package org.eclipse.swt.custom; | |
/* | |
* Copyright (c) 2000, 2002 IBM Corp. All rights reserved. | |
* This file is made available under the terms of the Common Public License v1.0 | |
* which accompanies this distribution, and is available at | |
* http://www.eclipse.org/legal/cpl-v10.html | |
*/ | |
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. | |
* | |
* <p> Here is an example of using a ControlEditor: | |
* | |
* <code><pre> | |
* 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); | |
* </pre></code> | |
*/ | |
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 minumum 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 minumum height value. The default value is 0. | |
*/ | |
public int minimumHeight = 0; | |
Composite parent; | |
Control editor; | |
private boolean hadFocus; | |
private Listener tableListener; | |
private Listener scrollbarListener; | |
/** | |
* 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; | |
tableListener = new Listener() { | |
public void handleEvent(Event e) { | |
resize (); | |
} | |
}; | |
parent.addListener (SWT.Resize, tableListener); | |
scrollbarListener = new Listener() { | |
public void handleEvent(Event e) { | |
scroll (e); | |
} | |
}; | |
ScrollBar hBar = parent.getHorizontalBar (); | |
if (hBar != null) hBar.addListener (SWT.Selection, scrollbarListener); | |
ScrollBar vBar = parent.getVerticalBar (); | |
if (vBar != null) vBar.addListener (SWT.Selection, scrollbarListener); | |
} | |
Rectangle computeBounds () { | |
Rectangle clientArea = parent.getClientArea(); | |
Rectangle editorRect = new Rectangle(clientArea.x, clientArea.y, minimumWidth, minimumHeight); | |
if (grabHorizontal) | |
editorRect.width = Math.max(clientArea.width, minimumWidth); | |
if (grabVertical) | |
editorRect.height = Math.max(clientArea.height, minimumHeight); | |
switch (horizontalAlignment) { | |
case SWT.RIGHT: | |
editorRect.x += clientArea.width - editorRect.width; | |
break; | |
case SWT.LEFT: | |
// do nothing - clientArea.x is the right answer | |
break; | |
default: | |
// default is CENTER | |
editorRect.x += (clientArea.width - editorRect.width)/2; | |
} | |
switch (verticalAlignment) { | |
case SWT.BOTTOM: | |
editorRect.y += clientArea.height - editorRect.height; | |
break; | |
case SWT.TOP: | |
// do nothing - clientArea.y is the right answer | |
break; | |
default : | |
// default is CENTER | |
editorRect.y += (clientArea.height - editorRect.height)/2; | |
} | |
return editorRect; | |
} | |
/** | |
* Removes all associations between the Editor and the underlying composite. The | |
* composite and the editor Control are <b>not</b> disposed. | |
*/ | |
public void dispose () { | |
if (!parent.isDisposed()) { | |
parent.removeListener (SWT.Resize, tableListener); | |
ScrollBar hBar = parent.getHorizontalBar (); | |
if (hBar != null) hBar.removeListener (SWT.Selection, scrollbarListener); | |
ScrollBar vBar = parent.getVerticalBar (); | |
if (vBar != null) vBar.removeListener (SWT.Selection, scrollbarListener); | |
} | |
parent = null; | |
editor = null; | |
hadFocus = false; | |
tableListener = null; | |
scrollbarListener = null; | |
} | |
/** | |
* Returns the Control that is displayed above the composite being edited. | |
* | |
* @return the Control that is displayed above the composite being edited | |
*/ | |
public Control getEditor () { | |
return editor; | |
} | |
/** | |
* Lays out the control within the underlying composite. This | |
* method should be called after changing one or more fields to | |
* force the Editor to resize. | |
* | |
* @since 2.1 | |
*/ | |
public void layout () { | |
resize(); | |
} | |
void resize () { | |
if (editor == null || editor.isDisposed()) return; | |
if (editor.getVisible ()) { | |
hadFocus = editor.isFocusControl(); | |
} // this doesn't work because | |
// resizing the column takes the focus away | |
// before we get here | |
editor.setBounds (computeBounds ()); | |
if (hadFocus) editor.setFocus (); | |
} | |
void scroll (Event e) { | |
if (editor == null || editor.isDisposed()) return; | |
if (editor.getVisible ()) { | |
hadFocus = editor.isFocusControl(); | |
} | |
boolean visible = e.detail != SWT.DRAG; | |
if (visible) { | |
editor.setBounds (computeBounds ()); | |
} | |
editor.setVisible (visible); | |
if (visible && hadFocus) editor.setFocus (); | |
} | |
/** | |
* Specify the Control that is to be displayed. | |
* | |
* <p>Note: The Control provided as the editor <b>must</b> 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; | |
resize(); | |
editor.setVisible(true); | |
} | |
} |