ToolEntry.java

/*******************************************************************************
 * Copyright (c) 2000, 2007 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.gef.palette;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.core.runtime.Assert;

import org.eclipse.gef.Tool;

/**
 * A factory for returning Tools.
 */
public abstract class ToolEntry
	extends PaletteEntry
{

/** Type Identifier **/
public static final Object PALETTE_TYPE_TOOL = "$Palette Tool";//$NON-NLS-1$

private Map map;
private Class toolClass;

/** 
 * Creates a new ToolEntry.  Any parameter can be <code>null</code>.
 * @param label the entry's name
 * @param shortDesc the entry's description
 * @param iconSmall the entry's small icon
 * @param iconLarge the entry's large icon
 */
public ToolEntry(String label, String shortDesc, ImageDescriptor iconSmall, 
		ImageDescriptor iconLarge) {
	this(label, shortDesc, iconSmall, iconLarge, null);
}

/**
 * Constructor to create a new ToolEntry.  Any parameter can be <code>null</code>.
 * @param label the entry's name
 * @param description the entry's description
 * @param iconSmall the entry's small icon
 * @param iconLarge the entry's large icon
 * @param tool the type of tool that this entry uses
 * @since 3.1
 */
public ToolEntry (String label, String description, ImageDescriptor iconSmall, 
		ImageDescriptor iconLarge, Class tool) {
	super(label, description, iconSmall, iconLarge, PALETTE_TYPE_TOOL);
	setToolClass(tool);
}

/**
 * Creates the tool of the type specified by {@link #setToolClass(Class)} for this 
 * ToolEntry.  The tool is also configured with the properties set in 
 * {@link #setToolProperty(Object, Object)}.  Sub-classes overriding this method should
 * ensure that their tools are also configured with those properties.
 * @return the tool for this entry
 */
public Tool createTool() {
	if (toolClass == null)
		return null;
	Tool tool;
	try {
		tool = (Tool)toolClass.newInstance();
	} catch (IllegalAccessException iae) {
		return null;
	} catch (InstantiationException ie) {
		return null;
	}
	tool.setProperties(getToolProperties());
	return tool;
}

/**
 * @return the properties set in {@link #setToolProperty(Object, Object)}
 * @since 3.1
 */
protected Map getToolProperties() {
	return map;
}

/**
 * Returns the property value for the specified property key.
 * @param key the property key
 * @return the value for the requested property
 * @since 3.1
 */
public Object getToolProperty(Object key) {
	if (map != null)
		return map.get(key);
	return null;
}

/**
 * Sets the type of tool to be created.  This provides clients with a method of specifying
 * a different type of tool to be created without having to sub-class.  The provided class
 * should have a default constructor for this to work successfully.
 * @param toolClass the type of tool to be created by this entry
 * @since 3.1
 */
public void setToolClass(Class toolClass) {
	if (toolClass != null)
		Assert.isTrue(Tool.class.isAssignableFrom(toolClass));
	this.toolClass = toolClass;
}

/**
 * Clients can use this method to configure the associated tool without having to 
 * sub-class.
 * @param key the property name
 * @param value a value of type associated with the given property
 * @since 3.1
 * @see Tool#setProperties(Map)
 */
public void setToolProperty(Object key, Object value) {
	if (map == null)
		map = new HashMap();
	map.put(key, value);
}

}