org.eclipse.mylyn.context.ui/src/org/eclipse/mylyn/internal/context/ui/editors/ContextEditorFormPage.java - gerrit/mylyn/org.eclipse.mylyn.context - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2009 Tasktop Technologies 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:
  *     Tasktop Technologies - initial API and implementation
  *******************************************************************************/

 package org.eclipse.mylyn.internal.context.ui.editors;

 import java.lang.reflect.Method;
 import java.util.List;

 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.action.IMenuListener;
 import org.eclipse.jface.action.IMenuManager;
 import org.eclipse.jface.action.MenuManager;
 import org.eclipse.jface.action.Separator;
 import org.eclipse.jface.layout.GridDataFactory;
 import org.eclipse.jface.viewers.AbstractTreeViewer;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ITreeContentProvider;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.mylyn.commons.core.StatusHandler;
 import org.eclipse.mylyn.context.core.AbstractContextListener;
 import org.eclipse.mylyn.context.core.AbstractContextStructureBridge;
 import org.eclipse.mylyn.context.core.ContextChangeEvent;
 import org.eclipse.mylyn.context.core.ContextCore;
 import org.eclipse.mylyn.context.core.IInteractionElement;
 import org.eclipse.mylyn.internal.context.core.ContextCorePlugin;
 import org.eclipse.mylyn.internal.context.ui.ContextUiPlugin;
 import org.eclipse.mylyn.internal.context.ui.actions.ContextAttachAction;
 import org.eclipse.mylyn.internal.context.ui.actions.ContextClearAction;
 import org.eclipse.mylyn.internal.context.ui.actions.ContextCopyAction;
 import org.eclipse.mylyn.internal.context.ui.actions.ContextRetrieveAction;
 import org.eclipse.mylyn.internal.context.ui.views.ContextNodeOpenListener;
 import org.eclipse.mylyn.internal.provisional.commons.ui.CommonImages;
 import org.eclipse.mylyn.internal.provisional.commons.ui.DelayedRefreshJob;
 import org.eclipse.mylyn.tasks.core.ITask;
 import org.eclipse.mylyn.tasks.ui.TasksUi;
 import org.eclipse.mylyn.tasks.ui.TasksUiImages;
 import org.eclipse.mylyn.tasks.ui.editors.TaskEditorInput;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.MouseAdapter;
 import org.eclipse.swt.events.MouseEvent;
 import org.eclipse.swt.events.MouseListener;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Menu;
 import org.eclipse.swt.widgets.Scale;
 import org.eclipse.ui.IWorkbenchActionConstants;
 import org.eclipse.ui.forms.IManagedForm;
 import org.eclipse.ui.forms.editor.FormEditor;
 import org.eclipse.ui.forms.editor.FormPage;
 import org.eclipse.ui.forms.events.HyperlinkEvent;
 import org.eclipse.ui.forms.events.IHyperlinkListener;
 import org.eclipse.ui.forms.widgets.ExpandableComposite;
 import org.eclipse.ui.forms.widgets.FormToolkit;
 import org.eclipse.ui.forms.widgets.Hyperlink;
 import org.eclipse.ui.forms.widgets.ImageHyperlink;
 import org.eclipse.ui.forms.widgets.ScrolledForm;
 import org.eclipse.ui.forms.widgets.Section;
 import org.eclipse.ui.navigator.CommonViewer;
 import org.eclipse.ui.navigator.INavigatorContentExtension;

 /**
  * @author Mik Kersten
  */
 @SuppressWarnings("deprecation")
 public class ContextEditorFormPage extends FormPage {

 	private static final int SCALE_STEPS = 14;

 	public static final String ID_VIEWER = "org.eclipse.mylyn.context.ui.navigator.context"; //$NON-NLS-1$

 	private ScrolledForm form;

 	private Composite sectionClient;

 	private FormToolkit toolkit;

 	private CommonViewer commonViewer;

 	private Hyperlink activateTaskHyperlink;

 	private final ScalableInterestFilter interestFilter = new ScalableInterestFilter();

 	private Scale doiScale;

 	private ITask task;

 	private class ContextEditorDelayedRefreshJob extends DelayedRefreshJob {

 		public ContextEditorDelayedRefreshJob(StructuredViewer treeViewer, String name) {
 			super(treeViewer, name);
 		}

 		@Override
 		protected void doRefresh(Object[] items) {
 			if (commonViewer != null && !commonViewer.getTree().isDisposed()) {
 				commonViewer.refresh();
 				if (items != null) {
 					for (Object item : items) {
 						updateExpansionState(item);
 					}
 				} else {
 					updateExpansionState(null);
 				}
 			}
 			if (invisiblePart != null) {
 				invisiblePart.updateInvisibleElementsSection();
 			}
 		}

 		protected void updateExpansionState(Object item) {
 			if (commonViewer != null && !commonViewer.getTree().isDisposed()) {
 				try {
 					commonViewer.getTree().setRedraw(false);
 					if (/*!mouseDown && */item == null) {
 						commonViewer.expandAll();
 					} else if (item != null && item instanceof IInteractionElement) {
 						IInteractionElement node = (IInteractionElement) item;
 						AbstractContextStructureBridge structureBridge = ContextCorePlugin.getDefault()
 								.getStructureBridge(node.getContentType());
 						Object objectToRefresh = structureBridge.getObjectForHandle(node.getHandleIdentifier());
 						if (objectToRefresh != null) {
 							commonViewer.expandToLevel(objectToRefresh, AbstractTreeViewer.ALL_LEVELS);
 						}
 					}
 				} finally {
 					commonViewer.getTree().setRedraw(true);
 				}
 			}
 		}

 	}

 	private final AbstractContextListener CONTEXT_LISTENER = new AbstractContextListener() {

 		@Override
 		public void contextChanged(ContextChangeEvent event) {
 			Control partControl = getPartControl();
 			switch (event.getEventKind()) {
 			case ACTIVATED:
 				if (partControl != null && !partControl.isDisposed()) {
 					updateContentArea();
 					refresh();
 				}
 				break;
 			case DEACTIVATED:
 				if (partControl != null && !partControl.isDisposed()) {
 					updateContentArea();
 					refresh();
 				}
 				break;
 			case CLEARED:
 				if (event.isActiveContext()) {
 					refresh();
 				}
 				break;
 			case ELEMENTS_DELETED:
 			case INTEREST_CHANGED:
 			case LANDMARKS_ADDED:
 			case LANDMARKS_REMOVED:
 				refresh(event.getElements());
 				break;
 			}
 		}

 	};

 	public ContextEditorFormPage(FormEditor editor, String id, String title) {
 		super(editor, id, title);
 	}

 	@Override
 	protected void createFormContent(IManagedForm managedForm) {
 		ContextCore.getContextManager().addListener(CONTEXT_LISTENER);
 		task = ((TaskEditorInput) getEditorInput()).getTask();

 		form = managedForm.getForm();

 		toolkit = managedForm.getToolkit();

 		//form.setImage(TaskListImages.getImage(TaskListImages.TASK_ACTIVE_CENTERED));
 		//form.setText(LABEL);
 		//toolkit.decorateFormHeading(form.getForm());

 		form.getBody().setLayout(new FillLayout());
 		Composite composite = new Composite(form.getBody(), SWT.NONE) {
 			@Override
 			public Point computeSize(int widhtHint, int heigtHint, boolean changed) {
 				Rectangle clientArea = getClientArea();
 				return super.computeSize(widhtHint, clientArea.height, changed);
 			}
 		};
 		toolkit.adapt(composite);
 		composite.setLayout(new GridLayout(2, false));

 		createActionsSection(composite);
 		createContentSection(composite);

 		form.reflow(true);
 	}

 	@Override
 	public void dispose() {
 		super.dispose();
 		// ContextUiPlugin.getViewerManager().removeManagedViewer(commonViewer,
 		// this);
 		ContextCore.getContextManager().removeListener(CONTEXT_LISTENER);
 	}

 	private void createActionsSection(Composite composite) {
 		Section section = toolkit.createSection(composite, ExpandableComposite.TITLE_BAR | ExpandableComposite.EXPANDED);
 		section.setText(Messages.ContextEditorFormPage_Actions);

 		section.setLayout(new GridLayout());
 		GridData sectionGridData = new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
 		sectionGridData.widthHint = 80;
 		section.setLayoutData(sectionGridData);

 		Composite sectionClient = toolkit.createComposite(section);
 		section.setClient(sectionClient);
 		sectionClient.setLayout(new GridLayout(2, false));
 		sectionClient.setLayoutData(new GridData());

 		ImageHyperlink filterImage = toolkit.createImageHyperlink(sectionClient, SWT.NONE);
 		filterImage.setImage(CommonImages.getImage(CommonImages.FILTER));
 		filterImage.setToolTipText(Messages.ContextEditorFormPage_Show_All_Elements);
 		filterImage.addHyperlinkListener(new IHyperlinkListener() {

 			public void linkActivated(HyperlinkEvent e) {
 				doiScale.setSelection(0);
 				interestFilter.setThreshold(Integer.MIN_VALUE);
 				refresh();
 			}

 			public void linkEntered(HyperlinkEvent e) {
 				// ignore
 			}

 			public void linkExited(HyperlinkEvent e) {
 				// ignore
 			}
 		});

 		doiScale = new Scale(sectionClient, SWT.FLAT);
 		GridData scaleGridData = new GridData(GridData.FILL_HORIZONTAL);
 		scaleGridData.heightHint = 36;
 		scaleGridData.widthHint = 80;
 		doiScale.setLayoutData(scaleGridData);
 		doiScale.setPageIncrement(1);
 		doiScale.setMinimum(0);
 		doiScale.setSelection(SCALE_STEPS / 2);
 		doiScale.setMaximum(SCALE_STEPS);
 		doiScale.addSelectionListener(new SelectionListener() {
 			public void widgetSelected(SelectionEvent e) {
 				updateFilterThreshold();
 			}

 			public void widgetDefaultSelected(SelectionEvent e) {
 				// don't care about default selection
 			}
 		});

 		if (!isActiveTask()) {
 			doiScale.setEnabled(false);
 		}

 		Label attachImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
 		attachImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_ATTACH));
 		attachImage.setEnabled(task != null);
 		Hyperlink attachHyperlink = toolkit.createHyperlink(sectionClient,
 				Messages.ContextEditorFormPage_Attach_context_, SWT.NONE);
 		attachHyperlink.setEnabled(task != null);
 		attachHyperlink.addMouseListener(new MouseListener() {

 			public void mouseUp(MouseEvent e) {
 				new ContextAttachAction().run(task);
 			}

 			public void mouseDoubleClick(MouseEvent e) {
 				// ignore
 			}

 			public void mouseDown(MouseEvent e) {
 				// ignore
 			}
 		});

 		Label retrieveImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
 		retrieveImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_RETRIEVE));
 		retrieveImage.setEnabled(task != null);
 		Hyperlink retrieveHyperlink = toolkit.createHyperlink(sectionClient,
 				Messages.ContextEditorFormPage_Retrieve_Context_, SWT.NONE);
 		retrieveHyperlink.setEnabled(task != null);
 		retrieveHyperlink.addMouseListener(new MouseListener() {

 			public void mouseUp(MouseEvent e) {
 				new ContextRetrieveAction().run(task);
 			}

 			public void mouseDoubleClick(MouseEvent e) {
 				// ignore
 			}

 			public void mouseDown(MouseEvent e) {
 				// ignore
 			}
 		});

 		Label copyImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
 		copyImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_COPY));
 		Hyperlink copyHyperlink = toolkit.createHyperlink(sectionClient,
 				Messages.ContextEditorFormPage_Copy_Context_to_, SWT.NONE);
 		copyHyperlink.addMouseListener(new MouseListener() {

 			public void mouseUp(MouseEvent e) {
 				new ContextCopyAction().run(task);
 			}

 			public void mouseDoubleClick(MouseEvent e) {
 				// ignore
 			}

 			public void mouseDown(MouseEvent e) {
 				// ignore
 			}
 		});

 		Label clearImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
 		clearImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_CLEAR));
 		Hyperlink clearHyperlink = toolkit.createHyperlink(sectionClient, Messages.ContextEditorFormPage_RemoveAll,
 				SWT.NONE);
 		clearHyperlink.addMouseListener(new MouseListener() {

 			public void mouseUp(MouseEvent e) {
 				new ContextClearAction().run(task);
 			}

 			public void mouseDoubleClick(MouseEvent e) {
 				// ignore
 			}

 			public void mouseDown(MouseEvent e) {
 				// ignore
 			}
 		});
 		section.setExpanded(true);
 	}

 	private ContextEditorDelayedRefreshJob refreshJob;

 	private InvisibleContextElementsPart invisiblePart;

 	/**
 	 * Scales logarithmically to a reasonable interest threshold range (e.g. -10000..10000).
 	 */
 	protected void updateFilterThreshold() {
 		if (doiScale.getSelection() == 0) {
 			interestFilter.setThreshold(Integer.MIN_VALUE);
 		} else if (doiScale.getSelection() == SCALE_STEPS) {
 			interestFilter.setThreshold(Integer.MAX_VALUE);
 		} else {
 			double setting = doiScale.getSelection() - (SCALE_STEPS / 2);
 			double threshold = Math.signum(setting) * Math.pow(Math.exp(Math.abs(setting)), 1.5);
 			interestFilter.setThreshold(threshold);
 		}
 		refresh();
 	}

 	private void refresh() {
 		createRefreshJob();
 		if (refreshJob != null) {
 			refreshJob.refresh();
 		}
 	}

 	private synchronized void createRefreshJob() {
 		if (commonViewer == null) {
 			return;
 		}
 		if (refreshJob == null) {
 			refreshJob = new ContextEditorDelayedRefreshJob(commonViewer, "refresh viewer"); //$NON-NLS-1$
 		}
 	}

 	private void refresh(List<IInteractionElement> elements) {
 		createRefreshJob();
 		if (refreshJob != null) {
 			refreshJob.doRefresh(elements.toArray());
 		}
 	}

 	private void createContentSection(Composite composite) {
 		Section section = toolkit.createSection(composite, ExpandableComposite.TITLE_BAR | ExpandableComposite.EXPANDED);
 		section.setText(Messages.ContextEditorFormPage_Elements);
 		section.setLayoutData(new GridData(GridData.FILL_BOTH));

 		sectionClient = toolkit.createComposite(section);
 		sectionClient.setLayout(new FillLayout());
 		section.setClient(sectionClient);

 		updateContentArea();

 		toolkit.createLabel(composite, "  "); //$NON-NLS-1$

 		invisiblePart = new InvisibleContextElementsPart(commonViewer);
 		Control invisibleControl = invisiblePart.createControl(toolkit, composite);
 		GridDataFactory.fillDefaults().applyTo(invisibleControl);
 	}

 	private void createActivateTaskHyperlink(Composite parent) {
 		activateTaskHyperlink = toolkit.createHyperlink(parent,
 				Messages.ContextEditorFormPage_Activate_task_to_edit_context, SWT.NONE);
 		activateTaskHyperlink.addMouseListener(new MouseAdapter() {
 			@Override
 			public void mouseUp(MouseEvent e) {
 				TasksUi.getTaskActivityManager().activateTask(task);
 			}
 		});
 	}

 	/**
 	 * Disposes the viewer when the current task is not active or creates it if task is activated.
 	 */
 	private void updateContentArea() {
 		if (isActiveTask()) {
 			doiScale.setEnabled(true);
 			doiScale.setSelection(SCALE_STEPS / 2);
 			if (activateTaskHyperlink != null) {
 				activateTaskHyperlink.dispose();
 				activateTaskHyperlink = null;
 			}
 			if (commonViewer == null) {
 				createViewer(sectionClient);
 			}

 			if (invisiblePart != null) {
 				invisiblePart.setCommonViewer(commonViewer);
 			}
 			updateFilterThreshold();
 		} else {
 			doiScale.setEnabled(false);
 			doiScale.setSelection(SCALE_STEPS / 2);
 			if (commonViewer != null) {
 				commonViewer.getControl().dispose();
 				commonViewer = null;
 				if (invisiblePart != null) {
 					invisiblePart.setCommonViewer(commonViewer);
 				}
 				disposeRefreshJob();
 			}
 			if (activateTaskHyperlink == null) {
 				createActivateTaskHyperlink(sectionClient);
 			}
 		}
 		sectionClient.layout();
 	}

 	private synchronized void disposeRefreshJob() {
 		if (refreshJob != null) {
 			refreshJob.cancel();
 			refreshJob = null;
 		}
 	}

 	private boolean isActiveTask() {
 		return task.equals(TasksUi.getTaskActivityManager().getActiveTask());
 	}

 	private void createViewer(Composite parent) {
 		commonViewer = new CommonViewer(ID_VIEWER, parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
 		commonViewer.setUseHashlookup(true);
 		commonViewer.addFilter(interestFilter);
 		commonViewer.addOpenListener(new ContextNodeOpenListener(commonViewer));
 		try {
 			commonViewer.getControl().setRedraw(false);

 			forceFlatLayoutOfJavaContent(commonViewer);

 			commonViewer.setInput(getSite().getPage().getInput());
 			getSite().setSelectionProvider(commonViewer);
 			hookContextMenu();
 			commonViewer.expandAll();
 		} finally {
 			commonViewer.getControl().setRedraw(true);
 		}
 	}

 	public static void forceFlatLayoutOfJavaContent(CommonViewer commonViewer) {
 		INavigatorContentExtension javaContent = commonViewer.getNavigatorContentService().getContentExtensionById(
 				"org.eclipse.jdt.java.ui.javaContent"); //$NON-NLS-1$
 		if (javaContent != null) {
 			ITreeContentProvider treeContentProvider = javaContent.getContentProvider();
 			// TODO: find a sane way of doing this, perhaps via AbstractContextUiBridge, should be:
 			// if (javaContent.getContentProvider() != null) {
 			// JavaNavigatorContentProvider java =
 			// (JavaNavigatorContentProvider)javaContent.getContentProvider();
 			// java.setIsFlatLayout(true);
 			// }
 			try {
 				Class<?> clazz = treeContentProvider.getClass().getSuperclass();
 				Method method = clazz.getDeclaredMethod("setIsFlatLayout", new Class[] { boolean.class }); //$NON-NLS-1$
 				method.invoke(treeContentProvider, new Object[] { true });
 			} catch (Exception e) {
 				StatusHandler.log(new Status(IStatus.ERROR, ContextUiPlugin.ID_PLUGIN,
 						"Could not set flat layout on Java content provider", e)); //$NON-NLS-1$
 			}
 		}
 	}

 	private void hookContextMenu() {
 		MenuManager menuManager = new MenuManager("#PopupMenu"); //$NON-NLS-1$
 		menuManager.setRemoveAllWhenShown(true);
 		menuManager.addMenuListener(new IMenuListener() {
 			public void menuAboutToShow(IMenuManager manager) {
 				fillContextMenu(manager);
 			}
 		});
 		Menu menu = menuManager.createContextMenu(commonViewer.getControl());
 		commonViewer.getControl().setMenu(menu);
 		getSite().registerContextMenu(menuManager, commonViewer);
 	}

 	protected void fillContextMenu(IMenuManager manager) {
 		//manager.add(removeFromContextAction);
 		manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
 	}

 	public ISelection getSelection() {
 		if (getSite() != null && getSite().getSelectionProvider() != null) {
 			return getSite().getSelectionProvider().getSelection();
 		} else {
 			return StructuredSelection.EMPTY;
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2009 Tasktop Technologies 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:
	* Tasktop Technologies - initial API and implementation
	*******************************************************************************/

	package org.eclipse.mylyn.internal.context.ui.editors;

	import java.lang.reflect.Method;
	import java.util.List;

	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.action.IMenuListener;
	import org.eclipse.jface.action.IMenuManager;
	import org.eclipse.jface.action.MenuManager;
	import org.eclipse.jface.action.Separator;
	import org.eclipse.jface.layout.GridDataFactory;
	import org.eclipse.jface.viewers.AbstractTreeViewer;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ITreeContentProvider;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jface.viewers.StructuredViewer;
	import org.eclipse.mylyn.commons.core.StatusHandler;
	import org.eclipse.mylyn.context.core.AbstractContextListener;
	import org.eclipse.mylyn.context.core.AbstractContextStructureBridge;
	import org.eclipse.mylyn.context.core.ContextChangeEvent;
	import org.eclipse.mylyn.context.core.ContextCore;
	import org.eclipse.mylyn.context.core.IInteractionElement;
	import org.eclipse.mylyn.internal.context.core.ContextCorePlugin;
	import org.eclipse.mylyn.internal.context.ui.ContextUiPlugin;
	import org.eclipse.mylyn.internal.context.ui.actions.ContextAttachAction;
	import org.eclipse.mylyn.internal.context.ui.actions.ContextClearAction;
	import org.eclipse.mylyn.internal.context.ui.actions.ContextCopyAction;
	import org.eclipse.mylyn.internal.context.ui.actions.ContextRetrieveAction;
	import org.eclipse.mylyn.internal.context.ui.views.ContextNodeOpenListener;
	import org.eclipse.mylyn.internal.provisional.commons.ui.CommonImages;
	import org.eclipse.mylyn.internal.provisional.commons.ui.DelayedRefreshJob;
	import org.eclipse.mylyn.tasks.core.ITask;
	import org.eclipse.mylyn.tasks.ui.TasksUi;
	import org.eclipse.mylyn.tasks.ui.TasksUiImages;
	import org.eclipse.mylyn.tasks.ui.editors.TaskEditorInput;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.MouseAdapter;
	import org.eclipse.swt.events.MouseEvent;
	import org.eclipse.swt.events.MouseListener;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.events.SelectionListener;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.FillLayout;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Menu;
	import org.eclipse.swt.widgets.Scale;
	import org.eclipse.ui.IWorkbenchActionConstants;
	import org.eclipse.ui.forms.IManagedForm;
	import org.eclipse.ui.forms.editor.FormEditor;
	import org.eclipse.ui.forms.editor.FormPage;
	import org.eclipse.ui.forms.events.HyperlinkEvent;
	import org.eclipse.ui.forms.events.IHyperlinkListener;
	import org.eclipse.ui.forms.widgets.ExpandableComposite;
	import org.eclipse.ui.forms.widgets.FormToolkit;
	import org.eclipse.ui.forms.widgets.Hyperlink;
	import org.eclipse.ui.forms.widgets.ImageHyperlink;
	import org.eclipse.ui.forms.widgets.ScrolledForm;
	import org.eclipse.ui.forms.widgets.Section;
	import org.eclipse.ui.navigator.CommonViewer;
	import org.eclipse.ui.navigator.INavigatorContentExtension;

	/**
	* @author Mik Kersten
	*/
	@SuppressWarnings("deprecation")
	public class ContextEditorFormPage extends FormPage {

	private static final int SCALE_STEPS = 14;

	public static final String ID_VIEWER = "org.eclipse.mylyn.context.ui.navigator.context"; //$NON-NLS-1$

	private ScrolledForm form;

	private Composite sectionClient;

	private FormToolkit toolkit;

	private CommonViewer commonViewer;

	private Hyperlink activateTaskHyperlink;

	private final ScalableInterestFilter interestFilter = new ScalableInterestFilter();

	private Scale doiScale;

	private ITask task;

	private class ContextEditorDelayedRefreshJob extends DelayedRefreshJob {

	public ContextEditorDelayedRefreshJob(StructuredViewer treeViewer, String name) {
	super(treeViewer, name);
	}

	@Override
	protected void doRefresh(Object[] items) {
	if (commonViewer != null && !commonViewer.getTree().isDisposed()) {
	commonViewer.refresh();
	if (items != null) {
	for (Object item : items) {
	updateExpansionState(item);
	}
	} else {
	updateExpansionState(null);
	}
	}
	if (invisiblePart != null) {
	invisiblePart.updateInvisibleElementsSection();
	}
	}

	protected void updateExpansionState(Object item) {
	if (commonViewer != null && !commonViewer.getTree().isDisposed()) {
	try {
	commonViewer.getTree().setRedraw(false);
	if (/!mouseDown && /item == null) {
	commonViewer.expandAll();
	} else if (item != null && item instanceof IInteractionElement) {
	IInteractionElement node = (IInteractionElement) item;
	AbstractContextStructureBridge structureBridge = ContextCorePlugin.getDefault()
	.getStructureBridge(node.getContentType());
	Object objectToRefresh = structureBridge.getObjectForHandle(node.getHandleIdentifier());
	if (objectToRefresh != null) {
	commonViewer.expandToLevel(objectToRefresh, AbstractTreeViewer.ALL_LEVELS);
	}
	}
	} finally {
	commonViewer.getTree().setRedraw(true);
	}
	}
	}

	}

	private final AbstractContextListener CONTEXT_LISTENER = new AbstractContextListener() {

	@Override
	public void contextChanged(ContextChangeEvent event) {
	Control partControl = getPartControl();
	switch (event.getEventKind()) {
	case ACTIVATED:
	if (partControl != null && !partControl.isDisposed()) {
	updateContentArea();
	refresh();
	}
	break;
	case DEACTIVATED:
	if (partControl != null && !partControl.isDisposed()) {
	updateContentArea();
	refresh();
	}
	break;
	case CLEARED:
	if (event.isActiveContext()) {
	refresh();
	}
	break;
	case ELEMENTS_DELETED:
	case INTEREST_CHANGED:
	case LANDMARKS_ADDED:
	case LANDMARKS_REMOVED:
	refresh(event.getElements());
	break;
	}
	}

	};

	public ContextEditorFormPage(FormEditor editor, String id, String title) {
	super(editor, id, title);
	}

	@Override
	protected void createFormContent(IManagedForm managedForm) {
	ContextCore.getContextManager().addListener(CONTEXT_LISTENER);
	task = ((TaskEditorInput) getEditorInput()).getTask();

	form = managedForm.getForm();

	toolkit = managedForm.getToolkit();

	//form.setImage(TaskListImages.getImage(TaskListImages.TASK_ACTIVE_CENTERED));
	//form.setText(LABEL);
	//toolkit.decorateFormHeading(form.getForm());

	form.getBody().setLayout(new FillLayout());
	Composite composite = new Composite(form.getBody(), SWT.NONE) {
	@Override
	public Point computeSize(int widhtHint, int heigtHint, boolean changed) {
	Rectangle clientArea = getClientArea();
	return super.computeSize(widhtHint, clientArea.height, changed);
	}
	};
	toolkit.adapt(composite);
	composite.setLayout(new GridLayout(2, false));

	createActionsSection(composite);
	createContentSection(composite);

	form.reflow(true);
	}

	@Override
	public void dispose() {
	super.dispose();
	// ContextUiPlugin.getViewerManager().removeManagedViewer(commonViewer,
	// this);
	ContextCore.getContextManager().removeListener(CONTEXT_LISTENER);
	}

	private void createActionsSection(Composite composite) {
	Section section = toolkit.createSection(composite, ExpandableComposite.TITLE_BAR \| ExpandableComposite.EXPANDED);
	section.setText(Messages.ContextEditorFormPage_Actions);

	section.setLayout(new GridLayout());
	GridData sectionGridData = new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
	sectionGridData.widthHint = 80;
	section.setLayoutData(sectionGridData);

	Composite sectionClient = toolkit.createComposite(section);
	section.setClient(sectionClient);
	sectionClient.setLayout(new GridLayout(2, false));
	sectionClient.setLayoutData(new GridData());

	ImageHyperlink filterImage = toolkit.createImageHyperlink(sectionClient, SWT.NONE);
	filterImage.setImage(CommonImages.getImage(CommonImages.FILTER));
	filterImage.setToolTipText(Messages.ContextEditorFormPage_Show_All_Elements);
	filterImage.addHyperlinkListener(new IHyperlinkListener() {

	public void linkActivated(HyperlinkEvent e) {
	doiScale.setSelection(0);
	interestFilter.setThreshold(Integer.MIN_VALUE);
	refresh();
	}

	public void linkEntered(HyperlinkEvent e) {
	// ignore
	}

	public void linkExited(HyperlinkEvent e) {
	// ignore
	}
	});

	doiScale = new Scale(sectionClient, SWT.FLAT);
	GridData scaleGridData = new GridData(GridData.FILL_HORIZONTAL);
	scaleGridData.heightHint = 36;
	scaleGridData.widthHint = 80;
	doiScale.setLayoutData(scaleGridData);
	doiScale.setPageIncrement(1);
	doiScale.setMinimum(0);
	doiScale.setSelection(SCALE_STEPS / 2);
	doiScale.setMaximum(SCALE_STEPS);
	doiScale.addSelectionListener(new SelectionListener() {
	public void widgetSelected(SelectionEvent e) {
	updateFilterThreshold();
	}

	public void widgetDefaultSelected(SelectionEvent e) {
	// don't care about default selection
	}
	});

	if (!isActiveTask()) {
	doiScale.setEnabled(false);
	}

	Label attachImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
	attachImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_ATTACH));
	attachImage.setEnabled(task != null);
	Hyperlink attachHyperlink = toolkit.createHyperlink(sectionClient,
	Messages.ContextEditorFormPage_Attach_context_, SWT.NONE);
	attachHyperlink.setEnabled(task != null);
	attachHyperlink.addMouseListener(new MouseListener() {

	public void mouseUp(MouseEvent e) {
	new ContextAttachAction().run(task);
	}

	public void mouseDoubleClick(MouseEvent e) {
	// ignore
	}

	public void mouseDown(MouseEvent e) {
	// ignore
	}
	});

	Label retrieveImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
	retrieveImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_RETRIEVE));
	retrieveImage.setEnabled(task != null);
	Hyperlink retrieveHyperlink = toolkit.createHyperlink(sectionClient,
	Messages.ContextEditorFormPage_Retrieve_Context_, SWT.NONE);
	retrieveHyperlink.setEnabled(task != null);
	retrieveHyperlink.addMouseListener(new MouseListener() {

	public void mouseUp(MouseEvent e) {
	new ContextRetrieveAction().run(task);
	}

	public void mouseDoubleClick(MouseEvent e) {
	// ignore
	}

	public void mouseDown(MouseEvent e) {
	// ignore
	}
	});

	Label copyImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
	copyImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_COPY));
	Hyperlink copyHyperlink = toolkit.createHyperlink(sectionClient,
	Messages.ContextEditorFormPage_Copy_Context_to_, SWT.NONE);
	copyHyperlink.addMouseListener(new MouseListener() {

	public void mouseUp(MouseEvent e) {
	new ContextCopyAction().run(task);
	}

	public void mouseDoubleClick(MouseEvent e) {
	// ignore
	}

	public void mouseDown(MouseEvent e) {
	// ignore
	}
	});

	Label clearImage = toolkit.createLabel(sectionClient, ""); //$NON-NLS-1$
	clearImage.setImage(CommonImages.getImage(TasksUiImages.CONTEXT_CLEAR));
	Hyperlink clearHyperlink = toolkit.createHyperlink(sectionClient, Messages.ContextEditorFormPage_RemoveAll,
	SWT.NONE);
	clearHyperlink.addMouseListener(new MouseListener() {

	public void mouseUp(MouseEvent e) {
	new ContextClearAction().run(task);
	}

	public void mouseDoubleClick(MouseEvent e) {
	// ignore
	}

	public void mouseDown(MouseEvent e) {
	// ignore
	}
	});
	section.setExpanded(true);
	}

	private ContextEditorDelayedRefreshJob refreshJob;

	private InvisibleContextElementsPart invisiblePart;

	/**
	* Scales logarithmically to a reasonable interest threshold range (e.g. -10000..10000).
	*/
	protected void updateFilterThreshold() {
	if (doiScale.getSelection() == 0) {
	interestFilter.setThreshold(Integer.MIN_VALUE);
	} else if (doiScale.getSelection() == SCALE_STEPS) {
	interestFilter.setThreshold(Integer.MAX_VALUE);
	} else {
	double setting = doiScale.getSelection() - (SCALE_STEPS / 2);
	double threshold = Math.signum(setting) * Math.pow(Math.exp(Math.abs(setting)), 1.5);
	interestFilter.setThreshold(threshold);
	}
	refresh();
	}

	private void refresh() {
	createRefreshJob();
	if (refreshJob != null) {
	refreshJob.refresh();
	}
	}

	private synchronized void createRefreshJob() {
	if (commonViewer == null) {
	return;
	}
	if (refreshJob == null) {
	refreshJob = new ContextEditorDelayedRefreshJob(commonViewer, "refresh viewer"); //$NON-NLS-1$
	}
	}

	private void refresh(List<IInteractionElement> elements) {
	createRefreshJob();
	if (refreshJob != null) {
	refreshJob.doRefresh(elements.toArray());
	}
	}

	private void createContentSection(Composite composite) {
	Section section = toolkit.createSection(composite, ExpandableComposite.TITLE_BAR \| ExpandableComposite.EXPANDED);
	section.setText(Messages.ContextEditorFormPage_Elements);
	section.setLayoutData(new GridData(GridData.FILL_BOTH));

	sectionClient = toolkit.createComposite(section);
	sectionClient.setLayout(new FillLayout());
	section.setClient(sectionClient);

	updateContentArea();

	toolkit.createLabel(composite, " "); //$NON-NLS-1$

	invisiblePart = new InvisibleContextElementsPart(commonViewer);
	Control invisibleControl = invisiblePart.createControl(toolkit, composite);
	GridDataFactory.fillDefaults().applyTo(invisibleControl);
	}

	private void createActivateTaskHyperlink(Composite parent) {
	activateTaskHyperlink = toolkit.createHyperlink(parent,
	Messages.ContextEditorFormPage_Activate_task_to_edit_context, SWT.NONE);
	activateTaskHyperlink.addMouseListener(new MouseAdapter() {
	@Override
	public void mouseUp(MouseEvent e) {
	TasksUi.getTaskActivityManager().activateTask(task);
	}
	});
	}

	/**
	* Disposes the viewer when the current task is not active or creates it if task is activated.
	*/
	private void updateContentArea() {
	if (isActiveTask()) {
	doiScale.setEnabled(true);
	doiScale.setSelection(SCALE_STEPS / 2);
	if (activateTaskHyperlink != null) {
	activateTaskHyperlink.dispose();
	activateTaskHyperlink = null;
	}
	if (commonViewer == null) {
	createViewer(sectionClient);
	}

	if (invisiblePart != null) {
	invisiblePart.setCommonViewer(commonViewer);
	}
	updateFilterThreshold();
	} else {
	doiScale.setEnabled(false);
	doiScale.setSelection(SCALE_STEPS / 2);
	if (commonViewer != null) {
	commonViewer.getControl().dispose();
	commonViewer = null;
	if (invisiblePart != null) {
	invisiblePart.setCommonViewer(commonViewer);
	}
	disposeRefreshJob();
	}
	if (activateTaskHyperlink == null) {
	createActivateTaskHyperlink(sectionClient);
	}
	}
	sectionClient.layout();
	}

	private synchronized void disposeRefreshJob() {
	if (refreshJob != null) {
	refreshJob.cancel();
	refreshJob = null;
	}
	}

	private boolean isActiveTask() {
	return task.equals(TasksUi.getTaskActivityManager().getActiveTask());
	}

	private void createViewer(Composite parent) {
	commonViewer = new CommonViewer(ID_VIEWER, parent, SWT.MULTI \| SWT.H_SCROLL \| SWT.V_SCROLL);
	commonViewer.setUseHashlookup(true);
	commonViewer.addFilter(interestFilter);
	commonViewer.addOpenListener(new ContextNodeOpenListener(commonViewer));
	try {
	commonViewer.getControl().setRedraw(false);

	forceFlatLayoutOfJavaContent(commonViewer);

	commonViewer.setInput(getSite().getPage().getInput());
	getSite().setSelectionProvider(commonViewer);
	hookContextMenu();
	commonViewer.expandAll();
	} finally {
	commonViewer.getControl().setRedraw(true);
	}
	}

	public static void forceFlatLayoutOfJavaContent(CommonViewer commonViewer) {
	INavigatorContentExtension javaContent = commonViewer.getNavigatorContentService().getContentExtensionById(
	"org.eclipse.jdt.java.ui.javaContent"); //$NON-NLS-1$
	if (javaContent != null) {
	ITreeContentProvider treeContentProvider = javaContent.getContentProvider();
	// TODO: find a sane way of doing this, perhaps via AbstractContextUiBridge, should be:
	// if (javaContent.getContentProvider() != null) {
	// JavaNavigatorContentProvider java =
	// (JavaNavigatorContentProvider)javaContent.getContentProvider();
	// java.setIsFlatLayout(true);
	// }
	try {
	Class<?> clazz = treeContentProvider.getClass().getSuperclass();
	Method method = clazz.getDeclaredMethod("setIsFlatLayout", new Class[] { boolean.class }); //$NON-NLS-1$
	method.invoke(treeContentProvider, new Object[] { true });
	} catch (Exception e) {
	StatusHandler.log(new Status(IStatus.ERROR, ContextUiPlugin.ID_PLUGIN,
	"Could not set flat layout on Java content provider", e)); //$NON-NLS-1$
	}
	}
	}

	private void hookContextMenu() {
	MenuManager menuManager = new MenuManager("#PopupMenu"); //$NON-NLS-1$
	menuManager.setRemoveAllWhenShown(true);
	menuManager.addMenuListener(new IMenuListener() {
	public void menuAboutToShow(IMenuManager manager) {
	fillContextMenu(manager);
	}
	});
	Menu menu = menuManager.createContextMenu(commonViewer.getControl());
	commonViewer.getControl().setMenu(menu);
	getSite().registerContextMenu(menuManager, commonViewer);
	}

	protected void fillContextMenu(IMenuManager manager) {
	//manager.add(removeFromContextAction);
	manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
	}

	public ISelection getSelection() {
	if (getSite() != null && getSite().getSelectionProvider() != null) {
	return getSite().getSelectionProvider().getSelection();
	} else {
	return StructuredSelection.EMPTY;
	}
	}
	}