EDIT

/*******************************************************************************

 * 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.swt;

import java.io.File;

import java.io.InputStream;

import java.lang.reflect.Constructor;

import java.lang.reflect.Method;

import java.net.MalformedURLException;

import java.net.URL;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import org.eclipse.core.runtime.Platform;

import org.eclipse.jface.resource.CompositeImageDescriptor;

import org.eclipse.jface.resource.ImageDescriptor;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.osgi.framework.Bundle;

/**

 * Utility class for managing OS resources associated with SWT/JFace controls such as colors, fonts, images,

 * etc.

 * 

 * !!! IMPORTANT !!! Application code must explicitly invoke the <code>dispose()</code> method to release the

 * operating system resources managed by cached objects when those objects and OS resources are no longer

 * needed (e.g. on application shutdown)

 * 

 * This class may be freely distributed as part of any application or plugin.

 * <p>

 * 

 * @author scheglov_ke

 * @author Dan Rubel

 */

public class ResourceManager extends SWTResourceManager {

	////////////////////////////////////////////////////////////////////////////

	//

	// Image

	//

	////////////////////////////////////////////////////////////////////////////

	private static Map<ImageDescriptor, Image> m_descriptorImageMap = new HashMap<ImageDescriptor, Image>();

	/**

	 * Returns an {@link ImageDescriptor} stored in the file at the specified path relative to the specified

	 * class.

	 * 

	 * @param clazz

	 *            the {@link Class} relative to which to find the image descriptor.

	 * @param path

	 *            the path to the image file.

	 * @return the {@link ImageDescriptor} stored in the file at the specified path.

	 */

	public static ImageDescriptor getImageDescriptor(Class<?> clazz, String path) {

		return ImageDescriptor.createFromFile(clazz, path);

	}

	/**

	 * Returns an {@link ImageDescriptor} stored in the file at the specified path.

	 * 

	 * @param path

	 *            the path to the image file.

	 * @return the {@link ImageDescriptor} stored in the file at the specified path.

	 */

	public static ImageDescriptor getImageDescriptor(String path) {

		try {

			return ImageDescriptor.createFromURL(new File(path).toURI().toURL());

		} catch (MalformedURLException e) {

			return null;

		}

	}

	/**

	 * Returns an {@link Image} based on the specified {@link ImageDescriptor}.

	 * 

	 * @param descriptor

	 *            the {@link ImageDescriptor} for the {@link Image}.

	 * @return the {@link Image} based on the specified {@link ImageDescriptor}.

	 */

	public static Image getImage(ImageDescriptor descriptor) {

		if (descriptor == null) {

			return null;

		}

		Image image = m_descriptorImageMap.get(descriptor);

		if (image == null) {

			image = descriptor.createImage();

			m_descriptorImageMap.put(descriptor, image);

		}

		return image;

	}

	/**

	 * Maps images to decorated images.

	 */

	@SuppressWarnings("unchecked")

	private static Map<Image, Map<Image, Image>>[] m_decoratedImageMap = new Map[LAST_CORNER_KEY];

	/**

	 * Returns an {@link Image} composed of a base image decorated by another image.

	 * 

	 * @param baseImage

	 *            the base {@link Image} that should be decorated.

	 * @param decorator

	 *            the {@link Image} to decorate the base image.

	 * @return {@link Image} The resulting decorated image.

	 */

	public static Image decorateImage(Image baseImage, Image decorator) {

		return decorateImage(baseImage, decorator, BOTTOM_RIGHT);

	}

	/**

	 * Returns an {@link Image} composed of a base image decorated by another image.

	 * 

	 * @param baseImage

	 *            the base {@link Image} that should be decorated.

	 * @param decorator

	 *            the {@link Image} to decorate the base image.

	 * @param corner

	 *            the corner to place decorator image.

	 * @return the resulting decorated {@link Image}.

	 */

	public static Image decorateImage(final Image baseImage, final Image decorator, final int corner) {

		if (corner <= 0 || corner >= LAST_CORNER_KEY) {

			throw new IllegalArgumentException("Wrong decorate corner");

		}

		Map<Image, Map<Image, Image>> cornerDecoratedImageMap = m_decoratedImageMap[corner];

		if (cornerDecoratedImageMap == null) {

			cornerDecoratedImageMap = new HashMap<Image, Map<Image, Image>>();

			m_decoratedImageMap[corner] = cornerDecoratedImageMap;

		}

		Map<Image, Image> decoratedMap = cornerDecoratedImageMap.get(baseImage);

		if (decoratedMap == null) {

			decoratedMap = new HashMap<Image, Image>();

			cornerDecoratedImageMap.put(baseImage, decoratedMap);

		}

		//

		Image result = decoratedMap.get(decorator);

		if (result == null) {

			final Rectangle bib = baseImage.getBounds();

			final Rectangle dib = decorator.getBounds();

			final Point baseImageSize = new Point(bib.width, bib.height);

			CompositeImageDescriptor compositImageDesc = new CompositeImageDescriptor() {

				@Override

				protected void drawCompositeImage(int width, int height) {

					drawImage(baseImage.getImageData(), 0, 0);

					if (corner == TOP_LEFT) {

						drawImage(decorator.getImageData(), 0, 0);

					} else if (corner == TOP_RIGHT) {

						drawImage(decorator.getImageData(), bib.width - dib.width, 0);

					} else if (corner == BOTTOM_LEFT) {

						drawImage(decorator.getImageData(), 0, bib.height - dib.height);

					} else if (corner == BOTTOM_RIGHT) {

						drawImage(decorator.getImageData(), bib.width - dib.width, bib.height - dib.height);

					}

				}

				@Override

				protected Point getSize() {

					return baseImageSize;

				}

			};

			//

			result = compositImageDesc.createImage();

			decoratedMap.put(decorator, result);

		}

		return result;

	}

	/**

	 * Dispose all of the cached images.

	 */

	public static void disposeImages() {

		SWTResourceManager.disposeImages();

		// dispose ImageDescriptor images

		{

			for (Iterator<Image> I = m_descriptorImageMap.values().iterator(); I.hasNext();) {

				I.next().dispose();

			}

			m_descriptorImageMap.clear();

		}

		// dispose decorated images

		for (int i = 0; i < m_decoratedImageMap.length; i++) {

			Map<Image, Map<Image, Image>> cornerDecoratedImageMap = m_decoratedImageMap[i];

			if (cornerDecoratedImageMap != null) {

				for (Map<Image, Image> decoratedMap : cornerDecoratedImageMap.values()) {

					for (Image image : decoratedMap.values()) {

						image.dispose();

					}

					decoratedMap.clear();

				}

				cornerDecoratedImageMap.clear();

			}

		}

		// dispose plugin images

		{

			for (Iterator<Image> I = m_URLImageMap.values().iterator(); I.hasNext();) {

				I.next().dispose();

			}

			m_URLImageMap.clear();

		}

	}

	////////////////////////////////////////////////////////////////////////////

	//

	// Plugin images support

	//

	////////////////////////////////////////////////////////////////////////////

	/**

	 * Maps URL to images.

	 */

	private static Map<String, Image> m_URLImageMap = new HashMap<String, Image>();

	/**

	 * Provider for plugin resources, used by WindowBuilder at design time.

	 */

	public interface PluginResourceProvider {

		URL getEntry(String symbolicName, String path);

	}

	/**

	 * Instance of {@link PluginResourceProvider}, used by WindowBuilder at design time.

	 */

	private static PluginResourceProvider m_designTimePluginResourceProvider = null;

	/**

	 * Returns an {@link Image} based on a plugin and file path.

	 * 

	 * @param plugin

	 *            the plugin {@link Object} containing the image

	 * @param name

	 *            the path to the image within the plugin

	 * @return the {@link Image} stored in the file at the specified path

	 * 

	 * @deprecated Use {@link #getPluginImage(String, String)} instead.

	 */

	@Deprecated

	public static Image getPluginImage(Object plugin, String name) {

		try {

			URL url = getPluginImageURL(plugin, name);

			if (url != null) {

				return getPluginImageFromUrl(url);

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		return null;

	}

	/**

	 * Returns an {@link Image} based on a {@link Bundle} and resource entry path.

	 * 

	 * @param symbolicName

	 *            the symbolic name of the {@link Bundle}.

	 * @param path

	 *            the path of the resource entry.

	 * @return the {@link Image} stored in the file at the specified path.

	 */

	public static Image getPluginImage(String symbolicName, String path) {

		try {

			URL url = getPluginImageURL(symbolicName, path);

			if (url != null) {

				return getPluginImageFromUrl(url);

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		return null;

	}

	/**

	 * Returns an {@link Image} based on given {@link URL}.

	 */

	private static Image getPluginImageFromUrl(URL url) {

		try {

			try {

				String key = url.toExternalForm();

				Image image = m_URLImageMap.get(key);

				if (image == null) {

					InputStream stream = url.openStream();

					try {

						image = getImage(stream);

						m_URLImageMap.put(key, image);

					} finally {

						stream.close();

					}

				}

				return image;

			} catch (Throwable e) {

				// Ignore any exceptions

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		return null;

	}

	/**

	 * Returns an {@link ImageDescriptor} based on a plugin and file path.

	 * 

	 * @param plugin

	 *            the plugin {@link Object} containing the image.

	 * @param name

	 *            the path to th eimage within the plugin.

	 * @return the {@link ImageDescriptor} stored in the file at the specified path.

	 * 

	 * @deprecated Use {@link #getPluginImageDescriptor(String, String)} instead.

	 */

	@Deprecated

	public static ImageDescriptor getPluginImageDescriptor(Object plugin, String name) {

		try {

			try {

				URL url = getPluginImageURL(plugin, name);

				return ImageDescriptor.createFromURL(url);

			} catch (Throwable e) {

				// Ignore any exceptions

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		return null;

	}

	/**

	 * Returns an {@link ImageDescriptor} based on a {@link Bundle} and resource entry path.

	 * 

	 * @param symbolicName

	 *            the symbolic name of the {@link Bundle}.

	 * @param path

	 *            the path of the resource entry.

	 * @return the {@link ImageDescriptor} based on a {@link Bundle} and resource entry path.

	 */

	public static ImageDescriptor getPluginImageDescriptor(String symbolicName, String path) {

		try {

			URL url = getPluginImageURL(symbolicName, path);

			if (url != null) {

				return ImageDescriptor.createFromURL(url);

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		return null;

	}

	/**

	 * Returns an {@link URL} based on a {@link Bundle} and resource entry path.

	 */

	private static URL getPluginImageURL(String symbolicName, String path) {

		// try runtime plugins

		{

			Bundle bundle = Platform.getBundle(symbolicName);

			if (bundle != null) {

				return bundle.getEntry(path);

			}

		}

		// try design time provider

		if (m_designTimePluginResourceProvider != null) {

			return m_designTimePluginResourceProvider.getEntry(symbolicName, path);

		}

		// no such resource

		return null;

	}

	/**

	 * Returns an {@link URL} based on a plugin and file path.

	 * 

	 * @param plugin

	 *            the plugin {@link Object} containing the file path.

	 * @param name

	 *            the file path.

	 * @return the {@link URL} representing the file at the specified path.

	 * @throws Exception

	 */

	private static URL getPluginImageURL(Object plugin, String name) throws Exception {

		// try to work with 'plugin' as with OSGI BundleContext

		try {

			Class<?> BundleClass = Class.forName("org.osgi.framework.Bundle"); //$NON-NLS-1$

			Class<?> BundleContextClass = Class.forName("org.osgi.framework.BundleContext"); //$NON-NLS-1$

			if (BundleContextClass.isAssignableFrom(plugin.getClass())) {

				Method getBundleMethod = BundleContextClass.getMethod("getBundle", new Class[0]); //$NON-NLS-1$

				Object bundle = getBundleMethod.invoke(plugin, new Object[0]);

				//

				Class<?> PathClass = Class.forName("org.eclipse.core.runtime.Path"); //$NON-NLS-1$

				Constructor<?> pathConstructor = PathClass.getConstructor(new Class[]{String.class});

				Object path = pathConstructor.newInstance(new Object[]{name});

				//

				Class<?> IPathClass = Class.forName("org.eclipse.core.runtime.IPath"); //$NON-NLS-1$

				Class<?> PlatformClass = Class.forName("org.eclipse.core.runtime.Platform"); //$NON-NLS-1$

				Method findMethod = PlatformClass.getMethod("find", new Class[]{BundleClass, IPathClass}); //$NON-NLS-1$

				return (URL) findMethod.invoke(null, new Object[]{bundle, path});

			}

		} catch (Throwable e) {

			// Ignore any exceptions

		}

		// else work with 'plugin' as with usual Eclipse plugin

		{

			Class<?> PluginClass = Class.forName("org.eclipse.core.runtime.Plugin"); //$NON-NLS-1$

			if (PluginClass.isAssignableFrom(plugin.getClass())) {

				//

				Class<?> PathClass = Class.forName("org.eclipse.core.runtime.Path"); //$NON-NLS-1$

				Constructor<?> pathConstructor = PathClass.getConstructor(new Class[]{String.class});

				Object path = pathConstructor.newInstance(new Object[]{name});

				//

				Class<?> IPathClass = Class.forName("org.eclipse.core.runtime.IPath"); //$NON-NLS-1$

				Method findMethod = PluginClass.getMethod("find", new Class[]{IPathClass}); //$NON-NLS-1$

				return (URL) findMethod.invoke(plugin, new Object[]{path});

			}

		}

		return null;

	}

	////////////////////////////////////////////////////////////////////////////

	//

	// General

	//

	////////////////////////////////////////////////////////////////////////////

	/**

	 * Dispose of cached objects and their underlying OS resources. This should only be called when the cached

	 * objects are no longer needed (e.g. on application shutdown).

	 */

	public static void dispose() {

		disposeColors();

		disposeFonts();

		disposeImages();

	}

}