ImageDescriptor.java

/*******************************************************************************
 * Copyright (c) 2000, 2013 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.jface.resource;

/**
 * An image descriptor is an object that knows how to create
 * an SWT image.  It does not hold onto images or cache them,
 * but rather just creates them on demand.  An image descriptor
 * is intended to be a lightweight representation of an image
 * that can be manipulated even when no SWT display exists.
 * <p>
 * This package defines a concrete image descriptor implementation
 * which reads an image from a file (<code>FileImageDescriptor</code>).
 * It also provides abstract framework classes (this one and
 * <code>CompositeImageDescriptor</code>) which may be subclassed to define
 * news kinds of image descriptors.
 * </p>
 * <p>
 * Using this abstract class involves defining a concrete subclass
 * and providing an implementation for the <code>getImageData</code>
 * method.
 * </p>
 * <p>
 * There are two ways to get an Image from an ImageDescriptor. The method
 * createImage will always return a new Image which must be disposed by
 * the caller. Alternatively, createResource() returns a shared
 * Image. When the caller is done with an image obtained from createResource,
 * they must call destroyResource() rather than disposing the Image directly.
 * The result of createResource() can be safely cast to an Image.
 * </p>
 *
 * @see org.eclipse.swt.graphics.Image
 */
public class ImageDescriptor {
    private String image;
    private static final ImageDescriptor missingImageDescriptor = new ImageDescriptor("missing");

    public ImageDescriptor(String image) {
        this.image = image;
    }

    public static ImageDescriptor getMissingImageDescriptor() {
        return missingImageDescriptor;
    }

    public String getImage() {
        return image;
    }
}