Java tutorial
/******************************************************************************* * Copyright (c) 2008 Laurent Muller. * 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: * Laurent Muller - initial API and implementation *******************************************************************************/ package nu.bibi.breadcrumb.files; import java.io.File; import java.io.InputStream; import org.eclipse.core.runtime.Path; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.resource.ImageRegistry; import org.eclipse.jface.resource.ResourceManager; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.program.Program; import org.eclipse.swt.widgets.Display; /** * An image file registry maintains a mapping between a file extension and SWT * image descriptor objects. * * @author Laurent Muller * @version 1.0 */ public class ImageFileRegistry extends ImageRegistry { /** * The key name for a computer. */ public final static String KEY_COMPUTER = "computer.png"; //$NON-NLS-1$ /** * The key name for a normal drive. */ public final static String KEY_DRIVE_DEFAULT = "drive_default.png"; //$NON-NLS-1$ /** * The key name for a hidden drive. */ public final static String KEY_DRIVE_HIDDEN = "drive_hidden.png"; //$NON-NLS-1$ /** * The key name for a normal folder. */ public final static String KEY_FOLDER_DEFAULT = "folder_default.png"; //$NON-NLS-1$ /** * The key name for a hidden folder. */ public final static String KEY_FOLDER_HIDDEN = "folder_hidden.png"; //$NON-NLS-1$ /** * The key name for a normal file. */ public final static String KEY_FILE_DEFAULT = "file_default.png"; //$NON-NLS-1$ /** * The key name for a hidden file. */ public final static String KEY_FILE_HIDDEN = "file_hidden.png"; //$NON-NLS-1$ /** * The key name for the right arrow image. */ public final static String KEY_ARROW_RIGHT = "arrow_right.png"; //$NON-NLS-1$ /** * The key name for the left arrow image. */ public final static String KEY_ARROW_LEFT = "arrow_left.png"; //$NON-NLS-1$ /** * The key name for the down arrow image. */ public final static String KEY_ARROW_DOWN = "arrow_down.png"; //$NON-NLS-1 /* * The icons path */ private static String ICONS_PATH = "icons/"; /** * Gets a image descriptor from a resource key. * <p> * Images are stored in the <code>nu.bibi.breadcrumb.files.icons</code> * folder. * * @param keyName * the resource key name used to load the image. This key must * contains a valid file name. * @return the image descriptor if success, <code>null</code> if error. */ public static ImageDescriptor getResource(final String keyName) { ImageDescriptor descriptor = null; try { final InputStream stream = ImageFileRegistry.class.getResourceAsStream(ICONS_PATH + keyName); if (stream != null) { final ImageData data = new ImageData(stream); descriptor = ImageDescriptor.createFromImageData(data); stream.close(); } } catch (final Exception e) { } return descriptor; } /** * Creates an empty image file registry. * <p> * There must be an SWT Display created in the current thread before calling * this method. * </p> */ public ImageFileRegistry() { super(); initializeImages(); } /** * Creates an empty image file registry. * * @param display * this <code>Display</code> must not be <code>null</code> and * must not be disposed in order to use this registry. */ public ImageFileRegistry(final Display display) { super(display); initializeImages(); } /** * Creates an empty image file registry using the given resource manager to * allocate images. * * @param manager * the resource manager used to allocate images. */ public ImageFileRegistry(final ResourceManager manager) { super(manager); initializeImages(); } /** * Returns a image for the given file. * * @param file * a file used to retrieve image. * @return an image for the given file. */ public Image get(final File file) { // file ? if (file == null) { return null; } // the hidden flag final boolean hidden = file.isHidden(); // drive if (file.getParentFile() == null) { return hidden ? get(KEY_DRIVE_HIDDEN) : get(KEY_DRIVE_DEFAULT); } // folder if (file.isDirectory()) { return hidden ? get(KEY_FOLDER_HIDDEN) : get(KEY_FOLDER_DEFAULT); } // get extension final Path path = new Path(file.getAbsolutePath()); final String extension = path.getFileExtension(); // image already saved ? final Image image = get(extension); if (image != null) { return image; } // get program image if (extension != null) { final Program program = Program.findProgram(extension); // program ? if (program != null) { // get image data final ImageData imageData = program.getImageData(); if (imageData != null) { // add final ImageDescriptor descriptor = ImageDescriptor.createFromImageData(imageData); this.put(extension, descriptor); return get(extension); } } } // default image return hidden ? get(KEY_FILE_HIDDEN) : get(KEY_FILE_DEFAULT); } /** * Load the default images. */ private void initializeImages() { // computer image putImageByKey(KEY_COMPUTER); // drive images putImageByKey(KEY_DRIVE_DEFAULT); putImageByKey(KEY_DRIVE_HIDDEN); // folder images putImageByKey(KEY_FOLDER_DEFAULT); putImageByKey(KEY_FOLDER_HIDDEN); // file images putImageByKey(KEY_FILE_DEFAULT); putImageByKey(KEY_FILE_HIDDEN); // arrow images putImageByKey(KEY_ARROW_RIGHT); putImageByKey(KEY_ARROW_LEFT); putImageByKey(KEY_ARROW_DOWN); } /** * Adds a image descriptor for the given key. * * @param key * the image key. */ private void putImageByKey(final String key) { // get image final ImageDescriptor image = getResource(key); if (image != null) { put(key, image); } } }