visualization/plugins/org.eclipse.draw2d/src/org/eclipse/draw2d/LayeredPane.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 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.draw2d;

import java.util.ArrayList;
import java.util.List;

/**
 * A figure capable of holding any number of layers. Only layers can be added to this 
 * figure. Layers are added to this figure with thier respective keys, which are used to
 * identify them.
 */
public class LayeredPane
	extends Layer
{

private List layerKeys = new ArrayList();

/**
 * Constructs a new layered pane with no layers in it.
 */
public LayeredPane() {
	setLayoutManager(new StackLayout());
}

/**
 * Adds the given layer figure, identifiable with the given key, at the specified index. 
 * While adding the layer, it informs the surrounding layers of the addition.
 *
 * @param figure the layer
 * @param layerKey the layer's key
 * @param index the index where the layer should be added
 * @since 2.0
 */
public void add(IFigure figure, Object layerKey, int index) {
	if (index == -1) 
		index = layerKeys.size();
	super.add(figure, null, index);
	layerKeys.add(index, layerKey);
}

/**
 * Adds the given layer, identifiable with the given key, under the <i>after</i> layer 
 * provided in the input.
 *
 * @param layer the layer
 * @param key the layer's key
 * @param after the layer under which the input layer should be added
 * @since 2.0
 */
public void addLayerAfter(Layer layer, Object key, Object after) {
	int index = layerKeys.indexOf(after);
	add(layer, key, ++index);
}

/**
 * Adds the given layer, identifiable with the given key, above the <i>before</i> layer 
 * provided in the input.
 *
 * @param layer the layer
 * @param key the layer's key
 * @param before the layer above which the input layer should be added
 * @since 2.0
 */
public void addLayerBefore(Layer layer, Object key, Object before) {
	int index = layerKeys.indexOf(before);
	add(layer, key, index);
}

/**
 * Returns the layer identified by the key given in the input.
 *
 * @param key the key to identify the desired layer
 * @return the desired layer
 * @since 2.0
 */
public Layer getLayer(Object key) {
	int index = layerKeys.indexOf(key);
	if (index == -1)
		return null;
	return (Layer)getChildren().get(index);
}

/**
 * Returns the layer at the specified index in this pane.
 *
 * @param index the index of the desired layer
 * @return the desired layer
 * @since 2.0
 */
protected Layer getLayer(int index) {
	return (Layer)getChildren().get(index);
}

/**
 * @see org.eclipse.draw2d.IFigure#remove(org.eclipse.draw2d.IFigure)
 */
public void remove(IFigure figure) {
	int index = getChildren().indexOf(figure);
	if (index != -1)
		layerKeys.remove(index);
	super.remove(figure);
}

/**
 * Removes the layer identified by the given key from this layered pane.
 *
 * @param key the key of the layer to be removed
 * @since 2.0
 */
public void removeLayer(Object key) {
	removeLayer(layerKeys.indexOf(key));
}

/**
 * Removes the given layer from this layered pane.
 *
 * @deprecated call {@link IFigure#remove(IFigure)} instead
 * @param layer the layer to be removed
 * @since 2.0
 */
public void removeLayer(IFigure layer) {
	remove(layer);
}

/**
 * Removes the layer at the specified index from the list of layers in this layered pane. 
 * It collapses the layers, occupying the space vacated by the removed layer.
 *
 * @param index the index of the layer to be removed
 * @since 2.0
 */
protected void removeLayer(int index) {
	Layer removeLayer = getLayer(index);
	remove(removeLayer);	 	
}

}