itemdescriptor.java

eclipse建立工程 org.eclipse.swt.examples.launcher.rar

/*******************************************************************************
 * Copyright (c) 2000, 2004 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.swt.examples.launcher;


import org.eclipse.core.runtime.*;
import org.eclipse.swt.graphics.*;

/**
 * ItemDescriptor collects information about a launch item.
 */
class ItemDescriptor {
	private String id;
	private String name;
	private String description;
	private Image  icon;
	private String view;
	private String mainType;
	private String pluginId;
	private IConfigurationElement element;
	
	
	/**
	 * Constructs an ItemDescriptor.
	 *
	 * @param id the id
	 * @param name the name
	 * @param description the description
	 * @param icon the icon
	 * @param view the host view may be null if it is a standalone application
	 * @param mainType the fully qualified class name to run may be null if it is a view
	 * @param pluginId the name of the plugin which contains the main class
	 */
	public ItemDescriptor(String id, String name, String description,
		Image icon, String view, String mainType, String pluginId, IConfigurationElement element) {
		this.id = id;
		this.name = name;
		this.description = description;
		this.icon = icon;
		this.view = view;
		this.mainType = mainType;
		this.pluginId = pluginId;
		this.element = element;
	}

	/**
	 * Creates and returns an instance of the extension's specified type,
	 * or <code>null</code> if no type was specified by the extension.
	 * 
	 * @return an instance of the extension's specified type or <code>null</code>
	 */
	public Object createItemInstance() throws CoreException {
		if (element == null) return null;
		return element.createExecutableExtension(LauncherPlugin.LAUNCH_ITEMS_XML_PROGRAM_CLASS);
	}

	/**
	 * Returns the ID for this program.
	 *
	 * @return the user-specified ID for this program
	 */
	public String getId() {
		return id;
	}
	
	/**
	 * Returns the translated name for the program.
	 * 
	 * @return the name of the program
	 */
	public String getName() {
		return name;
	}
	
	/**
	 * Returns a short description for the program.
	 * 
	 * @return a newline-delimited string describing the program, null if no description is available
	 */
	public String getDescription() {
		return description;
	}

	/**
	 * Returns an icon for this descriptor
	 * 
	 * @returns an icon, null if the item is a folder
	 */
	public Image getIcon() {
		return icon;
	}
	
	/**
	 * Returns the host view for the program.
	 * 
	 * @return the host view, null if the item is a standalone program.
	 */
	public String getView () {
		return view;
	}
	
	/**
	 * Returns the fully qualified class to run
	 * for the program.
	 * 
	 * @return the class to run for the program.
	 */
	public String getMainType () {
		return mainType;
	}
	
	/**
	 * Returns the name of the plugin that contains the program.
	 * 
	 * @return the name of the plugin that contains the program.
	 */
	public String getPluginId () {
		return pluginId;
	}
	
	/**
	 * Determines if an item is a folder.
	 *
	 * @return true if the item is a folder
	 */
	public boolean isFolder() {
		return (mainType == null && view == null);
	}
	
	/**
	 * Determines the equality of descriptors.
	 * 
	 * @return true if this.getId().equalsIgnoreCase(other.getId())
	 */
	public boolean equals(Object other) {
		if (other instanceof ItemDescriptor) {
			ItemDescriptor otherDescriptor = (ItemDescriptor) other;
			return getId().equalsIgnoreCase(otherDescriptor.getId());
		}
		return false;
	}
	
	/**
	 * Produces a hashcode.
	 * 
	 * @return the hashcode
	 */
	public int hashCode() {
		return id.toUpperCase().hashCode();
	}
}