preferencedialog.java

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	/**
	 * Creates the inner page container.
	 * 
	 * @param parent
	 * @return Composite
	 */
	protected Composite createPageContainer(Composite parent) {
		
		//Create an outer composite for spacing
		Composite outer = new Composite(parent, SWT.NONE);
		
		GridData outerData = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL
				| GridData.GRAB_VERTICAL);
				
		outer.setLayout(new GridLayout());
		outer.setLayoutData(outerData);

		Composite result = new Composite(outer, SWT.NONE);
		
		GridData resultData = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL
				| GridData.GRAB_VERTICAL);
				
		result.setLayout(getPageLayout());
		result.setLayoutData(resultData);
		
		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 PreferenceMessageArea(this);
		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) {
				Object selection = getSingleSelection(event.getSelection());
				if (selection instanceof IPreferenceNode) {
					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) {
				// call perform help on the current page
				if (currentPage != null) {
					currentPage.performHelp();
				}
			}
		});
	}

	/**
	 * 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 3.0
	 */
	protected 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) {
						MessageDialog
								.openError(
										getShell(),
										JFaceResources.getString("PreferenceDialog.saveErrorTitle"), //$NON-NLS-1$
										JFaceResources
												.format(
														"PreferenceDialog.saveErrorMessage", new Object[] { page.getTitle(), e.getMessage() })); //$NON-NLS-1$
					}
				}
			}
		}
	}

	/**
	 * 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"); //$NON-NLS-1$
				MessageDialog.openError(getShell(), JFaceResources.getString("Error"), message); //$NON-NLS-1$

			}
		});
	}

	/**
	 * 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.getRoot().getSubNodes();
			if (nodes.length > 0) {
				node = nodes[0];
			}
		}
		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>