StackLayout.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.List;

import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Rectangle;

/**
 * Figures using the StackLayout as their layout manager have their children placed on top 
 * of one another. Order of placement is determined by the order in which the children
 * were added, first child added placed on the bottom.
 */
public class StackLayout
	extends AbstractHintLayout
{

/**
 * Returns the minimum size required by the input container. This is the size of the 
 * largest child of the container, as all other children fit into this size.
 * 
 * @see AbstractHintLayout#calculateMinimumSize(IFigure, int, int)
 */
protected Dimension calculateMinimumSize(IFigure figure, int wHint, int hHint) {
	if (wHint > -1)
		wHint = Math.max(0, wHint - figure.getInsets().getWidth());
	if (hHint > -1)
		hHint = Math.max(0, hHint - figure.getInsets().getHeight());
	Dimension d = new Dimension();
	List children = figure.getChildren();
	IFigure child;
	for (int i = 0; i < children.size(); i++) {
		child = (IFigure)children.get(i);
		if (!isObservingVisibility() || child.isVisible())
			d.union(child.getMinimumSize(wHint, hHint));
	}
	
	d.expand(figure.getInsets().getWidth(),
	         figure.getInsets().getHeight());
	d.union(getBorderPreferredSize(figure));
	return d;

}

/**
 * Calculates and returns the preferred size of the given figure.  This is the union of 
 * the preferred sizes of the widest and the tallest of all its children. 
 * 
 * @see AbstractLayout#calculatePreferredSize(IFigure, int, int)
 */
protected Dimension calculatePreferredSize(IFigure figure, int wHint, int hHint) {
	if (wHint > -1)
		wHint = Math.max(0, wHint - figure.getInsets().getWidth());
	if (hHint > -1)
		hHint = Math.max(0, hHint - figure.getInsets().getHeight());
	Dimension d = new Dimension();
	List children = figure.getChildren();
	IFigure child;
	for (int i = 0; i < children.size(); i++) {
		child = (IFigure)children.get(i);
		if (!isObservingVisibility() || child.isVisible())
			d.union(child.getPreferredSize(wHint, hHint));
	}
	
	d.expand(figure.getInsets().getWidth(),
	         figure.getInsets().getHeight());
	d.union(getBorderPreferredSize(figure));
	return d;
}

/**
 * @see org.eclipse.draw2d.LayoutManager#layout(IFigure)
 */
public void layout(IFigure figure) {
	Rectangle r = figure.getClientArea();
	List children = figure.getChildren();
	IFigure child;
	for (int i = 0; i < children.size(); i++) {
		child = (IFigure)children.get(i);
		child.setBounds(r);
	}
}

}