Java tutorial
/******************************************************************************* * Copyright (c) 2011 Google, Inc. * 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: * Google, Inc. - initial API and implementation *******************************************************************************/ package org.eclipse.wb.internal.core; import com.google.common.collect.Maps; import com.google.common.io.CharStreams; import com.google.common.io.Closeables; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Status; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; import org.eclipse.ui.IWorkbenchWindow; import org.eclipse.ui.plugin.AbstractUIPlugin; import java.io.Closeable; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URL; import java.nio.charset.Charset; import java.util.Map; /** * The DesignerPlugin class is the "nexus" of the propertysheet. In WindowBuilder, * it's the plugin activator, and contains a number of important utility methods, such * as resource loading, logging, obtaining a display and shell, etc. * <p> * In the AOSP fork, most of the functionality has been ripped out, except for the * above mentioned pieces, and this class is no longer a plugin. Instead, it *delegates* * to the plugin which initializes it via the {@link #initialize} method for things * like logging. For things like image loading, it has its own local code such that * it can find its image resources locally instead of requiring the embedding plugin * to copy the images into its own jar. * <p> * "DesignerPlugin" is not a very good name for this class since it is not a plugin, * but it was left that way to avoid modifying all the various propertysheet classes; * we'd like to keep those as unmodified as possible to make absorbing future * WindowBuilder improvements as easy as possible. */ public class DesignerPlugin { private static AbstractUIPlugin sPlugin; private static String sPluginId; /** * Initialize the property sheet for use in the ADT plugin * * @param hostPlugin the plugin to embed the property sheet * @param pluginId the id of the plugin to use in status messages etc * @param isWindows whether we're running on Windows * @param isMac whether we're running on Mac * @param isLinux whether we're running on Linux */ public static void initialize(AbstractUIPlugin hostPlugin, String pluginId, boolean isWindows, boolean isMac, boolean isLinux) { assert sPlugin == null; // Can only be used by one client in the same classloader sPlugin = hostPlugin; sPluginId = pluginId; EnvironmentUtils.IS_WINDOWS = isWindows; EnvironmentUtils.IS_MAC = isMac; EnvironmentUtils.IS_LINUX = isLinux; } /** * Dispose the propertysheet library: free up images from the cache, unregister the * plugin reference etc. */ public static void dispose() { sPlugin = null; for (Image image : sImageCache.values()) { image.dispose(); } sImageCache.clear(); sDescriptorCache.clear(); } /** * Reads the contents of an {@link InputStreamReader} using the default * platform encoding and return it as a String. This method will close the * input stream. * * @param inputStream the input stream to be read from * @param charset the charset to use * @return the String read from the stream, or null if there was an error */ public static String readFile(InputStream inputStream, Charset charset) { if (inputStream == null) { return null; } Closeable closeMe = inputStream; try { final InputStreamReader isr = new InputStreamReader(inputStream, charset); closeMe = isr; try { return CharStreams.toString(isr); } catch (Exception ioe) { // pass -- ignore files we can't read return null; } } finally { Closeables.closeQuietly(closeMe); } } /** * @return the instance of {@link DesignerPlugin} */ public static AbstractUIPlugin getDefault() { assert sPlugin != null; return sPlugin; } // ////////////////////////////////////////////////////////////////////////// // // Display/Shell // // ////////////////////////////////////////////////////////////////////////// /** * @return the {@link Display} instance, current (if in GUI thread) or * default. */ public static Display getStandardDisplay() { Display display = Display.getCurrent(); if (display == null) { display = Display.getDefault(); } return display; } /** * @return the active {@link IWorkbenchWindow}. */ public static IWorkbenchWindow getActiveWorkbenchWindow() { return getDefault().getWorkbench().getActiveWorkbenchWindow(); } /** * @return the {@link Shell} of active {@link IWorkbenchWindow}. */ public static Shell getShell() { if (getActiveWorkbenchWindow() != null) { return getActiveWorkbenchWindow().getShell(); } return null; } /** * Logs given {@link IStatus} into Eclipse .log. */ public static void log(IStatus status) { getDefault().getLog().log(status); } /** * Logs {@link IStatus} with given message into Eclipse .log. */ public static void log(String message) { log(new Status(IStatus.INFO, sPluginId, IStatus.INFO, message, null)); } /** * Logs {@link IStatus} with given exception into Eclipse .log. */ public static void log(Throwable e) { Status status = new Status(IStatus.ERROR, sPluginId, "", e); getDefault().getLog().log(status); } /** * Logs {@link IStatus} with given message and exception into Eclipse .log. */ public static void log(String message, Throwable e) { log(createStatus(message, e)); } /** * Creates {@link IStatus} for given message and exception. */ public static Status createStatus(String message, Throwable e) { return new Status(IStatus.ERROR, "wb", IStatus.ERROR, message, e) { @Override public boolean isMultiStatus() { return true; } }; } // ////////////////////////////////////////////////////////////////////////// // // Resources // // ////////////////////////////////////////////////////////////////////////// private static Map<String, ImageDescriptor> sDescriptorCache = Maps.newHashMap(); private static Map<String, Image> sImageCache = Maps.newHashMap(); public static Image getImage(String path) { Image image = sImageCache.get(path); if (image == null) { ImageDescriptor descriptor = getImageDescriptor(path); if (descriptor != null) { image = descriptor.createImage(); } sImageCache.put(path, image); } return image; } public static ImageDescriptor getImageDescriptor(String path) { ImageDescriptor descriptor = sDescriptorCache.get(path); if (descriptor == null) { URL url = DesignerPlugin.class.getResource("icons/" + path); //$NON-NLS-1$ if (url != null) { descriptor = ImageDescriptor.createFromURL(url); sDescriptorCache.put(path, descriptor); } } return descriptor; } }