bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/ColorDialog.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2003 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are 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
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.swt.widgets;


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

 /**
  * Instances of this class allow the user to select a color
  * from a predefined set of available colors.
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>(none)</dd>
  * <dt><b>Events:</b></dt>
  * <dd>(none)</dd>
  * </dl>
  * <p>
  * IMPORTANT: This class is intended to be subclassed <em>only</em>
  * within the SWT implementation.
  * </p>
  */
 public class ColorDialog extends Dialog {
 	private static final int COLORSWATCH_SIZE_DEPTH4 = 40;
 	private static final int COLORSWATCH_SIZE_DEPTH8 = 15;
 	private static final int COLORSWATCH_SIZE_DEPTH16 = 10;
 	private static final int COLORSWATCH_BORDER = 1;	// border between each color pad

 	private Shell shell;								// the dialog shell
 	private Canvas colorsCanvas;
 	private Label sampleLabel, selectionLabel;
 	private Canvas sampleCanvas, selectionCanvas;
 	private Button okButton, cancelButton;
 	private int colorChooserWidth, colorChooserHeight;

 	private boolean okSelected;
 	private RGB rgb;
 	private int colorDepth;								// color depth of the display
 	private int colorSwatchExtent;						// the size of each color square
 	private Color colorGrid[][];						// the colors displayed in the dialog

 /**
  * Constructs a new instance of this class given only its parent.
  *
  * @param parent a composite control which will be the parent of the new instance
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
  * </ul>
  * @exception SWTException <ul>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
  *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
  * </ul>
  *
  * @see SWT
  * @see Widget#checkSubclass
  * @see Widget#getStyle
  */
 public ColorDialog(Shell parent) {
 	this(parent, SWT.NULL);
 }
 /**
  * Constructs a new instance of this class given its parent
  * and a style value describing its behavior and appearance.
  * <p>
  * The style value is either one of the style constants defined in
  * class <code>SWT</code> which is applicable to instances of this
  * class, or must be built by <em>bitwise OR</em>'ing together
  * (that is, using the <code>int</code> "|" operator) two or more
  * of those <code>SWT</code> style constants. The class description
  * lists the style constants that are applicable to the class.
  * Style bits are also inherited from superclasses.
  * </p>
  *
  * @param parent a composite control which will be the parent of the new instance (cannot be null)
  * @param style the style of control to construct
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
  * </ul>
  * @exception SWTException <ul>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
  *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
  * </ul>
  *
  * @see SWT
  * @see Widget#checkSubclass
  * @see Widget#getStyle
  */
 public ColorDialog(Shell parent, int style) {
 	super(parent, style | SWT.TITLE | SWT.BORDER | SWT.APPLICATION_MODAL);
 	checkSubclass ();
 }
 void createChildren() {
 	Shell dialog = shell;
 	GridLayout layout = new GridLayout (2, false);
 	dialog.setLayout(layout);

 	colorChooserWidth = colorSwatchExtent * colorGrid.length - 1;
 	colorChooserHeight = colorSwatchExtent * colorGrid[0].length - 1;
 	colorsCanvas = new Canvas(dialog, SWT.BORDER);
 	GridData data = new GridData ();
 	data.widthHint = colorChooserWidth;
 	data.heightHint = colorChooserHeight;
 	colorsCanvas.setLayoutData(data);

 	Composite buttonsGroup = new Composite (dialog, SWT.NONE);
 	buttonsGroup.setLayout(new GridLayout());
 	buttonsGroup.setLayoutData(new GridData(GridData.BEGINNING));
 	createOkCancel(buttonsGroup);

 	Composite bottomGroup = new Composite (dialog,SWT.NONE);
 	layout = new GridLayout(2, true);
 	layout.marginHeight = 0;
 	layout.marginWidth = 0;
 	bottomGroup.setLayout(layout);
 	bottomGroup.setLayoutData(new GridData(GridData.FILL_BOTH));

 	createSampleGroup(bottomGroup);
 	createSelectionGroup(bottomGroup);
 }
 void createOkCancel(Composite parent) {
 	okButton = new Button(parent, SWT.PUSH);
 	okButton.setText(SWT.getMessage("SWT_OK"));
 	shell.setDefaultButton(okButton);
 	GridData data = new GridData(GridData.FILL_HORIZONTAL);
 	okButton.setLayoutData(data);

 	cancelButton = new Button(parent, SWT.PUSH);
 	cancelButton.setText(SWT.getMessage("SWT_Cancel"));
 	data = new GridData(GridData.FILL_HORIZONTAL);
 	cancelButton.setLayoutData(data);
 }
 void createSampleGroup(Composite parent) {
 	Group sampleGroup = new Group(parent, SWT.NULL);
 	GridData data = new GridData(GridData.FILL_BOTH);
 	data.grabExcessHorizontalSpace = true;
 	sampleGroup.setLayout(new GridLayout());
 	sampleGroup.setLayoutData(data);
 	sampleGroup.setText(SWT.getMessage("SWT_Sample"));

 	sampleLabel = new Label(sampleGroup, SWT.CENTER | SWT.BORDER);
 	sampleLabel.setAlignment(SWT.CENTER);
 	sampleLabel.setText(SWT.getMessage("SWT_A_Sample_Text"));
 	data = new GridData(GridData.FILL_HORIZONTAL);
 	sampleLabel.setLayoutData(data);

 	sampleCanvas = new Canvas(sampleGroup, SWT.BORDER);
 	data = new GridData(GridData.FILL_HORIZONTAL);
 	data.heightHint = 15;
 	sampleCanvas.setLayoutData(data);
 }
 void createSelectionGroup(Composite parent) {
 	Group selectionGroup = new Group(parent, SWT.NULL);
 	GridData data = new GridData(GridData.FILL_BOTH);
 	data.grabExcessHorizontalSpace = true;
 	selectionGroup.setLayout(new GridLayout());
 	selectionGroup.setLayoutData(data);
 	selectionGroup.setText(SWT.getMessage("SWT_Selection"));

 	selectionLabel = new Label(selectionGroup, SWT.CENTER | SWT.BORDER);
 	selectionLabel.setAlignment(SWT.CENTER);
 	selectionLabel.setText(SWT.getMessage("SWT_Current_Selection"));
 	data = new GridData(GridData.FILL_HORIZONTAL);
 	data.grabExcessHorizontalSpace = true;
 	selectionLabel.setLayoutData(data);

 	selectionCanvas = new Canvas(selectionGroup, SWT.BORDER);
 	data = new GridData(GridData.FILL_HORIZONTAL);
 	data.grabExcessHorizontalSpace = true;
 	data.heightHint = 15;
 	selectionCanvas.setLayoutData(data);
 }
 void disposeColors() {
 	for (int row = 0; row < colorGrid.length; row++) {
 		for (int column = 0; column < colorGrid[row].length; column++) {
 			colorGrid[row][column].dispose();
 		}
 	}
 }
 void drawColor(int xIndex, int yIndex, Color color, GC gc) {
 	int colorExtent = colorSwatchExtent - COLORSWATCH_BORDER;
 	gc.setBackground(color);
 	gc.fillRectangle(
 		xIndex * colorSwatchExtent,
 		yIndex * colorSwatchExtent,
 		colorExtent, colorExtent);
 }
 /**
  * Returns the currently selected color in the receiver.
  *
  * @return the RGB value for the selected color, may be null
  *
  * @see PaletteData#getRGBs
  */
 public RGB getRGB() {
 	return rgb;
 }
 void handleEvents(Event event) {
 	if (event.type == SWT.Paint) {
 		paint(event);
 	}
 	else
 	if (event.type == SWT.MouseDown) {
 		mouseDown(event);
 	}
 	else
 	if (event.type == SWT.MouseMove) {
 		mouseMove(event);
 	}
 	else
 	if (event.type == SWT.Selection) {
 		if (event.widget == okButton) {
 			okSelected = true;
 			shell.setVisible(false);
 		}
 		else
 		if (event.widget == cancelButton) {
 			okSelected = false;
 			shell.setVisible(false);
 		}
 	}
 }
 void initialize4BitColors() {
 	Display display = shell.display;

 	colorGrid[0][0] = new Color(display, 0, 0, 0);
 	colorGrid[0][1] = new Color(display, 255, 255, 255);
 	colorGrid[1][0] = new Color(display, 128, 128, 128);
 	colorGrid[1][1] = new Color(display, 192, 192, 192);

 	colorGrid[2][0] = new Color(display, 0, 0, 128);
 	colorGrid[2][1] = new Color(display, 0, 0, 255);
 	colorGrid[3][0] = new Color(display, 0, 128, 128);
 	colorGrid[3][1] = new Color(display, 0, 255, 255);

 	colorGrid[4][0] = new Color(display, 0, 128, 0);
 	colorGrid[4][1] = new Color(display, 0, 255, 0);
 	colorGrid[5][0] = new Color(display, 128, 128, 0);
 	colorGrid[5][1] = new Color(display, 255, 255, 0);

 	colorGrid[6][0] = new Color(display, 128, 0, 0);
 	colorGrid[6][1] = new Color(display, 255, 0, 0);
 	colorGrid[7][0] = new Color(display, 128, 0, 128);
 	colorGrid[7][1] = new Color(display, 255, 0, 255);
 }
 void initialize8BitColors() {
 	Display display = shell.display;
 	int numRows = colorGrid[0].length;
 	int iterationStep = 64;
 	int row = 0, column = 0;
 	int red, green, blue;
 	// run the loops from 0 to 256 inclusive since this is easiest for the step
 	// size, then adjust the 256 case to the proper 255 value when needed
 	for (red = 0; red <= 256; red += iterationStep) {
 		for (blue = 0; blue <= 256; blue += iterationStep) {
 			for (green = 0; green <= 256; green += iterationStep) {
 				if (row == numRows) {
 					row = 0;
 					column++;
 				}
 				if (red == 256) red = 255;
 				if (blue == 256) blue = 255;
 				if (green == 256) green = 255;
 				colorGrid[column][row++] = new Color(display, red, green, blue);
 			}
 		}
 	}
 }
 void initialize16BitColors() {
 	Display display = shell.display;
 	int numRows = colorGrid[0].length;
 	int iterationStep = 51;
 	int row = 0, column = 0;
 	int red, green, blue;

 	for (red = 0; red <= 255; red += iterationStep) {
 		for (blue = 0; blue <= 255; blue += iterationStep) {
 			if (blue == iterationStep && column < 20) {		// hack to evenly distribute 256 colors on 32 columns
 				blue += iterationStep;
 			}
 			for (green = 0; green <= 255; green += iterationStep) {
 				if (row == 2 || row == 5) {					// hack to evenly distribute 256 colors on 8 rows
 					colorGrid[column][row++] = new Color(display, red, green - iterationStep / 2, blue);
 				}
 				if (row == numRows) {
 					row = 0;
 					column++;
 				}
 				colorGrid[column][row++] = new Color(display, red, green, blue);
 			}
 		}
 	}
 }
 void initializeWidgets() {
 	Display display = shell.display;
 	if (rgb != null) {
 		Color selectionColor = new Color(display, rgb);
 		selectionCanvas.setBackground(selectionColor);
 		selectionLabel.setBackground(selectionColor);
 		selectionColor.dispose();
 	}
 }
 void installListeners() {
 	Listener listener = new Listener() {
 		public void handleEvent(Event event) {handleEvents(event);}
 	};
 	okButton.addListener(SWT.Selection, listener);
 	cancelButton.addListener(SWT.Selection, listener);
 	colorsCanvas.addListener(SWT.Paint, listener);
 	colorsCanvas.addListener(SWT.MouseDown, listener);
 	colorsCanvas.addListener(SWT.MouseMove, listener);
 }
 void mouseDown(Event event) {
 	int swatchExtent = colorSwatchExtent;
 	Color color = colorGrid[event.x / swatchExtent][event.y / swatchExtent];
 	selectionCanvas.setBackground(color);
 	selectionLabel.setBackground(color);
 }
 void mouseMove(Event event) {
 	int swatchExtent = colorSwatchExtent;
 	// adjust for events received from moving over the Canvas' border
 	if (!(0 <= event.x && event.x <= colorChooserWidth)) return;
 	if (!(0 <= event.y && event.y <= colorChooserHeight)) return;
 	int xgrid = Math.min(colorGrid.length - 1, event.x / swatchExtent);
 	int ygrid = Math.min(colorGrid[0].length - 1, event.y / swatchExtent);
 	Color color = colorGrid[xgrid][ygrid];
 	sampleCanvas.setBackground(color);
 	sampleLabel.setBackground(color);
 }
 /**
  * Makes the receiver visible and brings it to the front
  * of the display.
  *
  * @return the selected color, or null if the dialog was
  *         cancelled, no color was selected, or an error
  *         occurred
  *
  * @exception SWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  * </ul>
  */
 public RGB open() {
 	shell = new Shell(parent, getStyle() | SWT.TITLE | SWT.BORDER | SWT.APPLICATION_MODAL);
 	Display display = shell.display;
 	setColorDepth(display.getDepth());
 	createChildren();
 	installListeners();
 	openModal();
 	if (okSelected) {
 		Color selectionColor = selectionCanvas.getBackground();
 		rgb = new RGB(
 			selectionColor.getRed(),
 			selectionColor.getGreen(),
 			selectionColor.getBlue());
 	}
 	disposeColors();
 	if (shell.isDisposed() == false) {
 		shell.dispose();
 	}
 	if (!okSelected) return null;
 	return rgb;
 }
 /**
  * Open the receiver and set its size to the size calculated by
  * the layout manager.
  */
 void openDialog() {
 	Shell dialog = shell;

 	// Start everything off by setting the shell size to its computed size.
 	Point pt = dialog.computeSize(-1, -1, false);

 	// Ensure that the width of the shell fits the display.
 	Display display = dialog.display;
 	Rectangle displayRect = display.getBounds();
 	int widthLimit = displayRect.width * 7 / 8;
 	int heightLimit = displayRect.height * 7 / 8;
 	if (pt.x > widthLimit) {
 		pt = dialog.computeSize (widthLimit, -1, false);
 	}

 	// centre the dialog on its parent, and ensure that the
 	// whole dialog appears within the screen bounds
 	Rectangle parentBounds = getParent ().getBounds ();
 	int originX = (parentBounds.width - pt.x) / 2 + parentBounds.x;
 	originX = Math.max (originX, 0);
 	originX = Math.min (originX, widthLimit - pt.x);
 	int originY = (parentBounds.height - pt.y) / 2 + parentBounds.y;
 	originY = Math.max (originY, 0);
 	originY = Math.min (originY, heightLimit - pt.y);
 	dialog.setBounds (originX, originY, pt.x, pt.y);

 	String title = getText ();
 	if (title.length () == 0) title = SWT.getMessage ("SWT_ColorDialog_Title");
 	shell.setText(title);

 	dialog.open();
 }
 void openModal() {
 	Display display = shell.display;
 	initializeWidgets();
 	openDialog();
 	while (shell.isDisposed() == false && shell.getVisible() == true) {
 		if (display.readAndDispatch() == false) {
 			display.sleep();
 		}
 	}
 }
 void paint(Event event) {
 	for (int column = 0; column < colorGrid.length; column++) {
 		for (int row = 0; row < colorGrid[0].length; row++) {
 			drawColor(column, row, colorGrid[column][row], event.gc);
 		}
 	}
 }
 void setColorDepth(int bits) {
 	colorDepth = bits;
 	if (bits == 4) {
 		colorSwatchExtent = COLORSWATCH_SIZE_DEPTH4;
 		colorGrid = new Color[8][2];
 		initialize4BitColors();
 		return;
 	}
 	if (bits == 8) {
 		colorSwatchExtent = COLORSWATCH_SIZE_DEPTH8;
 		colorGrid = new Color[25][5];
 		initialize8BitColors();
 		return;
 	}
 	// default case: 16, 24 or 32 bits
 	colorSwatchExtent = COLORSWATCH_SIZE_DEPTH16;
 	colorGrid = new Color[32][8];
 	initialize16BitColors();
 }
 /**
  * Sets the receiver's selected color to be the argument.
  *
  * @param rgb the new RGB value for the selected color, may be
  *        null to let the platform select a default when
  *        open() is called
  * @see PaletteData#getRGBs
  */
 public void setRGB(RGB rgb) {
 	this.rgb = rgb;
 }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2003 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are 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
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.swt.widgets;


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

	/**
	* Instances of this class allow the user to select a color
	* from a predefined set of available colors.
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>(none)</dd>
	* <dt><b>Events:</b></dt>
	* <dd>(none)</dd>
	* </dl>
	* <p>
	* IMPORTANT: This class is intended to be subclassed <em>only</em>
	* within the SWT implementation.
	* </p>
	*/
	public class ColorDialog extends Dialog {
	private static final int COLORSWATCH_SIZE_DEPTH4 = 40;
	private static final int COLORSWATCH_SIZE_DEPTH8 = 15;
	private static final int COLORSWATCH_SIZE_DEPTH16 = 10;
	private static final int COLORSWATCH_BORDER = 1; // border between each color pad

	private Shell shell; // the dialog shell
	private Canvas colorsCanvas;
	private Label sampleLabel, selectionLabel;
	private Canvas sampleCanvas, selectionCanvas;
	private Button okButton, cancelButton;
	private int colorChooserWidth, colorChooserHeight;

	private boolean okSelected;
	private RGB rgb;
	private int colorDepth; // color depth of the display
	private int colorSwatchExtent; // the size of each color square
	private Color colorGrid[][]; // the colors displayed in the dialog

	/**
	* Constructs a new instance of this class given only its parent.
	*
	* @param parent a composite control which will be the parent of the new instance
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
	* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
	* </ul>
	*
	* @see SWT
	* @see Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public ColorDialog(Shell parent) {
	this(parent, SWT.NULL);
	}
	/**
	* Constructs a new instance of this class given its parent
	* and a style value describing its behavior and appearance.
	* <p>
	* The style value is either one of the style constants defined in
	* class <code>SWT</code> which is applicable to instances of this
	* class, or must be built by <em>bitwise OR</em>'ing together
	* (that is, using the <code>int</code> "\|" operator) two or more
	* of those <code>SWT</code> style constants. The class description
	* lists the style constants that are applicable to the class.
	* Style bits are also inherited from superclasses.
	* </p>
	*
	* @param parent a composite control which will be the parent of the new instance (cannot be null)
	* @param style the style of control to construct
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
	* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
	* </ul>
	*
	* @see SWT
	* @see Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public ColorDialog(Shell parent, int style) {
	super(parent, style \| SWT.TITLE \| SWT.BORDER \| SWT.APPLICATION_MODAL);
	checkSubclass ();
	}
	void createChildren() {
	Shell dialog = shell;
	GridLayout layout = new GridLayout (2, false);
	dialog.setLayout(layout);

	colorChooserWidth = colorSwatchExtent * colorGrid.length - 1;
	colorChooserHeight = colorSwatchExtent * colorGrid[0].length - 1;
	colorsCanvas = new Canvas(dialog, SWT.BORDER);
	GridData data = new GridData ();
	data.widthHint = colorChooserWidth;
	data.heightHint = colorChooserHeight;
	colorsCanvas.setLayoutData(data);

	Composite buttonsGroup = new Composite (dialog, SWT.NONE);
	buttonsGroup.setLayout(new GridLayout());
	buttonsGroup.setLayoutData(new GridData(GridData.BEGINNING));
	createOkCancel(buttonsGroup);

	Composite bottomGroup = new Composite (dialog,SWT.NONE);
	layout = new GridLayout(2, true);
	layout.marginHeight = 0;
	layout.marginWidth = 0;
	bottomGroup.setLayout(layout);
	bottomGroup.setLayoutData(new GridData(GridData.FILL_BOTH));

	createSampleGroup(bottomGroup);
	createSelectionGroup(bottomGroup);
	}
	void createOkCancel(Composite parent) {
	okButton = new Button(parent, SWT.PUSH);
	okButton.setText(SWT.getMessage("SWT_OK"));
	shell.setDefaultButton(okButton);
	GridData data = new GridData(GridData.FILL_HORIZONTAL);
	okButton.setLayoutData(data);

	cancelButton = new Button(parent, SWT.PUSH);
	cancelButton.setText(SWT.getMessage("SWT_Cancel"));
	data = new GridData(GridData.FILL_HORIZONTAL);
	cancelButton.setLayoutData(data);
	}
	void createSampleGroup(Composite parent) {
	Group sampleGroup = new Group(parent, SWT.NULL);
	GridData data = new GridData(GridData.FILL_BOTH);
	data.grabExcessHorizontalSpace = true;
	sampleGroup.setLayout(new GridLayout());
	sampleGroup.setLayoutData(data);
	sampleGroup.setText(SWT.getMessage("SWT_Sample"));

	sampleLabel = new Label(sampleGroup, SWT.CENTER \| SWT.BORDER);
	sampleLabel.setAlignment(SWT.CENTER);
	sampleLabel.setText(SWT.getMessage("SWT_A_Sample_Text"));
	data = new GridData(GridData.FILL_HORIZONTAL);
	sampleLabel.setLayoutData(data);

	sampleCanvas = new Canvas(sampleGroup, SWT.BORDER);
	data = new GridData(GridData.FILL_HORIZONTAL);
	data.heightHint = 15;
	sampleCanvas.setLayoutData(data);
	}
	void createSelectionGroup(Composite parent) {
	Group selectionGroup = new Group(parent, SWT.NULL);
	GridData data = new GridData(GridData.FILL_BOTH);
	data.grabExcessHorizontalSpace = true;
	selectionGroup.setLayout(new GridLayout());
	selectionGroup.setLayoutData(data);
	selectionGroup.setText(SWT.getMessage("SWT_Selection"));

	selectionLabel = new Label(selectionGroup, SWT.CENTER \| SWT.BORDER);
	selectionLabel.setAlignment(SWT.CENTER);
	selectionLabel.setText(SWT.getMessage("SWT_Current_Selection"));
	data = new GridData(GridData.FILL_HORIZONTAL);
	data.grabExcessHorizontalSpace = true;
	selectionLabel.setLayoutData(data);

	selectionCanvas = new Canvas(selectionGroup, SWT.BORDER);
	data = new GridData(GridData.FILL_HORIZONTAL);
	data.grabExcessHorizontalSpace = true;
	data.heightHint = 15;
	selectionCanvas.setLayoutData(data);
	}
	void disposeColors() {
	for (int row = 0; row < colorGrid.length; row++) {
	for (int column = 0; column < colorGrid[row].length; column++) {
	colorGrid[row][column].dispose();
	}
	}
	}
	void drawColor(int xIndex, int yIndex, Color color, GC gc) {
	int colorExtent = colorSwatchExtent - COLORSWATCH_BORDER;
	gc.setBackground(color);
	gc.fillRectangle(
	xIndex * colorSwatchExtent,
	yIndex * colorSwatchExtent,
	colorExtent, colorExtent);
	}
	/**
	* Returns the currently selected color in the receiver.
	*
	* @return the RGB value for the selected color, may be null
	*
	* @see PaletteData#getRGBs
	*/
	public RGB getRGB() {
	return rgb;
	}
	void handleEvents(Event event) {
	if (event.type == SWT.Paint) {
	paint(event);
	}
	else
	if (event.type == SWT.MouseDown) {
	mouseDown(event);
	}
	else
	if (event.type == SWT.MouseMove) {
	mouseMove(event);
	}
	else
	if (event.type == SWT.Selection) {
	if (event.widget == okButton) {
	okSelected = true;
	shell.setVisible(false);
	}
	else
	if (event.widget == cancelButton) {
	okSelected = false;
	shell.setVisible(false);
	}
	}
	}
	void initialize4BitColors() {
	Display display = shell.display;

	colorGrid[0][0] = new Color(display, 0, 0, 0);
	colorGrid[0][1] = new Color(display, 255, 255, 255);
	colorGrid[1][0] = new Color(display, 128, 128, 128);
	colorGrid[1][1] = new Color(display, 192, 192, 192);

	colorGrid[2][0] = new Color(display, 0, 0, 128);
	colorGrid[2][1] = new Color(display, 0, 0, 255);
	colorGrid[3][0] = new Color(display, 0, 128, 128);
	colorGrid[3][1] = new Color(display, 0, 255, 255);

	colorGrid[4][0] = new Color(display, 0, 128, 0);
	colorGrid[4][1] = new Color(display, 0, 255, 0);
	colorGrid[5][0] = new Color(display, 128, 128, 0);
	colorGrid[5][1] = new Color(display, 255, 255, 0);

	colorGrid[6][0] = new Color(display, 128, 0, 0);
	colorGrid[6][1] = new Color(display, 255, 0, 0);
	colorGrid[7][0] = new Color(display, 128, 0, 128);
	colorGrid[7][1] = new Color(display, 255, 0, 255);
	}
	void initialize8BitColors() {
	Display display = shell.display;
	int numRows = colorGrid[0].length;
	int iterationStep = 64;
	int row = 0, column = 0;
	int red, green, blue;
	// run the loops from 0 to 256 inclusive since this is easiest for the step
	// size, then adjust the 256 case to the proper 255 value when needed
	for (red = 0; red <= 256; red += iterationStep) {
	for (blue = 0; blue <= 256; blue += iterationStep) {
	for (green = 0; green <= 256; green += iterationStep) {
	if (row == numRows) {
	row = 0;
	column++;
	}
	if (red == 256) red = 255;
	if (blue == 256) blue = 255;
	if (green == 256) green = 255;
	colorGrid[column][row++] = new Color(display, red, green, blue);
	}
	}
	}
	}
	void initialize16BitColors() {
	Display display = shell.display;
	int numRows = colorGrid[0].length;
	int iterationStep = 51;
	int row = 0, column = 0;
	int red, green, blue;

	for (red = 0; red <= 255; red += iterationStep) {
	for (blue = 0; blue <= 255; blue += iterationStep) {
	if (blue == iterationStep && column < 20) { // hack to evenly distribute 256 colors on 32 columns
	blue += iterationStep;
	}
	for (green = 0; green <= 255; green += iterationStep) {
	if (row == 2 \|\| row == 5) { // hack to evenly distribute 256 colors on 8 rows
	colorGrid[column][row++] = new Color(display, red, green - iterationStep / 2, blue);
	}
	if (row == numRows) {
	row = 0;
	column++;
	}
	colorGrid[column][row++] = new Color(display, red, green, blue);
	}
	}
	}
	}
	void initializeWidgets() {
	Display display = shell.display;
	if (rgb != null) {
	Color selectionColor = new Color(display, rgb);
	selectionCanvas.setBackground(selectionColor);
	selectionLabel.setBackground(selectionColor);
	selectionColor.dispose();
	}
	}
	void installListeners() {
	Listener listener = new Listener() {
	public void handleEvent(Event event) {handleEvents(event);}
	};
	okButton.addListener(SWT.Selection, listener);
	cancelButton.addListener(SWT.Selection, listener);
	colorsCanvas.addListener(SWT.Paint, listener);
	colorsCanvas.addListener(SWT.MouseDown, listener);
	colorsCanvas.addListener(SWT.MouseMove, listener);
	}
	void mouseDown(Event event) {
	int swatchExtent = colorSwatchExtent;
	Color color = colorGrid[event.x / swatchExtent][event.y / swatchExtent];
	selectionCanvas.setBackground(color);
	selectionLabel.setBackground(color);
	}
	void mouseMove(Event event) {
	int swatchExtent = colorSwatchExtent;
	// adjust for events received from moving over the Canvas' border
	if (!(0 <= event.x && event.x <= colorChooserWidth)) return;
	if (!(0 <= event.y && event.y <= colorChooserHeight)) return;
	int xgrid = Math.min(colorGrid.length - 1, event.x / swatchExtent);
	int ygrid = Math.min(colorGrid[0].length - 1, event.y / swatchExtent);
	Color color = colorGrid[xgrid][ygrid];
	sampleCanvas.setBackground(color);
	sampleLabel.setBackground(color);
	}
	/**
	* Makes the receiver visible and brings it to the front
	* of the display.
	*
	* @return the selected color, or null if the dialog was
	* cancelled, no color was selected, or an error
	* occurred
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
	* </ul>
	*/
	public RGB open() {
	shell = new Shell(parent, getStyle() \| SWT.TITLE \| SWT.BORDER \| SWT.APPLICATION_MODAL);
	Display display = shell.display;
	setColorDepth(display.getDepth());
	createChildren();
	installListeners();
	openModal();
	if (okSelected) {
	Color selectionColor = selectionCanvas.getBackground();
	rgb = new RGB(
	selectionColor.getRed(),
	selectionColor.getGreen(),
	selectionColor.getBlue());
	}
	disposeColors();
	if (shell.isDisposed() == false) {
	shell.dispose();
	}
	if (!okSelected) return null;
	return rgb;
	}
	/**
	* Open the receiver and set its size to the size calculated by
	* the layout manager.
	*/
	void openDialog() {
	Shell dialog = shell;

	// Start everything off by setting the shell size to its computed size.
	Point pt = dialog.computeSize(-1, -1, false);

	// Ensure that the width of the shell fits the display.
	Display display = dialog.display;
	Rectangle displayRect = display.getBounds();
	int widthLimit = displayRect.width * 7 / 8;
	int heightLimit = displayRect.height * 7 / 8;
	if (pt.x > widthLimit) {
	pt = dialog.computeSize (widthLimit, -1, false);
	}

	// centre the dialog on its parent, and ensure that the
	// whole dialog appears within the screen bounds
	Rectangle parentBounds = getParent ().getBounds ();
	int originX = (parentBounds.width - pt.x) / 2 + parentBounds.x;
	originX = Math.max (originX, 0);
	originX = Math.min (originX, widthLimit - pt.x);
	int originY = (parentBounds.height - pt.y) / 2 + parentBounds.y;
	originY = Math.max (originY, 0);
	originY = Math.min (originY, heightLimit - pt.y);
	dialog.setBounds (originX, originY, pt.x, pt.y);

	String title = getText ();
	if (title.length () == 0) title = SWT.getMessage ("SWT_ColorDialog_Title");
	shell.setText(title);

	dialog.open();
	}
	void openModal() {
	Display display = shell.display;
	initializeWidgets();
	openDialog();
	while (shell.isDisposed() == false && shell.getVisible() == true) {
	if (display.readAndDispatch() == false) {
	display.sleep();
	}
	}
	}
	void paint(Event event) {
	for (int column = 0; column < colorGrid.length; column++) {
	for (int row = 0; row < colorGrid[0].length; row++) {
	drawColor(column, row, colorGrid[column][row], event.gc);
	}
	}
	}
	void setColorDepth(int bits) {
	colorDepth = bits;
	if (bits == 4) {
	colorSwatchExtent = COLORSWATCH_SIZE_DEPTH4;
	colorGrid = new Color[8][2];
	initialize4BitColors();
	return;
	}
	if (bits == 8) {
	colorSwatchExtent = COLORSWATCH_SIZE_DEPTH8;
	colorGrid = new Color[25][5];
	initialize8BitColors();
	return;
	}
	// default case: 16, 24 or 32 bits
	colorSwatchExtent = COLORSWATCH_SIZE_DEPTH16;
	colorGrid = new Color[32][8];
	initialize16BitColors();
	}
	/**
	* Sets the receiver's selected color to be the argument.
	*
	* @param rgb the new RGB value for the selected color, may be
	* null to let the platform select a default when
	* open() is called
	* @see PaletteData#getRGBs
	*/
	public void setRGB(RGB rgb) {
	this.rgb = rgb;
	}
	}