org.eclipse.ui.internal.decorators.OverlayCache.java Source code

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Here is the source code for org.eclipse.ui.internal.decorators.OverlayCache.java

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/*******************************************************************************
 * Copyright (c) 2000, 2007 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.ui.internal.decorators;

import java.util.HashSet;
import java.util.Set;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.resource.LocalResourceManager;
import org.eclipse.jface.viewers.DecorationOverlayIcon;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.ui.PlatformUI;

/**
 * The OverlayCache is a helper class used by the DecoratorManger to manage the
 * life cycle of overlaid images.
 * 
 * @since 1.1
 */
class OverlayCache {

    /**
     * The CacheEntry
     */

    private Set keys = new HashSet(); // Hold onto the cache entries we
    // created
    // Use a resource manager to hold onto any images we have to create
    private LocalResourceManager resourceManager;

    /**
     * 
     */
    public OverlayCache() {
        super();
        //As we are not in the UI Thread lookup the Display
        resourceManager = new LocalResourceManager(
                JFaceResources.getResources(PlatformUI.getWorkbench().getDisplay()));
    }

    /**
     * Returns and caches an image corresponding to the specified icon.
     * 
     * @param icon
     *            the icon
     * @return the image
     */
    private Image getImageFor(DecorationOverlayIcon icon) {
        keys.add(icon);// Cache the keys so there is a reference somewhere
        return resourceManager.createImage(icon);
    }

    /**
     * Disposes of all images in the cache.
     */
    void disposeAll() {
        keys.clear();
        resourceManager.dispose();
    }

    /**
     * Apply the descriptors for the receiver to the supplied image.
     * 
     * @param source
     * @param descriptors
     * @return Image
     */

    Image applyDescriptors(Image source, ImageDescriptor[] descriptors) {
        Rectangle bounds = source.getBounds();
        Point size = new Point(bounds.width, bounds.height);
        DecorationOverlayIcon icon = new DecorationOverlayIcon(source, descriptors, size);
        return getImageFor(icon);
    }

}