examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/controlexample/Tab.java - platform/eclipse.platform.swt - Git at Google

 package org.eclipse.swt.examples.controlexample;

 /*
  * (c) Copyright IBM Corp. 2000, 2001.
  * All Rights Reserved
  */

 import org.eclipse.swt.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.widgets.*;
 import org.eclipse.swt.layout.*;
 import org.eclipse.swt.events.*;
 import java.util.ResourceBundle;

 /**
  * <code>Tab</code> is the abstract superclass of every page
  * in the example's tab folder.  Each page in the tab folder
  * describes a control.
  *
  * A Tab itself is not a control but instead provides a
  * hierarchy with which to share code that is common to
  * every page in the folder.
  *
  * A typical page in a Tab contains a two column composite.
  * The left column contains the "Example" group.  The right
  * column contains "Control" group.  The "Control" group
  * contains controls that allow the user to interact with
  * the example control.  The "Control" group typically
  * contains a "Style", "Display" and "Size" group.  Subclasses
  * can override these defaults to augment a group or stop
  * a group from being created.
  */
 abstract class Tab {
 	/* Common control buttons */
 	Button borderButton, enabledButton, visibleButton;
 	Button preferredButton, tooSmallButton, smallButton, largeButton, fillButton;

 	/* Common groups and composites */
 	Composite tabFolderPage;
 	Group exampleGroup, controlGroup, displayGroup, sizeGroup, styleGroup, colorGroup;

 	/* Controlling instance */
 	final ControlExample instance;

 	/* Sizing constants for the "Size" group */
 	static final int TOO_SMALL_SIZE	= 10;
 	static final int SMALL_SIZE		= 50;
 	static final int LARGE_SIZE		= 100;

 	/* Common controls for the "Colors" group */
 	Button backgroundButton, foregroundButton, fontButton;
 	Color backgroundColor, foregroundColor;
 	Font font;

 	/**
 	 * Creates the Tab within a given instance of ControlExample.
 	 */
 	Tab(ControlExample instance) {
 		this.instance = instance;
 	}

 	/**
 	 * Creates the "Control" group.  The "Control" group
 	 * is typically the right hand column in the tab.
 	 */
 	void createControlGroup () {

 		/*
 		 * Create the "Control" group.  This is the group on the
 		 * left half of each example tab.  It consists of the
 		 * style group, the display group and the size group.
 		 */
 		controlGroup = new Group (tabFolderPage, SWT.NONE);
 		GridLayout gridLayout= new GridLayout ();
 		controlGroup.setLayout (gridLayout);
 		gridLayout.numColumns = 2;
 		gridLayout.makeColumnsEqualWidth = true;
 		controlGroup.setLayoutData (new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
 		controlGroup.setText (ControlExample.getResourceString("Parameters"));

 		/* Create individual groups inside the "Control" group */
 		createStyleGroup ();
 		createDisplayGroup ();
 		createSizeGroup ();
 		createColorGroup ();

 		/*
 		 * For each Button child in the style group, add a selection
 		 * listener that will recreate the example controls.  If the
 		 * style group button is a RADIO button, ensure that the radio
 		 * button is selected before recreating the example controls.
 		 * When the user selects a RADIO button, the curreont RADIO
 		 * button in the group is deselected and the new RADIO button
 		 * is selected automatically.  The listeners are notified for
 		 * both these operations but typically only do work when a RADIO
 		 * button is selected.
 		 */
 		SelectionListener selectionListener = new SelectionAdapter () {
 			public void widgetSelected (SelectionEvent event) {
 				if ((event.widget.getStyle () & SWT.RADIO) != 0) {
 					if (!((Button) event.widget).getSelection ()) return;
 				}
 				recreateExampleWidgets ();
 			};
 		};
 		Control [] children = styleGroup.getChildren ();
 		for (int i=0; i<children.length; i++) {
 			if (children [i] instanceof Button) {
 				Button button = (Button) children [i];
 				button.addSelectionListener (selectionListener);
 			}
 		}
 	}

 	/**
 	 * Creates the "Control" widget children.
 	 * Subclasses override this method to augment
 	 * the standard controls created in the "Style",
 	 * "Display" and "Size" groups.
 	 */
 	void createControlWidgets () {
 	}

 	/**
 	 * Creates the "Color" group. This is typically
 	 * a child of the "Control" group. Subclasses override
 	 * this method to customize and set system colors.
 	 */
 	void createColorGroup () {
 		/* Create the group */
 		colorGroup = new Group(controlGroup, SWT.NULL);
 		colorGroup.setLayout (new GridLayout (2, false));
 		colorGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
 		colorGroup.setText (ControlExample.getResourceString ("Colors"));
 		new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Foreground_Color"));
 		foregroundButton = new Button (colorGroup, SWT.PUSH);
 		new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Background_Color"));
 		backgroundButton = new Button (colorGroup, SWT.PUSH);
 		fontButton = new Button (colorGroup, SWT.PUSH);
 		fontButton.setText(ControlExample.getResourceString("Font"));

 		Shell shell = backgroundButton.getShell ();
 		final ColorDialog backgroundDialog = new ColorDialog (shell);
 		final ColorDialog foregroundDialog = new ColorDialog (shell);
 		final FontDialog fontDialog = new FontDialog (shell);

 		/* Create images to display current colors */
 		int imageSize = 12;
 		Display display = shell.getDisplay ();
 		final Image backgroundImage = new Image (display, imageSize, imageSize);
 		final Image foregroundImage = new Image (display, imageSize, imageSize);

 		/* Add listeners to set the colors and font */
 		backgroundButton.setImage(backgroundImage);
 		backgroundButton.addSelectionListener(new SelectionAdapter() {
 			public void widgetSelected(SelectionEvent event) {
 				RGB rgb = backgroundDialog.open();
 				if (rgb == null) return;
 				Color oldColor = backgroundColor;
 				backgroundColor = new Color (backgroundButton.getDisplay(), rgb);
 				setExampleWidgetBackground ();
 				if (oldColor != null) oldColor.dispose ();
 			}
 		});
 		foregroundButton.setImage(foregroundImage);
 		foregroundButton.addSelectionListener(new SelectionAdapter() {
 			public void widgetSelected(SelectionEvent event) {
 				RGB rgb = foregroundDialog.open();
 				if (rgb == null) return;
 				Color oldColor = foregroundColor;
 				foregroundColor = new Color (foregroundButton.getDisplay(), rgb);
 				setExampleWidgetForeground ();
 				if (oldColor != null) oldColor.dispose ();
 			}
 		});
 		fontButton.addSelectionListener(new SelectionAdapter () {
 			public void widgetSelected (SelectionEvent e) {
 				FontData fontData = fontDialog.open ();
 				if (fontData == null) return;
 				Font oldFont = font;
 				font = new Font (fontButton.getDisplay(), fontData);
 				setExampleWidgetFont ();
 				if (oldFont != null) oldFont.dispose ();
 			}
 		});
 		backgroundButton.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent event) {
 				if (backgroundImage != null) backgroundImage.dispose();
 				if (foregroundImage != null) foregroundImage.dispose();
 				if (backgroundColor != null) backgroundColor.dispose();
 				if (foregroundColor != null) foregroundColor.dispose();
 				if (font != null) font.dispose();
 				backgroundColor = null;
 				foregroundColor = null;
 				font = null;
 			}
 		});
 	}

 	/**
 	 * Creates the "Display" group.  This is typically
 	 * a child of the "Control" group.
 	 */
 	void createDisplayGroup () {
 		/* Create the group */
 		displayGroup = new Group (controlGroup, SWT.NONE);
 		displayGroup.setLayout (new GridLayout ());
 		displayGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
 		displayGroup.setText (ControlExample.getResourceString("State"));

 		/* Create the controls */
 		enabledButton = new Button(displayGroup, SWT.CHECK);
 		enabledButton.setText(ControlExample.getResourceString("Enabled"));
 		visibleButton = new Button(displayGroup, SWT.CHECK);
 		visibleButton.setText(ControlExample.getResourceString("Visible"));

 		/* Add the listeners */
 		enabledButton.addSelectionListener (new SelectionAdapter () {
 			public void widgetSelected (SelectionEvent event) {
 				setExampleWidgetEnabled ();
 			}
 		});
 		visibleButton.addSelectionListener (new SelectionAdapter () {
 			public void widgetSelected (SelectionEvent event) {
 				setExampleWidgetVisibility ();
 			}
 		});

 		/* Set the default state */
 		enabledButton.setSelection(true);
 		visibleButton.setSelection(true);
 	}

 	/**
 	 * Creates the "Example" group.  The "Example" group
 	 * is typically the left hand column in the tab.
 	 */
 	void createExampleGroup () {
 		exampleGroup = new Group (tabFolderPage, SWT.NONE);
 		GridLayout gridLayout = new GridLayout ();
 		exampleGroup.setLayout (gridLayout);
 		exampleGroup.setLayoutData (new GridData (GridData.FILL_BOTH));
 	}

 	/**
 	 * Creates the "Example" widget children of the "Example" group.
 	 * Subclasses override this method to create the particular
 	 * example control.
 	 */
 	void createExampleWidgets () {
 		/* Do nothing */
 	}

 	/**
 	 * Creates the "Size" group.  The "Size" group contains
 	 * controls that allow the user to change the size of
 	 * the example widgets.
 	 */
 	void createSizeGroup () {
 		/* Create the group */
 		sizeGroup = new Group (controlGroup, SWT.NONE);
 		sizeGroup.setLayout (new GridLayout());
 		sizeGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
 		sizeGroup.setText (ControlExample.getResourceString("Size"));

 		/* Create the controls */

 		/*
 		 * The preferred size of a widget is the size returned
 		 * by widget.computeSize (SWT.DEFAULT, SWT.DEFAULT).
 		 * This size is defined on a widget by widget basis.
 		 * Many widgets will attempt to display their contents.
 		 */
 		preferredButton = new Button (sizeGroup, SWT.RADIO);
 		preferredButton.setText (ControlExample.getResourceString("Preferred"));
 		tooSmallButton = new Button (sizeGroup, SWT.RADIO);
 		tooSmallButton.setText (TOO_SMALL_SIZE + " X " + TOO_SMALL_SIZE);
 		smallButton = new Button(sizeGroup, SWT.RADIO);
 		smallButton.setText (SMALL_SIZE + " X " + SMALL_SIZE);
 		largeButton = new Button (sizeGroup, SWT.RADIO);
 		largeButton.setText (LARGE_SIZE + " X " + LARGE_SIZE);
 		fillButton = new Button (sizeGroup, SWT.RADIO);
 		fillButton.setText (ControlExample.getResourceString("Fill"));

 		/* Add the listeners */
 		SelectionAdapter selectionListener = new SelectionAdapter () {
 			public void widgetSelected (SelectionEvent event) {
 				if (!((Button) event.widget).getSelection ()) return;
 				setExampleWidgetSize ();
 			};
 		};
 		preferredButton.addSelectionListener(selectionListener);
 		tooSmallButton.addSelectionListener(selectionListener);
 		smallButton.addSelectionListener(selectionListener);
 		largeButton.addSelectionListener(selectionListener);
 		fillButton.addSelectionListener(selectionListener);

 		/* Set the default state */
 		preferredButton.setSelection (true);
 	}

 	/**
 	 * Creates the "Style" group.  The "Style" group contains
 	 * controls that allow the user to change the style of
 	 * the example widgets.  Changing a widget "Style" causes
 	 * the widget to be destroyed and recreated.
 	 */
 	void createStyleGroup () {
 		styleGroup = new Group (controlGroup, SWT.NONE);
 		styleGroup.setLayout (new GridLayout ());
 		styleGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
 		styleGroup.setText (ControlExample.getResourceString("Styles"));
 	}

 	/**
 	 * Creates the tab folder page.
 	 *
 	 * @param tabFolder org.eclipse.swt.widgets.TabFolder
 	 * @return the new page for the tab folder
 	 */
 	Composite createTabFolderPage (TabFolder tabFolder) {
 		/*
 		* Create a two column page.
 		*/
 		tabFolderPage = new Composite (tabFolder, SWT.NULL);
 		GridLayout gridLayout = new GridLayout ();
 		tabFolderPage.setLayout (gridLayout);
 		gridLayout.numColumns = 2;

 		/* Create the "Example" and "Control" columns */
 		createExampleGroup ();
 		createControlGroup ();

 		/* Create the widgets in the two columns */
 		createExampleWidgets ();
 		createControlWidgets ();
 		setExampleWidgetState ();

 		return tabFolderPage;
 	}

 	/**
 	 * Disposes the "Example" widgets.
 	 */
 	void disposeExampleWidgets () {
 		Control [] controls = getExampleWidgets ();
 		for (int i=0; i<controls.length; i++) {
 			controls [i].dispose ();
 		}
 	}

 	void drawImage (Image image, Color color) {
 		GC gc = new GC(image);
 		gc.setBackground(color);
 		Rectangle bounds = image.getBounds();
 		gc.fillRectangle(0, 0, bounds.width, bounds.height);
 		gc.drawRectangle(0, 0, bounds.width - 1, bounds.height - 1);
 		gc.dispose();
 	}

 	/**
 	 * Gets the "Example" widget children.
 	 *
 	 * @return an array of example widget children
 	 */
 	Control [] getExampleWidgets () {
 		return new Control [0];
 	}

 	/**
 	 * Gets the text for the tab folder item.
 	 *
 	 * @return the text for the tab item
 	 */
 	String getTabText () {
 		return "";
 	}

 	/**
 	 * Recreates the "Example" widgets.
 	 */
 	void recreateExampleWidgets () {
 		disposeExampleWidgets ();
 		createExampleWidgets ();
 		setExampleWidgetState ();
 	}

 	/**
 	 * Sets the background color of the "Example" widgets.
 	 */
 	void setExampleWidgetBackground () {
 		if (backgroundButton == null) return;
 		Control [] controls = getExampleWidgets ();
 		Color color = backgroundColor;
 		if (color == null) color = controls [0].getBackground ();
 		Image image = backgroundButton.getImage ();
 		drawImage (image, color);
 		backgroundButton.setImage (image);
 		if (backgroundColor == null) return;
 		for (int i = 0; i < controls.length; i++) {
 			Control control = controls[i];
 			control.setBackground (backgroundColor);
 		}
 	}

 	/**
 	 * Sets the enabled state of the "Example" widgets.
 	 */
 	void setExampleWidgetEnabled () {
 		Control [] controls = getExampleWidgets ();
 		for (int i=0; i<controls.length; i++) {
 			controls [i].setEnabled (enabledButton.getSelection ());
 		}
 	}

 	/**
 	 * Sets the font of the "Example" widgets.
 	 */
 	void setExampleWidgetFont () {
 		if (font == null) return;
 		Control [] controls = getExampleWidgets ();
 		for (int i = 0; i < controls.length; i++) {
 			Control control = controls[i];
 			control.setFont(font);
 		}
 	}

 	/**
 	 * Sets the foreground color of the "Example" widgets.
 	 */
 	void setExampleWidgetForeground () {
 		if (foregroundButton == null) return;
 		Control [] controls = getExampleWidgets ();
 		Color color = foregroundColor;
 		if (color == null) color = controls [0].getForeground ();
 		Image image = foregroundButton.getImage ();
 		drawImage (image, color);
 		foregroundButton.setImage (image);
 		if (foregroundColor == null) return;
 		for (int i = 0; i < controls.length; i++) {
 			Control control = controls[i];
 			control.setForeground (foregroundColor);
 		}
 	}

 	/**
 	 * Sets the size of the "Example" widgets.
 	 */
 	void setExampleWidgetSize () {
 		int size = SWT.DEFAULT;
 		if (preferredButton == null) return;
 		if (preferredButton.getSelection()) size = SWT.DEFAULT;
 		if (tooSmallButton.getSelection()) size = TOO_SMALL_SIZE;
 		if (smallButton.getSelection()) size = SMALL_SIZE;
 		if (largeButton.getSelection()) size = LARGE_SIZE;
 		Control [] controls = getExampleWidgets ();
 		for (int i=0; i<controls.length; i++) {
 			GridData gridData;
 			if (fillButton.getSelection()) {
 				gridData = new GridData (GridData.FILL_BOTH);
 			} else {
 				gridData = new GridData ();
 				gridData.widthHint = size;
 				gridData.heightHint = size;
 			}
 			controls [i].setLayoutData (gridData);
 		}
 		/*
 		 * Force the entire widget tree to layout,
 		 * even when the child sizes may not have
 		 * changed.
 		 */
 		int seenCount = 0;
 		Composite [] seen = new Composite [4];
 		for (int i=0; i<controls.length; i++) {
 			Control control = controls [i];
 			while (control != exampleGroup) {
 				Composite parent = control.getParent ();
 				int index = 0;
 				while (index < seenCount) {
 					if (seen [index] == parent) break;
 					index++;
 				}
 				if (index == seenCount) parent.layout ();
 				if (seenCount == seen.length) {
 					Composite [] newSeen = new Composite [seen.length + 4];
 					System.arraycopy (seen, 0, newSeen, 0, seen.length);
 					seen = newSeen;
 				}
 				seen [seenCount++] = parent;
 				control = control.getParent ();
 			}
 		}
 	}

 	/**
 	 * Sets the state of the "Example" widgets.  Subclasses
 	 * reimplement this method to set "Example" widget state
 	 * that is specific to the widget.
 	 */
 	void setExampleWidgetState () {
 		setExampleWidgetEnabled ();
 		setExampleWidgetVisibility ();
 		setExampleWidgetSize ();
 		setExampleWidgetBackground ();
 		setExampleWidgetForeground ();
 		setExampleWidgetFont ();
 	}

 	/**
 	 * Sets the visibility of the "Example" widgets.
 	 */
 	void setExampleWidgetVisibility () {
 		Control [] controls = getExampleWidgets ();
 		for (int i=0; i<controls.length; i++) {
 			controls [i].setVisible (visibleButton.getSelection ());
 		}
 	}
 }
	package org.eclipse.swt.examples.controlexample;

	/*
	* (c) Copyright IBM Corp. 2000, 2001.
	* All Rights Reserved
	*/

	import org.eclipse.swt.*;
	import org.eclipse.swt.graphics.*;
	import org.eclipse.swt.widgets.*;
	import org.eclipse.swt.layout.*;
	import org.eclipse.swt.events.*;
	import java.util.ResourceBundle;

	/**
	* <code>Tab</code> is the abstract superclass of every page
	* in the example's tab folder. Each page in the tab folder
	* describes a control.
	*
	* A Tab itself is not a control but instead provides a
	* hierarchy with which to share code that is common to
	* every page in the folder.
	*
	* A typical page in a Tab contains a two column composite.
	* The left column contains the "Example" group. The right
	* column contains "Control" group. The "Control" group
	* contains controls that allow the user to interact with
	* the example control. The "Control" group typically
	* contains a "Style", "Display" and "Size" group. Subclasses
	* can override these defaults to augment a group or stop
	* a group from being created.
	*/
	abstract class Tab {
	/* Common control buttons */
	Button borderButton, enabledButton, visibleButton;
	Button preferredButton, tooSmallButton, smallButton, largeButton, fillButton;

	/* Common groups and composites */
	Composite tabFolderPage;
	Group exampleGroup, controlGroup, displayGroup, sizeGroup, styleGroup, colorGroup;

	/* Controlling instance */
	final ControlExample instance;

	/* Sizing constants for the "Size" group */
	static final int TOO_SMALL_SIZE = 10;
	static final int SMALL_SIZE = 50;
	static final int LARGE_SIZE = 100;

	/* Common controls for the "Colors" group */
	Button backgroundButton, foregroundButton, fontButton;
	Color backgroundColor, foregroundColor;
	Font font;

	/**
	* Creates the Tab within a given instance of ControlExample.
	*/
	Tab(ControlExample instance) {
	this.instance = instance;
	}

	/**
	* Creates the "Control" group. The "Control" group
	* is typically the right hand column in the tab.
	*/
	void createControlGroup () {

	/*
	* Create the "Control" group. This is the group on the
	* left half of each example tab. It consists of the
	* style group, the display group and the size group.
	*/
	controlGroup = new Group (tabFolderPage, SWT.NONE);
	GridLayout gridLayout= new GridLayout ();
	controlGroup.setLayout (gridLayout);
	gridLayout.numColumns = 2;
	gridLayout.makeColumnsEqualWidth = true;
	controlGroup.setLayoutData (new GridData(GridData.HORIZONTAL_ALIGN_FILL \| GridData.VERTICAL_ALIGN_FILL));
	controlGroup.setText (ControlExample.getResourceString("Parameters"));

	/* Create individual groups inside the "Control" group */
	createStyleGroup ();
	createDisplayGroup ();
	createSizeGroup ();
	createColorGroup ();

	/*
	* For each Button child in the style group, add a selection
	* listener that will recreate the example controls. If the
	* style group button is a RADIO button, ensure that the radio
	* button is selected before recreating the example controls.
	* When the user selects a RADIO button, the curreont RADIO
	* button in the group is deselected and the new RADIO button
	* is selected automatically. The listeners are notified for
	* both these operations but typically only do work when a RADIO
	* button is selected.
	*/
	SelectionListener selectionListener = new SelectionAdapter () {
	public void widgetSelected (SelectionEvent event) {
	if ((event.widget.getStyle () & SWT.RADIO) != 0) {
	if (!((Button) event.widget).getSelection ()) return;
	}
	recreateExampleWidgets ();
	};
	};
	Control [] children = styleGroup.getChildren ();
	for (int i=0; i<children.length; i++) {
	if (children [i] instanceof Button) {
	Button button = (Button) children [i];
	button.addSelectionListener (selectionListener);
	}
	}
	}

	/**
	* Creates the "Control" widget children.
	* Subclasses override this method to augment
	* the standard controls created in the "Style",
	* "Display" and "Size" groups.
	*/
	void createControlWidgets () {
	}

	/**
	* Creates the "Color" group. This is typically
	* a child of the "Control" group. Subclasses override
	* this method to customize and set system colors.
	*/
	void createColorGroup () {
	/* Create the group */
	colorGroup = new Group(controlGroup, SWT.NULL);
	colorGroup.setLayout (new GridLayout (2, false));
	colorGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL \| GridData.VERTICAL_ALIGN_FILL));
	colorGroup.setText (ControlExample.getResourceString ("Colors"));
	new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Foreground_Color"));
	foregroundButton = new Button (colorGroup, SWT.PUSH);
	new Label (colorGroup, SWT.NONE).setText (ControlExample.getResourceString ("Background_Color"));
	backgroundButton = new Button (colorGroup, SWT.PUSH);
	fontButton = new Button (colorGroup, SWT.PUSH);
	fontButton.setText(ControlExample.getResourceString("Font"));

	Shell shell = backgroundButton.getShell ();
	final ColorDialog backgroundDialog = new ColorDialog (shell);
	final ColorDialog foregroundDialog = new ColorDialog (shell);
	final FontDialog fontDialog = new FontDialog (shell);

	/* Create images to display current colors */
	int imageSize = 12;
	Display display = shell.getDisplay ();
	final Image backgroundImage = new Image (display, imageSize, imageSize);
	final Image foregroundImage = new Image (display, imageSize, imageSize);

	/* Add listeners to set the colors and font */
	backgroundButton.setImage(backgroundImage);
	backgroundButton.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent event) {
	RGB rgb = backgroundDialog.open();
	if (rgb == null) return;
	Color oldColor = backgroundColor;
	backgroundColor = new Color (backgroundButton.getDisplay(), rgb);
	setExampleWidgetBackground ();
	if (oldColor != null) oldColor.dispose ();
	}
	});
	foregroundButton.setImage(foregroundImage);
	foregroundButton.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent event) {
	RGB rgb = foregroundDialog.open();
	if (rgb == null) return;
	Color oldColor = foregroundColor;
	foregroundColor = new Color (foregroundButton.getDisplay(), rgb);
	setExampleWidgetForeground ();
	if (oldColor != null) oldColor.dispose ();
	}
	});
	fontButton.addSelectionListener(new SelectionAdapter () {
	public void widgetSelected (SelectionEvent e) {
	FontData fontData = fontDialog.open ();
	if (fontData == null) return;
	Font oldFont = font;
	font = new Font (fontButton.getDisplay(), fontData);
	setExampleWidgetFont ();
	if (oldFont != null) oldFont.dispose ();
	}
	});
	backgroundButton.addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent event) {
	if (backgroundImage != null) backgroundImage.dispose();
	if (foregroundImage != null) foregroundImage.dispose();
	if (backgroundColor != null) backgroundColor.dispose();
	if (foregroundColor != null) foregroundColor.dispose();
	if (font != null) font.dispose();
	backgroundColor = null;
	foregroundColor = null;
	font = null;
	}
	});
	}

	/**
	* Creates the "Display" group. This is typically
	* a child of the "Control" group.
	*/
	void createDisplayGroup () {
	/* Create the group */
	displayGroup = new Group (controlGroup, SWT.NONE);
	displayGroup.setLayout (new GridLayout ());
	displayGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL \| GridData.VERTICAL_ALIGN_FILL));
	displayGroup.setText (ControlExample.getResourceString("State"));

	/* Create the controls */
	enabledButton = new Button(displayGroup, SWT.CHECK);
	enabledButton.setText(ControlExample.getResourceString("Enabled"));
	visibleButton = new Button(displayGroup, SWT.CHECK);
	visibleButton.setText(ControlExample.getResourceString("Visible"));

	/* Add the listeners */
	enabledButton.addSelectionListener (new SelectionAdapter () {
	public void widgetSelected (SelectionEvent event) {
	setExampleWidgetEnabled ();
	}
	});
	visibleButton.addSelectionListener (new SelectionAdapter () {
	public void widgetSelected (SelectionEvent event) {
	setExampleWidgetVisibility ();
	}
	});

	/* Set the default state */
	enabledButton.setSelection(true);
	visibleButton.setSelection(true);
	}

	/**
	* Creates the "Example" group. The "Example" group
	* is typically the left hand column in the tab.
	*/
	void createExampleGroup () {
	exampleGroup = new Group (tabFolderPage, SWT.NONE);
	GridLayout gridLayout = new GridLayout ();
	exampleGroup.setLayout (gridLayout);
	exampleGroup.setLayoutData (new GridData (GridData.FILL_BOTH));
	}

	/**
	* Creates the "Example" widget children of the "Example" group.
	* Subclasses override this method to create the particular
	* example control.
	*/
	void createExampleWidgets () {
	/* Do nothing */
	}

	/**
	* Creates the "Size" group. The "Size" group contains
	* controls that allow the user to change the size of
	* the example widgets.
	*/
	void createSizeGroup () {
	/* Create the group */
	sizeGroup = new Group (controlGroup, SWT.NONE);
	sizeGroup.setLayout (new GridLayout());
	sizeGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL \| GridData.VERTICAL_ALIGN_FILL));
	sizeGroup.setText (ControlExample.getResourceString("Size"));

	/* Create the controls */

	/*
	* The preferred size of a widget is the size returned
	* by widget.computeSize (SWT.DEFAULT, SWT.DEFAULT).
	* This size is defined on a widget by widget basis.
	* Many widgets will attempt to display their contents.
	*/
	preferredButton = new Button (sizeGroup, SWT.RADIO);
	preferredButton.setText (ControlExample.getResourceString("Preferred"));
	tooSmallButton = new Button (sizeGroup, SWT.RADIO);
	tooSmallButton.setText (TOO_SMALL_SIZE + " X " + TOO_SMALL_SIZE);
	smallButton = new Button(sizeGroup, SWT.RADIO);
	smallButton.setText (SMALL_SIZE + " X " + SMALL_SIZE);
	largeButton = new Button (sizeGroup, SWT.RADIO);
	largeButton.setText (LARGE_SIZE + " X " + LARGE_SIZE);
	fillButton = new Button (sizeGroup, SWT.RADIO);
	fillButton.setText (ControlExample.getResourceString("Fill"));

	/* Add the listeners */
	SelectionAdapter selectionListener = new SelectionAdapter () {
	public void widgetSelected (SelectionEvent event) {
	if (!((Button) event.widget).getSelection ()) return;
	setExampleWidgetSize ();
	};
	};
	preferredButton.addSelectionListener(selectionListener);
	tooSmallButton.addSelectionListener(selectionListener);
	smallButton.addSelectionListener(selectionListener);
	largeButton.addSelectionListener(selectionListener);
	fillButton.addSelectionListener(selectionListener);

	/* Set the default state */
	preferredButton.setSelection (true);
	}

	/**
	* Creates the "Style" group. The "Style" group contains
	* controls that allow the user to change the style of
	* the example widgets. Changing a widget "Style" causes
	* the widget to be destroyed and recreated.
	*/
	void createStyleGroup () {
	styleGroup = new Group (controlGroup, SWT.NONE);
	styleGroup.setLayout (new GridLayout ());
	styleGroup.setLayoutData (new GridData (GridData.HORIZONTAL_ALIGN_FILL \| GridData.VERTICAL_ALIGN_FILL));
	styleGroup.setText (ControlExample.getResourceString("Styles"));
	}

	/**
	* Creates the tab folder page.
	*
	* @param tabFolder org.eclipse.swt.widgets.TabFolder
	* @return the new page for the tab folder
	*/
	Composite createTabFolderPage (TabFolder tabFolder) {
	/*
	* Create a two column page.
	*/
	tabFolderPage = new Composite (tabFolder, SWT.NULL);
	GridLayout gridLayout = new GridLayout ();
	tabFolderPage.setLayout (gridLayout);
	gridLayout.numColumns = 2;

	/* Create the "Example" and "Control" columns */
	createExampleGroup ();
	createControlGroup ();

	/* Create the widgets in the two columns */
	createExampleWidgets ();
	createControlWidgets ();
	setExampleWidgetState ();

	return tabFolderPage;
	}

	/**
	* Disposes the "Example" widgets.
	*/
	void disposeExampleWidgets () {
	Control [] controls = getExampleWidgets ();
	for (int i=0; i<controls.length; i++) {
	controls [i].dispose ();
	}
	}

	void drawImage (Image image, Color color) {
	GC gc = new GC(image);
	gc.setBackground(color);
	Rectangle bounds = image.getBounds();
	gc.fillRectangle(0, 0, bounds.width, bounds.height);
	gc.drawRectangle(0, 0, bounds.width - 1, bounds.height - 1);
	gc.dispose();
	}

	/**
	* Gets the "Example" widget children.
	*
	* @return an array of example widget children
	*/
	Control [] getExampleWidgets () {
	return new Control [0];
	}

	/**
	* Gets the text for the tab folder item.
	*
	* @return the text for the tab item
	*/
	String getTabText () {
	return "";
	}

	/**
	* Recreates the "Example" widgets.
	*/
	void recreateExampleWidgets () {
	disposeExampleWidgets ();
	createExampleWidgets ();
	setExampleWidgetState ();
	}

	/**
	* Sets the background color of the "Example" widgets.
	*/
	void setExampleWidgetBackground () {
	if (backgroundButton == null) return;
	Control [] controls = getExampleWidgets ();
	Color color = backgroundColor;
	if (color == null) color = controls [0].getBackground ();
	Image image = backgroundButton.getImage ();
	drawImage (image, color);
	backgroundButton.setImage (image);
	if (backgroundColor == null) return;
	for (int i = 0; i < controls.length; i++) {
	Control control = controls[i];
	control.setBackground (backgroundColor);
	}
	}

	/**
	* Sets the enabled state of the "Example" widgets.
	*/
	void setExampleWidgetEnabled () {
	Control [] controls = getExampleWidgets ();
	for (int i=0; i<controls.length; i++) {
	controls [i].setEnabled (enabledButton.getSelection ());
	}
	}

	/**
	* Sets the font of the "Example" widgets.
	*/
	void setExampleWidgetFont () {
	if (font == null) return;
	Control [] controls = getExampleWidgets ();
	for (int i = 0; i < controls.length; i++) {
	Control control = controls[i];
	control.setFont(font);
	}
	}

	/**
	* Sets the foreground color of the "Example" widgets.
	*/
	void setExampleWidgetForeground () {
	if (foregroundButton == null) return;
	Control [] controls = getExampleWidgets ();
	Color color = foregroundColor;
	if (color == null) color = controls [0].getForeground ();
	Image image = foregroundButton.getImage ();
	drawImage (image, color);
	foregroundButton.setImage (image);
	if (foregroundColor == null) return;
	for (int i = 0; i < controls.length; i++) {
	Control control = controls[i];
	control.setForeground (foregroundColor);
	}
	}

	/**
	* Sets the size of the "Example" widgets.
	*/
	void setExampleWidgetSize () {
	int size = SWT.DEFAULT;
	if (preferredButton == null) return;
	if (preferredButton.getSelection()) size = SWT.DEFAULT;
	if (tooSmallButton.getSelection()) size = TOO_SMALL_SIZE;
	if (smallButton.getSelection()) size = SMALL_SIZE;
	if (largeButton.getSelection()) size = LARGE_SIZE;
	Control [] controls = getExampleWidgets ();
	for (int i=0; i<controls.length; i++) {
	GridData gridData;
	if (fillButton.getSelection()) {
	gridData = new GridData (GridData.FILL_BOTH);
	} else {
	gridData = new GridData ();
	gridData.widthHint = size;
	gridData.heightHint = size;
	}
	controls [i].setLayoutData (gridData);
	}
	/*
	* Force the entire widget tree to layout,
	* even when the child sizes may not have
	* changed.
	*/
	int seenCount = 0;
	Composite [] seen = new Composite [4];
	for (int i=0; i<controls.length; i++) {
	Control control = controls [i];
	while (control != exampleGroup) {
	Composite parent = control.getParent ();
	int index = 0;
	while (index < seenCount) {
	if (seen [index] == parent) break;
	index++;
	}
	if (index == seenCount) parent.layout ();
	if (seenCount == seen.length) {
	Composite [] newSeen = new Composite [seen.length + 4];
	System.arraycopy (seen, 0, newSeen, 0, seen.length);
	seen = newSeen;
	}
	seen [seenCount++] = parent;
	control = control.getParent ();
	}
	}
	}

	/**
	* Sets the state of the "Example" widgets. Subclasses
	* reimplement this method to set "Example" widget state
	* that is specific to the widget.
	*/
	void setExampleWidgetState () {
	setExampleWidgetEnabled ();
	setExampleWidgetVisibility ();
	setExampleWidgetSize ();
	setExampleWidgetBackground ();
	setExampleWidgetForeground ();
	setExampleWidgetFont ();
	}

	/**
	* Sets the visibility of the "Example" widgets.
	*/
	void setExampleWidgetVisibility () {
	Control [] controls = getExampleWidgets ();
	for (int i=0; i<controls.length; i++) {
	controls [i].setVisible (visibleButton.getSelection ());
	}
	}
	}