org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/infoviews/AbstractInfoView.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.infoviews;

 import org.eclipse.core.runtime.IAdaptable;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Menu;
 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.action.IMenuListener;
 import org.eclipse.jface.action.IMenuManager;
 import org.eclipse.jface.action.IToolBarManager;
 import org.eclipse.jface.action.MenuManager;
 import org.eclipse.jface.action.Separator;
 import org.eclipse.jface.resource.ColorRegistry;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.jface.viewers.IStructuredSelection;

 import org.eclipse.jface.text.ITextSelection;

 import org.eclipse.ui.IActionBars;
 import org.eclipse.ui.IPartListener2;
 import org.eclipse.ui.ISelectionListener;
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.IWorkbenchPartReference;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.actions.ActionFactory;
 import org.eclipse.ui.part.ViewPart;
 import org.eclipse.ui.texteditor.ITextEditorActionConstants;

 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.ILocalVariable;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.JavaModelException;

 import org.eclipse.jdt.ui.IContextMenuConstants;
 import org.eclipse.jdt.ui.JavaElementLabels;
 import org.eclipse.jdt.ui.actions.SelectionDispatchAction;

 import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;
 import org.eclipse.jdt.internal.ui.util.SelectionUtil;

 /**
  * Abstract class for views which show information for a given element.
  *
  * @since 3.0
  */
 abstract class AbstractInfoView extends ViewPart implements ISelectionListener, IMenuListener, IPropertyChangeListener {


 	/** JavaElementLabels flags used for the title */
 	private final long TITLE_FLAGS=  JavaElementLabels.ALL_FULLY_QUALIFIED
 		| JavaElementLabels.M_PRE_RETURNTYPE | JavaElementLabels.M_PARAMETER_TYPES | JavaElementLabels.M_PARAMETER_NAMES | JavaElementLabels.M_EXCEPTIONS
 		| JavaElementLabels.F_PRE_TYPE_SIGNATURE | JavaElementLabels.M_PRE_TYPE_PARAMETERS | JavaElementLabels.T_TYPE_PARAMETERS
 		| JavaElementLabels.USE_RESOLVED;
 	private final long LOCAL_VARIABLE_TITLE_FLAGS= TITLE_FLAGS & ~JavaElementLabels.F_FULLY_QUALIFIED | JavaElementLabels.F_POST_QUALIFIED;

 	/** JavaElementLabels flags used for the tool tip text */
 	private static final long TOOLTIP_LABEL_FLAGS= JavaElementLabels.DEFAULT_QUALIFIED | JavaElementLabels.ROOT_POST_QUALIFIED | JavaElementLabels.APPEND_ROOT_PATH |
 			JavaElementLabels.M_PARAMETER_TYPES | JavaElementLabels.M_PARAMETER_NAMES | JavaElementLabels.M_APP_RETURNTYPE | JavaElementLabels.M_EXCEPTIONS |
 			JavaElementLabels.F_APP_TYPE_SIGNATURE | JavaElementLabels.T_TYPE_PARAMETERS;


 	/*
 	 * @see IPartListener2
 	 */
 	private IPartListener2 fPartListener= new IPartListener2() {
 		public void partVisible(IWorkbenchPartReference ref) {
 			if (ref.getId().equals(getSite().getId())) {
 				IWorkbenchPart activePart= ref.getPage().getActivePart();
 				if (activePart != null)
 					selectionChanged(activePart, ref.getPage().getSelection());
 				startListeningForSelectionChanges();
 			}
 		}
 		public void partHidden(IWorkbenchPartReference ref) {
 			if (ref.getId().equals(getSite().getId()))
 				stopListeningForSelectionChanges();
 		}
 		public void partInputChanged(IWorkbenchPartReference ref) {
 			if (!ref.getId().equals(getSite().getId()))
 				computeAndSetInput(ref.getPart(false));
 		}
 		public void partActivated(IWorkbenchPartReference ref) {
 		}
 		public void partBroughtToTop(IWorkbenchPartReference ref) {
 		}
 		public void partClosed(IWorkbenchPartReference ref) {
 		}
 		public void partDeactivated(IWorkbenchPartReference ref) {
 		}
 		public void partOpened(IWorkbenchPartReference ref) {
 		}
 	};


 	/** The current input. */
 	protected IJavaElement fCurrentViewInput;
 	/** The copy to clipboard action. */
 	private SelectionDispatchAction fCopyToClipboardAction;
 	/** The goto input action. */
 	private GotoInputAction fGotoInputAction;
 	/** Counts the number of background computation requests. */
 	private volatile int fComputeCount;

 	/**
 	 * Background color.
 	 * @since 3.2
 	 */
 	private Color fBackgroundColor;
 	private RGB fBackgroundColorRGB;


 	/**
 	 * Set the input of this view.
 	 *
 	 * @param input the input object
 	 */
 	abstract protected void setInput(Object input);

 	/**
 	 * Computes the input for this view based on the given element.
 	 *
 	 * @param element the element from which to compute the input
 	 * @return	the input or <code>null</code> if the input was not computed successfully
 	 */
 	abstract protected Object computeInput(Object element);

 	/**
 	 * Create the part control.
 	 *
  	 * @param parent the parent control
 	 * @see IWorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
 	 */
 	abstract protected void internalCreatePartControl(Composite parent);

 	/**
 	 * Set the view's foreground color.
 	 *
 	 * @param color the SWT color
 	 */
 	abstract protected void setForeground(Color color);

 	/**
 	 * Set the view's background color.
 	 *
 	 * @param color the SWT color
 	 */
 	abstract protected void setBackground(Color color);

 	/**
 	 * Returns the view's primary control.
 	 *
 	 * @return the primary control
 	 */
 	abstract Control getControl();

 	/**
 	 * Returns the context ID for the Help system
 	 *
 	 * @return	the string used as ID for the Help context
 	 * @since 3.1
 	 */
 	abstract protected String getHelpContextId();

 	/*
 	 * @see IWorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
 	 */
 	public final void createPartControl(Composite parent) {
 		internalCreatePartControl(parent);
 		inititalizeColors();
 		getSite().getWorkbenchWindow().getPartService().addPartListener(fPartListener);
 		createContextMenu();
 		createActions();
 		fillActionBars(getViewSite().getActionBars());
 		PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(), getHelpContextId());
 	}

 	/**
 	 * Creates the actions and action groups for this view.
 	 */
 	protected void createActions() {
 		fGotoInputAction= new GotoInputAction(this);
 		fGotoInputAction.setEnabled(false);
 		fCopyToClipboardAction= new CopyToClipboardAction(getViewSite());

 		ISelectionProvider provider= getSelectionProvider();
 		if (provider != null)
 			provider.addSelectionChangedListener(fCopyToClipboardAction);
 	}

 	/**
 	 * Creates the context menu for this view.
 	 */
 	protected void createContextMenu() {
 		MenuManager menuManager= new MenuManager("#PopupMenu"); //$NON-NLS-1$
 		menuManager.setRemoveAllWhenShown(true);
 		menuManager.addMenuListener(this);
 		Menu contextMenu= menuManager.createContextMenu(getControl());
 		getControl().setMenu(contextMenu);
 		getSite().registerContextMenu(menuManager, getSelectionProvider());
 	}

 	/*
 	 * @see IMenuListener#menuAboutToShow(org.eclipse.jface.action.IMenuManager)
 	 */
 	public void menuAboutToShow(IMenuManager menu) {
 		menu.add(new Separator(IContextMenuConstants.GROUP_OPEN));
 		menu.add(new Separator(ITextEditorActionConstants.GROUP_EDIT));
 		menu.add(new Separator(IContextMenuConstants.GROUP_ADDITIONS));

 		IAction action;

 		action= getCopyToClipboardAction();
 		if (action != null)
 			menu.appendToGroup(ITextEditorActionConstants.GROUP_EDIT, action);

 		action= getSelectAllAction();
 		if (action != null)
 			menu.appendToGroup(ITextEditorActionConstants.GROUP_EDIT, action);

 		menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, fGotoInputAction);
 	}

 	protected IAction getSelectAllAction() {
 		return null;
 	}

 	protected IAction getCopyToClipboardAction() {
 		return fCopyToClipboardAction;
 	}

 	/**
 	 * Returns the input of this view.
 	 *
 	 * @return input the input object or <code>null</code> if not input is set
 	 */
 	protected IJavaElement getInput() {
 		return fCurrentViewInput;
 	}

 	// Helper method
 	ISelectionProvider getSelectionProvider() {
 		return getViewSite().getSelectionProvider();
 	}

 	/**
 	 * Fills the actions bars.
 	 * <p>
 	 * Subclasses may extend.
 	 *
 	 * @param actionBars the action bars
 	 */
 	protected void fillActionBars(IActionBars actionBars) {
 		IToolBarManager toolBar= actionBars.getToolBarManager();
 		fillToolBar(toolBar);

 		IAction action;

 		action= getCopyToClipboardAction();
 		if (action != null)
 			actionBars.setGlobalActionHandler(ActionFactory.COPY.getId(), action);

 		action= getSelectAllAction();
 		if (action != null)
 			actionBars.setGlobalActionHandler(ActionFactory.SELECT_ALL.getId(), action);
 	}

 	/**
 	 * Fills the tool bar.
 	 * <p>
 	 * Default is to do nothing.</p>
 	 *
 	 * @param tbm the tool bar manager
 	 */
 	protected void fillToolBar(IToolBarManager tbm) {
 		tbm.add(fGotoInputAction);
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.infoviews.AbstractInfoView#inititalizeColors()
 	 * @since 3.2
 	 */
 	private void inititalizeColors() {
 		if (getSite().getShell().isDisposed())
 			return;

 		Display display= getSite().getShell().getDisplay();
 		if (display == null || display.isDisposed())
 			return;

 		setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));

 		ColorRegistry registry= JFaceResources.getColorRegistry();
 		registry.addListener(this);

 		fBackgroundColorRGB= registry.getRGB(getBackgroundColorKey());
 		Color bgColor;
 		if (fBackgroundColorRGB == null) {
 			bgColor= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND);
 			fBackgroundColorRGB= bgColor.getRGB();
 		} else {
 			bgColor= new Color(display, fBackgroundColorRGB);
 			fBackgroundColor= bgColor;
 		}

 		setBackground(bgColor);
 	}

 	/**
 	 * The preference key for the background color.
 	 *
 	 * @return the background color key
 	 * @since 3.2
 	 */
 	abstract protected String getBackgroundColorKey();

 	public void propertyChange(PropertyChangeEvent event) {
 		if (getBackgroundColorKey().equals(event.getProperty()))
 			inititalizeColors();
 	}

 	/**
 	 * Start to listen for selection changes.
 	 */
 	protected void startListeningForSelectionChanges() {
 		getSite().getPage().addPostSelectionListener(this);
 	}

 	/**
 	 * Stop to listen for selection changes.
 	 */
 	protected void stopListeningForSelectionChanges() {
 		getSite().getPage().removePostSelectionListener(this);
 	}

 	/*
 	 * @see ISelectionListener#selectionChanged(org.eclipse.ui.IWorkbenchPart, org.eclipse.jface.viewers.ISelection)
 	 */
 	public void selectionChanged(IWorkbenchPart part, ISelection selection) {
 		if (part.equals(this))
 			return;

 		computeAndSetInput(part);
 	}

 	/**
 	 * Tells whether the new input should be ignored
 	 * if the current input is the same.
 	 *
 	 * @param je the new input
 	 * @param selection the current selection from the part that provides the input
 	 * @return <code>true</code> if the new input should be ignored
 	 */
 	protected boolean isIgnoringNewInput(IJavaElement je, IWorkbenchPart part, ISelection selection) {
 		return fCurrentViewInput != null && fCurrentViewInput.equals(je) && je != null;
 	}

 	/**
 	 * Finds and returns the Java element selected in the given part.
 	 *
 	 * @param part the workbench part for which to find the selected Java element
 	 * @param selection the selection
 	 * @return the selected Java element
 	 */
 	protected IJavaElement findSelectedJavaElement(IWorkbenchPart part, ISelection selection) {
 		Object element;
 		try {
 			if (part instanceof JavaEditor && selection instanceof ITextSelection) {
 				IJavaElement[] elements= TextSelectionConverter.codeResolve((JavaEditor)part, (ITextSelection)selection);
 				if (elements != null && elements.length > 0)
 					return elements[0];
 				else
 					return null;
 			} else if (selection instanceof IStructuredSelection) {
 				element= SelectionUtil.getSingleElement(selection);
 			} else {
 				return null;
 			}
 		} catch (JavaModelException e) {
 			return null;
 		}

 		return findJavaElement(element);
 	}

 	/**
 	 * Tries to get a Java element out of the given element.
 	 *
 	 * @param element an object
 	 * @return the Java element represented by the given element or <code>null</code>
 	 */
 	private IJavaElement findJavaElement(Object element) {

 		if (element == null)
 			return null;

 		IJavaElement je= null;
 		if (element instanceof IAdaptable)
 			je= (IJavaElement)((IAdaptable)element).getAdapter(IJavaElement.class);

 		return je;
 	}

 	/**
 	 * Finds and returns the type for the given CU.
 	 *
 	 * @param cu	the compilation unit
 	 * @return	the type with same name as the given CU or the first type in the CU
 	 */
 	protected IType getTypeForCU(ICompilationUnit cu) {

 		if (cu == null || !cu.exists())
 			return null;

 		// Use primary type if possible
 		IType primaryType= cu.findPrimaryType();
 		if (primaryType != null)
 			return primaryType;

 		// Use first top-level type
 		try {
 			IType[] types= cu.getTypes();
 			if (types.length > 0)
 				return types[0];
 			else
 				return null;
 		} catch (JavaModelException ex) {
 			return null;
 		}
 	}

 	/*
 	 * @see IWorkbenchPart#dispose()
 	 */
 	final public void dispose() {
 		// cancel possible running computation
 		fComputeCount++;

 		getSite().getWorkbenchWindow().getPartService().removePartListener(fPartListener);

 		ISelectionProvider provider= getSelectionProvider();
 		if (provider != null)
 			provider.removeSelectionChangedListener(fCopyToClipboardAction);

 		JFaceResources.getColorRegistry().removeListener(this);
 		fBackgroundColorRGB= null;
 		if (fBackgroundColor != null) {
 			fBackgroundColor.dispose();
 			fBackgroundColor= null;
 		}

 		internalDispose();

 	}

 	/*
 	 * @see IWorkbenchPart#dispose()
 	 */
 	abstract protected void internalDispose();

 	/**
 	 * Determines all necessary details and delegates the computation into
 	 * a background thread.
 	 *
 	 * @param part the workbench part
 	 */
 	private void computeAndSetInput(final IWorkbenchPart part) {

 		final int currentCount= ++fComputeCount;

 		ISelectionProvider provider= part.getSite().getSelectionProvider();
 		if (provider == null)
 			return;

 		final ISelection selection= provider.getSelection();
 		if (selection == null || selection.isEmpty())
 			return;

 		Thread thread= new Thread("Info view input computer") { //$NON-NLS-1$
 			public void run() {
 				if (currentCount != fComputeCount)
 					return;

 				final IJavaElement je= findSelectedJavaElement(part, selection);

 				if (isIgnoringNewInput(je, part, selection))
 					return;

 				// The actual computation
 				final Object input= computeInput(je);
 				if (input == null)
 					return;

 				Shell shell= getSite().getShell();
 				if (shell.isDisposed())
 					return;

 				Display display= shell.getDisplay();
 				if (display.isDisposed())
 					return;

 				display.asyncExec(new Runnable() {
 					/*
 					 * @see java.lang.Runnable#run()
 					 */
 					public void run() {

 						if (fComputeCount != currentCount || getViewSite().getShell().isDisposed())
 							return;

 						fCurrentViewInput= je;
 						doSetInput(input);
 					}
 				});
 			}
 		};

 		thread.setDaemon(true);
 		thread.setPriority(Thread.MIN_PRIORITY);
 		thread.start();
 	}

 	private void doSetInput(Object input) {
 		setInput(input);

 		fGotoInputAction.setEnabled(true);

 		long flags;

 		if (getInput() instanceof ILocalVariable)
 			flags= LOCAL_VARIABLE_TITLE_FLAGS;
 		else
 			flags= TITLE_FLAGS;

 		setContentDescription(JavaElementLabels.getElementLabel(getInput(), flags));
 		setTitleToolTip(JavaElementLabels.getElementLabel(getInput(), TOOLTIP_LABEL_FLAGS));
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2006 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.infoviews;

	import org.eclipse.core.runtime.IAdaptable;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Menu;
	import org.eclipse.swt.widgets.Shell;

	import org.eclipse.jface.action.IAction;
	import org.eclipse.jface.action.IMenuListener;
	import org.eclipse.jface.action.IMenuManager;
	import org.eclipse.jface.action.IToolBarManager;
	import org.eclipse.jface.action.MenuManager;
	import org.eclipse.jface.action.Separator;
	import org.eclipse.jface.resource.ColorRegistry;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionProvider;
	import org.eclipse.jface.viewers.IStructuredSelection;

	import org.eclipse.jface.text.ITextSelection;

	import org.eclipse.ui.IActionBars;
	import org.eclipse.ui.IPartListener2;
	import org.eclipse.ui.ISelectionListener;
	import org.eclipse.ui.IWorkbenchPart;
	import org.eclipse.ui.IWorkbenchPartReference;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.actions.ActionFactory;
	import org.eclipse.ui.part.ViewPart;
	import org.eclipse.ui.texteditor.ITextEditorActionConstants;

	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.ILocalVariable;
	import org.eclipse.jdt.core.IType;
	import org.eclipse.jdt.core.JavaModelException;

	import org.eclipse.jdt.ui.IContextMenuConstants;
	import org.eclipse.jdt.ui.JavaElementLabels;
	import org.eclipse.jdt.ui.actions.SelectionDispatchAction;

	import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;
	import org.eclipse.jdt.internal.ui.util.SelectionUtil;

	/**
	* Abstract class for views which show information for a given element.
	*
	* @since 3.0
	*/
	abstract class AbstractInfoView extends ViewPart implements ISelectionListener, IMenuListener, IPropertyChangeListener {


	/** JavaElementLabels flags used for the title */
	private final long TITLE_FLAGS= JavaElementLabels.ALL_FULLY_QUALIFIED
	\| JavaElementLabels.M_PRE_RETURNTYPE \| JavaElementLabels.M_PARAMETER_TYPES \| JavaElementLabels.M_PARAMETER_NAMES \| JavaElementLabels.M_EXCEPTIONS
	\| JavaElementLabels.F_PRE_TYPE_SIGNATURE \| JavaElementLabels.M_PRE_TYPE_PARAMETERS \| JavaElementLabels.T_TYPE_PARAMETERS
	\| JavaElementLabels.USE_RESOLVED;
	private final long LOCAL_VARIABLE_TITLE_FLAGS= TITLE_FLAGS & ~JavaElementLabels.F_FULLY_QUALIFIED \| JavaElementLabels.F_POST_QUALIFIED;

	/** JavaElementLabels flags used for the tool tip text */
	private static final long TOOLTIP_LABEL_FLAGS= JavaElementLabels.DEFAULT_QUALIFIED \| JavaElementLabels.ROOT_POST_QUALIFIED \| JavaElementLabels.APPEND_ROOT_PATH \|
	JavaElementLabels.M_PARAMETER_TYPES \| JavaElementLabels.M_PARAMETER_NAMES \| JavaElementLabels.M_APP_RETURNTYPE \| JavaElementLabels.M_EXCEPTIONS \|
	JavaElementLabels.F_APP_TYPE_SIGNATURE \| JavaElementLabels.T_TYPE_PARAMETERS;


	/*
	* @see IPartListener2
	*/
	private IPartListener2 fPartListener= new IPartListener2() {
	public void partVisible(IWorkbenchPartReference ref) {
	if (ref.getId().equals(getSite().getId())) {
	IWorkbenchPart activePart= ref.getPage().getActivePart();
	if (activePart != null)
	selectionChanged(activePart, ref.getPage().getSelection());
	startListeningForSelectionChanges();
	}
	}
	public void partHidden(IWorkbenchPartReference ref) {
	if (ref.getId().equals(getSite().getId()))
	stopListeningForSelectionChanges();
	}
	public void partInputChanged(IWorkbenchPartReference ref) {
	if (!ref.getId().equals(getSite().getId()))
	computeAndSetInput(ref.getPart(false));
	}
	public void partActivated(IWorkbenchPartReference ref) {
	}
	public void partBroughtToTop(IWorkbenchPartReference ref) {
	}
	public void partClosed(IWorkbenchPartReference ref) {
	}
	public void partDeactivated(IWorkbenchPartReference ref) {
	}
	public void partOpened(IWorkbenchPartReference ref) {
	}
	};


	/** The current input. */
	protected IJavaElement fCurrentViewInput;
	/** The copy to clipboard action. */
	private SelectionDispatchAction fCopyToClipboardAction;
	/** The goto input action. */
	private GotoInputAction fGotoInputAction;
	/** Counts the number of background computation requests. */
	private volatile int fComputeCount;

	/**
	* Background color.
	* @since 3.2
	*/
	private Color fBackgroundColor;
	private RGB fBackgroundColorRGB;


	/**
	* Set the input of this view.
	*
	* @param input the input object
	*/
	abstract protected void setInput(Object input);

	/**
	* Computes the input for this view based on the given element.
	*
	* @param element the element from which to compute the input
	* @return the input or <code>null</code> if the input was not computed successfully
	*/
	abstract protected Object computeInput(Object element);

	/**
	* Create the part control.
	*
	* @param parent the parent control
	* @see IWorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	*/
	abstract protected void internalCreatePartControl(Composite parent);

	/**
	* Set the view's foreground color.
	*
	* @param color the SWT color
	*/
	abstract protected void setForeground(Color color);

	/**
	* Set the view's background color.
	*
	* @param color the SWT color
	*/
	abstract protected void setBackground(Color color);

	/**
	* Returns the view's primary control.
	*
	* @return the primary control
	*/
	abstract Control getControl();

	/**
	* Returns the context ID for the Help system
	*
	* @return the string used as ID for the Help context
	* @since 3.1
	*/
	abstract protected String getHelpContextId();

	/*
	* @see IWorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	*/
	public final void createPartControl(Composite parent) {
	internalCreatePartControl(parent);
	inititalizeColors();
	getSite().getWorkbenchWindow().getPartService().addPartListener(fPartListener);
	createContextMenu();
	createActions();
	fillActionBars(getViewSite().getActionBars());
	PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(), getHelpContextId());
	}

	/**
	* Creates the actions and action groups for this view.
	*/
	protected void createActions() {
	fGotoInputAction= new GotoInputAction(this);
	fGotoInputAction.setEnabled(false);
	fCopyToClipboardAction= new CopyToClipboardAction(getViewSite());

	ISelectionProvider provider= getSelectionProvider();
	if (provider != null)
	provider.addSelectionChangedListener(fCopyToClipboardAction);
	}

	/**
	* Creates the context menu for this view.
	*/
	protected void createContextMenu() {
	MenuManager menuManager= new MenuManager("#PopupMenu"); //$NON-NLS-1$
	menuManager.setRemoveAllWhenShown(true);
	menuManager.addMenuListener(this);
	Menu contextMenu= menuManager.createContextMenu(getControl());
	getControl().setMenu(contextMenu);
	getSite().registerContextMenu(menuManager, getSelectionProvider());
	}

	/*
	* @see IMenuListener#menuAboutToShow(org.eclipse.jface.action.IMenuManager)
	*/
	public void menuAboutToShow(IMenuManager menu) {
	menu.add(new Separator(IContextMenuConstants.GROUP_OPEN));
	menu.add(new Separator(ITextEditorActionConstants.GROUP_EDIT));
	menu.add(new Separator(IContextMenuConstants.GROUP_ADDITIONS));

	IAction action;

	action= getCopyToClipboardAction();
	if (action != null)
	menu.appendToGroup(ITextEditorActionConstants.GROUP_EDIT, action);

	action= getSelectAllAction();
	if (action != null)
	menu.appendToGroup(ITextEditorActionConstants.GROUP_EDIT, action);

	menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, fGotoInputAction);
	}

	protected IAction getSelectAllAction() {
	return null;
	}

	protected IAction getCopyToClipboardAction() {
	return fCopyToClipboardAction;
	}

	/**
	* Returns the input of this view.
	*
	* @return input the input object or <code>null</code> if not input is set
	*/
	protected IJavaElement getInput() {
	return fCurrentViewInput;
	}

	// Helper method
	ISelectionProvider getSelectionProvider() {
	return getViewSite().getSelectionProvider();
	}

	/**
	* Fills the actions bars.
	* <p>
	* Subclasses may extend.
	*
	* @param actionBars the action bars
	*/
	protected void fillActionBars(IActionBars actionBars) {
	IToolBarManager toolBar= actionBars.getToolBarManager();
	fillToolBar(toolBar);

	IAction action;

	action= getCopyToClipboardAction();
	if (action != null)
	actionBars.setGlobalActionHandler(ActionFactory.COPY.getId(), action);

	action= getSelectAllAction();
	if (action != null)
	actionBars.setGlobalActionHandler(ActionFactory.SELECT_ALL.getId(), action);
	}

	/**
	* Fills the tool bar.
	* <p>
	* Default is to do nothing.</p>
	*
	* @param tbm the tool bar manager
	*/
	protected void fillToolBar(IToolBarManager tbm) {
	tbm.add(fGotoInputAction);
	}

	/*
	* @see org.eclipse.jdt.internal.ui.infoviews.AbstractInfoView#inititalizeColors()
	* @since 3.2
	*/
	private void inititalizeColors() {
	if (getSite().getShell().isDisposed())
	return;

	Display display= getSite().getShell().getDisplay();
	if (display == null \|\| display.isDisposed())
	return;

	setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));

	ColorRegistry registry= JFaceResources.getColorRegistry();
	registry.addListener(this);

	fBackgroundColorRGB= registry.getRGB(getBackgroundColorKey());
	Color bgColor;
	if (fBackgroundColorRGB == null) {
	bgColor= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND);
	fBackgroundColorRGB= bgColor.getRGB();
	} else {
	bgColor= new Color(display, fBackgroundColorRGB);
	fBackgroundColor= bgColor;
	}

	setBackground(bgColor);
	}

	/**
	* The preference key for the background color.
	*
	* @return the background color key
	* @since 3.2
	*/
	abstract protected String getBackgroundColorKey();

	public void propertyChange(PropertyChangeEvent event) {
	if (getBackgroundColorKey().equals(event.getProperty()))
	inititalizeColors();
	}

	/**
	* Start to listen for selection changes.
	*/
	protected void startListeningForSelectionChanges() {
	getSite().getPage().addPostSelectionListener(this);
	}

	/**
	* Stop to listen for selection changes.
	*/
	protected void stopListeningForSelectionChanges() {
	getSite().getPage().removePostSelectionListener(this);
	}

	/*
	* @see ISelectionListener#selectionChanged(org.eclipse.ui.IWorkbenchPart, org.eclipse.jface.viewers.ISelection)
	*/
	public void selectionChanged(IWorkbenchPart part, ISelection selection) {
	if (part.equals(this))
	return;

	computeAndSetInput(part);
	}

	/**
	* Tells whether the new input should be ignored
	* if the current input is the same.
	*
	* @param je the new input
	* @param selection the current selection from the part that provides the input
	* @return <code>true</code> if the new input should be ignored
	*/
	protected boolean isIgnoringNewInput(IJavaElement je, IWorkbenchPart part, ISelection selection) {
	return fCurrentViewInput != null && fCurrentViewInput.equals(je) && je != null;
	}

	/**
	* Finds and returns the Java element selected in the given part.
	*
	* @param part the workbench part for which to find the selected Java element
	* @param selection the selection
	* @return the selected Java element
	*/
	protected IJavaElement findSelectedJavaElement(IWorkbenchPart part, ISelection selection) {
	Object element;
	try {
	if (part instanceof JavaEditor && selection instanceof ITextSelection) {
	IJavaElement[] elements= TextSelectionConverter.codeResolve((JavaEditor)part, (ITextSelection)selection);
	if (elements != null && elements.length > 0)
	return elements[0];
	else
	return null;
	} else if (selection instanceof IStructuredSelection) {
	element= SelectionUtil.getSingleElement(selection);
	} else {
	return null;
	}
	} catch (JavaModelException e) {
	return null;
	}

	return findJavaElement(element);
	}

	/**
	* Tries to get a Java element out of the given element.
	*
	* @param element an object
	* @return the Java element represented by the given element or <code>null</code>
	*/
	private IJavaElement findJavaElement(Object element) {

	if (element == null)
	return null;

	IJavaElement je= null;
	if (element instanceof IAdaptable)
	je= (IJavaElement)((IAdaptable)element).getAdapter(IJavaElement.class);

	return je;
	}

	/**
	* Finds and returns the type for the given CU.
	*
	* @param cu the compilation unit
	* @return the type with same name as the given CU or the first type in the CU
	*/
	protected IType getTypeForCU(ICompilationUnit cu) {

	if (cu == null \|\| !cu.exists())
	return null;

	// Use primary type if possible
	IType primaryType= cu.findPrimaryType();
	if (primaryType != null)
	return primaryType;

	// Use first top-level type
	try {
	IType[] types= cu.getTypes();
	if (types.length > 0)
	return types[0];
	else
	return null;
	} catch (JavaModelException ex) {
	return null;
	}
	}

	/*
	* @see IWorkbenchPart#dispose()
	*/
	final public void dispose() {
	// cancel possible running computation
	fComputeCount++;

	getSite().getWorkbenchWindow().getPartService().removePartListener(fPartListener);

	ISelectionProvider provider= getSelectionProvider();
	if (provider != null)
	provider.removeSelectionChangedListener(fCopyToClipboardAction);

	JFaceResources.getColorRegistry().removeListener(this);
	fBackgroundColorRGB= null;
	if (fBackgroundColor != null) {
	fBackgroundColor.dispose();
	fBackgroundColor= null;
	}

	internalDispose();

	}

	/*
	* @see IWorkbenchPart#dispose()
	*/
	abstract protected void internalDispose();

	/**
	* Determines all necessary details and delegates the computation into
	* a background thread.
	*
	* @param part the workbench part
	*/
	private void computeAndSetInput(final IWorkbenchPart part) {

	final int currentCount= ++fComputeCount;

	ISelectionProvider provider= part.getSite().getSelectionProvider();
	if (provider == null)
	return;

	final ISelection selection= provider.getSelection();
	if (selection == null \|\| selection.isEmpty())
	return;

	Thread thread= new Thread("Info view input computer") { //$NON-NLS-1$
	public void run() {
	if (currentCount != fComputeCount)
	return;

	final IJavaElement je= findSelectedJavaElement(part, selection);

	if (isIgnoringNewInput(je, part, selection))
	return;

	// The actual computation
	final Object input= computeInput(je);
	if (input == null)
	return;

	Shell shell= getSite().getShell();
	if (shell.isDisposed())
	return;

	Display display= shell.getDisplay();
	if (display.isDisposed())
	return;

	display.asyncExec(new Runnable() {
	/*
	* @see java.lang.Runnable#run()
	*/
	public void run() {

	if (fComputeCount != currentCount \|\| getViewSite().getShell().isDisposed())
	return;

	fCurrentViewInput= je;
	doSetInput(input);
	}
	});
	}
	};

	thread.setDaemon(true);
	thread.setPriority(Thread.MIN_PRIORITY);
	thread.start();
	}

	private void doSetInput(Object input) {
	setInput(input);

	fGotoInputAction.setEnabled(true);

	long flags;

	if (getInput() instanceof ILocalVariable)
	flags= LOCAL_VARIABLE_TITLE_FLAGS;
	else
	flags= TITLE_FLAGS;

	setContentDescription(JavaElementLabels.getElementLabel(getInput(), flags));
	setTitleToolTip(JavaElementLabels.getElementLabel(getInput(), TOOLTIP_LABEL_FLAGS));
	}
	}