org.eclipse.swt.custom.StackLayout Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.swt.win32.win32.x86 Show documentation
SWT is an open source widget toolkit for Java designed to provide efficient, portable access to the user-interface facilities of the operating systems on which it is implemented.
The newest version!
/*******************************************************************************
 * Copyright (c) 2000, 2011 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.custom;


import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

/**
 * This Layout stacks all the controls one on top of the other and resizes all controls
 * to have the same size and location.
 * The control specified in topControl is visible and all other controls are not visible.
 * Users must set the topControl value to flip between the visible items and then call 
 * layout() on the composite which has the StackLayout.
 * 
 *  Here is an example which places ten buttons in a stack layout and 
 * flips between them:
 * 
 * 

 * 	public static void main(String[] args) {
 * 		Display display = new Display();
 * 		Shell shell = new Shell(display);
 * 		shell.setLayout(new GridLayout());
 * 	
 * 		final Composite parent = new Composite(shell, SWT.NONE);
 * 		parent.setLayoutData(new GridData(GridData.FILL_BOTH));
 * 		final StackLayout layout = new StackLayout();
 * 		parent.setLayout(layout);
 * 		final Button[] bArray = new Button[10];
 * 		for (int i = 0; i < 10; i++) {
 * 			bArray[i] = new Button(parent, SWT.PUSH);
 * 			bArray[i].setText("Button "+i);
 * 		}
 * 		layout.topControl = bArray[0];
 * 	
 * 		Button b = new Button(shell, SWT.PUSH);
 * 		b.setText("Show Next Button");
 * 		final int[] index = new int[1];
 * 		b.addListener(SWT.Selection, new Listener(){
 * 			public void handleEvent(Event e) {
 * 				index[0] = (index[0] + 1) % 10;
 * 				layout.topControl = bArray[index[0]];
 * 				parent.layout();
 * 			}
 * 		});
 * 	
 * 		shell.open();
 * 		while (shell != null && !shell.isDisposed()) {
 * 			if (!display.readAndDispatch())
 * 				display.sleep(); 
 * 		} 	
 * 	}
 * 
 *
 * @see StackLayout snippets
 * @see SWT Example: LayoutExample
 * @see Sample code and further information
 */

public class StackLayout extends Layout {
	
 	/**
	 * marginWidth specifies the number of pixels of horizontal margin
	 * that will be placed along the left and right edges of the layout.
	 *
	 * The default value is 0.
	 */
 	public int marginWidth = 0;
	/**
	 * marginHeight specifies the number of pixels of vertical margin
	 * that will be placed along the top and bottom edges of the layout.
	 *
	 * The default value is 0.
	 */
	public int marginHeight = 0;

 	/**
 	 * topControl the Control that is displayed at the top of the stack.
 	 * All other controls that are children of the parent composite will not be visible.
 	 */
 	public Control topControl;

protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {
	Control children[] = composite.getChildren();
	int maxWidth = 0;
	int maxHeight = 0;
	for (int i = 0; i < children.length; i++) {
		Point size = children[i].computeSize(wHint, hHint, flushCache);
		maxWidth = Math.max(size.x, maxWidth);
		maxHeight = Math.max(size.y, maxHeight);
	}
	int width = maxWidth + 2 * marginWidth;
	int height = maxHeight + 2 * marginHeight;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	return new Point(width, height);
}

protected boolean flushCache(Control control) {
	return true;
}

protected void layout(Composite composite, boolean flushCache) {
	Control children[] = composite.getChildren();
	Rectangle rect = composite.getClientArea();
	rect.x += marginWidth;
	rect.y += marginHeight;
	rect.width -= 2 * marginWidth;
	rect.height -= 2 * marginHeight;
	for (int i = 0; i < children.length; i++) {
		children[i].setBounds(rect);
		children[i].setVisible(children[i] == topControl);
	}
}

String getName () {
	String string = getClass ().getName ();
	int index = string.lastIndexOf ('.');
	if (index == -1) return string;
	return string.substring (index + 1, string.length ());
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the layout
 */
public String toString () {
 	String string = getName ()+" {";
 	if (marginWidth != 0) string += "marginWidth="+marginWidth+" ";
 	if (marginHeight != 0) string += "marginHeight="+marginHeight+" ";
 	if (topControl != null) string += "topControl="+topControl+" ";
 	string = string.trim();
 	string += "}";
 	return string;
}
}