bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/dialogs/ShowViewDialog.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2012 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
  *     Sebastian Davids - bug 128526, bug 128529
  *******************************************************************************/
 package org.eclipse.ui.internal.dialogs;

 import java.util.ArrayList;
 import java.util.Iterator;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.IDialogSettings;
 import org.eclipse.jface.dialogs.PopupDialog;
 import org.eclipse.jface.viewers.DoubleClickEvent;
 import org.eclipse.jface.viewers.IDoubleClickListener;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.ITreeContentProvider;
 import org.eclipse.jface.viewers.ITreeSelection;
 import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.FocusAdapter;
 import org.eclipse.swt.events.FocusEvent;
 import org.eclipse.swt.events.KeyAdapter;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Text;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.dialogs.FilteredTree;
 import org.eclipse.ui.dialogs.PatternFilter;
 import org.eclipse.ui.internal.IWorkbenchHelpContextIds;
 import org.eclipse.ui.internal.WorkbenchMessages;
 import org.eclipse.ui.internal.WorkbenchPlugin;
 import org.eclipse.ui.internal.registry.ViewRegistry;
 import org.eclipse.ui.views.IViewCategory;
 import org.eclipse.ui.views.IViewDescriptor;
 import org.eclipse.ui.views.IViewRegistry;

 /**
  * The Show View dialog.
  */
 public class ShowViewDialog extends Dialog implements
         ISelectionChangedListener, IDoubleClickListener {

     private static final String DIALOG_SETTING_SECTION_NAME = "ShowViewDialog"; //$NON-NLS-1$

     private static final int LIST_HEIGHT = 300;

     private static final int LIST_WIDTH = 250;

     private static final String STORE_EXPANDED_CATEGORIES_ID = DIALOG_SETTING_SECTION_NAME
             + ".STORE_EXPANDED_CATEGORIES_ID"; //$NON-NLS-1$

     private static final String STORE_SELECTED_VIEW_ID = DIALOG_SETTING_SECTION_NAME
             + ".STORE_SELECTED_VIEW_ID"; //$NON-NLS-1$

     private FilteredTree filteredTree;

     private Button okButton;

     private IViewDescriptor[] viewDescs = new IViewDescriptor[0];

     private IViewRegistry viewReg;

 	private IWorkbenchWindow window;

 	private Color dimmedForeground;

 	private Label descriptionHint;

     /**
      * Constructs a new ShowViewDialog.
      *
      * @param window the workbench window
      * @param viewReg the view registry
      */
     public ShowViewDialog(IWorkbenchWindow window, IViewRegistry viewReg) {
         super(window.getShell());
         this.window = window;
         this.viewReg = viewReg;
     }

     /**
      * This method is called if a button has been pressed.
      */
     protected void buttonPressed(int buttonId) {
         if (buttonId == IDialogConstants.OK_ID) {
 			saveWidgetValues();
 		}
         super.buttonPressed(buttonId);
     }

     /**
      * Notifies that the cancel button of this dialog has been pressed.
      */
     protected void cancelPressed() {
         viewDescs = new IViewDescriptor[0];
         super.cancelPressed();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)
      */
     protected void configureShell(Shell shell) {
         super.configureShell(shell);
         shell.setText(WorkbenchMessages.ShowView_shellTitle);
         PlatformUI.getWorkbench().getHelpSystem().setHelp(shell,
 				IWorkbenchHelpContextIds.SHOW_VIEW_DIALOG);
     }

     /**
      * Adds buttons to this dialog's button bar.
      * <p>
      * The default implementation of this framework method adds standard ok and
      * cancel buttons using the <code>createButton</code> framework method.
      * Subclasses may override.
      * </p>
      *
      * @param parent the button bar composite
      */
     protected void createButtonsForButtonBar(Composite parent) {
         okButton = createButton(parent, IDialogConstants.OK_ID,
                 IDialogConstants.OK_LABEL, true);
         createButton(parent, IDialogConstants.CANCEL_ID,
                 IDialogConstants.CANCEL_LABEL, false);
         updateButtons();
     }

     /**
      * Creates and returns the contents of the upper part of this dialog (above
      * the button bar).
      *
      * @param parent the parent composite to contain the dialog area
      * @return the dialog area control
      */
     protected Control createDialogArea(Composite parent) {
         // Run super.
         Composite composite = (Composite) super.createDialogArea(parent);
         composite.setFont(parent.getFont());

         createFilteredTreeViewer(composite);

         layoutTopControl(filteredTree);

         // Use F2... label
 		descriptionHint = new Label(composite, SWT.WRAP);
 		descriptionHint.setText(WorkbenchMessages.ShowView_selectViewHelp);
 		descriptionHint.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
 		descriptionHint.setVisible(false);

         // Restore the last state
         restoreWidgetValues();

 		applyDialogFont(composite);

 		// Return results.
         return composite;
     }

 	/**
 	 * Blends c1 and c2 based in the provided ratio.
 	 *
 	 * @param c1
 	 *            first color
 	 * @param c2
 	 *            second color
 	 * @param ratio
 	 *            percentage of the first color in the blend (0-100)
 	 * @return the RGB value of the blended color
 	 *
 	 * copied from FormColors.java
 	 */
 	private static RGB blend(RGB c1, RGB c2, int ratio) {
 		int r = blend(c1.red, c2.red, ratio);
 		int g = blend(c1.green, c2.green, ratio);
 		int b = blend(c1.blue, c2.blue, ratio);
 		return new RGB(r, g, b);
 	}

 	private static int blend(int v1, int v2, int ratio) {
 		int b = (ratio * v1 + (100 - ratio) * v2) / 100;
 		return Math.min(255, b);
 	}

 	/**
      * Create a new filtered tree viewer in the parent.
      *
      * @param parent the parent <code>Composite</code>.
      */
     private void createFilteredTreeViewer(Composite parent) {
 		PatternFilter filter = new ViewPatternFilter();
 		int styleBits = SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER;
 		filteredTree = new FilteredTree(parent, styleBits, filter, true);
 		filteredTree.setBackground(parent.getDisplay().getSystemColor(
 				SWT.COLOR_WIDGET_BACKGROUND));

 		TreeViewer treeViewer = filteredTree.getViewer();
 		Control treeControl = treeViewer.getControl();
 		RGB dimmedRGB = blend(treeControl.getForeground().getRGB(), treeControl.getBackground().getRGB(), 60);
 		dimmedForeground = new Color(treeControl.getDisplay(), dimmedRGB);
 		treeControl.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				dimmedForeground.dispose();
 			}
 		});

 		treeViewer.setLabelProvider(new ViewLabelProvider(window, dimmedForeground));
 		treeViewer.setContentProvider(new ViewContentProvider());
 		treeViewer.setComparator(new ViewComparator((ViewRegistry) viewReg));
 		treeViewer.setInput(viewReg);
 		treeViewer.addSelectionChangedListener(this);
 		treeViewer.addDoubleClickListener(this);
 		treeViewer.addFilter(new CapabilityFilter());
 		treeViewer.getControl().addKeyListener(new KeyAdapter() {
             public void keyPressed(KeyEvent e) {
                 handleTreeViewerKeyPressed(e);
             }
         });

 		// if the tree has only one or zero views, disable the filter text control
 		if (hasAtMostOneView(filteredTree.getViewer())) {
 			Text filterText = filteredTree.getFilterControl();
 			if (filterText != null) {
 				filterText.setEnabled(false);
 			}
 		}
 	}

 	/**
 	 * Return whether or not there are less than two views in the list.
 	 *
 	 * @param tree
 	 * @return <code>true</code> if there are less than two views in the list.
 	 */
 	private boolean hasAtMostOneView(TreeViewer tree) {
 		ITreeContentProvider contentProvider = (ITreeContentProvider) tree
 				.getContentProvider();
 		Object[] children = contentProvider.getElements(tree.getInput());

 		if (children.length <= 1) {
 			if (children.length == 0) {
 				return true;
 			}
 			return !contentProvider.hasChildren(children[0]);
 		}
 		return false;
 	}

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.jface.viewers.IDoubleClickListener#doubleClick(org.eclipse.jface.viewers.DoubleClickEvent)
      */
     public void doubleClick(DoubleClickEvent event) {
         IStructuredSelection s = (IStructuredSelection) event.getSelection();
         Object element = s.getFirstElement();
         if (filteredTree.getViewer().isExpandable(element)) {
             filteredTree.getViewer().setExpandedState(element, !filteredTree.getViewer().getExpandedState(element));
         } else if (viewDescs.length > 0) {
             saveWidgetValues();
             setReturnCode(OK);
             close();
         }
     }

     /**
      * Return the dialog store to cache values into
      */
     protected IDialogSettings getDialogSettings() {
         IDialogSettings workbenchSettings = WorkbenchPlugin.getDefault()
                 .getDialogSettings();
         IDialogSettings section = workbenchSettings
                 .getSection(DIALOG_SETTING_SECTION_NAME);
         if (section == null) {
 			section = workbenchSettings
                     .addNewSection(DIALOG_SETTING_SECTION_NAME);
 		}
         return section;
     }

     /**
      * Returns the descriptors for the selected views.
      *
      * @return the descriptors for the selected views
      */
     public IViewDescriptor[] getSelection() {
         return viewDescs;
     }

     /**
      * Layout the top control.
      *
      * @param control the control.
      */
     private void layoutTopControl(Control control) {
         GridData spec = new GridData(GridData.FILL_BOTH);
         spec.widthHint = LIST_WIDTH;
         spec.heightHint = LIST_HEIGHT;
         control.setLayoutData(spec);
     }

     /**
      * Use the dialog store to restore widget values to the values that they
      * held last time this dialog was used to completion.
      */
     protected void restoreWidgetValues() {
 		Object selection = null;

         IDialogSettings settings = getDialogSettings();
         String[] expandedCategoryIds = settings
                 .getArray(STORE_EXPANDED_CATEGORIES_ID);
 		if (expandedCategoryIds != null) {
 			ViewRegistry reg = (ViewRegistry) viewReg;
 			ArrayList categoriesToExpand = new ArrayList(expandedCategoryIds.length);
 			for (int i = 0; i < expandedCategoryIds.length; i++) {
 				IViewCategory category = reg.findCategory(expandedCategoryIds[i]);
 				if (category != null) {
 					categoriesToExpand.add(category);
 				}
 			}

 			if (!categoriesToExpand.isEmpty()) {
 				filteredTree.getViewer().setExpandedElements(categoriesToExpand.toArray());
 			}

 			String selectedViewId = settings.get(STORE_SELECTED_VIEW_ID);
 			if (selectedViewId != null) {
 				selection = reg.find(selectedViewId);
 			}
         }

 		// Make sure there's a selection in the tree
 		if (selection == null)
 			selection = filteredTree.getViewer().getTree().getItem(0).getData();

 		filteredTree.getViewer().setSelection(new StructuredSelection(selection), true);

     }

     /**
      * Since OK was pressed, write widget values to the dialog store so that
      * they will persist into the next invocation of this dialog
      */
     protected void saveWidgetValues() {
         IDialogSettings settings = getDialogSettings();

         // Collect the ids of the all expanded categories
         Object[] expandedElements = filteredTree.getViewer().getExpandedElements();
         String[] expandedCategoryIds = new String[expandedElements.length];
         for (int i = 0; i < expandedElements.length; ++i) {
 			expandedCategoryIds[i] = ((IViewCategory) expandedElements[i]).getId();
 		}

         // Save them for next time.
         settings.put(STORE_EXPANDED_CATEGORIES_ID, expandedCategoryIds);

         String selectedViewId = ""; //$NON-NLS-1$
         if (viewDescs.length > 0) {
             // in the case of a multi-selection, it's probably less confusing
             // to store just the first rather than the whole multi-selection
             selectedViewId = viewDescs[0].getId();
         }
         settings.put(STORE_SELECTED_VIEW_ID, selectedViewId);
     }

     /**
      * Notifies that the selection has changed.
      *
      * @param event event object describing the change
      */
     public void selectionChanged(SelectionChangedEvent event) {
         updateSelection(event);
         updateButtons();
 		descriptionHint.setVisible(viewDescs.length == 1
 				&& viewDescs[0].getDescription().length() > 0);
 	}

     /**
      * Update the button enablement state.
      */
     protected void updateButtons() {
         if (okButton != null) {
             okButton.setEnabled(getSelection().length > 0);
         }
     }

     /**
      * Update the selection object.
      */
     protected void updateSelection(SelectionChangedEvent event) {
         ArrayList descs = new ArrayList();
         IStructuredSelection sel = (IStructuredSelection) event.getSelection();
         for (Iterator i = sel.iterator(); i.hasNext();) {
             Object o = i.next();
             if (o instanceof IViewDescriptor) {
                 descs.add(o);
             }
         }

         viewDescs = new IViewDescriptor[descs.size()];
         descs.toArray(viewDescs);
     }


 	/* (non-Javadoc)
      * @see org.eclipse.jface.window.Dialog#getDialogBoundsSettings()
      *
      * @since 3.4
      */
 	protected IDialogSettings getDialogBoundsSettings() {
         return getDialogSettings();
 	}
     void handleTreeViewerKeyPressed(KeyEvent event) {

 		// popup the description for the selected view
 		if (descriptionHint.isVisible() && event.keyCode == SWT.F2
 				&& event.stateMask == 0) {
 			ITreeSelection selection = (ITreeSelection) filteredTree
 					.getViewer().getSelection();
 			// only show description if one view is selected
 			if (selection.size() == 1) {
 				Object o = selection.getFirstElement();
 				if (o instanceof IViewDescriptor) {
 					String description = ((IViewDescriptor) o).getDescription();
 					if (description.length() == 0)
 						description = WorkbenchMessages.ShowView_noDesc;
 					popUp(description);
 				}
 			}
 		}
 	}

 	private void popUp(final String description) {
 		new PopupDialog(filteredTree.getShell(), PopupDialog.HOVER_SHELLSTYLE,
 				true, false, false, false, false, null, null) {
 			private static final int CURSOR_SIZE = 15;

 			protected Point getInitialLocation(Point initialSize) {
 				//show popup relative to cursor
 				Display display = getShell().getDisplay();
 				Point location = display.getCursorLocation();
 				location.x += CURSOR_SIZE;
 				location.y += CURSOR_SIZE;
 				return location;
 			}

 			protected Control createDialogArea(Composite parent) {
 				Label label = new Label(parent, SWT.WRAP);
 				label.setText(description);
 				label.addFocusListener(new FocusAdapter() {
 					public void focusLost(FocusEvent event) {
 						close();
 					}
 				});
 				// Use the compact margins employed by PopupDialog.
 				GridData gd = new GridData(GridData.BEGINNING
 						| GridData.FILL_BOTH);
 				gd.horizontalIndent = PopupDialog.POPUP_HORIZONTALSPACING;
 				gd.verticalIndent = PopupDialog.POPUP_VERTICALSPACING;
 				label.setLayoutData(gd);
 				return label;
 			}
 		}.open();
 	}
     /*
      * (non-Javadoc)
      * @see org.eclipse.jface.dialogs.Dialog#isResizable()
      */
     protected boolean isResizable() {
     	return true;
     }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2012 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
	* Sebastian Davids - bug 128526, bug 128529
	*******************************************************************************/
	package org.eclipse.ui.internal.dialogs;

	import java.util.ArrayList;
	import java.util.Iterator;
	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.dialogs.IDialogConstants;
	import org.eclipse.jface.dialogs.IDialogSettings;
	import org.eclipse.jface.dialogs.PopupDialog;
	import org.eclipse.jface.viewers.DoubleClickEvent;
	import org.eclipse.jface.viewers.IDoubleClickListener;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.ITreeContentProvider;
	import org.eclipse.jface.viewers.ITreeSelection;
	import org.eclipse.jface.viewers.SelectionChangedEvent;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jface.viewers.TreeViewer;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.FocusAdapter;
	import org.eclipse.swt.events.FocusEvent;
	import org.eclipse.swt.events.KeyAdapter;
	import org.eclipse.swt.events.KeyEvent;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Text;
	import org.eclipse.ui.IWorkbenchWindow;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.dialogs.FilteredTree;
	import org.eclipse.ui.dialogs.PatternFilter;
	import org.eclipse.ui.internal.IWorkbenchHelpContextIds;
	import org.eclipse.ui.internal.WorkbenchMessages;
	import org.eclipse.ui.internal.WorkbenchPlugin;
	import org.eclipse.ui.internal.registry.ViewRegistry;
	import org.eclipse.ui.views.IViewCategory;
	import org.eclipse.ui.views.IViewDescriptor;
	import org.eclipse.ui.views.IViewRegistry;

	/**
	* The Show View dialog.
	*/
	public class ShowViewDialog extends Dialog implements
	ISelectionChangedListener, IDoubleClickListener {

	private static final String DIALOG_SETTING_SECTION_NAME = "ShowViewDialog"; //$NON-NLS-1$

	private static final int LIST_HEIGHT = 300;

	private static final int LIST_WIDTH = 250;

	private static final String STORE_EXPANDED_CATEGORIES_ID = DIALOG_SETTING_SECTION_NAME
	+ ".STORE_EXPANDED_CATEGORIES_ID"; //$NON-NLS-1$

	private static final String STORE_SELECTED_VIEW_ID = DIALOG_SETTING_SECTION_NAME
	+ ".STORE_SELECTED_VIEW_ID"; //$NON-NLS-1$

	private FilteredTree filteredTree;

	private Button okButton;

	private IViewDescriptor[] viewDescs = new IViewDescriptor[0];

	private IViewRegistry viewReg;

	private IWorkbenchWindow window;

	private Color dimmedForeground;

	private Label descriptionHint;

	/**
	* Constructs a new ShowViewDialog.
	*
	* @param window the workbench window
	* @param viewReg the view registry
	*/
	public ShowViewDialog(IWorkbenchWindow window, IViewRegistry viewReg) {
	super(window.getShell());
	this.window = window;
	this.viewReg = viewReg;
	}

	/**
	* This method is called if a button has been pressed.
	*/
	protected void buttonPressed(int buttonId) {
	if (buttonId == IDialogConstants.OK_ID) {
	saveWidgetValues();
	}
	super.buttonPressed(buttonId);
	}

	/**
	* Notifies that the cancel button of this dialog has been pressed.
	*/
	protected void cancelPressed() {
	viewDescs = new IViewDescriptor[0];
	super.cancelPressed();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)
	*/
	protected void configureShell(Shell shell) {
	super.configureShell(shell);
	shell.setText(WorkbenchMessages.ShowView_shellTitle);
	PlatformUI.getWorkbench().getHelpSystem().setHelp(shell,
	IWorkbenchHelpContextIds.SHOW_VIEW_DIALOG);
	}

	/**
	* Adds buttons to this dialog's button bar.
	* <p>
	* The default implementation of this framework method adds standard ok and
	* cancel buttons using the <code>createButton</code> framework method.
	* Subclasses may override.
	* </p>
	*
	* @param parent the button bar composite
	*/
	protected void createButtonsForButtonBar(Composite parent) {
	okButton = createButton(parent, IDialogConstants.OK_ID,
	IDialogConstants.OK_LABEL, true);
	createButton(parent, IDialogConstants.CANCEL_ID,
	IDialogConstants.CANCEL_LABEL, false);
	updateButtons();
	}

	/**
	* Creates and returns the contents of the upper part of this dialog (above
	* the button bar).
	*
	* @param parent the parent composite to contain the dialog area
	* @return the dialog area control
	*/
	protected Control createDialogArea(Composite parent) {
	// Run super.
	Composite composite = (Composite) super.createDialogArea(parent);
	composite.setFont(parent.getFont());

	createFilteredTreeViewer(composite);

	layoutTopControl(filteredTree);

	// Use F2... label
	descriptionHint = new Label(composite, SWT.WRAP);
	descriptionHint.setText(WorkbenchMessages.ShowView_selectViewHelp);
	descriptionHint.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
	descriptionHint.setVisible(false);

	// Restore the last state
	restoreWidgetValues();

	applyDialogFont(composite);

	// Return results.
	return composite;
	}

	/**
	* Blends c1 and c2 based in the provided ratio.
	*
	* @param c1
	* first color
	* @param c2
	* second color
	* @param ratio
	* percentage of the first color in the blend (0-100)
	* @return the RGB value of the blended color
	*
	* copied from FormColors.java
	*/
	private static RGB blend(RGB c1, RGB c2, int ratio) {
	int r = blend(c1.red, c2.red, ratio);
	int g = blend(c1.green, c2.green, ratio);
	int b = blend(c1.blue, c2.blue, ratio);
	return new RGB(r, g, b);
	}

	private static int blend(int v1, int v2, int ratio) {
	int b = (ratio * v1 + (100 - ratio) * v2) / 100;
	return Math.min(255, b);
	}

	/**
	* Create a new filtered tree viewer in the parent.
	*
	* @param parent the parent <code>Composite</code>.
	*/
	private void createFilteredTreeViewer(Composite parent) {
	PatternFilter filter = new ViewPatternFilter();
	int styleBits = SWT.MULTI \| SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.BORDER;
	filteredTree = new FilteredTree(parent, styleBits, filter, true);
	filteredTree.setBackground(parent.getDisplay().getSystemColor(
	SWT.COLOR_WIDGET_BACKGROUND));

	TreeViewer treeViewer = filteredTree.getViewer();
	Control treeControl = treeViewer.getControl();
	RGB dimmedRGB = blend(treeControl.getForeground().getRGB(), treeControl.getBackground().getRGB(), 60);
	dimmedForeground = new Color(treeControl.getDisplay(), dimmedRGB);
	treeControl.addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	dimmedForeground.dispose();
	}
	});

	treeViewer.setLabelProvider(new ViewLabelProvider(window, dimmedForeground));
	treeViewer.setContentProvider(new ViewContentProvider());
	treeViewer.setComparator(new ViewComparator((ViewRegistry) viewReg));
	treeViewer.setInput(viewReg);
	treeViewer.addSelectionChangedListener(this);
	treeViewer.addDoubleClickListener(this);
	treeViewer.addFilter(new CapabilityFilter());
	treeViewer.getControl().addKeyListener(new KeyAdapter() {
	public void keyPressed(KeyEvent e) {
	handleTreeViewerKeyPressed(e);
	}
	});

	// if the tree has only one or zero views, disable the filter text control
	if (hasAtMostOneView(filteredTree.getViewer())) {
	Text filterText = filteredTree.getFilterControl();
	if (filterText != null) {
	filterText.setEnabled(false);
	}
	}
	}

	/**
	* Return whether or not there are less than two views in the list.
	*
	* @param tree
	* @return <code>true</code> if there are less than two views in the list.
	*/
	private boolean hasAtMostOneView(TreeViewer tree) {
	ITreeContentProvider contentProvider = (ITreeContentProvider) tree
	.getContentProvider();
	Object[] children = contentProvider.getElements(tree.getInput());

	if (children.length <= 1) {
	if (children.length == 0) {
	return true;
	}
	return !contentProvider.hasChildren(children[0]);
	}
	return false;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.jface.viewers.IDoubleClickListener#doubleClick(org.eclipse.jface.viewers.DoubleClickEvent)
	*/
	public void doubleClick(DoubleClickEvent event) {
	IStructuredSelection s = (IStructuredSelection) event.getSelection();
	Object element = s.getFirstElement();
	if (filteredTree.getViewer().isExpandable(element)) {
	filteredTree.getViewer().setExpandedState(element, !filteredTree.getViewer().getExpandedState(element));
	} else if (viewDescs.length > 0) {
	saveWidgetValues();
	setReturnCode(OK);
	close();
	}
	}

	/**
	* Return the dialog store to cache values into
	*/
	protected IDialogSettings getDialogSettings() {
	IDialogSettings workbenchSettings = WorkbenchPlugin.getDefault()
	.getDialogSettings();
	IDialogSettings section = workbenchSettings
	.getSection(DIALOG_SETTING_SECTION_NAME);
	if (section == null) {
	section = workbenchSettings
	.addNewSection(DIALOG_SETTING_SECTION_NAME);
	}
	return section;
	}

	/**
	* Returns the descriptors for the selected views.
	*
	* @return the descriptors for the selected views
	*/
	public IViewDescriptor[] getSelection() {
	return viewDescs;
	}

	/**
	* Layout the top control.
	*
	* @param control the control.
	*/
	private void layoutTopControl(Control control) {
	GridData spec = new GridData(GridData.FILL_BOTH);
	spec.widthHint = LIST_WIDTH;
	spec.heightHint = LIST_HEIGHT;
	control.setLayoutData(spec);
	}

	/**
	* Use the dialog store to restore widget values to the values that they
	* held last time this dialog was used to completion.
	*/
	protected void restoreWidgetValues() {
	Object selection = null;

	IDialogSettings settings = getDialogSettings();
	String[] expandedCategoryIds = settings
	.getArray(STORE_EXPANDED_CATEGORIES_ID);
	if (expandedCategoryIds != null) {
	ViewRegistry reg = (ViewRegistry) viewReg;
	ArrayList categoriesToExpand = new ArrayList(expandedCategoryIds.length);
	for (int i = 0; i < expandedCategoryIds.length; i++) {
	IViewCategory category = reg.findCategory(expandedCategoryIds[i]);
	if (category != null) {
	categoriesToExpand.add(category);
	}
	}

	if (!categoriesToExpand.isEmpty()) {
	filteredTree.getViewer().setExpandedElements(categoriesToExpand.toArray());
	}

	String selectedViewId = settings.get(STORE_SELECTED_VIEW_ID);
	if (selectedViewId != null) {
	selection = reg.find(selectedViewId);
	}
	}

	// Make sure there's a selection in the tree
	if (selection == null)
	selection = filteredTree.getViewer().getTree().getItem(0).getData();

	filteredTree.getViewer().setSelection(new StructuredSelection(selection), true);

	}

	/**
	* Since OK was pressed, write widget values to the dialog store so that
	* they will persist into the next invocation of this dialog
	*/
	protected void saveWidgetValues() {
	IDialogSettings settings = getDialogSettings();

	// Collect the ids of the all expanded categories
	Object[] expandedElements = filteredTree.getViewer().getExpandedElements();
	String[] expandedCategoryIds = new String[expandedElements.length];
	for (int i = 0; i < expandedElements.length; ++i) {
	expandedCategoryIds[i] = ((IViewCategory) expandedElements[i]).getId();
	}

	// Save them for next time.
	settings.put(STORE_EXPANDED_CATEGORIES_ID, expandedCategoryIds);

	String selectedViewId = ""; //$NON-NLS-1$
	if (viewDescs.length > 0) {
	// in the case of a multi-selection, it's probably less confusing
	// to store just the first rather than the whole multi-selection
	selectedViewId = viewDescs[0].getId();
	}
	settings.put(STORE_SELECTED_VIEW_ID, selectedViewId);
	}

	/**
	* Notifies that the selection has changed.
	*
	* @param event event object describing the change
	*/
	public void selectionChanged(SelectionChangedEvent event) {
	updateSelection(event);
	updateButtons();
	descriptionHint.setVisible(viewDescs.length == 1
	&& viewDescs[0].getDescription().length() > 0);
	}

	/**
	* Update the button enablement state.
	*/
	protected void updateButtons() {
	if (okButton != null) {
	okButton.setEnabled(getSelection().length > 0);
	}
	}

	/**
	* Update the selection object.
	*/
	protected void updateSelection(SelectionChangedEvent event) {
	ArrayList descs = new ArrayList();
	IStructuredSelection sel = (IStructuredSelection) event.getSelection();
	for (Iterator i = sel.iterator(); i.hasNext();) {
	Object o = i.next();
	if (o instanceof IViewDescriptor) {
	descs.add(o);
	}
	}

	viewDescs = new IViewDescriptor[descs.size()];
	descs.toArray(viewDescs);
	}


	/* (non-Javadoc)
	* @see org.eclipse.jface.window.Dialog#getDialogBoundsSettings()
	*
	* @since 3.4
	*/
	protected IDialogSettings getDialogBoundsSettings() {
	return getDialogSettings();
	}
	void handleTreeViewerKeyPressed(KeyEvent event) {

	// popup the description for the selected view
	if (descriptionHint.isVisible() && event.keyCode == SWT.F2
	&& event.stateMask == 0) {
	ITreeSelection selection = (ITreeSelection) filteredTree
	.getViewer().getSelection();
	// only show description if one view is selected
	if (selection.size() == 1) {
	Object o = selection.getFirstElement();
	if (o instanceof IViewDescriptor) {
	String description = ((IViewDescriptor) o).getDescription();
	if (description.length() == 0)
	description = WorkbenchMessages.ShowView_noDesc;
	popUp(description);
	}
	}
	}
	}

	private void popUp(final String description) {
	new PopupDialog(filteredTree.getShell(), PopupDialog.HOVER_SHELLSTYLE,
	true, false, false, false, false, null, null) {
	private static final int CURSOR_SIZE = 15;

	protected Point getInitialLocation(Point initialSize) {
	//show popup relative to cursor
	Display display = getShell().getDisplay();
	Point location = display.getCursorLocation();
	location.x += CURSOR_SIZE;
	location.y += CURSOR_SIZE;
	return location;
	}

	protected Control createDialogArea(Composite parent) {
	Label label = new Label(parent, SWT.WRAP);
	label.setText(description);
	label.addFocusListener(new FocusAdapter() {
	public void focusLost(FocusEvent event) {
	close();
	}
	});
	// Use the compact margins employed by PopupDialog.
	GridData gd = new GridData(GridData.BEGINNING
	\| GridData.FILL_BOTH);
	gd.horizontalIndent = PopupDialog.POPUP_HORIZONTALSPACING;
	gd.verticalIndent = PopupDialog.POPUP_VERTICALSPACING;
	label.setLayoutData(gd);
	return label;
	}
	}.open();
	}
	/*
	* (non-Javadoc)
	* @see org.eclipse.jface.dialogs.Dialog#isResizable()
	*/
	protected boolean isResizable() {
	return true;
	}
	}