bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TrayDialog.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2005, 2007 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.jface.dialogs;

 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.window.IShellProvider;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.graphics.Cursor;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Layout;
 import org.eclipse.swt.widgets.Link;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Sash;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.ToolBar;
 import org.eclipse.swt.widgets.ToolItem;

 /**
  * A <code>TrayDialog</code> is a specialized <code>Dialog</code> that can contain
  * a tray on its side. The tray's content is provided as a <code>DialogTray</code>.
  * <p>
  * It is recommended to subclass this class instead of <code>Dialog</code> in all
  * cases except where the dialog should never show a tray. For example, dialogs
  * which are very short, simple, and quick to dismiss (e.g. a message dialog with
  * an OK button) should subclass <code>Dialog</code>.
  * </p>
  * <p>
  * Note: Trays are not supported on dialogs that use a custom layout on the <code>
  * Shell</code> by overriding <code>Window#getLayout()</code>.
  * </p>
  *
  * @see org.eclipse.jface.dialogs.DialogTray
  * @see org.eclipse.jface.window.Window#getLayout()
  * @since 3.2
  */
 public abstract class TrayDialog extends Dialog {

 	private static boolean dialogHelpAvailable;

 	/*
 	 * The dialog's tray (null if none).
 	 */
 	private DialogTray tray;

 	/*
 	 * The tray's control.
 	 */
 	private Control trayControl;

 	/*
 	 * The separator to the left of the sash.
 	 */
 	private Label leftSeparator;

 	/*
 	 * The separator to the right of the sash.
 	 */
 	private Label rightSeparator;

 	/*
 	 * The sash that allows the user to resize the tray.
 	 */
 	private Sash sash;

 	/*
 	 * Whether or not help is available for this dialog.
 	 */
 	private boolean helpAvailable = isDialogHelpAvailable();

 	/**
 	 * Creates a tray dialog instance. Note that the window will have no visual
 	 * representation (no widgets) until it is told to open.
 	 *
 	 * @param shell the parent shell, or <code>null</code> to create a top-level shell
 	 */
 	protected TrayDialog(Shell shell) {
 		super(shell);
 	}

 	/**
 	 * Creates a tray dialog with the given parent.
 	 *
 	 * @param parentShell the object that returns the current parent shell
 	 */
 	protected TrayDialog(IShellProvider parentShell) {
 		super(parentShell);
 	}

 	/**
 	 * Closes this dialog's tray, disposing its widgets.
 	 *
 	 * @throws IllegalStateException if the tray was not open
 	 */
 	public void closeTray() throws IllegalStateException {
 		if (getTray() == null) {
 			throw new IllegalStateException("Tray was not open"); //$NON-NLS-1$
 		}
 		int trayWidth = trayControl.getSize().x + leftSeparator.getSize().x + sash.getSize().x + rightSeparator.getSize().x;
 		trayControl.dispose();
 		trayControl = null;
 		tray = null;
 		leftSeparator.dispose();
 		leftSeparator = null;
 		rightSeparator.dispose();
 		rightSeparator = null;
 		sash.dispose();
 		sash = null;
 		Shell shell = getShell();
 		Rectangle bounds = shell.getBounds();
 		shell.setBounds(bounds.x + ((getDefaultOrientation() == SWT.RIGHT_TO_LEFT) ? trayWidth : 0), bounds.y, bounds.width - trayWidth, bounds.height);
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.jface.dialogs.Dialog#close()
 	 */
 	public boolean close() {
 		/*
 		 * Close the tray to ensure that those dialogs that remember their
 		 * size do not store the tray size.
 		 */
 		if (getTray() != null) {
 			closeTray();
 		}
 		return super.close();
 	}

     /* (non-Javadoc)
      * @see org.eclipse.jface.dialogs.Dialog#createButtonBar(org.eclipse.swt.widgets.Composite)
      */
 	protected Control createButtonBar(Composite parent) {
     	Composite composite = new Composite(parent, SWT.NONE);
     	GridLayout layout = new GridLayout();
     	layout.marginWidth = 0;
     	layout.marginHeight = 0;
     	layout.horizontalSpacing = 0;
     	composite.setLayout(layout);
     	composite.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false));
     	composite.setFont(parent.getFont());

 		// create help control if needed
         if (isHelpAvailable()) {
         	Control helpControl = createHelpControl(composite);
         	((GridData) helpControl.getLayoutData()).horizontalIndent = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN);
 		}
         Control buttonSection = super.createButtonBar(composite);
         ((GridData) buttonSection.getLayoutData()).grabExcessHorizontalSpace = true;
         return composite;
 	}

 	/**
 	 * Creates a new help control that provides access to context help.
 	 * <p>
 	 * The <code>TrayDialog</code> implementation of this method creates
 	 * the control, registers it for selection events including selection,
 	 * Note that the parent's layout is assumed to be a <code>GridLayout</code>
 	 * and the number of columns in this layout is incremented. Subclasses may
 	 * override.
 	 * </p>
 	 *
 	 * @param parent the parent composite
 	 * @return the help control
 	 */
     protected Control createHelpControl(Composite parent) {
 		Image helpImage = JFaceResources.getImage(DLG_IMG_HELP);
 		if (helpImage != null) {
 			return createHelpImageButton(parent, helpImage);
 		}
 		return createHelpLink(parent);
     }

     /*
      * Creates a button with a help image. This is only used if there
      * is an image available.
      */
 	private ToolBar createHelpImageButton(Composite parent, Image image) {
         ToolBar toolBar = new ToolBar(parent, SWT.FLAT | SWT.NO_FOCUS);
         ((GridLayout) parent.getLayout()).numColumns++;
 		toolBar.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));
 		final Cursor cursor = new Cursor(parent.getDisplay(), SWT.CURSOR_HAND);
 		toolBar.setCursor(cursor);
 		toolBar.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				cursor.dispose();
 			}
 		});
         ToolItem item = new ToolItem(toolBar, SWT.NONE);
 		item.setImage(image);
 		item.setToolTipText(JFaceResources.getString("helpToolTip")); //$NON-NLS-1$
 		item.addSelectionListener(new SelectionAdapter() {
             public void widgetSelected(SelectionEvent e) {
 				helpPressed();
             }
         });
 		return toolBar;
 	}

 	/*
 	 * Creates a help link. This is used when there is no help image
 	 * available.
 	 */
 	private Link createHelpLink(Composite parent) {
 		Link link = new Link(parent, SWT.WRAP | SWT.NO_FOCUS);
         ((GridLayout) parent.getLayout()).numColumns++;
 		link.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));
 		link.setText("<a>"+IDialogConstants.HELP_LABEL+"</a>"); //$NON-NLS-1$ //$NON-NLS-2$
 		link.setToolTipText(IDialogConstants.HELP_LABEL);
 		link.addSelectionListener(new SelectionAdapter() {
             public void widgetSelected(SelectionEvent e) {
 				helpPressed();
             }
         });
 		return link;
 	}

 	/*
 	 * Returns whether or not the given layout can support the addition of a tray.
 	 */
 	private boolean isCompatibleLayout(Layout layout) {
 		if (layout != null && layout instanceof GridLayout) {
 			GridLayout grid = (GridLayout)layout;
 			return !grid.makeColumnsEqualWidth && (grid.horizontalSpacing == 0) &&
 					(grid.marginWidth == 0) && (grid.marginHeight == 0) &&
 					(grid.numColumns == 5);
 		}
 		return false;
 	}

 	/**
 	 * Returns whether or not context help is available for this dialog. This
 	 * can affect whether or not the dialog will display additional help
 	 * mechanisms such as a help control in the button bar.
 	 *
 	 * @return whether or not context help is available for this dialog
 	 */
 	public boolean isHelpAvailable() {
 		return helpAvailable;
 	}

 	/**
 	 * The tray dialog's default layout is a modified version of the default
 	 * <code>Window</code> layout that can accomodate a tray, however it still
 	 * conforms to the description of the <code>Window</code> default layout.
 	 * <p>
 	 * Note: Trays may not be supported with all custom layouts on the dialog's
 	 * Shell. To avoid problems, use a single outer <code>Composite</code> for
 	 * your dialog area, and set your custom layout on that <code>Composite</code>.
 	 * </p>
 	 *
 	 * @see org.eclipse.jface.window.Window#getLayout()
 	 * @return a newly created layout or <code>null</code> for no layout
 	 */
 	protected Layout getLayout() {
 		GridLayout layout = (GridLayout)super.getLayout();
 		layout.numColumns = 5;
 		layout.horizontalSpacing = 0;
 		return layout;
 	}

 	/**
 	 * Returns the tray currently shown in the dialog, or <code>null</code>
 	 * if there is no tray.
 	 *
 	 * @return the dialog's current tray, or <code>null</code> if there is none
 	 */
 	public DialogTray getTray() {
 		return tray;
 	}

 	/*
 	 * Called when the help control is invoked. This emulates the keyboard
 	 * context help behavior (e.g. F1 on Windows). It traverses the widget
 	 * tree upward until it finds a widget that has a help listener on it,
 	 * then invokes a help event on that widget.
 	 */
 	private void helpPressed() {
     	if (getShell() != null) {
 	    	Control c = getShell().getDisplay().getFocusControl();
 	    	while (c != null) {
 	    		if (c.isListening(SWT.Help)) {
 	    			c.notifyListeners(SWT.Help, new Event());
 	    			break;
 	    		}
 	    		c = c.getParent();
 	    	}
     	}
 	}

 	/**
 	 * Constructs the tray's widgets and displays the tray in this dialog. The
 	 * dialog's size will be adjusted to accomodate the tray.
 	 *
 	 * @param tray the tray to show in this dialog
 	 * @throws IllegalStateException if the dialog already has a tray open
 	 * @throws UnsupportedOperationException if the dialog does not support trays,
 	 *            for example if it uses a custom layout.
 	 */
 	public void openTray(DialogTray tray) throws IllegalStateException, UnsupportedOperationException {
 		if (tray == null) {
 			throw new NullPointerException("Tray was null"); //$NON-NLS-1$
 		}
 		if (getTray() != null) {
 			throw new IllegalStateException("Tray was already open"); //$NON-NLS-1$
 		}
 		if (!isCompatibleLayout(getShell().getLayout())) {
 			throw new UnsupportedOperationException("Trays not supported with custom layouts"); //$NON-NLS-1$
 		}
 		final Shell shell = getShell();
 		leftSeparator = new Label(shell, SWT.SEPARATOR | SWT.VERTICAL);
 		leftSeparator.setLayoutData(new GridData(GridData.FILL_VERTICAL));
 		sash = new Sash(shell, SWT.VERTICAL);
 		sash.setLayoutData(new GridData(GridData.FILL_VERTICAL));
 		rightSeparator = new Label(shell, SWT.SEPARATOR | SWT.VERTICAL);
 		rightSeparator.setLayoutData(new GridData(GridData.FILL_VERTICAL));
 		trayControl = tray.createContents(shell);
 		Rectangle clientArea = shell.getClientArea();
 		final GridData data = new GridData(GridData.FILL_VERTICAL);
 		data.widthHint = trayControl.computeSize(SWT.DEFAULT, clientArea.height).x;
 		trayControl.setLayoutData(data);
 		int trayWidth = leftSeparator.computeSize(SWT.DEFAULT, clientArea.height).x + sash.computeSize(SWT.DEFAULT, clientArea.height).x + rightSeparator.computeSize(SWT.DEFAULT, clientArea.height).x + data.widthHint;
 		Rectangle bounds = shell.getBounds();
 		shell.setBounds(bounds.x - ((getDefaultOrientation() == SWT.RIGHT_TO_LEFT) ? trayWidth : 0), bounds.y, bounds.width + trayWidth, bounds.height);
 		sash.addListener(SWT.Selection, new Listener() {
 			public void handleEvent(Event event) {
 				if (event.detail != SWT.DRAG) {
 					Rectangle clientArea = shell.getClientArea();
 					int newWidth = clientArea.width - event.x - (sash.getSize().x + rightSeparator.getSize().x);
 					if (newWidth != data.widthHint) {
 						data.widthHint = newWidth;
 						shell.layout();
 					}
 				}
 			}
 		});
 		this.tray = tray;
 	}

 	/**
 	 * Sets whether or not context help is available for this dialog. This
 	 * can affect whether or not the dialog will display additional help
 	 * mechanisms such as a help control in the button bar.
 	 *
 	 * @param helpAvailable whether or not context help is available for the dialog
 	 */
 	public void setHelpAvailable(boolean helpAvailable) {
 		this.helpAvailable = helpAvailable;
 	}

 	/**
 	 * Tests if dialogs that have help control should show it
 	 * all the time or only when explicitly requested for
 	 * each dialog instance.
 	 *
 	 * @return <code>true</code> if dialogs that support help
 	 * control should show it by default, <code>false</code> otherwise.
 	 * @since 3.2
 	 */
 	public static boolean isDialogHelpAvailable() {
 		return dialogHelpAvailable;
 	}

 	/**
 	 * Sets whether JFace dialogs that support help control should
 	 * show the control by default. If set to <code>false</code>,
 	 * help control can still be shown on a per-dialog basis.
 	 *
 	 * @param helpAvailable <code>true</code> to show the help
 	 * control, <code>false</code> otherwise.
 	 * @since 3.2
 	 */
 	public static void setDialogHelpAvailable(boolean helpAvailable) {
 		dialogHelpAvailable = helpAvailable;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2005, 2007 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.jface.dialogs;

	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.window.IShellProvider;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.SelectionAdapter;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.graphics.Cursor;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Layout;
	import org.eclipse.swt.widgets.Link;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.Sash;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.ToolBar;
	import org.eclipse.swt.widgets.ToolItem;

	/**
	* A <code>TrayDialog</code> is a specialized <code>Dialog</code> that can contain
	* a tray on its side. The tray's content is provided as a <code>DialogTray</code>.
	* <p>
	* It is recommended to subclass this class instead of <code>Dialog</code> in all
	* cases except where the dialog should never show a tray. For example, dialogs
	* which are very short, simple, and quick to dismiss (e.g. a message dialog with
	* an OK button) should subclass <code>Dialog</code>.
	* </p>
	* <p>
	* Note: Trays are not supported on dialogs that use a custom layout on the <code>
	* Shell</code> by overriding <code>Window#getLayout()</code>.
	* </p>
	*
	* @see org.eclipse.jface.dialogs.DialogTray
	* @see org.eclipse.jface.window.Window#getLayout()
	* @since 3.2
	*/
	public abstract class TrayDialog extends Dialog {

	private static boolean dialogHelpAvailable;

	/*
	* The dialog's tray (null if none).
	*/
	private DialogTray tray;

	/*
	* The tray's control.
	*/
	private Control trayControl;

	/*
	* The separator to the left of the sash.
	*/
	private Label leftSeparator;

	/*
	* The separator to the right of the sash.
	*/
	private Label rightSeparator;

	/*
	* The sash that allows the user to resize the tray.
	*/
	private Sash sash;

	/*
	* Whether or not help is available for this dialog.
	*/
	private boolean helpAvailable = isDialogHelpAvailable();

	/**
	* Creates a tray dialog instance. Note that the window will have no visual
	* representation (no widgets) until it is told to open.
	*
	* @param shell the parent shell, or <code>null</code> to create a top-level shell
	*/
	protected TrayDialog(Shell shell) {
	super(shell);
	}

	/**
	* Creates a tray dialog with the given parent.
	*
	* @param parentShell the object that returns the current parent shell
	*/
	protected TrayDialog(IShellProvider parentShell) {
	super(parentShell);
	}

	/**
	* Closes this dialog's tray, disposing its widgets.
	*
	* @throws IllegalStateException if the tray was not open
	*/
	public void closeTray() throws IllegalStateException {
	if (getTray() == null) {
	throw new IllegalStateException("Tray was not open"); //$NON-NLS-1$
	}
	int trayWidth = trayControl.getSize().x + leftSeparator.getSize().x + sash.getSize().x + rightSeparator.getSize().x;
	trayControl.dispose();
	trayControl = null;
	tray = null;
	leftSeparator.dispose();
	leftSeparator = null;
	rightSeparator.dispose();
	rightSeparator = null;
	sash.dispose();
	sash = null;
	Shell shell = getShell();
	Rectangle bounds = shell.getBounds();
	shell.setBounds(bounds.x + ((getDefaultOrientation() == SWT.RIGHT_TO_LEFT) ? trayWidth : 0), bounds.y, bounds.width - trayWidth, bounds.height);
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.dialogs.Dialog#close()
	*/
	public boolean close() {
	/*
	* Close the tray to ensure that those dialogs that remember their
	* size do not store the tray size.
	*/
	if (getTray() != null) {
	closeTray();
	}
	return super.close();
	}

	/* (non-Javadoc)
	* @see org.eclipse.jface.dialogs.Dialog#createButtonBar(org.eclipse.swt.widgets.Composite)
	*/
	protected Control createButtonBar(Composite parent) {
	Composite composite = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.marginWidth = 0;
	layout.marginHeight = 0;
	layout.horizontalSpacing = 0;
	composite.setLayout(layout);
	composite.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false));
	composite.setFont(parent.getFont());

	// create help control if needed
	if (isHelpAvailable()) {
	Control helpControl = createHelpControl(composite);
	((GridData) helpControl.getLayoutData()).horizontalIndent = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN);
	}
	Control buttonSection = super.createButtonBar(composite);
	((GridData) buttonSection.getLayoutData()).grabExcessHorizontalSpace = true;
	return composite;
	}

	/**
	* Creates a new help control that provides access to context help.
	* <p>
	* The <code>TrayDialog</code> implementation of this method creates
	* the control, registers it for selection events including selection,
	* Note that the parent's layout is assumed to be a <code>GridLayout</code>
	* and the number of columns in this layout is incremented. Subclasses may
	* override.
	* </p>
	*
	* @param parent the parent composite
	* @return the help control
	*/
	protected Control createHelpControl(Composite parent) {
	Image helpImage = JFaceResources.getImage(DLG_IMG_HELP);
	if (helpImage != null) {
	return createHelpImageButton(parent, helpImage);
	}
	return createHelpLink(parent);
	}

	/*
	* Creates a button with a help image. This is only used if there
	* is an image available.
	*/
	private ToolBar createHelpImageButton(Composite parent, Image image) {
	ToolBar toolBar = new ToolBar(parent, SWT.FLAT \| SWT.NO_FOCUS);
	((GridLayout) parent.getLayout()).numColumns++;
	toolBar.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));
	final Cursor cursor = new Cursor(parent.getDisplay(), SWT.CURSOR_HAND);
	toolBar.setCursor(cursor);
	toolBar.addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	cursor.dispose();
	}
	});
	ToolItem item = new ToolItem(toolBar, SWT.NONE);
	item.setImage(image);
	item.setToolTipText(JFaceResources.getString("helpToolTip")); //$NON-NLS-1$
	item.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent e) {
	helpPressed();
	}
	});
	return toolBar;
	}

	/*
	* Creates a help link. This is used when there is no help image
	* available.
	*/
	private Link createHelpLink(Composite parent) {
	Link link = new Link(parent, SWT.WRAP \| SWT.NO_FOCUS);
	((GridLayout) parent.getLayout()).numColumns++;
	link.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));
	link.setText("<a>"+IDialogConstants.HELP_LABEL+"</a>"); //$NON-NLS-1$ //$NON-NLS-2$
	link.setToolTipText(IDialogConstants.HELP_LABEL);
	link.addSelectionListener(new SelectionAdapter() {
	public void widgetSelected(SelectionEvent e) {
	helpPressed();
	}
	});
	return link;
	}

	/*
	* Returns whether or not the given layout can support the addition of a tray.
	*/
	private boolean isCompatibleLayout(Layout layout) {
	if (layout != null && layout instanceof GridLayout) {
	GridLayout grid = (GridLayout)layout;
	return !grid.makeColumnsEqualWidth && (grid.horizontalSpacing == 0) &&
	(grid.marginWidth == 0) && (grid.marginHeight == 0) &&
	(grid.numColumns == 5);
	}
	return false;
	}

	/**
	* Returns whether or not context help is available for this dialog. This
	* can affect whether or not the dialog will display additional help
	* mechanisms such as a help control in the button bar.
	*
	* @return whether or not context help is available for this dialog
	*/
	public boolean isHelpAvailable() {
	return helpAvailable;
	}

	/**
	* The tray dialog's default layout is a modified version of the default
	* <code>Window</code> layout that can accomodate a tray, however it still
	* conforms to the description of the <code>Window</code> default layout.
	* <p>
	* Note: Trays may not be supported with all custom layouts on the dialog's
	* Shell. To avoid problems, use a single outer <code>Composite</code> for
	* your dialog area, and set your custom layout on that <code>Composite</code>.
	* </p>
	*
	* @see org.eclipse.jface.window.Window#getLayout()
	* @return a newly created layout or <code>null</code> for no layout
	*/
	protected Layout getLayout() {
	GridLayout layout = (GridLayout)super.getLayout();
	layout.numColumns = 5;
	layout.horizontalSpacing = 0;
	return layout;
	}

	/**
	* Returns the tray currently shown in the dialog, or <code>null</code>
	* if there is no tray.
	*
	* @return the dialog's current tray, or <code>null</code> if there is none
	*/
	public DialogTray getTray() {
	return tray;
	}

	/*
	* Called when the help control is invoked. This emulates the keyboard
	* context help behavior (e.g. F1 on Windows). It traverses the widget
	* tree upward until it finds a widget that has a help listener on it,
	* then invokes a help event on that widget.
	*/
	private void helpPressed() {
	if (getShell() != null) {
	Control c = getShell().getDisplay().getFocusControl();
	while (c != null) {
	if (c.isListening(SWT.Help)) {
	c.notifyListeners(SWT.Help, new Event());
	break;
	}
	c = c.getParent();
	}
	}
	}

	/**
	* Constructs the tray's widgets and displays the tray in this dialog. The
	* dialog's size will be adjusted to accomodate the tray.
	*
	* @param tray the tray to show in this dialog
	* @throws IllegalStateException if the dialog already has a tray open
	* @throws UnsupportedOperationException if the dialog does not support trays,
	* for example if it uses a custom layout.
	*/
	public void openTray(DialogTray tray) throws IllegalStateException, UnsupportedOperationException {
	if (tray == null) {
	throw new NullPointerException("Tray was null"); //$NON-NLS-1$
	}
	if (getTray() != null) {
	throw new IllegalStateException("Tray was already open"); //$NON-NLS-1$
	}
	if (!isCompatibleLayout(getShell().getLayout())) {
	throw new UnsupportedOperationException("Trays not supported with custom layouts"); //$NON-NLS-1$
	}
	final Shell shell = getShell();
	leftSeparator = new Label(shell, SWT.SEPARATOR \| SWT.VERTICAL);
	leftSeparator.setLayoutData(new GridData(GridData.FILL_VERTICAL));
	sash = new Sash(shell, SWT.VERTICAL);
	sash.setLayoutData(new GridData(GridData.FILL_VERTICAL));
	rightSeparator = new Label(shell, SWT.SEPARATOR \| SWT.VERTICAL);
	rightSeparator.setLayoutData(new GridData(GridData.FILL_VERTICAL));
	trayControl = tray.createContents(shell);
	Rectangle clientArea = shell.getClientArea();
	final GridData data = new GridData(GridData.FILL_VERTICAL);
	data.widthHint = trayControl.computeSize(SWT.DEFAULT, clientArea.height).x;
	trayControl.setLayoutData(data);
	int trayWidth = leftSeparator.computeSize(SWT.DEFAULT, clientArea.height).x + sash.computeSize(SWT.DEFAULT, clientArea.height).x + rightSeparator.computeSize(SWT.DEFAULT, clientArea.height).x + data.widthHint;
	Rectangle bounds = shell.getBounds();
	shell.setBounds(bounds.x - ((getDefaultOrientation() == SWT.RIGHT_TO_LEFT) ? trayWidth : 0), bounds.y, bounds.width + trayWidth, bounds.height);
	sash.addListener(SWT.Selection, new Listener() {
	public void handleEvent(Event event) {
	if (event.detail != SWT.DRAG) {
	Rectangle clientArea = shell.getClientArea();
	int newWidth = clientArea.width - event.x - (sash.getSize().x + rightSeparator.getSize().x);
	if (newWidth != data.widthHint) {
	data.widthHint = newWidth;
	shell.layout();
	}
	}
	}
	});
	this.tray = tray;
	}

	/**
	* Sets whether or not context help is available for this dialog. This
	* can affect whether or not the dialog will display additional help
	* mechanisms such as a help control in the button bar.
	*
	* @param helpAvailable whether or not context help is available for the dialog
	*/
	public void setHelpAvailable(boolean helpAvailable) {
	this.helpAvailable = helpAvailable;
	}

	/**
	* Tests if dialogs that have help control should show it
	* all the time or only when explicitly requested for
	* each dialog instance.
	*
	* @return <code>true</code> if dialogs that support help
	* control should show it by default, <code>false</code> otherwise.
	* @since 3.2
	*/
	public static boolean isDialogHelpAvailable() {
	return dialogHelpAvailable;
	}

	/**
	* Sets whether JFace dialogs that support help control should
	* show the control by default. If set to <code>false</code>,
	* help control can still be shown on a per-dialog basis.
	*
	* @param helpAvailable <code>true</code> to show the help
	* control, <code>false</code> otherwise.
	* @since 3.2
	*/
	public static void setDialogHelpAvailable(boolean helpAvailable) {
	dialogHelpAvailable = helpAvailable;
	}
	}