* Copyright (c) 2000, 2011 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

*     Teddy Walker <teddy.walker@googlemail.com>

*       - Bug 188056 [Preferences] PreferencePages have to less indent in PreferenceDialog

*******************************************************************************/

* A preference dialog is a hierarchical presentation of preference pages. Each

* page is represented by a node in the tree shown on the left hand side of the

* dialog; when a node is selected, the corresponding page is shown on the right

* hand side.

*/

   * Layout for the page container.

   *

   */

  private class PageLayout extends Layout {

    public Point computeSize(Composite composite, int wHint, int hHint, boolean force) {

      if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT) {

        return new Point(wHint, hHint);

      }

      int x = minimumPageSize.x;

      int y = minimumPageSize.y;

      Control[] children = composite.getChildren();

      for (int i = 0; i < children.length; i++) {

        Point size = children[i].computeSize(SWT.DEFAULT, SWT.DEFAULT, force);

        x = Math.max(x, size.x);

        y = Math.max(y, size.y);

      }

     

      //As pages can implement thier own computeSize

      //take it into account

      if(currentPage != null){

        Point size = currentPage.computeSize();

        x = Math.max(x, size.x);

        y = Math.max(y, size.y);

      }

     

      if (wHint != SWT.DEFAULT) {

        x = wHint;

      }

      if (hHint != SWT.DEFAULT) {

        y = hHint;

      }

      return new Point(x, y);

    }

    public void layout(Composite composite, boolean force) {

      Rectangle rect = composite.getClientArea();

      Control[] children = composite.getChildren();

      for (int i = 0; i < children.length; i++) {

        children[i].setSize(rect.width, rect.height);

      }

    }

  }

  //The id of the last page that was selected

  private static String lastPreferenceId = null;

  //The last known tree width

  private static int lastTreeWidth = 180;

  /**

   * Indentifier for the error image

   */

  public static final String PREF_DLG_IMG_TITLE_ERROR = DLG_IMG_MESSAGE_ERROR;

  /**

   * Title area fields

   */

  public static final String PREF_DLG_TITLE_IMG = "preference_dialog_title_image"; //$NON-NLS-1$

  /**

   * Return code used when dialog failed

   */

  protected static final int FAILED = 2;

 

  /**

   * The current preference page, or <code>null</code> if there is none.

   */

  private IPreferencePage currentPage;

  private DialogMessageArea messageArea;

  private Point lastShellSize;

  private IPreferenceNode lastSuccessfulNode;

  /**

   * The minimum page size; 400 by 400 by default.

   *

   * @see #setMinimumPageSize(Point)

   */

  private Point minimumPageSize = new Point(400, 400);

  /**

   * The OK button.

   */

  private Button okButton;

  /**

   * The Composite in which a page is shown.

   */

  private Composite pageContainer;

  /**

   * The preference manager.

   */

  private PreferenceManager preferenceManager;

  /**

   * Flag for the presence of the error message.

   */

  private boolean showingError = false;

  /**

   * Preference store, initially <code>null</code> meaning none.

   *

   * @see #setPreferenceStore

   */

  private IPreferenceStore preferenceStore;

  private Composite titleArea;

  /**

   * The tree viewer.

   */

  private TreeViewer treeViewer;

 

    private ListenerList pageChangedListeners = new ListenerList();

    /**

     *  Composite with a FormLayout to contain the title area

     */

    Composite formTitleComposite;

  private ScrolledComposite scrolled;

  /**

   * Creates a new preference dialog under the control of the given preference

   * manager.

   *

   * @param parentShell

   *            the parent shell

   * @param manager

   *            the preference manager

   */

  public PreferenceDialog(Shell parentShell, PreferenceManager manager) {

    super(parentShell);

    preferenceManager = manager;

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.dialogs.Dialog#buttonPressed(int)

   */

  protected void buttonPressed(int buttonId) {

    switch (buttonId) {

    case IDialogConstants.OK_ID: {

      okPressed();

      return;

    }

    case IDialogConstants.CANCEL_ID: {

      cancelPressed();

      return;

    }

    case IDialogConstants.HELP_ID: {

      helpPressed();

      return;

    }

    }

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.dialogs.Dialog#cancelPressed()

   */

  protected void cancelPressed() {

    // Inform all pages that we are cancelling

    Iterator nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER).iterator();

    final boolean[] cancelOK = new boolean[] { true };

    while (nodes.hasNext()) {

      final IPreferenceNode node = (IPreferenceNode) nodes.next();

      if (getPage(node) != null) {

        SafeRunnable.run(new SafeRunnable() {

          public void run() {

            if (!getPage(node).performCancel()) {

              cancelOK[0] = false;

            }

          }

        });

        if (!cancelOK[0])

          return;

      }

    }

   

    // Give subclasses the choice to save the state of the preference pages if needed

    handleSave();

    setReturnCode(CANCEL);

    close();

  }

  /**

   * Clear the last selected node. This is so that we not chache the last

   * selection in case of an error.

   */

  void clearSelectedNode() {

    setSelectedNodePreference(null);

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.window.Window#close()

   */

  public boolean close() {

   

    //Do this is in a SafeRunnable as it may run client code

    SafeRunnable runnable = new SafeRunnable(){

      /* (non-Javadoc)

       * @see org.eclipse.core.runtime.ISafeRunnable#run()

       */

      public void run() throws Exception {

        List nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER);

        for (int i = 0; i < nodes.size(); i++) {

          IPreferenceNode node = (IPreferenceNode) nodes.get(i);

          node.disposeResources();

        }

       

      }

     

      /* (non-Javadoc)

       * @see org.eclipse.jface.util.SafeRunnable#handleException(java.lang.Throwable)

       */

      public void handleException(Throwable e) {

        super.handleException(e);

        clearSelectedNode();//Do not cache a node with problems

      }

    };

   

    SafeRunner.run(runnable);

   

    return super.close();

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)

   */

  protected void configureShell(Shell newShell) {

    super.configureShell(newShell);

    newShell.setText(JFaceResources.getString("PreferenceDialog.title")); //$NON-NLS-1$

    newShell.addShellListener(new ShellAdapter() {

      public void shellActivated(ShellEvent e) {

        if (lastShellSize == null) {

          lastShellSize = getShell().getSize();

        }

      }

    });

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.window.Window#constrainShellSize()

   */

  protected void constrainShellSize() {

    super.constrainShellSize();

    // record opening shell size

    if (lastShellSize == null) {

      lastShellSize = getShell().getSize();

    }

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar(org.eclipse.swt.widgets.Composite)

   */

  protected void createButtonsForButtonBar(Composite parent) {

    // create OK and Cancel buttons by default

    okButton = createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL, true);

    getShell().setDefaultButton(okButton);

    createButton(parent, IDialogConstants.CANCEL_ID, IDialogConstants.CANCEL_LABEL, false);

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.window.Window#createContents(org.eclipse.swt.widgets.Composite)

   */

  protected Control createContents(final Composite parent) {

    final Control[] control = new Control[1];

    BusyIndicator.showWhile(getShell().getDisplay(), new Runnable() {

      public void run() {

        control[0] = PreferenceDialog.super.createContents(parent);

        // Add the first page

        selectSavedItem();

      }

    });

    return control[0];

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.dialogs.Dialog#createDialogArea(org.eclipse.swt.widgets.Composite)

   */

  protected Control createDialogArea(Composite parent) {

    final Composite composite = (Composite) super.createDialogArea(parent);

    GridLayout parentLayout = ((GridLayout) composite.getLayout());

    parentLayout.numColumns = 4;

    parentLayout.marginHeight = 0;

    parentLayout.marginWidth = 0;

    parentLayout.verticalSpacing = 0;

    parentLayout.horizontalSpacing = 0;

   

    composite.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND));

   

    Control treeControl = createTreeAreaContents(composite);

    createSash(composite,treeControl);

   

    Label versep = new Label(composite, SWT.SEPARATOR | SWT.VERTICAL);

    GridData verGd = new GridData(GridData.FILL_VERTICAL | GridData.GRAB_VERTICAL);

 

    versep.setLayoutData(verGd);

    versep.setLayoutData(new GridData(SWT.LEFT, SWT.FILL, false, true));

   

    Composite pageAreaComposite = new Composite(composite, SWT.NONE);

    pageAreaComposite.setLayoutData(new GridData(GridData.FILL_BOTH));

    GridLayout layout = new GridLayout(1, true);

    layout.marginHeight = 0;

    layout.marginWidth = 0;

    layout.verticalSpacing = 0;

    pageAreaComposite.setLayout(layout);

   

    formTitleComposite = new Composite(pageAreaComposite, SWT.NONE);

    FormLayout titleLayout = new FormLayout();

    titleLayout.marginWidth = 0;

    titleLayout.marginHeight = 0;

    formTitleComposite.setLayout(titleLayout);

   

    GridData titleGridData = new GridData(GridData.FILL_HORIZONTAL);

    titleGridData.horizontalIndent = IDialogConstants.HORIZONTAL_MARGIN;

    formTitleComposite.setLayoutData(titleGridData);

   

    // Build the title area and separator line

    Composite titleComposite = new Composite(formTitleComposite, SWT.NONE);

    layout = new GridLayout();

    layout.marginBottom = 5;

    layout.marginHeight = 0;

    layout.marginWidth = 0;

    layout.horizontalSpacing = 0;

    titleComposite.setLayout(layout);

   

    FormData titleFormData = new FormData();

       titleFormData.top = new FormAttachment(0,0);

      titleFormData.left = new FormAttachment(0,0);

      titleFormData.right = new FormAttachment(100,0);

      titleFormData.bottom = new FormAttachment(100,0);

   

    titleComposite.setLayoutData(titleFormData);

    createTitleArea(titleComposite);

   

    Label separator = new Label(pageAreaComposite, SWT.HORIZONTAL | SWT.SEPARATOR);

    separator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.GRAB_HORIZONTAL));

   

   

    // Build the Page container

    pageContainer = createPageContainer(pageAreaComposite);

    GridData pageContainerData = new GridData(GridData.FILL_BOTH);

    pageContainerData.horizontalIndent = IDialogConstants.HORIZONTAL_MARGIN;

    pageContainer.setLayoutData(pageContainerData);

    // Build the separator line

    Label bottomSeparator = new Label(parent, SWT.HORIZONTAL | SWT.SEPARATOR);

    bottomSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.GRAB_HORIZONTAL));

    return composite;

  }

  /**

   * Create the sash with right control on the right. Note

   * that this method assumes GridData for the layout data

   * of the rightControl.

   * @param composite

   * @param rightControl

   * @return Sash

   *

   * @since 3.1

   */

  protected Sash createSash(final Composite composite, final Control rightControl) {

    final Sash sash = new Sash(composite, SWT.VERTICAL);

    sash.setLayoutData(new GridData(GridData.FILL_VERTICAL));

    sash.setBackground(composite.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND));

    // the following listener resizes the tree control based on sash deltas.

    // If necessary, it will also grow/shrink the dialog.

    sash.addListener(SWT.Selection, new Listener() {

      /*

       * (non-Javadoc)

       *

       * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)

       */

      public void handleEvent(Event event) {

        if (event.detail == SWT.DRAG) {

          return;

        }

        int shift = event.x - sash.getBounds().x;

        GridData data = (GridData) rightControl.getLayoutData();

        int newWidthHint = data.widthHint + shift;

        if (newWidthHint < 20) {

          return;

        }

        Point computedSize = getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);

        Point currentSize = getShell().getSize();

        // if the dialog wasn't of a custom size we know we can shrink

        // it if necessary based on sash movement.

        boolean customSize = !computedSize.equals(currentSize);

        data.widthHint = newWidthHint;

        setLastTreeWidth(newWidthHint);

        composite.layout(true);

        // recompute based on new widget size

        computedSize = getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);

        // if the dialog was of a custom size then increase it only if

        // necessary.

        if (customSize) {

          computedSize.x = Math.max(computedSize.x, currentSize.x);

        }

        computedSize.y = Math.max(computedSize.y, currentSize.y);

        if (computedSize.equals(currentSize)) {

          return;

        }

        setShellSize(computedSize.x, computedSize.y);

        lastShellSize = getShell().getSize();

      }

    });

    return sash;

  }

  /**

   * Creates the inner page container.

   *

   * @param parent

   * @return Composite

   */

  protected Composite createPageContainer(Composite parent) {

 

    Composite outer = new Composite(parent, SWT.NONE);

   

    GridData outerData = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL

        | GridData.GRAB_VERTICAL);

    outerData.horizontalIndent = IDialogConstants.HORIZONTAL_MARGIN;

       

    outer.setLayout(new GridLayout());

    outer.setLayoutData(outerData);

   

    //Create an outer composite for spacing

    scrolled = new ScrolledComposite(outer, SWT.V_SCROLL | SWT.H_SCROLL);

    // always show the focus control

    scrolled.setShowFocusedControl(true);

    scrolled.setExpandHorizontal(true);

    scrolled.setExpandVertical(true);

   

    GridData scrolledData = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL

        | GridData.GRAB_VERTICAL);

       

    scrolled.setLayoutData(scrolledData);

   

    Composite result = new Composite(scrolled, SWT.NONE);

   

    GridData resultData = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL

        | GridData.GRAB_VERTICAL);

       

    result.setLayout(getPageLayout());

    result.setLayoutData(resultData);

   

    scrolled.setContent(result);

   

    return result;

  }

  /**

   * Return the layout for the composite that contains

   * the pages.

   * @return PageLayout

   *

   * @since 3.1

   */

  protected Layout getPageLayout() {

    return new PageLayout();

  }

  /**

   * Creates the wizard's title area.

   *

   * @param parent

   *            the SWT parent for the title area composite.

   * @return the created title area composite.

   */

  protected Composite createTitleArea(Composite parent) {

    // Create the title area which will contain

    // a title, message, and image.

    int margins = 2;

    titleArea = new Composite(parent, SWT.NONE);

    FormLayout layout = new FormLayout();

    layout.marginHeight = 0;

    layout.marginWidth = margins;

    titleArea.setLayout(layout);

   

    GridData layoutData = new GridData(GridData.FILL_HORIZONTAL);

    layoutData.verticalAlignment = SWT.TOP;

    titleArea.setLayoutData(layoutData);

    // Message label

    messageArea = new DialogMessageArea();

    messageArea.createContents(titleArea);

    titleArea.addControlListener(new ControlAdapter() {

      /* (non-Javadoc)

       * @see org.eclipse.swt.events.ControlAdapter#controlResized(org.eclipse.swt.events.ControlEvent)

       */

      public void controlResized(ControlEvent e) {

        updateMessage();

      }

    });

    final IPropertyChangeListener fontListener = new IPropertyChangeListener() {

      public void propertyChange(PropertyChangeEvent event) {

        if (JFaceResources.BANNER_FONT.equals(event.getProperty())) {

          updateMessage();

        }

        if (JFaceResources.DIALOG_FONT.equals(event.getProperty())) {

          updateMessage();

          Font dialogFont = JFaceResources.getDialogFont();

          updateTreeFont(dialogFont);

          Control[] children = ((Composite) buttonBar).getChildren();

          for (int i = 0; i < children.length; i++) {

            children[i].setFont(dialogFont);

          }

        }

      }

    };

    titleArea.addDisposeListener(new DisposeListener() {

      public void widgetDisposed(DisposeEvent event) {

        JFaceResources.getFontRegistry().removeListener(fontListener);

      }

    });

    JFaceResources.getFontRegistry().addListener(fontListener);

    messageArea.setTitleLayoutData(createMessageAreaData());

    messageArea.setMessageLayoutData(createMessageAreaData());

    return titleArea;

  }

  /**

   * Create the layout data for the message area.

   *

   * @return FormData for the message area.

   */

  private FormData createMessageAreaData() {

    FormData messageData = new FormData();

    messageData.top = new FormAttachment(0);

    messageData.bottom = new FormAttachment(100);

    messageData.right = new FormAttachment(100);

    messageData.left = new FormAttachment(0);

    return messageData;

  }

  /**

   * @param parent

   *            the SWT parent for the tree area controls.

   * @return the new <code>Control</code>.

   * @since 3.0

   */

  protected Control createTreeAreaContents(Composite parent) {

    // Build the tree an put it into the composite.

    treeViewer = createTreeViewer(parent);

    treeViewer.setInput(getPreferenceManager());

    updateTreeFont(JFaceResources.getDialogFont());

    layoutTreeAreaControl(treeViewer.getControl());

    return treeViewer.getControl();

  }

  /**

   * Create a new <code>TreeViewer</code>.

   *

   * @param parent

   *            the parent <code>Composite</code>.

   * @return the <code>TreeViewer</code>.

   * @since 3.0

   */

  protected TreeViewer createTreeViewer(Composite parent) {

    final TreeViewer viewer = new TreeViewer(parent, SWT.NONE);

    addListeners(viewer);

    viewer.setLabelProvider(new PreferenceLabelProvider());

    viewer.setContentProvider(new PreferenceContentProvider());

    return viewer;

  }

  /**

   * Add the listeners to the tree viewer.

   * @param viewer

   *

   * @since 3.1

   */

  protected void addListeners(final TreeViewer viewer) {

    viewer.addPostSelectionChangedListener(new ISelectionChangedListener() {

      private void handleError() {

        try {

          // remove the listener temporarily so that the events caused

          // by the error handling dont further cause error handling

          // to occur.

          viewer.removePostSelectionChangedListener(this);

          showPageFlippingAbortDialog();

          selectCurrentPageAgain();

          clearSelectedNode();

        } finally {

          viewer.addPostSelectionChangedListener(this);

        }

      }

      public void selectionChanged(SelectionChangedEvent event) {

        final Object selection = getSingleSelection(event.getSelection());

        if (selection instanceof IPreferenceNode) {

          BusyIndicator.showWhile(getShell().getDisplay(), new Runnable(){

            public void run() {

              if (!isCurrentPageValid()) {

                handleError();

              } else if (!showPage((IPreferenceNode) selection)) {

                // Page flipping wasn't successful

                handleError();

              } else {

                // Everything went well

                lastSuccessfulNode = (IPreferenceNode) selection;

              }

            }

          });

        }

      }

    });

    ((Tree) viewer.getControl()).addSelectionListener(new SelectionAdapter() {

      public void widgetDefaultSelected(final SelectionEvent event) {

        ISelection selection = viewer.getSelection();

        if (selection.isEmpty()) {

          return;

        }

        IPreferenceNode singleSelection = getSingleSelection(selection);

        boolean expanded = viewer.getExpandedState(singleSelection);

        viewer.setExpandedState(singleSelection, !expanded);

      }

    });

    //Register help listener on the tree to use context sensitive help

    viewer.getControl().addHelpListener(new HelpListener() {

      public void helpRequested(HelpEvent event) {

        if (currentPage == null) { // no current page? open dialog's help

          openDialogHelp();

          return;

        }

        // A) A typical path: the current page has registered its own help link

        // via WorkbenchHelpSystem#setHelp(). When just call it and let

        // it handle the help request.

        Control pageControl = currentPage.getControl();

        if (pageControl != null && pageControl.isListening(SWT.Help)) {

          currentPage.performHelp();

          return;

        }

       

        // B) Less typical path: no standard listener has been created for the page.

        // In this case we may or may not have an override of page's #performHelp().

        // 1) Try to get default help opened for the dialog;

        openDialogHelp();

        // 2) Next call currentPage's #performHelp(). If it was overridden, it might switch help

        // to something else.

        currentPage.performHelp();

      }

     

      private void openDialogHelp() {

        if (pageContainer == null)

          return;

          for(Control currentControl = pageContainer; currentControl != null; currentControl = currentControl.getParent()) { 

            if (currentControl.isListening(SWT.Help)) {

              currentControl.notifyListeners(SWT.Help, new Event());

              break;

            }

          }

      }

    });

  }

  /**

   * Find the <code>IPreferenceNode</code> that has data the same id as the

   * supplied value.

   *

   * @param nodeId

   *            the id to search for.

   * @return <code>IPreferenceNode</code> or <code>null</code> if not

   *         found.

   */

  protected IPreferenceNode findNodeMatching(String nodeId) {

    List nodes = preferenceManager.getElements(PreferenceManager.POST_ORDER);

    for (Iterator i = nodes.iterator(); i.hasNext();) {

      IPreferenceNode node = (IPreferenceNode) i.next();

      if (node.getId().equals(nodeId)) {

        return node;

      }

    }

    return null;

  }

  /**

   * Get the last known right side width.

   *

   * @return the width.

   */

  protected int getLastRightWidth() {

    return lastTreeWidth;

  }

  /**

   * Returns the preference mananger used by this preference dialog.

   *

   * @return the preference mananger

   */

  public PreferenceManager getPreferenceManager() {

    return preferenceManager;

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.preference.IPreferencePageContainer#getPreferenceStore()

   */

  public IPreferenceStore getPreferenceStore() {

    return preferenceStore;

  }

  /**

   * Get the name of the selected item preference

   *

   * @return String

   */

  protected String getSelectedNodePreference() {

    return lastPreferenceId;

  }

  /**

   * @param selection

   *            the <code>ISelection</code> to examine.

   * @return the first element, or null if empty.

   */

  protected IPreferenceNode getSingleSelection(ISelection selection) {

    if (!selection.isEmpty()) {

      IStructuredSelection structured = (IStructuredSelection) selection;

      if (structured.getFirstElement() instanceof IPreferenceNode) {

        return (IPreferenceNode) structured.getFirstElement();

      }

    }

    return null;

  }

  /**

   * @return the <code>TreeViewer</code> for this dialog.

   * @since 3.3

   */

  public TreeViewer getTreeViewer() {

    return treeViewer;

  }

  /**

   * Save the values specified in the pages.

   * <p>

   * The default implementation of this framework method saves all pages of

   * type <code>PreferencePage</code> (if their store needs saving and is a

   * <code>PreferenceStore</code>).

   * </p>

   * <p>

   * Subclasses may override.

   * </p>

   */

  protected void handleSave() {

    Iterator nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER).iterator();

    while (nodes.hasNext()) {

      IPreferenceNode node = (IPreferenceNode) nodes.next();

      IPreferencePage page = node.getPage();

      if (page instanceof PreferencePage) {

        // Save now in case tbe workbench does not shutdown cleanly

        IPreferenceStore store = ((PreferencePage) page).getPreferenceStore();

        if (store != null && store.needsSaving()

            && store instanceof IPersistentPreferenceStore) {

          try {

            ((IPersistentPreferenceStore) store).save();

          } catch (IOException e) {

            String message =JFaceResources.format(

                                "PreferenceDialog.saveErrorMessage", new Object[] { page.getTitle(), e.getMessage() }); //$NON-NLS-1$

                  Policy.getStatusHandler().show(

                          new Status(IStatus.ERROR, Policy.JFACE, message, e),

                          JFaceResources.getString("PreferenceDialog.saveErrorTitle")); //$NON-NLS-1$

                   

          }

        }

      }

    }

  }

  /**

   * Notifies that the window's close button was pressed, the close menu was

   * selected, or the ESCAPE key pressed.

   * <p>

   * The default implementation of this framework method sets the window's

   * return code to <code>CANCEL</code> and closes the window using

   * <code>close</code>. Subclasses may extend or reimplement.

   * </p>

   */

  protected void handleShellCloseEvent() {

    // handle the same as pressing cancel

    cancelPressed();

  }

  /**

   * Notifies of the pressing of the Help button.

   * <p>

   * The default implementation of this framework method calls

   * <code>performHelp</code> on the currently active page.

   * </p>

   */

  protected void helpPressed() {

    if (currentPage != null) {

      currentPage.performHelp();

    }

  }

  /**

   * Returns whether the current page is valid.

   *

   * @return <code>false</code> if the current page is not valid, or or

   *         <code>true</code> if the current page is valid or there is no

   *         current page

   */

  protected boolean isCurrentPageValid() {

    if (currentPage == null) {

      return true;

    }

    return currentPage.isValid();

  }

  /**

   * @param control

   *            the <code>Control</code> to lay out.

   * @since 3.0

   */

  protected void layoutTreeAreaControl(Control control) {

    GridData gd = new GridData(GridData.FILL_VERTICAL);

    gd.widthHint = getLastRightWidth();

    gd.verticalSpan = 1;

    control.setLayoutData(gd);

  }

  /**

   * The preference dialog implementation of this <code>Dialog</code>

   * framework method sends <code>performOk</code> to all pages of the

   * preference dialog, then calls <code>handleSave</code> on this dialog to

   * save any state, and then calls <code>close</code> to close this dialog.

   */

  protected void okPressed() {

    SafeRunnable.run(new SafeRunnable() {

      private boolean errorOccurred;

      /*

       * (non-Javadoc)

       *

       * @see org.eclipse.core.runtime.ISafeRunnable#run()

       */

      public void run() {

        getButton(IDialogConstants.OK_ID).setEnabled(false);

        errorOccurred = false;

        boolean hasFailedOK = false;

        try {

          // Notify all the pages and give them a chance to abort

          Iterator nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER)

              .iterator();

          while (nodes.hasNext()) {

            IPreferenceNode node = (IPreferenceNode) nodes.next();

            IPreferencePage page = node.getPage();

            if (page != null) {

              if (!page.performOk()){

                hasFailedOK = true;

                return;

              }

            }

          }

        } catch (Exception e) {

          handleException(e);

        } finally {

          //Don't bother closing if the OK failed

          if(hasFailedOK){

            setReturnCode(FAILED);

            getButton(IDialogConstants.OK_ID).setEnabled(true);

            return;

          }

         

          if (!errorOccurred) {

            //Give subclasses the choice to save the state of the

              //preference pages.

            handleSave();

          }

          setReturnCode(OK);

          close();

        }

      }

      /*

       * (non-Javadoc)

       *

       * @see org.eclipse.core.runtime.ISafeRunnable#handleException(java.lang.Throwable)

       */

      public void handleException(Throwable e) {

        errorOccurred = true;

       

        Policy.getLog().log(new Status(IStatus.ERROR, Policy.JFACE, 0, e.toString(), e));

        clearSelectedNode();

        String message = JFaceResources.getString("SafeRunnable.errorMessage"); //$NON-NLS-1$

                Policy.getStatusHandler().show(

                        new Status(IStatus.ERROR, Policy.JFACE, message, e),

                        JFaceResources.getString("Error")); //$NON-NLS-1$

      }

    });

  }

  /**

   * Selects the page determined by <code>lastSuccessfulNode</code> in the

   * page hierarchy.

   */

  void selectCurrentPageAgain() {

    if (lastSuccessfulNode == null) {

      return;

    }

    getTreeViewer().setSelection(new StructuredSelection(lastSuccessfulNode));

    currentPage.setVisible(true);

  }

  /**

   * Selects the saved item in the tree of preference pages. If it cannot do

   * this it saves the first one.

   */

  protected void selectSavedItem() {

    IPreferenceNode node = findNodeMatching(getSelectedNodePreference());

    if (node == null) {

      IPreferenceNode[] nodes = preferenceManager.getRootSubNodes();

      ViewerComparator comparator = getTreeViewer().getComparator();

      if (comparator != null)  {

        comparator.sort(null, nodes);

      }

      ViewerFilter[] filters = getTreeViewer().getFilters();

      for (int i = 0; i < nodes.length; i++) {

        IPreferenceNode selectedNode = nodes[i];

        // See if it passes all filters

        for (int j = 0; j < filters.length; j++) {

          if (!filters[j].select(this.treeViewer, preferenceManager

              .getRoot(), selectedNode)) {

            selectedNode = null;

            break;

          }

        }

        // if it passes all filters select it

        if (selectedNode != null) {

          node = selectedNode;

          break;

        }

      }

    }

    if (node != null) {

      getTreeViewer().setSelection(new StructuredSelection(node), true);

      // Keep focus in tree. See bugs 2692, 2621, and 6775.

      getTreeViewer().getControl().setFocus();

    }

  }

  /**

   * Display the given error message. The currently displayed message is saved

   * and will be redisplayed when the error message is set to

   * <code>null</code>.

   *

   * @param newErrorMessage

   *            the errorMessage to display or <code>null</code>

   */

  public void setErrorMessage(String newErrorMessage) {

    if (newErrorMessage == null) {

      messageArea.clearErrorMessage();

    } else {

      messageArea.updateText(newErrorMessage, IMessageProvider.ERROR);

    }

  }

  /**

   * Save the last known tree width.

   *

   * @param width

   *            the width.

   */

  private void setLastTreeWidth(int width) {

    lastTreeWidth = width;

  }

  /**

   * Set the message text. If the message line currently displays an error,

   * the message is stored and will be shown after a call to clearErrorMessage

   * <p>

   * Shortcut for <code>setMessage(newMessage, NONE)</code>

   * </p>

   *

   * @param newMessage

   *            the message, or <code>null</code> to clear the message

   */

  public void setMessage(String newMessage) {

    setMessage(newMessage, IMessageProvider.NONE);

  }

  /**

   * Sets the message for this dialog with an indication of what type of

   * message it is.

   * <p>

   * The valid message types are one of <code>NONE</code>,

   * <code>INFORMATION</code>,<code>WARNING</code>, or

   * <code>ERROR</code>.

   * </p>

   * <p>

   * Note that for backward compatibility, a message of type

   * <code>ERROR</code> is different than an error message (set using

   * <code>setErrorMessage</code>). An error message overrides the current

   * message until the error message is cleared. This method replaces the

   * current message and does not affect the error message.

   * </p>

   *

   * @param newMessage

   *            the message, or <code>null</code> to clear the message

   * @param newType

   *            the message type

   * @since 2.0

   */

  public void setMessage(String newMessage, int newType) {

    messageArea.updateText(newMessage, newType);

  }

  /**

   * Sets the minimum page size.

   *

   * @param minWidth

   *            the minimum page width

   * @param minHeight

   *            the minimum page height

   * @see #setMinimumPageSize(Point)

   */

  public void setMinimumPageSize(int minWidth, int minHeight) {

    minimumPageSize.x = minWidth;

    minimumPageSize.y = minHeight;

  }

  /**

   * Sets the minimum page size.

   *

   * @param size

   *            the page size encoded as <code>new Point(width,height)</code>

   * @see #setMinimumPageSize(int,int)

   */

  public void setMinimumPageSize(Point size) {

    minimumPageSize.x = size.x;

    minimumPageSize.y = size.y;

  }

  /**

   * Sets the preference store for this preference dialog.

   *

   * @param store

   *            the preference store

   * @see #getPreferenceStore

   */

  public void setPreferenceStore(IPreferenceStore store) {

    Assert.isNotNull(store);

    preferenceStore = store;

  }

  /**

   * Save the currently selected node.

   */

  private void setSelectedNode() {

    String storeValue = null;

    IStructuredSelection selection = (IStructuredSelection) getTreeViewer().getSelection();

    if (selection.size() == 1) {

      IPreferenceNode node = (IPreferenceNode) selection.getFirstElement();

      storeValue = node.getId();

    }

    setSelectedNodePreference(storeValue);

  }

  /**

   * Sets the name of the selected item preference. Public equivalent to

   * <code>setSelectedNodePreference</code>.

   *

   * @param pageId

   *            The identifier for the page

   * @since 3.0

   */

  public void setSelectedNode(String pageId) {

    setSelectedNodePreference(pageId);

  }

  /**

   * Sets the name of the selected item preference.

   *

   * @param pageId

   *            The identifier for the page

   */

  protected void setSelectedNodePreference(String pageId) {

    lastPreferenceId = pageId;

  }

  /**

   * Changes the shell size to the given size, ensuring that it is no larger

   * than the display bounds.

   *

   * @param width

   *            the shell width

   * @param height

   *            the shell height

   */

  private void setShellSize(int width, int height) {

    Rectangle preferred = getShell().getBounds();

    preferred.width = width;

    preferred.height = height;

    getShell().setBounds(getConstrainedShellBounds(preferred));

  }

  /**

   * Shows the preference page corresponding to the given preference node.

   * Does nothing if that page is already current.

   *

   * @param node

   *            the preference node, or <code>null</code> if none

   * @return <code>true</code> if the page flip was successful, and

   *         <code>false</code> is unsuccessful

   */

  protected boolean showPage(IPreferenceNode node) {

    if (node == null) {

      return false;

    }

    // Create the page if nessessary

    if (node.getPage() == null) {

      createPage(node);

    }

    if (node.getPage() == null) {

      return false;

    }

    IPreferencePage newPage = getPage(node);

    if (newPage == currentPage) {

      return true;

    }

    if (currentPage != null) {

      if (!currentPage.okToLeave()) {

        return false;

      }

    }

    IPreferencePage oldPage = currentPage;

    currentPage = newPage;

    // Set the new page's container

    currentPage.setContainer(this);

    // Ensure that the page control has been created

    // (this allows lazy page control creation)

    if (currentPage.getControl() == null) {

      final boolean[] failed = { false };

      SafeRunnable.run(new ISafeRunnable() {

        public void handleException(Throwable e) {

          failed[0] = true;

        }

        public void run() {

          createPageControl(currentPage, pageContainer);

        }

      });

      if (failed[0]) {

        return false;

      }

      // the page is responsible for ensuring the created control is

      // accessable

      // via getControl.

      Assert.isNotNull(currentPage.getControl());

    }

    // Force calculation of the page's description label because

    // label can be wrapped.

    final Point[] size = new Point[1];

    final Point failed = new Point(-1, -1);

    SafeRunnable.run(new ISafeRunnable() {

      public void handleException(Throwable e) {

        size[0] = failed;

      }

      public void run() {

        size[0] = currentPage.computeSize();

      }

    });

    if (size[0].equals(failed)) {

      return false;

    }

    Point contentSize = size[0];

    // Do we need resizing. Computation not needed if the

    // first page is inserted since computing the dialog's

    // size is done by calling dialog.open().

    // Also prevent auto resize if the user has manually resized

    Shell shell = getShell();

    Point shellSize = shell.getSize();

    if (oldPage != null) {

      Rectangle rect = pageContainer.getClientArea();

      Point containerSize = new Point(rect.width, rect.height);

      int hdiff = contentSize.x - containerSize.x;

      int vdiff = contentSize.y - containerSize.y;

      if ((hdiff > 0 || vdiff > 0) && shellSize.equals(lastShellSize)) {

          hdiff = Math.max(0, hdiff);

          vdiff = Math.max(0, vdiff);

          setShellSize(shellSize.x + hdiff, shellSize.y + vdiff);

          lastShellSize = shell.getSize();

          if (currentPage.getControl().getSize().x == 0) {

            currentPage.getControl().setSize(containerSize);

          }

       

      } else {

        currentPage.setSize(containerSize);

      }

    }

   

    scrolled.setMinSize(contentSize);

    // Ensure that all other pages are invisible

    // (including ones that triggered an exception during

    // their creation).

    Control[] children = pageContainer.getChildren();

    Control currentControl = currentPage.getControl();

    for (int i = 0; i < children.length; i++) {

      if (children[i] != currentControl) {

        children[i].setVisible(false);

      }

    }

    // Make the new page visible

    currentPage.setVisible(true);

    if (oldPage != null) {

      oldPage.setVisible(false);

    }

    // update the dialog controls

    update();

    return true;

  }

  /**

   * Create the page for the node.

   * @param node

   *

   * @since 3.1

   */

  protected void createPage(IPreferenceNode node) {

    node.createPage();

  }

  /**

   * Get the page for the node.

   * @param node

   * @return IPreferencePage

   *

   * @since 3.1

   */

  protected IPreferencePage getPage(IPreferenceNode node) {

    return node.getPage();

  }

  /**

   * Shows the "Page Flipping abort" dialog.

   */

  void showPageFlippingAbortDialog() {

    MessageDialog.open(MessageDialog.ERROR, getShell(), JFaceResources

        .getString("AbortPageFlippingDialog.title"), //$NON-NLS-1$

        JFaceResources.getString("AbortPageFlippingDialog.message"), SWT.SHEET); //$NON-NLS-1$

  }

  /**

   * Updates this dialog's controls to reflect the current page.

   */

  protected void update() {

    // Update the title bar

    updateTitle();

    // Update the message line

    updateMessage();

    // Update the buttons

    updateButtons();

    //Saved the selected node in the preferences

    setSelectedNode();

    firePageChanged(new PageChangedEvent(this, getCurrentPage()));

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.preference.IPreferencePageContainer#updateButtons()

   */

  public void updateButtons() {

    okButton.setEnabled(isCurrentPageValid());

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.preference.IPreferencePageContainer#updateMessage()

   */

  public void updateMessage() {

    String message = null;

    String errorMessage = null;

    if(currentPage != null){

      message = currentPage.getMessage();

      errorMessage = currentPage.getErrorMessage();

    }

    int messageType = IMessageProvider.NONE;

    if (message != null && currentPage instanceof IMessageProvider) {

      messageType = ((IMessageProvider) currentPage).getMessageType();

    }

    if (errorMessage == null){

      if (showingError) {

        // we were previously showing an error

        showingError = false;

      }

    }

    else {

      message = errorMessage;

      messageType = IMessageProvider.ERROR;

      if (!showingError) {

        // we were not previously showing an error

        showingError = true;

      }

    }

    messageArea.updateText(message,messageType);

  }

  /*

   * (non-Javadoc)

   *

   * @see org.eclipse.jface.preference.IPreferencePageContainer#updateTitle()

   */

  public void updateTitle() {

    if(currentPage == null) {

      return;

    }

    messageArea.showTitle(currentPage.getTitle(), currentPage.getImage());

  }

  /**

   * Update the tree to use the specified <code>Font</code>.

   *

   * @param dialogFont

   *            the <code>Font</code> to use.

   * @since 3.0

   */

  protected void updateTreeFont(Font dialogFont) {

    getTreeViewer().getControl().setFont(dialogFont);