org.eclipse.swt.custom.ControlEditor 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.*;

/**
*
* A ControlEditor is a manager for a Control that appears above a composite and tracks with the
* moving and resizing of that composite.  It can be used to display one control above 
* another control.  This could be used when editing a control that does not have editing 
* capabilities by using a text editor or for launching a dialog by placing a button 
* above a control.
*
*  Here is an example of using a ControlEditor:
*
* 
* Canvas canvas = new Canvas(shell, SWT.BORDER);
* canvas.setBounds(10, 10, 300, 300);	
* Color color = new Color(null, 255, 0, 0);
* canvas.setBackground(color);
* ControlEditor editor = new ControlEditor (canvas);
* // The editor will be a button in the bottom right corner of the canvas.
* // When selected, it will launch a Color dialog that will change the background 
* // of the canvas.
* Button button = new Button(canvas, SWT.PUSH);
* button.setText("Select Color...");
* button.addSelectionListener (new SelectionAdapter() {
* 	public void widgetSelected(SelectionEvent e) {
* 		ColorDialog dialog = new ColorDialog(shell);
* 		dialog.open();
* 		RGB rgb = dialog.getRGB();
* 		if (rgb != null) {
* 			if (color != null) color.dispose();
* 			color = new Color(null, rgb);
* 			canvas.setBackground(color);
* 		}
* 		
* 	}
* });
*
* editor.horizontalAlignment = SWT.RIGHT;
* editor.verticalAlignment = SWT.BOTTOM;
* editor.grabHorizontal = false;
* editor.grabVertical = false;
* Point size = button.computeSize(SWT.DEFAULT, SWT.DEFAULT);
* editor.minimumWidth = size.x;
* editor.minimumHeight = size.y;
* editor.setEditor (button);
* 
*
* @see Sample code and further information
*/
public class ControlEditor {

	/**
	* Specifies how the editor should be aligned relative to the control.  Allowed values
	* are SWT.LEFT, SWT.RIGHT and SWT.CENTER.  The default value is SWT.CENTER.
	*/
	public int horizontalAlignment = SWT.CENTER;
	
	/**
	* Specifies whether the editor should be sized to use the entire width of the control.
	* True means resize the editor to the same width as the cell.  False means do not adjust 
	* the width of the editor.	The default value is false.
	*/
	public boolean grabHorizontal = false;
	
	/**
	* Specifies the minimum width the editor can have.  This is used in association with
	* a true value of grabHorizontal.  If the cell becomes smaller than the minimumWidth, the 
	* editor will not made smaller than the minimum width value.  The default value is 0.
	*/
	public int minimumWidth = 0;
	
	/**
	* Specifies how the editor should be aligned relative to the control.  Allowed values
	* are SWT.TOP, SWT.BOTTOM and SWT.CENTER.  The default value is SWT.CENTER.
	*/
	public int verticalAlignment = SWT.CENTER;
	
	/**
	* Specifies whether the editor should be sized to use the entire height of the control.
	* True means resize the editor to the same height as the underlying control.  False means do not adjust 
	* the height of the editor.	The default value is false.
	*/
	public boolean grabVertical = false;
	
	/**
	* Specifies the minimum height the editor can have.  This is used in association with
	* a true value of grabVertical.  If the control becomes smaller than the minimumHeight, the 
	* editor will not made smaller than the minimum height value.  The default value is 0.
	*/
	public int minimumHeight = 0;

	Composite parent;
	Control editor;
	private boolean hadFocus;
	private Listener controlListener;
	private Listener scrollbarListener;
	
	private final static int [] EVENTS = {SWT.KeyDown, SWT.KeyUp, SWT.MouseDown, SWT.MouseUp, SWT.Resize};
/**
* Creates a ControlEditor for the specified Composite.
*
* @param parent the Composite above which this editor will be displayed
*
*/
public ControlEditor (Composite parent) {
	this.parent = parent;

	controlListener = new Listener() {
		public void handleEvent(Event e) {
			layout ();
		}
	};
	for (int i=0; inot disposed.
 */
public void dispose () {
	if (parent != null && !parent.isDisposed()) {
		for (int i=0; iNote: The Control provided as the editor must be created with its parent 
* being the Composite specified in the ControlEditor constructor.
* 
* @param editor the Control that is displayed above the composite being edited
*/
public void setEditor (Control editor) {
	
	if (editor == null) {
		// this is the case where the caller is setting the editor to be blank
		// set all the values accordingly
		this.editor = null;
		return;
	}
	
	this.editor = editor;
	layout();
	if (this.editor == null || this.editor.isDisposed()) return;
	editor.setVisible(true);
}
}