org.eclipse.gmf.runtime.common.ui/src/org/eclipse/gmf/runtime/common/ui/dialogs/ShowHideRelationshipsDialog.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2002, 2006 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.gmf.runtime.common.ui.dialogs;

 import java.util.List;

 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.jface.window.Window;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Tree;
 import org.eclipse.swt.widgets.TreeItem;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.plugin.AbstractUIPlugin;

 import org.eclipse.gmf.runtime.common.core.util.Log;
 import org.eclipse.gmf.runtime.common.core.util.StringStatics;
 import org.eclipse.gmf.runtime.common.core.util.Trace;
 import org.eclipse.gmf.runtime.common.ui.internal.CommonUIDebugOptions;
 import org.eclipse.gmf.runtime.common.ui.internal.CommonUIIconNames;
 import org.eclipse.gmf.runtime.common.ui.internal.CommonUIPlugin;
 import org.eclipse.gmf.runtime.common.ui.internal.CommonUIStatusCodes;
 import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementTreeSelectionChangedAndMouseAndKeyListener;
 import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementsContentProvider;
 import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementsTriStateLabelProvider;
 import org.eclipse.gmf.runtime.common.ui.internal.l10n.CommonUIMessages;
 import org.eclipse.gmf.runtime.common.ui.util.WindowUtil;

 /**
  * Show Hide Relationships dialog box, called from an action.
  *
  * When OK is clicked, returns Window.OK and result of the dialog is saved.
  *
  * When Cancel is clicked, returns Window.Cancel and result of dialog is not
  * saved.
  *
  * @author Wayne Diu, wdiu
  */
 public class ShowHideRelationshipsDialog
 	extends Dialog {

 	/* Controls */

 	/**
 	 * The viewer on the left side of the box
 	 */
 	private TreeViewer viewer;

 	/**
 	 * OK button
 	 */
 	private Button ok;

 	/**
 	 * Cancel button
 	 */
 	private Button cancel;

 	/* Data for the view control */

 	/**
 	 * The root element
 	 */
 	private SelectableElement rootElement;

 	/**
 	 * The context sensitive help id
 	 */
 	private String helpContextId;

 	/* Statics */

 	/**
 	 * Tree viewer control's width for the hint
 	 */
 	private static int MAX_VIEWER_WIDTH = 400;

 	/**
 	 * Tree viewer control's height for the hint
 	 */
 	private static int MAX_VIEWER_HEIGHT = 400;

 	/**
 	 * Expansion group's width for the hint
 	 */
 	private static int TEXT_AREA_HEIGHT = 46;

 	static {
 		try {
 			MAX_VIEWER_WIDTH = Integer
 				.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_MAX_VIEWER_WIDTH);
 			MAX_VIEWER_HEIGHT = Integer
 				.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_MAX_VIEWER_HEIGHT);
 			TEXT_AREA_HEIGHT = Integer
 				.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_TEXT_AREA_HEIGHT);
 		} catch (NumberFormatException e) {
 			/* already initialized with defaults */
 			Trace.catching(CommonUIPlugin.getDefault(),
 				CommonUIDebugOptions.EXCEPTIONS_CATCHING, CommonUIPlugin
 					.getDefault().getClass(), "NumberFormatException", e); //$NON-NLS-1$
 			Log
 				.error(
 					CommonUIPlugin.getDefault(),
 					CommonUIStatusCodes.RESOURCE_FAILURE,
 					"Failed to parse Show Hide Relationships Dialog's localized size", e); //$NON-NLS-1$
 		}
 	}

 	/**
 	 * The real viewer width
 	 */
 	private int viewerWidth = MAX_VIEWER_WIDTH;

 	/* Legend icons */

 	/**
 	 * Selected icon image
 	 */
 	Image selectedIcon;

 	/**
 	 * Unselected icon image
 	 */
 	Image unselectedIcon;

 	/**
 	 * Cleared icon image
 	 */
 	Image clearedIcon;

 	/**
 	 * Constructor takes the parent shell and data to add into the viewer
 	 *
 	 * @param parentShell
 	 *            the parent Shell
 	 * @param aRootElement
 	 *            the root SelectableElement to add into the viewer
 	 */
 	public ShowHideRelationshipsDialog(Shell parentShell,
 			SelectableElement aRootElement) {
 		super(parentShell);
 		this.rootElement = aRootElement.makeCopy();

 		try {
 			selectedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
 				CommonUIPlugin.getPluginId(),
 				CommonUIIconNames.IMG_CHECKBOX_SELECTED).createImage();
 			unselectedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
 				CommonUIPlugin.getPluginId(),
 				CommonUIIconNames.IMG_CHECKBOX_UNSELECTED).createImage();
 			clearedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
 				CommonUIPlugin.getPluginId(),
 				CommonUIIconNames.IMG_CHECKBOX_CLEARED).createImage();
 		} catch (Exception e) {
 			Trace.catching(CommonUIPlugin.getDefault(),
 				CommonUIDebugOptions.EXCEPTIONS_CATCHING, getClass(),
 				"ShowHideRelationshipsDialog", e); //$NON-NLS-1$
 			Log
 				.error(
 					CommonUIPlugin.getDefault(),
 					CommonUIStatusCodes.RESOURCE_FAILURE,
 					"Failed to get legend icons for Show Hide Relationships Dialog", e); //$NON-NLS-1$
 			// if even one is bad, then I'm not going to display the legend
 			disposeImages();
 			selectedIcon = null;
 			/*
 			 * don't have to do the rest, I'm just checking selectedIcon
 			 * unselectedIcon = null; clearedIcon = null;
 			 */
 		}

 	}

 	/**
 	 * Returns the tree viewer
 	 *
 	 * @return TreeViewer on the left side of the dialog
 	 */
 	protected TreeViewer getTreeViewer() {
 		return viewer;
 	}

 	/**
 	 * Sets the tree viewer
 	 *
 	 * @param aViewer
 	 *            is the TreeViewer on the left side of the dialog
 	 */
 	protected void setTreeViewer(TreeViewer aViewer) {
 		this.viewer = aViewer;
 	}

 	/**
 	 * Make the tree viewer on the left side of the dialog
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 */
 	protected void createViewer(Composite parent) {
 		setTreeViewer(new TreeViewer(parent, SWT.SINGLE | SWT.V_SCROLL
 			| SWT.BORDER));

 		GridData gridData = new GridData(GridData.FILL_BOTH);

 		gridData.widthHint = viewerWidth;

 		// calculate the tree viewer height
 		int viewerHeight = SelectableElement
 			.calculateNumberOfChildren(rootElement);
 		GC gc = new GC(getTreeViewer().getTree());
 		Point size = gc.textExtent(StringStatics.BLANK);
 		// the buffer is 64
 		viewerHeight = (viewerHeight * size.y) + 64;
 		gc.dispose();
 		if (viewerHeight > MAX_VIEWER_HEIGHT)
 			viewerHeight = MAX_VIEWER_HEIGHT;
 		gridData.heightHint = viewerHeight;

 		Tree tree = getTreeViewer().getTree();
 		tree.setLayoutData(gridData);
 		tree.setLayout(new GridLayout(1, true));

 		getTreeViewer().setUseHashlookup(true);

 		SelectableElementTreeSelectionChangedAndMouseAndKeyListener listener = new SelectableElementTreeSelectionChangedAndMouseAndKeyListener(
 			getTreeViewer()) {

 			protected void switchCheckType(SelectableElement element) {
 				if (element.getSelectedType() == SelectedType.LEAVE) {
 					element.setSelectedType(SelectedType.UNSELECTED);
 				} else if (element.getSelectedType() == SelectedType.UNSELECTED) {
 					element.setSelectedType(SelectedType.SELECTED);
 				} else if (element.getSelectedType() == SelectedType.SELECTED) {
 					element.setSelectedType(SelectedType.LEAVE);
 				}
 			}
 		};

 		getTreeViewer().addSelectionChangedListener(listener);
 		getTreeViewer().getTree().addMouseListener(listener);
 		getTreeViewer().getTree().addKeyListener(listener);

 	}

 	/**
 	 * Makes the buttons at the bottom of the dialog
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 */
 	protected void makeButtons(Composite parent) {
 		Composite empty = new Composite(parent, SWT.NULL);
 		GridData gridData = new GridData();
 		gridData.heightHint = 20;
 		empty.setLayoutData(gridData);

 		Composite right = new Composite(parent, SWT.NULL);
 		right.setLayout(new GridLayout(3, false));
 		right.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END));
 		ok = new Button(right, SWT.PUSH);
 		ok.setText(CommonUIMessages.ShowHideRelationshipsDialog_Button_OK);
 		ok.setLayoutData(WindowUtil.makeFixedButtonData(ok));
 		ok.addSelectionListener(new SelectionAdapter() {

 			public void widgetSelected(SelectionEvent e) {
 				performOk();
 			}
 		});
 		cancel = new Button(right, SWT.PUSH);
 		cancel
 			.setText(CommonUIMessages.ShowHideRelationshipsDialog_Button_Cancel);
 		cancel.setLayoutData(WindowUtil.makeFixedButtonData(cancel));
 		cancel.addSelectionListener(new SelectionAdapter() {

 			public void widgetSelected(SelectionEvent e) {
 				setReturnCode(Window.CANCEL);
 				disposeImages();
 				close();
 			}
 		});
 	}

 	/**
 	 * Creates the line of text at the top of the dialog
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 */
 	private void createLineOfTextAtTop(Composite parent) {
 		Composite top = new Composite(parent, SWT.NULL);

 		GridData gridData = new GridData(GridData.FILL_HORIZONTAL
 			| GridData.FILL_VERTICAL);

 		// Assume the fonts in the tree control and in the composite are the
 		// same.
 		// I calculate viewerWidth by doing
 		// text length in pixels + beginning + buffer
 		// text length in pixels + 32 + 64
 		viewerWidth = SelectableElement.calculateLongestStringLength(
 			rootElement, top) + 96;
 		if (viewerWidth > MAX_VIEWER_WIDTH)
 			viewerWidth = MAX_VIEWER_WIDTH;

 		// the width will be smaller by a little bit, but that's ok
 		gridData.widthHint = viewerWidth;
 		gridData.heightHint = TEXT_AREA_HEIGHT;

 		top.setLayoutData(gridData);
 		top.setLayout(new GridLayout(1, false));

 		Label label = new Label(top, SWT.WRAP);

 		label.setText(CommonUIMessages.ShowHideRelationshipsDialog_Description);
 		label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
 			| GridData.FILL_VERTICAL));
 	}

 	/**
 	 * Makes a little blank box
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 */
 	private void makeBlankBox(Composite parent) {
 		Composite blankBox = new Composite(parent, SWT.NULL);
 		GridData gridData = new GridData(GridData.FILL_HORIZONTAL);
 		gridData.heightHint = 10;
 		blankBox.setLayoutData(gridData);
 	}

 	/**
 	 * Creates the legend at the bottom of the dialog just above the buttons
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 */
 	private void createLegend(Composite parent) {
 		final int NUM_BOXES = 3;

 		makeBlankBox(parent);

 		Label label = new Label(parent, SWT.NULL);
 		label
 			.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_Legend);

 		Composite legendBox = new Composite(parent, SWT.BORDER);

 		GridData gridData = new GridData(GridData.FILL_HORIZONTAL);

 		legendBox.setLayoutData(gridData);
 		legendBox.setLayout(new GridLayout(3, true));

 		Composite[] elements = new Composite[NUM_BOXES];

 		for (int i = 0; i < NUM_BOXES; i++) {
 			elements[i] = new Composite(legendBox, SWT.NULL);

 			gridData = new GridData(GridData.FILL_HORIZONTAL);

 			elements[i].setLayoutData(gridData);
 			elements[i].setLayout(new GridLayout(2, false));
 		}

 		// 1
 		label = new Label(elements[0], SWT.NULL);
 		label.setImage(selectedIcon);

 		label = new Label(elements[0], SWT.NULL);
 		label
 			.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendShow);
 		label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
 			| GridData.FILL_VERTICAL));

 		// 2
 		label = new Label(elements[1], SWT.NULL);
 		label.setImage(unselectedIcon);

 		label = new Label(elements[1], SWT.NULL);
 		label
 			.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendHide);
 		label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
 			| GridData.FILL_VERTICAL));

 		// 3
 		label = new Label(elements[2], SWT.NULL);
 		label.setImage(clearedIcon);

 		label = new Label(elements[2], SWT.NULL);
 		label
 			.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendLeave);
 		label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
 			| GridData.FILL_VERTICAL));

 		makeBlankBox(parent);
 	}

 	/**
 	 * Makes the dialog
 	 *
 	 * @param parent
 	 *            the parent Composite
 	 * @return Control the parent Composite
 	 */
 	protected Control createContents(Composite parent) {

 		// if you want a line of text at the top of the dialog
 		createLineOfTextAtTop(parent);

 		Composite bottom = new Composite(parent, SWT.NULL);

 		bottom.setLayoutData(new GridData(GridData.FILL_BOTH));
 		bottom.setLayout(new GridLayout(1, false));

 		createViewer(bottom);

 		/*
 		 * don't have to do the rest, I'm just checking selectedIcon
 		 * unselectedIcon != null && clearedIcon != null
 		 */
 		if (selectedIcon != null)
 			createLegend(bottom);

 		makeButtons(bottom);

 		viewer.setLabelProvider(new SelectableElementsTriStateLabelProvider());
 		viewer.setContentProvider(new SelectableElementsContentProvider());

 		getTreeViewer().setInput(rootElement);

 		Tree tree = getTreeViewer().getTree();

 		// I just set the input to the root, so I make these asserts
 		TreeItem[] treeItems = tree.getItems();
 		assert null != treeItems : "treeItems cannot be null"; //$NON-NLS-1$
 		assert treeItems.length == 1 : "treeItems cannot be empty"; //$NON-NLS-1$
 		tree.setSelection(treeItems);

 		ok.setFocus();

 		resetDialog();

 		viewer.refresh();

 		getShell().setText(CommonUIMessages.ShowHideRelationshipsDialog_Title);

         // set context sensitive help
         if (helpContextId != null) {
             PlatformUI.getWorkbench().getHelpSystem().setHelp(parent,
                 helpContextId);
         } else {
             PlatformUI.getWorkbench().getHelpSystem().setHelp(parent,
                 "org.eclipse.gmf.runtime.common.ui.egmf0100"); //$NON-NLS-1$
         }

 		return parent;

 	}

 	/**
 	 * OK button click handler
 	 */
 	protected void performOk() {
 		disposeImages();
 		setReturnCode(Window.OK);
 		close();
 	}

 	/**
 	 * Reset button click handler, called to initialize the dialog
 	 */
 	void resetDialog() {
 		viewer.expandAll();
 	}

 	/**
 	 * Returns the root element of the RelatedElements that were in the viewer
 	 * control at the left of the dialog.
 	 *
 	 * @return SelectableElement with the root element.
 	 */
 	public SelectableElement getRootElement() {
 		return rootElement;
 	}

 	/**
 	 * Returns a list of the selected relationship types.
 	 *
 	 * @return List of the selected relationship types
 	 */
 	public List getSelectedRelationshipTypes() {
 		if (this.rootElement == null) {
 			return null;
 		}
 		return this.rootElement.getSelectedElementTypes();
 	}

 	/**
 	 * Returns a list of the unselected relationship types.
 	 *
 	 * @return List of the unselected relationship types
 	 */
 	public List getUnselectedRelationshipTypes() {
 		if (this.rootElement == null) {
 			return null;
 		}
 		return this.rootElement.getUnSelectedElementTypes();
 	}

 	/**
 	 * Initialize the context sensitive help id.
 	 *
 	 * @param helpId
 	 *            the help context id string
 	 */
 	public void initHelpContextId(String helpId) {
 		this.helpContextId = helpId;
 	}

 	/**
 	 * Disposes the images for the legend box
 	 */
 	public void disposeImages() {
 		if (selectedIcon != null && !selectedIcon.isDisposed())
 			selectedIcon.dispose();
 		if (unselectedIcon != null && !unselectedIcon.isDisposed())
 			unselectedIcon.dispose();
 		if (clearedIcon != null && !clearedIcon.isDisposed())
 			clearedIcon.dispose();
 	}

 }
	/******************************************************************************
	* Copyright (c) 2002, 2006 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.gmf.runtime.common.ui.dialogs;

	import java.util.List;

	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.viewers.TreeViewer;
	import org.eclipse.jface.window.Window;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.SelectionAdapter;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Tree;
	import org.eclipse.swt.widgets.TreeItem;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.plugin.AbstractUIPlugin;

	import org.eclipse.gmf.runtime.common.core.util.Log;
	import org.eclipse.gmf.runtime.common.core.util.StringStatics;
	import org.eclipse.gmf.runtime.common.core.util.Trace;
	import org.eclipse.gmf.runtime.common.ui.internal.CommonUIDebugOptions;
	import org.eclipse.gmf.runtime.common.ui.internal.CommonUIIconNames;
	import org.eclipse.gmf.runtime.common.ui.internal.CommonUIPlugin;
	import org.eclipse.gmf.runtime.common.ui.internal.CommonUIStatusCodes;
	import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementTreeSelectionChangedAndMouseAndKeyListener;
	import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementsContentProvider;
	import org.eclipse.gmf.runtime.common.ui.internal.dialogs.SelectableElementsTriStateLabelProvider;
	import org.eclipse.gmf.runtime.common.ui.internal.l10n.CommonUIMessages;
	import org.eclipse.gmf.runtime.common.ui.util.WindowUtil;

	/**
	* Show Hide Relationships dialog box, called from an action.
	*
	* When OK is clicked, returns Window.OK and result of the dialog is saved.
	*
	* When Cancel is clicked, returns Window.Cancel and result of dialog is not
	* saved.
	*
	* @author Wayne Diu, wdiu
	*/
	public class ShowHideRelationshipsDialog
	extends Dialog {

	/* Controls */

	/**
	* The viewer on the left side of the box
	*/
	private TreeViewer viewer;

	/**
	* OK button
	*/
	private Button ok;

	/**
	* Cancel button
	*/
	private Button cancel;

	/* Data for the view control */

	/**
	* The root element
	*/
	private SelectableElement rootElement;

	/**
	* The context sensitive help id
	*/
	private String helpContextId;

	/* Statics */

	/**
	* Tree viewer control's width for the hint
	*/
	private static int MAX_VIEWER_WIDTH = 400;

	/**
	* Tree viewer control's height for the hint
	*/
	private static int MAX_VIEWER_HEIGHT = 400;

	/**
	* Expansion group's width for the hint
	*/
	private static int TEXT_AREA_HEIGHT = 46;

	static {
	try {
	MAX_VIEWER_WIDTH = Integer
	.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_MAX_VIEWER_WIDTH);
	MAX_VIEWER_HEIGHT = Integer
	.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_MAX_VIEWER_HEIGHT);
	TEXT_AREA_HEIGHT = Integer
	.parseInt(CommonUIMessages.ShowHideRelationshipsDialog_TEXT_AREA_HEIGHT);
	} catch (NumberFormatException e) {
	/* already initialized with defaults */
	Trace.catching(CommonUIPlugin.getDefault(),
	CommonUIDebugOptions.EXCEPTIONS_CATCHING, CommonUIPlugin
	.getDefault().getClass(), "NumberFormatException", e); //$NON-NLS-1$
	Log
	.error(
	CommonUIPlugin.getDefault(),
	CommonUIStatusCodes.RESOURCE_FAILURE,
	"Failed to parse Show Hide Relationships Dialog's localized size", e); //$NON-NLS-1$
	}
	}

	/**
	* The real viewer width
	*/
	private int viewerWidth = MAX_VIEWER_WIDTH;

	/* Legend icons */

	/**
	* Selected icon image
	*/
	Image selectedIcon;

	/**
	* Unselected icon image
	*/
	Image unselectedIcon;

	/**
	* Cleared icon image
	*/
	Image clearedIcon;

	/**
	* Constructor takes the parent shell and data to add into the viewer
	*
	* @param parentShell
	* the parent Shell
	* @param aRootElement
	* the root SelectableElement to add into the viewer
	*/
	public ShowHideRelationshipsDialog(Shell parentShell,
	SelectableElement aRootElement) {
	super(parentShell);
	this.rootElement = aRootElement.makeCopy();

	try {
	selectedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
	CommonUIPlugin.getPluginId(),
	CommonUIIconNames.IMG_CHECKBOX_SELECTED).createImage();
	unselectedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
	CommonUIPlugin.getPluginId(),
	CommonUIIconNames.IMG_CHECKBOX_UNSELECTED).createImage();
	clearedIcon = AbstractUIPlugin.imageDescriptorFromPlugin(
	CommonUIPlugin.getPluginId(),
	CommonUIIconNames.IMG_CHECKBOX_CLEARED).createImage();
	} catch (Exception e) {
	Trace.catching(CommonUIPlugin.getDefault(),
	CommonUIDebugOptions.EXCEPTIONS_CATCHING, getClass(),
	"ShowHideRelationshipsDialog", e); //$NON-NLS-1$
	Log
	.error(
	CommonUIPlugin.getDefault(),
	CommonUIStatusCodes.RESOURCE_FAILURE,
	"Failed to get legend icons for Show Hide Relationships Dialog", e); //$NON-NLS-1$
	// if even one is bad, then I'm not going to display the legend
	disposeImages();
	selectedIcon = null;
	/*
	* don't have to do the rest, I'm just checking selectedIcon
	* unselectedIcon = null; clearedIcon = null;
	*/
	}

	}

	/**
	* Returns the tree viewer
	*
	* @return TreeViewer on the left side of the dialog
	*/
	protected TreeViewer getTreeViewer() {
	return viewer;
	}

	/**
	* Sets the tree viewer
	*
	* @param aViewer
	* is the TreeViewer on the left side of the dialog
	*/
	protected void setTreeViewer(TreeViewer aViewer) {
	this.viewer = aViewer;
	}

	/**
	* Make the tree viewer on the left side of the dialog
	*
	* @param parent
	* the parent Composite
	*/
	protected void createViewer(Composite parent) {
	setTreeViewer(new TreeViewer(parent, SWT.SINGLE \| SWT.V_SCROLL
	\| SWT.BORDER));

	GridData gridData = new GridData(GridData.FILL_BOTH);

	gridData.widthHint = viewerWidth;

	// calculate the tree viewer height
	int viewerHeight = SelectableElement
	.calculateNumberOfChildren(rootElement);
	GC gc = new GC(getTreeViewer().getTree());
	Point size = gc.textExtent(StringStatics.BLANK);
	// the buffer is 64
	viewerHeight = (viewerHeight * size.y) + 64;
	gc.dispose();
	if (viewerHeight > MAX_VIEWER_HEIGHT)
	viewerHeight = MAX_VIEWER_HEIGHT;
	gridData.heightHint = viewerHeight;

	Tree tree = getTreeViewer().getTree();
	tree.setLayoutData(gridData);
	tree.setLayout(new GridLayout(1, true));

	getTreeViewer().setUseHashlookup(true);

	SelectableElementTreeSelectionChangedAndMouseAndKeyListener listener = new SelectableElementTreeSelectionChangedAndMouseAndKeyListener(
	getTreeViewer()) {

	protected void switchCheckType(SelectableElement element) {
	if (element.getSelectedType() == SelectedType.LEAVE) {
	element.setSelectedType(SelectedType.UNSELECTED);
	} else if (element.getSelectedType() == SelectedType.UNSELECTED) {
	element.setSelectedType(SelectedType.SELECTED);
	} else if (element.getSelectedType() == SelectedType.SELECTED) {
	element.setSelectedType(SelectedType.LEAVE);
	}
	}
	};

	getTreeViewer().addSelectionChangedListener(listener);
	getTreeViewer().getTree().addMouseListener(listener);
	getTreeViewer().getTree().addKeyListener(listener);

	}

	/**
	* Makes the buttons at the bottom of the dialog
	*
	* @param parent
	* the parent Composite
	*/
	protected void makeButtons(Composite parent) {
	Composite empty = new Composite(parent, SWT.NULL);
	GridData gridData = new GridData();
	gridData.heightHint = 20;
	empty.setLayoutData(gridData);

	Composite right = new Composite(parent, SWT.NULL);
	right.setLayout(new GridLayout(3, false));
	right.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END));
	ok = new Button(right, SWT.PUSH);
	ok.setText(CommonUIMessages.ShowHideRelationshipsDialog_Button_OK);
	ok.setLayoutData(WindowUtil.makeFixedButtonData(ok));
	ok.addSelectionListener(new SelectionAdapter() {

	public void widgetSelected(SelectionEvent e) {
	performOk();
	}
	});
	cancel = new Button(right, SWT.PUSH);
	cancel
	.setText(CommonUIMessages.ShowHideRelationshipsDialog_Button_Cancel);
	cancel.setLayoutData(WindowUtil.makeFixedButtonData(cancel));
	cancel.addSelectionListener(new SelectionAdapter() {

	public void widgetSelected(SelectionEvent e) {
	setReturnCode(Window.CANCEL);
	disposeImages();
	close();
	}
	});
	}

	/**
	* Creates the line of text at the top of the dialog
	*
	* @param parent
	* the parent Composite
	*/
	private void createLineOfTextAtTop(Composite parent) {
	Composite top = new Composite(parent, SWT.NULL);

	GridData gridData = new GridData(GridData.FILL_HORIZONTAL
	\| GridData.FILL_VERTICAL);

	// Assume the fonts in the tree control and in the composite are the
	// same.
	// I calculate viewerWidth by doing
	// text length in pixels + beginning + buffer
	// text length in pixels + 32 + 64
	viewerWidth = SelectableElement.calculateLongestStringLength(
	rootElement, top) + 96;
	if (viewerWidth > MAX_VIEWER_WIDTH)
	viewerWidth = MAX_VIEWER_WIDTH;

	// the width will be smaller by a little bit, but that's ok
	gridData.widthHint = viewerWidth;
	gridData.heightHint = TEXT_AREA_HEIGHT;

	top.setLayoutData(gridData);
	top.setLayout(new GridLayout(1, false));

	Label label = new Label(top, SWT.WRAP);

	label.setText(CommonUIMessages.ShowHideRelationshipsDialog_Description);
	label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
	\| GridData.FILL_VERTICAL));
	}

	/**
	* Makes a little blank box
	*
	* @param parent
	* the parent Composite
	*/
	private void makeBlankBox(Composite parent) {
	Composite blankBox = new Composite(parent, SWT.NULL);
	GridData gridData = new GridData(GridData.FILL_HORIZONTAL);
	gridData.heightHint = 10;
	blankBox.setLayoutData(gridData);
	}

	/**
	* Creates the legend at the bottom of the dialog just above the buttons
	*
	* @param parent
	* the parent Composite
	*/
	private void createLegend(Composite parent) {
	final int NUM_BOXES = 3;

	makeBlankBox(parent);

	Label label = new Label(parent, SWT.NULL);
	label
	.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_Legend);

	Composite legendBox = new Composite(parent, SWT.BORDER);

	GridData gridData = new GridData(GridData.FILL_HORIZONTAL);

	legendBox.setLayoutData(gridData);
	legendBox.setLayout(new GridLayout(3, true));

	Composite[] elements = new Composite[NUM_BOXES];

	for (int i = 0; i < NUM_BOXES; i++) {
	elements[i] = new Composite(legendBox, SWT.NULL);

	gridData = new GridData(GridData.FILL_HORIZONTAL);

	elements[i].setLayoutData(gridData);
	elements[i].setLayout(new GridLayout(2, false));
	}

	// 1
	label = new Label(elements[0], SWT.NULL);
	label.setImage(selectedIcon);

	label = new Label(elements[0], SWT.NULL);
	label
	.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendShow);
	label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
	\| GridData.FILL_VERTICAL));

	// 2
	label = new Label(elements[1], SWT.NULL);
	label.setImage(unselectedIcon);

	label = new Label(elements[1], SWT.NULL);
	label
	.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendHide);
	label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
	\| GridData.FILL_VERTICAL));

	// 3
	label = new Label(elements[2], SWT.NULL);
	label.setImage(clearedIcon);

	label = new Label(elements[2], SWT.NULL);
	label
	.setText(CommonUIMessages.ShowHideRelationshipsDialog_Label_LegendLeave);
	label.setLayoutData(new GridData(GridData.FILL_HORIZONTAL
	\| GridData.FILL_VERTICAL));

	makeBlankBox(parent);
	}

	/**
	* Makes the dialog
	*
	* @param parent
	* the parent Composite
	* @return Control the parent Composite
	*/
	protected Control createContents(Composite parent) {

	// if you want a line of text at the top of the dialog
	createLineOfTextAtTop(parent);

	Composite bottom = new Composite(parent, SWT.NULL);

	bottom.setLayoutData(new GridData(GridData.FILL_BOTH));
	bottom.setLayout(new GridLayout(1, false));

	createViewer(bottom);

	/*
	* don't have to do the rest, I'm just checking selectedIcon
	* unselectedIcon != null && clearedIcon != null
	*/
	if (selectedIcon != null)
	createLegend(bottom);

	makeButtons(bottom);

	viewer.setLabelProvider(new SelectableElementsTriStateLabelProvider());
	viewer.setContentProvider(new SelectableElementsContentProvider());

	getTreeViewer().setInput(rootElement);

	Tree tree = getTreeViewer().getTree();

	// I just set the input to the root, so I make these asserts
	TreeItem[] treeItems = tree.getItems();
	assert null != treeItems : "treeItems cannot be null"; //$NON-NLS-1$
	assert treeItems.length == 1 : "treeItems cannot be empty"; //$NON-NLS-1$
	tree.setSelection(treeItems);

	ok.setFocus();

	resetDialog();

	viewer.refresh();

	getShell().setText(CommonUIMessages.ShowHideRelationshipsDialog_Title);

	// set context sensitive help
	if (helpContextId != null) {
	PlatformUI.getWorkbench().getHelpSystem().setHelp(parent,
	helpContextId);
	} else {
	PlatformUI.getWorkbench().getHelpSystem().setHelp(parent,
	"org.eclipse.gmf.runtime.common.ui.egmf0100"); //$NON-NLS-1$
	}

	return parent;

	}

	/**
	* OK button click handler
	*/
	protected void performOk() {
	disposeImages();
	setReturnCode(Window.OK);
	close();
	}

	/**
	* Reset button click handler, called to initialize the dialog
	*/
	void resetDialog() {
	viewer.expandAll();
	}

	/**
	* Returns the root element of the RelatedElements that were in the viewer
	* control at the left of the dialog.
	*
	* @return SelectableElement with the root element.
	*/
	public SelectableElement getRootElement() {
	return rootElement;
	}

	/**
	* Returns a list of the selected relationship types.
	*
	* @return List of the selected relationship types
	*/
	public List getSelectedRelationshipTypes() {
	if (this.rootElement == null) {
	return null;
	}
	return this.rootElement.getSelectedElementTypes();
	}

	/**
	* Returns a list of the unselected relationship types.
	*
	* @return List of the unselected relationship types
	*/
	public List getUnselectedRelationshipTypes() {
	if (this.rootElement == null) {
	return null;
	}
	return this.rootElement.getUnSelectedElementTypes();
	}

	/**
	* Initialize the context sensitive help id.
	*
	* @param helpId
	* the help context id string
	*/
	public void initHelpContextId(String helpId) {
	this.helpContextId = helpId;
	}

	/**
	* Disposes the images for the legend box
	*/
	public void disposeImages() {
	if (selectedIcon != null && !selectedIcon.isDisposed())
	selectedIcon.dispose();
	if (unselectedIcon != null && !unselectedIcon.isDisposed())
	unselectedIcon.dispose();
	if (clearedIcon != null && !clearedIcon.isDisposed())
	clearedIcon.dispose();
	}

	}