deviceeditorregistry.java

eclipseme的最新版本的source,欢迎j2me程序员使用

/**
 * Copyright (c) 2003-2006 Craig Setera
 * All Rights Reserved.
 * Licensed under the Eclipse Public License - v 1.0
 * For more information see http://www.eclipse.org/legal/epl-v10.html
 */
package eclipseme.ui.internal.devices;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.Platform;

import eclipseme.core.model.device.IDevice;
import eclipseme.ui.internal.EclipseMEUIPlugin;

/**
 * Provides registry functionality for attaching editors to
 * particular device types.
 * <p />
 * Copyright (c) 2003-2006 Craig Setera<br>
 * All Rights Reserved.<br>
 * Licensed under the Eclipse Public License - v 1.0<p/>
 * <br>
 * $Revision: 1.1 $
 * <br>
 * $Date: 2006/02/25 01:55:03 $
 * <br>
 * @author Craig Setera
 */
public class DeviceEditorRegistry {
	/** The extension point */
	public static final String ID_EXTENSION = "deviceEditor";
	
	private static DeviceEditorConfigElement[] editors;
	
	/**
	 * Return the editor configuration element for editing the specified
	 * device or <code>null</code> if no editor element can be found.
	 * 
	 * @param device
	 * @return
	 */
	public static DeviceEditorConfigElement findEditorElement(IDevice device) {
		DeviceEditorConfigElement element = null;
		
		DeviceEditorConfigElement[] elements = getEditors();
		Class deviceClass = device.getClass();
		for (int i = 0; i < elements.length; i++) {
			String matchClassName = elements[i].getDeviceClass();
			if (isMatchingType(deviceClass, matchClassName)) {
				element = elements[i];
				break;
			}
		}
		
		return element;
	}
	
	/**
	 * Return a boolean if the specified class matches the specified class
	 * name directly or via supertypes and interfaces.
	 * 
	 * @param type
	 * @param matchClassName
	 * @return
	 */
	private static boolean isMatchingType(Class type, String matchClassName) {
		boolean matches = false;
		
		if (type != null) {
			matches = type.getName().equals(matchClassName);
		
			// Test superclasses
			if (!matches) {
				matches = isMatchingType(type.getSuperclass(), matchClassName);
			}
			
			// Test interfaces
			if (!matches) {
				Class[] interfaces = type.getInterfaces();
				for (int i = 0; !matches && i < interfaces.length; i++) {
					matches = isMatchingType(interfaces[i], matchClassName);
				}
			}
		}
		
		return matches;
	}

	/**
	 * Return the editor extensions as an array of DeviceEditorConfigElement
	 * instances.
	 * 
	 * @return
	 */
	private static DeviceEditorConfigElement[] getEditors() {
		if (editors == null) {
			editors = readEditors();
		}
		
		return editors;
	}

	/**
	 * Return the editor extensions as a list of DeviceEditorConfigElement
	 * instances.
	 * 
	 * @return
	 */
	private static DeviceEditorConfigElement[] readEditors() {
		String plugin = EclipseMEUIPlugin.getDefault().getBundle().getSymbolicName();
		IConfigurationElement[] configElements =
			Platform.getExtensionRegistry().getConfigurationElementsFor(plugin, ID_EXTENSION);
		
		DeviceEditorConfigElement[] elements = new DeviceEditorConfigElement[configElements.length];
		for (int i = 0; i < configElements.length; i++) {
			elements[i] = new DeviceEditorConfigElement(configElements[i]);
		}
		
		return elements;
	}

	/**
	 * Static-only access.
	 */
	private DeviceEditorRegistry() {
		super();
	}
}