/*******************************************************************************
* Copyright (c) 2006 Sybase, Inc. 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:
* Sybase, Inc. - initial API and implementation
*******************************************************************************/
package org.eclipse.jst.jsf.common.ui.internal.utils;
import java.util.HashMap;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.plugin.AbstractUIPlugin;
/**
* @author mengbo
*/
public class PluginImageHelper {
private static PluginImageHelper _instance = null;
/**
* Gets the instance.
*
* @return Returns a TaglibPluginImageHelper
*/
public synchronized static PluginImageHelper getInstance() {
if (_instance == null) {
_instance = new PluginImageHelper();
}
return _instance;
}
// save a descriptor for each image
private HashMap _imageDescRegistry = null;
private final String PLUGIN_SEPARATOR = "^"; //$NON-NLS-1$
/**
* Creates an image from the given resource and adds the image to the image
* registry.
*
* @param resource
* @param pluginId
* @return Image
*/
private Image createImage(String resource, String pluginId) {
ImageDescriptor desc = getImageDescriptor(resource, pluginId);
Image image = null;
if (desc != null) {
image = desc.createImage();
// dont add the missing image descriptor image to the image
// registry
if (!desc.equals(ImageDescriptor.getMissingImageDescriptor())) {
String thePluginId = pluginId;
if (thePluginId == null) {
return null;
}
String key = thePluginId + PLUGIN_SEPARATOR + resource;
getImageRegistry().put(key, image);
}
}
return image;
}
/**
* Creates an image descriptor from the given imageFilePath in the given
* pluginId and adds the image descriptor to the image descriptor registry.
* If an image descriptor could not be created, the default "missing" image
* descriptor is returned but not added to the image descriptor registry.
*
* @param imageFilePath
* @param pluginId
* if null, look in this plugin
* @return ImageDescriptor image descriptor for imageFilePath or default
* "missing" image descriptor if resource could not be found
*/
private ImageDescriptor createImageDescriptor(String imageFilePath,
String pluginId) {
String thePluginId = pluginId;
if (thePluginId == null) {
return null;
}
ImageDescriptor imageDescriptor = AbstractUIPlugin
.imageDescriptorFromPlugin(thePluginId, imageFilePath);
if (imageDescriptor != null) {
String key = thePluginId + PLUGIN_SEPARATOR + imageFilePath;
getImageDescriptorRegistry().put(key, imageDescriptor);
} else {
imageDescriptor = ImageDescriptor.getMissingImageDescriptor();
}
return imageDescriptor;
}
/**
* Retrieves the image associated with resource from the image registry. If
* the image cannot be retrieved, attempt to find and load the image at the
* location specified in resource.
*
* @param resource
* the image to retrieve
* @return Image the image associated with resource or null if one could not
* be found
*/
public Image getImage(String resource) {
return getImage(resource, null);
}
/**
* Retrieves the image associated with resource from the image registry. If
* the image cannot be retrieved, attempt to find and load the image at the
* location specified in resource.
*
* @param resource
* the image to retrieve
* @param pluginId
* @return Image the image associated with resource or null if one could not
* be found
*/
public Image getImage(String resource, String pluginId) {
String thePluginId = pluginId;
if (thePluginId == null) {
return null;
}
String key = thePluginId + PLUGIN_SEPARATOR + resource;
Image image = getImageRegistry().get(key);
if (image == null) {
// create an image
image = createImage(resource, pluginId);
}
return image;
}
/**
* Retrieves the image descriptor associated with resource from the image
* descriptor registry. If the image descriptor cannot be retrieved, attempt
* to find and load the image descriptor at the location specified in
* resource.
*
* @param resource
* the image descriptor to retrieve
* @return ImageDescriptor the image descriptor assocated with resource or
* the default "missing" image descriptor if one could not be found
*/
public ImageDescriptor getImageDescriptor(String resource) {
return getImageDescriptor(resource, null);
}
/**
* Retrieves the image descriptor associated with resource in pluginId from
* the image descriptor registry. If the image descriptor cannot be
* retrieved, attempt to find and load the image descriptor at the location
* specified in resource in pluginId.
*
* @param resource
* the image descriptor to retrieve
* @param pluginId
* the plugin the resource is located. if null, use look in this
* plugin
* @return ImageDescriptor the image descriptor assocated with resource or
* the default "missing" image descriptor if one could not be found
*/
public ImageDescriptor getImageDescriptor(String resource, String pluginId) {
ImageDescriptor imageDescriptor = null;
String thePluginId = pluginId;
if (thePluginId == null) {
return null;
}
String key = thePluginId + PLUGIN_SEPARATOR + resource;
Object o = getImageDescriptorRegistry().get(key);
if (o == null) {
// create a descriptor
imageDescriptor = createImageDescriptor(resource, pluginId);
} else {
imageDescriptor = (ImageDescriptor) o;
}
return imageDescriptor;
}
/**
* Returns the image descriptor registry for this plugin.
*
* @return HashMap - image descriptor registry for this plugin
*/
private HashMap getImageDescriptorRegistry() {
if (_imageDescRegistry == null) {
_imageDescRegistry = new HashMap();
}
return _imageDescRegistry;
}
/**
* Returns the image registry for this plugin.
*
* @return ImageRegistry - image registry for this plugin
*/
private ImageRegistry getImageRegistry() {
return JFaceResources.getImageRegistry();
}
}