bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/WorkingSetDescriptor.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal.registry;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.ui.dialogs.IWorkingSetPage;
import org.eclipse.ui.internal.WorkbenchPlugin;
import org.eclipse.ui.plugin.AbstractUIPlugin;

/**
 * A working set descriptor stores the plugin registry data for 
 * a working set page extension.
 * 
 * @since 2.0
 */
public class WorkingSetDescriptor {
	private String id;
	private String name;
	private String icon;	
	private String pageClassName;
	private IConfigurationElement configElement;

	private static final String ATT_ID = "id"; //$NON-NLS-1$
	private static final String ATT_NAME = "name"; //$NON-NLS-1$
	private static final String ATT_ICON = "icon"; //$NON-NLS-1$	
	private static final String ATT_PAGE_CLASS = "pageClass"; //$NON-NLS-1$	

	/**
	 * Creates a descriptor from a configuration element.
	 * 
	 * @param configElement configuration element to create a descriptor from
	 */
	public WorkingSetDescriptor(IConfigurationElement configElement) throws CoreException {
		super();
		this.configElement = configElement;
		id = configElement.getAttribute(ATT_ID);
		name = configElement.getAttribute(ATT_NAME);
		icon = configElement.getAttribute(ATT_ICON);		
		pageClassName = configElement.getAttribute(ATT_PAGE_CLASS);

		if (name == null) {
			throw new CoreException(new Status(
				IStatus.ERROR, 
				WorkbenchPlugin.PI_WORKBENCH, 
				0, 
				"Invalid extension (missing class name): " + id, 		//$NON-NLS-1$
				null));
		}
		if (pageClassName == null) {
			throw new CoreException(new Status(
				IStatus.ERROR,
				WorkbenchPlugin.PI_WORKBENCH,
				0,
				"Invalid extension (missing page class name): " + id,	//$NON-NLS-1$
				null));
		}
	}
	/**
	 * Creates a working set page from this extension descriptor.
	 * 
	 * @return a working set page created from this extension 
	 * 	descriptor.
	 */
	public IWorkingSetPage createWorkingSetPage() {
		Object page = null;

		if (pageClassName != null) {
			try {
				page = WorkbenchPlugin.createExtension(configElement, ATT_PAGE_CLASS);
			} catch (CoreException exception) {
				WorkbenchPlugin.log("Unable to create working set page: " + //$NON-NLS-1$
				pageClassName, exception.getStatus());
			}
		}
		return (IWorkingSetPage) page;
	}
	/**
	 * Returns the page's icon
	 * 
	 * @return the page's icon
	 */
	public ImageDescriptor getIcon() {
		if (icon == null)
			return null;

		IExtension extension = configElement.getDeclaringExtension();
		String extendingPluginId = extension.getNamespace();
		return AbstractUIPlugin.imageDescriptorFromPlugin(
			extendingPluginId, icon);
	}
	/**
	 * Returns the working set page id.
	 * 
	 * @return the working set page id.
	 */
	public String getId() {
		return id;
	}
	/**
	 * Returns the working set page class name
	 * 
	 * @return the working set page class name
	 */
	public String getPageClassName() {
		return pageClassName;
	}
	/**
	 * Returns the name of the working set element type the 
	 * page works with.
	 * 
	 * @return the working set element type name
	 */
	public String getName() {
		return name;
	}
}