(); if (registry.getDescriptor(key) != null) // key has already been registered. do nothing. return; registry.put(key, createImageDescriptor(imageName)); } public static void registerImage(String key, Bundle bundle, String imageName) { ImageRegistry registry = UniversalIntroPlugin.getDefault().getVolatileImageRegistry(); if (registry.getDescriptor(key) != null) // key has already been registered. do nothing. return; registry.put(key, createImageDescriptor(bundle, imageName)); } public static void registerImage(String key, IPath base, String imageName) { ImageRegistry registry = UniversalIntroPlugin.getDefault().getVolatileImageRegistry(); if (registry.getDescriptor(key) != null) // key has already been registered. do nothing. return; registry.put(key, createImageDescriptor(base, imageName)); } /** * Tests for high contrast mode. Returns false if not called from a * UI thread (causes deadlocks during junit tests). * * @return whether or not the display is in high contrast mode */ public static boolean isHighContrast() { if (PlatformUI.isWorkbenchRunning()) { Display display = PlatformUI.getWorkbench().getDisplay(); if (Display.getCurrent() == display) { return display.getHighContrast(); } } return false; } }