FAQ1
FAQ: Can I dynamically change the contents of the System Filesystem at runtime?
 @ServiceProvider(service=FileSystem.class)
public class DynamicLayerContent extends MultiFileSystem {
    private static DynamicLayerContent INSTANCE;
    public DynamicLayerContent() {
        // will be created on startup, exactly once
        INSTANCE = this;
        setPropagateMasks(true); // permit *_hidden masks to be used
    }
    static boolean hasContent() {
        return INSTANCE.getDelegates().length > 0;
    }
    static void enable() {
        if (!hasContent()) {
            try {
                INSTANCE.setDelegates(new XMLFileSystem(
                        DynamicLayerContent.class.getResource(
                        "dynamicContent.xml")));
            } catch (SAXException ex) {
                Exceptions.printStackTrace(ex);
            }
        }
    }
    static void disable() {
        INSTANCE.setDelegates();
    }
}
FAQ2
FAQ: How do I create an Action that is automatically enabled and disabled depending on the selection?
public class FooAction extends AbstractAction implements LookupListener, ContextAwareAction {
    private Lookup context;
    Lookup.Result<Whatever> lkpInfo;
    public FooAction() {
        this(Utilities.actionsGlobalContext());
    }
    private FooAction(Lookup context) {
        putValue(Action.NAME, NbBundle.getMessage(FooAction.class, "LBL_Action"));
        this.context = context;
    }
    void init() {
        assert SwingUtilities.isEventDispatchThread() 
               : "this shall be called just from AWT thread";
        if (lkpInfo != null) {
            return;
        }
        //The thing we want to listen for the presence or absence of
        //on the global selection
        lkpInfo = context.lookupResult(Whatever.class);
        lkpInfo.addLookupListener(this);
        resultChanged(null);
    }
    public boolean isEnabled() {
        init();
        return super.isEnabled();
    }
    public void actionPerformed(ActionEvent e) {
        init();
        for (Whatever instance : lkpInfo.allInstances()) {
            // use it somehow...
        }
    }
    public void resultChanged(LookupEvent ev) {
        setEnabled(!lkpInfo.allInstances().isEmpty());
    }
    public Action createContextAwareInstance(Lookup context) {
        return new FooAction(context);
    }
}
FAQ3
FAQ: How do I add an action to a project node's popup menu of my own project type?
public final class AddActionActions implements ActionProvider {
    private final AddActionProject project; //suppose this is your project
    public AddActionActions(AddActionProject project) {
        this.project = project;
    }
    public String[] getSupportedActions() {
        return new String[] {
            ActionProvider.COMMAND_COPY
        };
    }
    public boolean isActionEnabled(String command, Lookup context) {
        if (command.equals(ActionProvider.COMMAND_COPY)) {
            return true;
        } else {
            throw new IllegalArgumentException(command);
        }
    }
    public void invokeAction(String command, Lookup context) {
        if (command.equalsIgnoreCase(ActionProvider.COMMAND_COPY)){
            DefaultProjectOperations.performDefaultCopyOperation(project);
        }
    }
}
FAQ4
FAQ: How can I add actions to all folder nodes?
 @ActionID(
        category = "Build",
        id = "com.foo.bar.OnAnyFolderAction")
@ActionRegistration(
        displayName = "#CTL_OnAnyFolderAction")
@ActionReferences({
    @ActionReference(path = "Loaders/folder/any/Actions", position = 0)
})
@Messages("CTL_OnAnyFolderAction=ActionOnAnyFolder")
public final class OnAnyFolderAction implements ActionListener {
    private final DataFolder context;
    public OnAnyFolderAction(DataFolder context) {
        this.context = context;
    }
    @Override
    public void actionPerformed(ActionEvent ev) {
        JOptionPane.showMessageDialog(null, context.toString());
    }
}
FAQ5
FAQ: How can I to add actions to the Java package node?
 @ActionID(
        category = "Build",
        id = "com.foo.bar.OnJavaPackageAction")
@ActionRegistration(
        displayName = "#CTL_OnJavaPackageAction")
@ActionReferences({
    @ActionReference(path = "Projects/package/Actions", position = 0)
})
@Messages("CTL_OnJavaPackageAction=OnJavaPackageAction")
public final class OnJavaPackageAction implements ActionListener {
    private final DataFolder context;
    public OnJavaPackageAction(DataFolder context) {
        this.context = context;
    }
    @Override
    public void actionPerformed(ActionEvent ev) {
        JOptionPane.showMessageDialog(null, context.toString());
    }
}
FAQ6
FAQ: How can I add a JSeparator to the main toolbar? 
package com.example.util.widgets;
public class VerticalSeparator extends JSeparator {
    public VerticalSeparator() {
        super(JSeparator.VERTICAL);
    }
    @Override
    public Dimension getMaximumSize() {
        return new Dimension(getPreferredSize().width, super.getMaximumSize().height);
    }
    @Override
    public Dimension getSize() {
        return new Dimension(getPreferredSize().width, super.getSize().height);
    }
}
FAQ7
FAQ: How do I Add Content to the Global Context?
 @ActionID(...)
@ActionRegistration(...)
@ActionReference(...)
public final class CloseProjectAction implements ActionListener
{
    private final Project project;
    public CloseProjectAction(Project context)
    {
        this.project = context;
    }
    @Override
    public void actionPerformed(ActionEvent e)
    {
        OpenProjects.getDefault().close(new Project[] { project });
    }
}
FAQ8
FAQ: What if multiple objects of the same type should be available?
class ObjectInterestedInFooObjects implements LookupListener {
   final Lookup.Result<Foo> result;  //result object is weakly referenced inside Lookup
   ObjectInterestedInFooObjects() {
        result = someLookup.lookupResult(Foo.class);
        result.addLookupListener(this);
        resultChanged(null);
    }
    public void resultChanged(LookupEvent evt) {
        Collection<? extends Foo> c = result.allInstances();
        // do something with the result
    }
}
FAQ9
FAQ: How can I add support for Lookups on nodes representing my file type?
public SomeObject implements Lookup.Provider {
   private InstanceContent content = new InstanceContent();
   private final AbstractLookup lkp = new AbstractLookup(content);
   public someMethod() {
      ic.set (someCollection...);
   }
   public Lookup getLookup() {
      return lkp;
   }
}
FAQ10
FAQ: How can I be notified when a file is modified and saved??
DataObject.Registry registries = DataObject.getRegistry();
registries.addChangeListener(new ChangeListener() {
    public void stateChanged(ChangeEvent e) {
        System.out.println("ChangedListener: o = " + e.getSource().getClass());
        System.out.println("ChangedListener: o.source = " + e.getSource());
    }
});
DataObject[] objects = registries.getModified();
for (int i = 0; i < objects.length; i++) {
    DataObject dataObj = objects[I];
    System.out.println("data object name = " + dataObj.getName());
    System.out.println("data object pimary file name = " + dataObj.getPrimaryFile().getName());
    Set fss = dataObj.files();
    Iterator iter = fss.iterator();
    while (iter.hasNext()) {
        FileObject fo = (FileObject) iter.next();
        System.out.println("\tset file object: " + fo.getName());
    }
}
FAQ11
FAQ: How can I open a file in the editor in read-only mode?
JFileChooser jfc = new JFileChooser();
if (jfc.showOpenDialog(null) != JFileChooser.APPROVE_OPTION) {
    return;
}
File f = jfc.getSelectedFile();
FileObject fo = FileUtil.toFileObject(f);
try {
    new ROEditor(fo).open();
} catch (DataObjectNotFoundException e) {
    e.printStackTrace();
}
FAQ12
FAQ: How can I get a list of open editor windows?
Node[] arr = TopComponent.getRegistry().getCurrentNodes();
for (int i = 0; i < arr.length; i++) {
    EditorCookie ec = (EditorCookie) arr[i].getCookie(EditorCookie.class);
    if (ec != null) {
        JEditorPane[] panes = ec.getOpenedPanes();
        if (panes != null) {
            // USE panes
        }
    }
}
FAQ13
FAQ: How can I get the position of the caret in the currently selected editor window?
Node[] n = TopComponent.getRegistry().getActivatedNodes();
if (n.length == 1) {
    EditorCookie ec = (EditorCookie) n[0].getCookie(EditorCookie.class);
    if (ec != null) {
        JEditorPane[] panes = ec.getOpenedPanes();
        if (panes.length > 0) {
            int cursor = panes[0].getCaret().getDot();
            String selection = panes[0].getSelectedText();
            // USE selection
        }
    }
}
FAQ14
FAQ: How can I open a particular file at a particular line number and column?
File f = ...;
int lineNumber = ...;
FileObject fobj = FileUtil.toFileObject(f);
DataObject dobj = null;
try {
    dobj = DataObject.find(fobj);
} catch (DataObjectNotFoundException ex) {
    ex.printStackTrace();
}
if (dobj != null)
    LineCookie lc = (LineCookie) dobj .getCookie(LineCookie.class);
    if (lc == null) {/* cannot do it */ return;}
    Line l = lc.getLineSet().getOriginal(lineNumber);
    l.show(Line.SHOW_GOTO);
}
FAQ15
FAQ: How can I track what file the user is currently editing?
import org.netbeans.api.editor.EditorRegistry;
PropertyChangeListener l = new PropertyChangeListener() {
  public void propertyChange(PropertyChangeEvent evt) {
    JTextComponent jtc = EditorRegistry.lastFocusedComponent();
    if (jtc != null) {
      Document d = jtc.getDocument();
      // use the document
    }
  }
};
EditorRegistry.addPropertyChangeListener(l);
FAQ16
FAQ: I want to make some programmatic changes to the edited file. How can I do it so one Undo undoes it all?
...
import org.openide.text.NbDocument;
import org.netbeans.api.editor.EditorRegistry;
...
public final class MyAction
    implements ActionListener
{
    private class RunnableAction
        implements Runnable
    {
        private JTextComponent ed;
        private Document doc;
        private RunnableAction( JTextComponent ed, Document doc )
        {
            this.ed = ed;
            this.doc = doc;
        }
        @Override
        public void run()
        {
            ...
        }
    }
    public void actionPerformed( ActionEvent e )
    {
        JTextComponent ed = EditorRegistry.lastFocusedComponent();
        StyledDocument doc = ( StyledDocument ) ed.getDocument();
        // Perform all of the changes atomically so that they can be undone with one undo.
        NbDocument.runAtomic( doc, new RunnableAction( ed, doc ) );
    }
}
FAQ17
FAQ:  How to add code completion to any JEditorPane
        JEditorPane editorPane = new JEditorPane();
        // This will find the Java editor kit and associate it with
        // our editor pane. But that does not give us code completion 
        // just yet because we have no Java context (i.e. no class path, etc.).
        // However, this does give us syntax coloring.
        EditorKit kit = CloneableEditorSupport.getEditorKit("text/x-java");
        editorPane.setEditorKit(kit);
        // You can specify any ".java" file.
        // If the file does not exist, it will be created.
        // The contents of the file does not matter.
        // The extension must be ".java", however.
        String newSourcePath = "tmp.java";
        File tmpFile = new File(newSourcePath);
        FileObject fob = FileUtil.createData(tmpFile);
        DataObject dob = DataObject.find(fob);
        editorPane.getDocument().putProperty(
                Document.StreamDescriptionProperty, 
                dob);
        // This sets up a default class path for us so that
        // we can find all the JDK classes via code completion.
        DialogBinding.bindComponentToFile(fob, 0, 0, editorPane);
        // Last but not least, we need to fill the editor pane with
        // some initial dummy code - as it seems somehow required to
        // kick-start code completion.
        // A simple dummy package declaration will do.
        editorPane.setText("package dummy;");
FAQ18
FAQ: How can I open a file in the IDE programatically?
FileObject fo = FileUtil.toFileObject(new File("test.js").getAbsoluteFile()); 
DataObject newDo = DataObject.find(fo); 
final Node node = newDo.getNodeDelegate(); 
Action a = node.getPreferredAction(); 
if (a instanceof ContextAwareAction) { 
       a = ((ContextAwareAction) a).createContextAwareInstance(node.getLookup()); 
} 
if (a != null) { 
      a.actionPerformed(new ActionEvent(node, ActionEvent.ACTION_PERFORMED, "")); // NOI18N 
FAQ19
FAQ:  How can code in one module be notified when other modules are loaded or unloaded?
 import some.Interface;
 // ...
 private static final Lookup.Result<Interface> services =
     Lookup.getDefault().lookupResult(Interface.class);
 static {
     services.addLookupListener(new LookupListener() {
         public void resultChanged(LookupEvent ev) {
             // some module was loaded or unloaded!
         }
     });
 }
 // ...
 for (Interface service : services.allInstances()) {
     // use a currently available service
 } 
FAQ20
FAQ: How do I create a TopComponent to show an explorer view?
public class MyView extends TopComponent implements ExplorerManager.Provider {
    private final ExplorerManager manager = new ExplorerManager();
    private final JComponent view = new BeanTreeView();
    public MyView() {
        setLayout (new BorderLayout());
        add(view, BorderLayout.CENTER);
        manager.setRootContext(someNode);
        // Probably boilerplate (depends on what you are doing):
        ActionMap map = getActionMap();
        map.put(DefaultEditorKit.copyAction, ExplorerUtils.actionCopy(manager));
        map.put(DefaultEditorKit.cutAction, ExplorerUtils.actionCut(manager));
        map.put(DefaultEditorKit.pasteAction, ExplorerUtils.actionPaste(manager));
        // This one is sometimes changed to say "false":
        map.put("delete", ExplorerUtils.actionDelete(manager, true));
        // Boilerplate:
        associateLookup(ExplorerUtils.createLookup(manager, map));
    }
    // This is optional:
    public boolean requestFocusInWindow() {
        super.requestFocusInWindow();
        // You will need to pick a view to focus:
        return view.requestFocusInWindow();
    }
    // The rest is boilerplate.
    public ExplorerManager getExplorerManager() {
        return manager;
    }
    protected void componentActivated() {
        ExplorerUtils.activateActions(manager, true);
    }
    protected void componentDeactivated() {
        ExplorerUtils.activateActions(manager, false);
    }
}
FAQ21
FAQ: FAQ How are resources created?
IWorkspace workspace = ResourcesPlugin.getWorkspace();
IWorkspaceRoot root = workspace.getRoot();
IProject project  = root.getProject("MyProject");
IFolder folder = project.getFolder("Folder1");
IFile file = folder.getFile("hello.txt");
//at this point, no resources have been created
if (!project.exists()) project.create(null);
if (!project.isOpen()) project.open(null);
if (!folder.exists()) 
    folder.create(IResource.NONE, true, null);
if (!file.exists()) {
    byte[] bytes = "File contents".getBytes();
    InputStream source = new ByteArrayInputStream(bytes);
    file.create(source, IResource.NONE, null);
}
FAQ22
FAQ: FAQ Why do the names of some interfaces end with the digit 2?
   public void runWithEvent(Event event) {
      ...
      if (delegate instanceof IActionDelegate2) {
         ((IActionDelegate2)delegate).runWithEvent(this, event);
         return;
      }
      // Keep for backward compatibility with R2.0
      if (delegate instanceof IActionDelegateWithEvent) {
         ((IActionDelegateWithEvent) delegate).
            runWithEvent(this, event);
         return;
      }
      ...
   }
FAQ23
FAQ: FAQ How do I create fixed views and perspectives?
   class RecipePerspective implements IPerspectiveFactory {
      public void createInitialLayout(IPageLayout page) {
         page.setEditorAreaVisible(true);
         page.setFixed(true);
         page.addStandaloneView(
            RecipePlugin.VIEW_CATEGORIES, 
            false, IPageLayout.TOP, 0.2f, 
            IPageLayout.ID_EDITOR_AREA);
         IViewLayout view = page.getViewLayout(
            RecipePlugin.VIEW_CATEGORIES);
         view.setCloseable(false);
         view.setMoveable(false);
      }
   }
FAQ24
FAQ: FAQ How do I make menus with dynamic contents?
 IMenuListener listener = new IMenuListener() {
      public void menuAboutToShow(IMenuManager m) {
        if (daytime) {
           m.add(workAction);
           m.add(playAction);
        } else {
           m.add(sleepAction);
        }
      }
   };
   menu.addMenuListener(listener);
FAQ25
FAQ: FAQ How do I customize the menus in an RCP application?
   public void fillActionBars(IWorkbenchWindow window,
      IActionBarConfigurer configurer, int flags) {
      if ((flags & FILL_MENU_BAR) == 0)
         return;
      IMenuManager mainMenu = configurer.getMenuManager();
      MenuManager windowMenu = new MenuManager("&Window", 
         IWorkbenchActionConstants.M_WINDOW);
      mainMenu.add(windowMenu);
      windowMenu.add(ActionFactory.MAXIMIZE.create(window));
      MenuManager helpMenu = new MenuManager("&Help", 
         IWorkbenchActionConstants.M_HELP);
      mainMenu.add(helpMenu);
      helpMenu.add(new AboutAction());
   }
FAQ26
FAQ: FAQ How and when do I save the workspace?
final MultiStatus status = new MultiStatus(...);
IRunnableWithProgress runnable = new IRunnableWithProgress() {
  public void run(IProgressMonitor monitor) {
    try {
      IWorkspace ws = ResourcesPlugin.getWorkspace();
      status.merge(ws.save(true, monitor));
    } catch (CoreException e) {
      status.merge(e.getStatus());
    }
  }
};
new ProgressMonitorDialog(null).run(false, false, runnable);
if (!status.isOK()) {
  ErrorDialog.openError(...);
}
FAQ27
FAQ: FAQ How do I implement Quick Fixes for my own language?
public class QuickFixer implements IMarkerResolutionGenerator {
      public IMarkerResolution[] getResolutions(IMarker mk) {
         try {
            Object problem = mk.getAttribute("WhatsUp");
            return new IMarkerResolution[] {
               new QuickFix("Fix #1 for "+problem),
               new QuickFix("Fix #2 for "+problem),
            };
         }
         catch (CoreException e) {
            return new IMarkerResolution[0];
         }
      }
   }
FAQ28
FAQ: FAQ How do I create a Java project?
   String name = "MyProject";
   IWorkspace workspace = ResourcesPlugin.getWorkspace();
   IWorkspaceRoot root= workspace.getRoot();
   IProject project= root.getProject(name);
   project.create(null);
   project.open(null);
   IProjectDescription desc = project.getDescription();
   desc.setNatureIds(new String[] {
      JavaCore.NATURE_ID});
   project.setDescription(desc);
   IJavaProject javaProj = JavaCore.create(project);
   IFolder binDir = project.getFolder("bin");
   IPath binPath = binDir.getFullPath();
   javaProj.setOutputLocation(binPath, null);
   String path = "c:\\jre\\lib\\rt.jar";
   IClasspathEntry cpe= JavaCore.newLibraryEntry(
      path, null, null);
   javaProj.setRawClasspath(new IClasspathEntry[] {cpe});
FAQ29
FAQ: FAQ How do I find all the plug-ins that contribute to my extension point?
IExtensionRegistry reg = Platform.getExtensionRegistry();
   IExtensionPoint ep = reg.getExtensionPoint(extensionID);
   IExtension[] extensions = ep.getExtensions();
   ArrayList contributors = new ArrayList();
   for (int i = 0; i < extensions.length; i++) {
      IExtension ext = extensions[i];
      IConfigurationElement[] ce = 
         ext.getConfigurationElements();
      for (int j = 0; j < ce.length; j++) {
         Object obj = ce[j].createExecutableExtension("class");
         contributors.add(obj);
      }
   }
FAQ30
FAQ: FAQ What is a label decorator?
 ImageDescriptor readOnlyOverlay = ...;
   public void decorate(Object element, IDecoration decoration) {
      if (!(element instanceof java.io.File))
         return;
      boolean readOnly = !((java.io.File) element).canWrite();
      if (!readOnly)
         return;
      decoration.addOverlay(readOnlyOverlay);
      decoration.addSuffix(" (read only)");
   }
FAQ31
FAQ: FAQ How do I run a lengthy process in a wizard?
getContainer().run(true, true, new IRunnableWithProgress() {
      public void run(IProgressMonitor monitor) {
         int sum = n1 + n2;
         monitor.beginTask("Computing sum: ", sum);
         for (int i = 0; i < sum; i++) {
            monitor.subTask(Integer.toString(i));
            //sleep to simulate long running operation
            Thread.sleep(100);
            monitor.worked(1);
         }
         monitor.done();
      }
   });
FAQ32
FAQ: FAQ Can I create an application that doesn't have views or editors?
 public class JFaceApp implements IPlatformRunnable {
      public Object run(Object args) throws Exception {
         Display display = new Display();
         JFaceAppWindow window = new JFaceAppWindow();
         window.open();
         Shell shell = window.getShell();
         while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
               display.sleep();
         }
         return EXIT_OK;
      }
   }
FAQ33
FAQ: FAQ How do I use the text document model?
 String searchAndReplace(String input, String search, 
     String replace) throws BadLocationException {
      Document doc = new Document(input);
      int offset = 0;
      while (offset < doc.getLength()) {
         offset = doc.search(offset, search, true, true, true);
         if (offset < 0)
            break;
         doc.replace(offset, search.length(), replace);
         offset += replace.length();
      }
      return doc.get();
   }
FAQ34
FAQ: FAQ How do I change the selection on a double-click in my editor?
 public void doubleClicked(ITextViewer part) {
      final int offset = part.getSelectedRange().x;
      int length = 0;
      IDocument doc = part.getDocument();
      while (true) {
         char c = doc.getChar(offset + length);
         if (c=='a'||c=='e'||c=='i'||c=='o'||c=='u')
            break;
         if (offset + ++length >= doc.getLength())
            return;
      }
      part.setSelectedRange(offset, length);
   }
FAQ35
FAQ: FAQ How do I access the active project?
  IResource extractSelection(ISelection sel) {
      if (!(sel instanceof IStructuredSelection))
         return null;
      IStructuredSelection ss = (IStructuredSelection) sel;
      Object element = ss.getFirstElement();
      if (element instanceof IResource)
         return (IResource) element;
      if (!(element instanceof IAdaptable))
         return null;
      IAdaptable adaptable = (IAdaptable)element;
      Object adapter = adaptable.getAdapter(IResource.class);
      return (IResource) adapter;
   }
FAQ36
FAQ: FAQ Why do I get an invalid thread access exception?
   new Thread(new Runnable() {
      public void run() {
         while (true) {
            try { Thread.sleep(1000); } catch (Exception e) { }
            Display.getDefault().asyncExec(new Runnable() {
               public void run() {
                  ... do any work that updates the screen ...
               }
            });
         }
      }
   }).start();
FAQ37
FAQ: FAQ How do I specify the order of pages in a wizard?
 public class AddingWizard extends Wizard {
      private AddingWizardPage page1, page2;
      ...
      public void addPages() {
         page1 = new AddingWizardPage("Page1", 
            "Please enter the first number");
         addPage(page1);
         page2 = new AddingWizardPage("Page2", 
            "Enter another number");
         addPage(page2);
      }
   }
FAQ38
FAQ: FAQ How do I create an image registry for my plug-in?
  public class ExamplesPlugin extends AbstractUIPlugin {
      public static final String PLUGIN_ID = "org.eclipse.faq.examples";
      public static final String IMAGE_ID = "sample.image";
      ...
      protected void initializeImageRegistry(ImageRegistry registry) {
         Bundle bundle = Platform.getBundle(PLUGIN_ID);
         IPath path = new Path("icons/sample.gif");
         URL url = FileLocator.find(bundle, path, null);
         ImageDescriptor desc = ImageDescriptor.createFromURL(url);
         registry.put(IMAGE_ID, desc);
      }
   }
FAQ39
FAQ: FAQ How do I get started with creating a custom text editor?
public class HTMLEditor extends AbstractTextEditor {
   public HTMLEditor() {
      //install the source configuration
      setSourceViewerConfiguration(new HTMLConfiguration());
      //install the document provider
      setDocumentProvider(new HTMLDocumentProvider());
   }
   protected void createActions() {
      super.createActions();
      //... add other editor actions here
   }
}
FAQ40
FAQ: FAQ How do I provide syntax coloring in an editor?
   ITokenScanner scanner = new RuleBasedScanner();
   IToken string = createToken(colorString);
   IRule[] rules = new IRule[3];
   // Add rule for double quotes
   rules[0] = new SingleLineRule("\"", "\"", string, '\\');
   // Add a rule for single quotes
   rules[1] = new SingleLineRule("'", "'", string, '\\');
   // Add generic whitespace rule.
   rules[2] = new WhitespaceRule(whitespaceDetector);
   scanner.setRules(rules);
   scanner.setDefaultReturnToken(createToken(colorTag));
FAQ41
FAQ: FAQ How do I write to the console from a plug-in?
   private MessageConsole findConsole(String name) {
      ConsolePlugin plugin = ConsolePlugin.getDefault();
      IConsoleManager conMan = plugin.getConsoleManager();
      IConsole[] existing = conMan.getConsoles();
      for (int i = 0; i < existing.length; i++)
         if (name.equals(existing[i].getName()))
            return (MessageConsole) existing[i];
      //no console found, so create a new one
      MessageConsole myConsole = new MessageConsole(name, null);
      conMan.addConsoles(new IConsole[]{myConsole});
      return myConsole;
   }
FAQ42
FAQ: FAQ What is a JDOM?
   String oldContents = ...;//original file contents
   IMethod method = ...;//the method to change
   String returnType = ...;//the new return type
   ICompilationUnit cu = method.getCompilationUnit();
   String unitName = cu.getElementName();
   String typeName = method.getParent().getElementName();
   String mName = method.getElementName();
   DOMFactory fac = new DOMFactory();
   IDOMCompilationUnit unit = fac.createCompilationUnit(oldContents, unitName);
   IDOMType type = (IDOMType) unit.getChild(typeName);
   IDOMMethod domMethod = (IDOMMethod) type.getChild(mName);
   domMethod.setReturnType(returnType);
FAQ43
FAQ: FAQ How do I use image and font registries?
 static final String IMAGE_ID = "my.image";
   ...
   //declaring the image
   ImageRegistry registry = new ImageRegistry();
   ImageDescriptor desc = ImageDescriptor.createFromURL(...);
   registry.put(IMAGE_ID, desc);
   ...
   //using the image
   Button button = new Button(...);
   Image image = registry.get(IMAGE_ID);
   button.setImage(image);
FAQ44
FAQ: FAQ How do I find out what view or editor is selected?
   IWorkbenchPage page = ...;
   //the active part
   IWorkbenchPart active = page.getActivePart();
   //adding a listener
   IPartListener2 pl = new IPartListener2() {
      public void partActivated(IWorkbenchPartReference ref)
         System.out.println("Active: "+ref.getTitle());
      }
      ... other listener methods ...
   };
   page.addPartListener(pl);
FAQ45
FAQ: FAQ How do I hook my editor to the Back and Forward buttons?
 public class MarkLocationAction extends Action {
      private IEditorPart editor;
      public MarkLocationAction(IEditorPart editor) {
         super("Mark Location in History", null);
         this.editor = editor;
      }
      public void run() {
         IWorkbenchPage page = editor.getSite().getPage();
         page.getNavigationHistory().markLocation(editor);
      }
   }
FAQ46
FAQ: FAQ How do I add Content Assist to my editor?
public IContentAssistant getContentAssistant(ISourceViewer sv) {
    ContentAssistant ca = new ContentAssistant();
    IContentAssistProcessor pr = new TagCompletionProcessor();
    ca.setContentAssistProcessor(pr, HTML_TAG);
    ca.setContentAssistProcessor(pr, IDocument.DEFAULT_CONTENT_TYPE);
    ca.setInformationControlCreator(getInformationControlCreator(sv));
    return ca;
}
FAQ47
FAQ: FAQ How do I open an editor on a file in the workspace?
IFile file = <choose the file to open>;
   IWorkbenchPage page = <the page to open the editor in>;
   HashMap map = new HashMap();
   map.put(IMarker.LINE_NUMBER, new Integer(5));
   map.put(IWorkbenchPage.EDITOR_ID_ATTR, 
      "org.eclipse.ui.DefaultTextEditor");
   IMarker marker = file.createMarker(IMarker.TEXT);
   marker.setAttributes(map);
   //page.openEditor(marker); //2.1 API
   IDE.openEditor(marker); //3.0 API
   marker.delete();
FAQ48
FAQ: FAQ What is a working copy?
 ICompilationUnit unit = ...; //get compilation unit handle
   unit.becomeWorkingCopy(null, null);
   try {
      IBuffer buffer = unit.getBuffer();
      String oldContents = buffer.getContents();
      String newContents = ...; //make some change
      buffer.setContents(newContents);
      unit.reconcile(false, null);
   } finally {
      unit.discardWorkingCopy();
   }
FAQ49
FAQ: FAQ How do I make my plug-in dynamic aware?
 public void startup() {
      IExtensionRegistry reg = Platform.getExtensionRegistry();
      IExtensionPoint pt = reg.getExtensionPoint(PT_ID);
      IExtension[] ext = pt.getExtensions();
      for (int i = 0; i < ext.length; i++)
         extensions.add(ext[i]);
      reg.addRegistryChangeListener(this);
   }
FAQ50
FAQ: FAQ How do I enable global actions such as Cut, Paste, and Print in my editor?
 IAction print = ...;
   public void setActiveEditor(IEditorPart part) {
      IActionBars bars= getActionBars();
      if (bars == null)
         return;
      print.setEditor(part);
      bars.setGlobalActionHandler(
         IWorkbenchActionConstants.PRINT, print);
      bars.updateActionBars();
   }
FAQ51
FAQ: How do I get at the file that a particular node represents?
Node n = ...;
DataObject dob = n.getLookup().lookup(DataObject.class);
if (dob == null) {
    // definitely not a file node
} else {
    // could also get all files in the data object, if desired:
    FileObject fo = dob.getPrimaryFile();
    // and if you really need java.io.File
    File f = FileUtil.toFile (fo);
    if (f != null) { //if it is null, it is a virtual file -
                     //its filesystem does not represent disk-based storage
       //do something
    }
}
FAQ52
FAQ: I need to add-to/remove-from/customize the content of my Node/DataObject/TopComponent's Lookup. How do I do it?
public class FooDataObject extends MultiDataObject {
  private final Lookup lookup;
  private final InstanceContent lookupContents = new InstanceContent();
  public FooDataObject(FileObject pf, MultiFileLoader loader) throws DataObjectExistsException, IOException {
    super(pf, loader);
    lookup = new ProxyLookup(getCookieSet().getLookup(), new AbstractLookup(lookupContents));
    lookupContents.add (...whatever...);
  }
  @Override
  public Lookup getLookup() {
    return lookup;
  }
  @Override
  protected Node createNodeDelegate() {
    return new DataNode (this, Children.LEAF, getLookup());
  }
 //...
FAQ53
FAQ: Decorating an entire tree of Nodes
class NodeProxy extends FilterNode {
    public NodeProxy(Node original) {
        super(original, new ProxyChildren(original));
    }
    // add your specialized behavior here...
}
class ProxyChildren extends FilterNode.Children {
    public ProxyChildren(Node owner) {
        super(owner);
    }
    protected Node copyNode(Node original) {
        return new NodeProxy(original);
    }
}
FAQ54
FAQ: Saving Column Attributes of a TreeTableView
    public void writeExternal(ObjectOutput out) throws IOException {
        super.writeExternal(out);
        out.writeInt(columns.length);
        for (int ii = 0; ii < columns.length; ii++) {
            Boolean b = (Boolean) columns[Ii].getValue("InvisibleInTreeTableView");
            if (b == null) {
                b = Boolean.FALSE;
            }
            out.writeBoolean(b.booleanValue());
            Integer i = (Integer) columns[Ii].getValue("OrderNumberTTV");
            if (i == null) {
                i = new Integer(ii);
            }
            out.writeInt(i.intValue());
            b = (Boolean) columns[Ii].getValue("SortingColumnTTV");
            if (b == null) {
                b = Boolean.FALSE;
            }
            out.writeBoolean(b.booleanValue());
            b = (Boolean) columns[Ii].getValue("DescendingOrderTTV");
            if (b == null) {
                b = Boolean.FALSE;
            }
            out.writeBoolean(b.booleanValue());
        }
        try {
            TableColumnModel tcm = treeTable.getColumnModel();
            int count = tcm.getColumnCount();
            for (int index = 0; index < count; index++) {
                TableColumn tc = tcm.getColumn(index);
                out.writeInt(tc.getWidth());
            }
        } catch (IOException ioe) {
            ErrorManager.getDefault().notify(ErrorManager.WARNING, ioe);
        }
    }
FAQ55
FAQ: Why do my nodes in the Explorer always have an expand-box by them, even though they have no children?
void myModelChanged() {
    if (this.isLeaf()) {
        if (getObject().hasChildren()) {
            initChildren();
        }
    } else {
        if (getObject().hasChildren()) {
            // Cause children to regenerate it's key list.
            this.getChildren().addNotify();
        } else {
            // We no longer have children. Change to leaf.
            setChildren(Children.LEAF);
        }
    }
} 
FAQ56
FAQ: How can I change my node's appearance?
public class MovieNode extends AbstractNode {
    private Movie movie;
    public MovieNode(Movie key) {
        super(Children.LEAF, Lookups.fixed(new Object[]{key}));
        this.movie = key;
        setName(key.getTitle());
        setDisplayName(key.getTitle());
        getHandle();
        setIconBaseWithExtension("org/nb/marilyn/pics/marilyn.gif");
    }
    @Override
    public String getHtmlDisplayName() {
        return "<b>" + this.getDisplayName() + "</b>";
    }
}
FAQ57
FAQ: I want to allow other modules to inject objects into my Node's Lookup or elsewhere (Actions, Properties...)
public class BaseNode<T> extends AbstractNode {
  final InstanceContent content;
  final Class<T> type;
  public BaseNode(Class<T> type, T modelObject) {
    this(type, modelObject, new InstanceContent());
  }
  public BaseNode(Class<T> type, T modelObject, InstanceContent content){
    super(Children.LEAF, new ProxyLookup(Lookups.fixed(modelObject), new AbstractLookup(content)));
    this.content = content;
    this.type = type;
    //Populate lookup based on declaratively registered factories
    String pathInSystemFS = getRegistrationPath("lookupContents");
    Collection<? extends InstanceContent.Convertor> all = 
       Lookups.forPath(pathInSystemFS).
       lookupAll(InstanceContent.Convertor.class);
    for (InstanceContent.Convertor<T, ?> factory : all) {
      content.add(modelObject, factory);
    }
    //if you want to handle modules being loaded/unloaded in a running app,
    //use lookupResult() instead of lookupAll(), retain a reference to the
    //Lookup.Result, listen on it for changes, and remove all acquired
    //InstanceContent objects if it changes, then rerun the above code
  }
  @Override
  public Action[] getActions(boolean context) {
    return Lookups.forPath(getRegistrationPath("actions")).
         lookupAll(Action.class).toArray(new Action[0]);
  }
  String getRegistrationPath(String subfolder) {
    //e.g. pass "lookupContents" and get 
    //MyModule/com/foo/mymodule/MyType/lookupContents
    return "MyModule/" + type.getName().replace('.', '/') + "/" + subfolder;
  }
}
FAQ58
FAQ: How to execute a long running task from an action without blocking the GUI?
 @ActionRegistration(asynchronous = true)
...
public void actionPerformed(ActionEvent ev) {
    if (isLongTaskRequired) {
        // maybe run a ProgressHandler
        doLongTask();
    }
    EventQueue.invokeLater(new Runnable() {
        @Override public void run() {
            // do domething with the gui
        }
    });
}
FAQ59
FAQ: How can I operation occasionally on a background thread, but reschedule it if something happens to delay it?
public class FooDataNode extends DataNode implements PropertyChangeListener, Runnable {
  private boolean error;
  private static final RequestProcessor THREAD_POOL = new RequestProcessor("FooDataNode processor", 1);
  private final RequestProcessor.Task task = THREAD_POOL.create(this);
  FooDataNode(FooDataObject obj) {
    super(obj, Children.LEAF);
    obj.addPropertyChangeListener(WeakListeners.propertyChange(this, obj));
    task.schedule(100);
  }
  public void propertyChange(PropertyChangeEvent evt) {
    DataObject obj = (DataObject) evt.getSource();
    if (DataObject.PROP_MODIFIED.equals(evt.getPropertyName()) && !obj.isModified()) { //file was saved
      task.schedule(100);
    }
  }
  @Override
  public String getHtmlDisplayName() {
    return error ? "<font color=\"!nb.errorForeground\">" + getDisplayName() : null;
  }
  public void run() {
    boolean old = error;
    error = doesTheFileHaveErrors();
    if (old != error) {
      fireDisplayNameChange(null, null);
    }
  }
  private boolean doesTheFileHaveErrors() {
    assert !EventQueue.isDispatchThread();
    //parse the file here
    return true; //whatever the value should be
  }
}
FAQ60
FAQ: My TopComponent always opens in the editor area, but I want it to open in the same place as XYZ?
public MyTopComponent extends TopComponent {
  public void open() {
     Mode m = WindowManager.getDefault().findMode ("output");
     if (m != null) {
        m.dockInto(this);
     }
     super.open();
  }
}
FAQ61
FAQ: I want to disable the popup menu on the toolbars in the main window. How do I do that?
package org.netbeans.modules.toolbarthing;
import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JToolBar;
import org.openide.modules.ModuleInstall;
import org.openide.windows.WindowManager;
public class Installer extends ModuleInstall implements Runnable {
    public void restored() {
         WindowManager.getDefault().invokeWhenUIReady(this);
    }
    public void run() {
        JToolBar[] tb = findToolbars();
        for (int i = 0; i < tb.length; i++) {
            processToolbar (tb[I]);
        }
    }
    private JToolBar[] findToolbars() {
        List l = new ArrayList();
        JFrame jf = (JFrame) WindowManager.getDefault().getMainWindow();
        findToolbars (jf.getContentPane(), l);
        JToolBar[[ | ]] tb = (JToolBar[[ | ]]) l.toArray(new JToolBar[L.size()]);
        return tb;
    }
    private void findToolbars(Component c, List l) {
        if (c instanceof JToolBar) {
            l.add(c);
        } else if (c instanceof Container) {
            Component[] cc = ((Container) c).getComponents();
            for (int i=0; i < cc.length; i++) {
                findToolbars(cc[I], l);
            }
        }
    }
    private void processToolbar (JToolBar bar) {
        MouseListener[] ml = bar.getMouseListeners();
        for (int i = 0; i < ml.length; i++) {
            if (ml[I].getClass().getName().indexOf("PopupListener") >= 0) {
                bar.removeMouseListener (ml[I]);
            }
        }
    }
}
FAQ62
FAQ: I want to create a TopComponent class to use as an editor, not a singleton
void init(final FooDataObject file) throws IOException {
    associateLookup(file.getLookup());
    setDisplayName(file.getName());
    setLayout(new BorderLayout());
    add(new JLabel(getDisplayName()), BorderLayout.NORTH);
    //If you expect large files, load the file in a background thread
    //and set the field's text under its Document's lock
    final JTextField field = new JTextField(file.getPrimaryFile().asText());
    add(field, BorderLayout.CENTER);
    field.getDocument().addDocumentListener(new DocumentListener() {
      @Override
      public void insertUpdate(DocumentEvent e) {
        changedUpdate(e);
      }
      @Override
      public void removeUpdate(DocumentEvent e) {
        changedUpdate(e);
      }
      @Override
      public void changedUpdate(DocumentEvent e) {
        FooDataObject foo = getLookup().lookup(FooDataObject.class);
        foo.setContent(field.getText());
      }
    });
    file.addPropertyChangeListener(new PropertyChangeListener() {
      @Override
      public void propertyChange(PropertyChangeEvent evt) {
        if (DataObject.PROP_MODIFIED.equals(evt.getPropertyName())) {
          //fire a dummy event
          setDisplayName(Boolean.TRUE.equals(evt.getNewValue()) ? file.getName() + "*" : file.getName());
        }
      }
    });
  }
FAQ63
FAQ: How can I control when the OK button is enabled?
public void actionPerformed(ActionEvent e) {
       MyForm form = new MyForm();
       DialogDescriptor desc = new DialogDescriptor(form,
         "Hello", true, DialogDescriptor.OK_CANCEL_OPTION,
          DialogDescriptor.OK_OPTION, null);
       desc.setValid(false);
       form.setDialogDescriptor(desc);
       DialogDisplayer.getDefault().notify(desc); // displays the dialog
   }
   static class MyForm extends JPanel implements DocumentListener {
       private JTextField field;
       private DialogDescriptor desc;
       MyForm() {
           super(new BorderLayout());
           field = new JTextField();
           add(new JLabel("Type Something Here"), BorderLayout.NORTH);
           add(field, BorderLayout.SOUTH);
       }
       void setDialogDescriptor(DialogDescriptor desc) {
           this.desc = desc;
           field.getDocument().addDocumentListener(this);
       }
       private void doEnablement() {
           if (field.getText().isEmpty()) {
               desc.setValid(false);
           } else {
               desc.setValid(true);
           }
       }
       @Override
       public void insertUpdate(DocumentEvent e) {
           doEnablement();
       }
       @Override
       public void removeUpdate(DocumentEvent e) {
           doEnablement();
       }
       @Override
       public void changedUpdate(DocumentEvent e) {
           doEnablement();
       }
   }
FAQ64
FAQ: How can I open a Project programatically?
                File projectToBeOpenedFile = new File(getPath());
                FileObject projectToBeOpened = FileUtil.toFileObject(projectToBeOpenedFile);
                Project project = ProjectManager.getDefault().findProject(projectToBeOpened);
                Project[] array = new Project[1];
                array[0] = project;
                OpenProjects.getDefault().open(array, false);
FAQ65
FAQ: How to get the project for the actual file in the editor?
Project p = TopComponent.getRegistry().getActivated().getLookup().lookup(Project.class);
if (p == null) {
    DataObject dob = TopComponent.getRegistry().getActivated().getLookup().lookup(DataObject.class);
    if (dob != null) {
       FileObject fo = dob.getPrimaryFile();
       p = FileOwnerQuery.getOwner(fo);
       ...
FAQ66
FAQ: How to get the name of the active project group
/**
     *
     * @return name of the current project group or null
     */
    public String getActiveProjectGroup() {
 Preferences groupNode = getPreferences("org/netbeans/modules/projectui/groups");
 if (null != groupNode) {
     final String groupId = groupNode.get("active", null);
     if (null != groupId) {
  final Preferences groupPref = getPreferences("org/netbeans/modules/projectui/groups/" + groupId);
  if (null != groupPref) {
      final String activeProjectGroup = groupPref.get("name", null);
      return activeProjectGroup;
  }
     }
 }
 return null;
    }
    /**
     * Get the preference for the given node path.
     *
     * @param path configuration path like "org/netbeans/modules/projectui"
     * @return {@link Preferences} or null
     */
    private Preferences getPreferences(String path) {
 try {
     if (NbPreferences.root().nodeExists(path)) {
  return NbPreferences.root().node(path);
     }
 } catch (BackingStoreException ex) {
     Exceptions.printStackTrace(ex);
 }
 return null;
    }
FAQ67
FAQ: How do I add a new panel to a Project Properties dialog?
 @ProjectCustomizer.CompositeCategoryProvider.Registration(
    projectType="org-netbeans-modules-java-j2seproject")
public class BlaPanelProvider implements ProjectCustomizer.CompositeCategoryProvider {
    public @Override Category createCategory(Lookup context) {
        return ProjectCustomizer.Category.create(
                "Bla",
                "Bla",
                null,
                null);
    }
    public @Override JComponent createComponent(Category category, Lookup context) {
        return new BlaPanel();
    }
}
FAQ68
FAQ: How do I add an action to a project popup menu of a specific project type?
 @ActionID(...)
@ActionRegistration(...)
@ActionReference(path="Projects/Actions")
public class DemoAction extends AbstractAction implements ContextAwareAction {
    public @Override void actionPerformed(ActionEvent e) {assert false;}
    public @Override Action createContextAwareInstance(Lookup context) {
        return new ContextAction(context);
    }
    private static final class ContextAction extends AbstractAction {
        private final Project p;
        public ContextAction(Lookup context) {
            p = context.lookup(Project.class);
            String name = ProjectUtils.getInformation(p).getDisplayName();
            // TODO state for which projects action should be enabled
            char c = name.charAt(0);
            setEnabled(c >= 'A' && c <= 'M');
            putValue(DynamicMenuContent.HIDE_WHEN_DISABLED, true);
            // TODO menu item label with optional mnemonics
            putValue(NAME, "&Info on " + name);
        }
        public @Override void actionPerformed(ActionEvent e) {
            // TODO what to do when run
            String msg = "Project location: "
                    + FileUtil.getFileDisplayName(p.getProjectDirectory());
            DialogDisplayer.getDefault().notify(new NotifyDescriptor.Message(msg));
        }
    }
}
FAQ69
FAQ: How do I identify the "main project"?
public final class ShowMainProjectAction extends CookieAction {
    protected void performAction(Node[] activatedNodes) {
        String projectPath = OpenProjects.getDefault().getMainProject().getProjectDirectory().getPath();
        JOptionPane.showMessageDialog(null, projectPath);
    }
    protected int mode() {
        return CookieAction.MODE_EXACTLY_ONE;
    }
    public String getName() {
        return NbBundle.getMessage(ShowMainProjectAction.class, "CTL_ShowMainProjectAction");
    }
    protected Class[] cookieClasses() {
        return new Class[]{Project.class};
    }
    @Override
    protected void initialize() {
        super.initialize();
        // see org.openide.util.actions.SystemAction.iconResource() Javadoc for more details
        putValue("noIconInMenu", Boolean.TRUE);
    }
    public HelpCtx getHelpCtx() {
        return HelpCtx.DEFAULT_HELP;
    }
    @Override
    protected boolean asynchronous() {
        return false;
    }
}
FAQ70
FAQ: How do I change the default behavior of PropertySheet editors?
class MyEditor implements ExPropertyEditor {
  PropertyEnv env;
  public void attachEnv(e) {
    env = e;
  }
  public void anyMethod() {
     Object[] arr =  env.getBeans();
     // now arr contains either the real bean objects if invoked on Object
     // or it contains Node that the properties belong to
  }
}
FAQ71
FAQ: How do I show my node's properties in the Properties view?
public class MyComponent extends TopComponent implements PropertyChangeListener {
    private ExplorerManager explorerManager;
    public MyComponent() {
        explorerManager = new ExplorerManager();
        explorerManager.addPropertyChangeListener(this);
    }
    public void propertyChange(PropertyChangeEvent evt) {
        if (evt.getSource() == explorerManager &&
                ExplorerManager.PROP_SELECTED_NODES.equals(evt.getPropertyName())) {
           setActivatedNodes(explorerManager.getSelectedNodes());
        }
    }
}
FAQ72
FAQ: How do I route the output from an external process to the output window?
private class ProcessLaunch implements Callable<Process> {
  private final String[] commandLine;
  public ProcessLaunch(String... commandLine) {
    this.commandLine = commandLine;
  }
  public Process call() throws Exception {
    ProcessBuilder pb = new ProcessBuilder(cmdline);
    pb.directory(new File(System.getProperty("user.home"))); //NOI18N
    pb.redirectErrorStream(true);
    return pb.start();
  }
}
FAQ73
FAQ: How to use color text in Output Window
InputOutput io = IOProvider.getDefault().getIO("test", true);
// change default color for output in corresponding tab
if (IOColors.isSupported(io)) {
    IOColors.setColor(io, IOColors.OutputType.OUTPUT, Color.GRAY);
}
// print line in specific color
if (IOColorLines.isSupported(io)) {
    IOColorLines.println(io, "Green line", Color.GREEN);
}
class L implements OutputListener {
//...
}
// print parts of line in specific color
if (IOColorPrint.isSupported(io)) {
    IOColorPrint.print(io, "Green part", Color.GREEN);
    IOColorPrint.print(io, " pink part", Color.PINK);
    IOColorPrint.print(io, " hyperlink with custom color", new L(), false, Color.MAGENTA);
}
FAQ74
FAQ: How do I remove the status bar?
   private static JComponent getCustomStatusLine() {
       try {
           String fileName = Constants.CUSTOM_STATUS_LINE_PATH;
           if (fileName == null) {
               return null;
           }
           FileObject fo = FileUtil.getConfigFile(fileName);
           if (fo != null) {
               DataObject dobj = DataObject.find(fo);
               InstanceCookie ic = (InstanceCookie)dobj.getCookie(InstanceCookie.class);
               if (ic != null) {
                   return (JComponent)ic.instanceCreate();
               }
           }
       } catch (Exception e) {
           Exceptions.printStackTrace(e);
       }
       return null;
   }
FAQ75
FAQ: Other strategies for authentication and authorization
package com.tomwheeler;
import java.lang.reflect.Method;
public class CustomStartup {
    private static final String NB_MAIN_CLASS = "org.netbeans.core.startup.Main";
    public static void main(String[] args) throws Exception {
        // do whatever you need here (e.g. show a custom login form)
        System.out.println("Hello world! I am a custom startup class");
        // once you're done with that, hand control back to NetBeans
        ClassLoader classloader = Thread.currentThread().getContextClassLoader();
        Class<?> mainClass = Class.forName(NB_MAIN_CLASS, true, classloader);
        Object mainObject = mainClass.newInstance();
        Method mainMethod = mainClass.getDeclaredMethod("main", new Class[]{String[].class});
        mainMethod.invoke(mainObject, (Object) args);
    }
}
FAQ76
FAQ: How Can I Hook Up JavaHelp to Property Sets or Individual Properties?
 @Override
protected Sheet createSheet() {
    Sheet s = super.createSheet();
    Sheet.Set ss = s.get(Sheet.PROPERTIES);
    if (ss == null) {
        ss = Sheet.createPropertiesSet();
        s.put(ss);
    }
    // Do this to specify help for a whole sheet set
    ss.setValue("helpID", "my.help.ctx");
    ss.put(new FirstNameProperty("Abe"));
    ss.put(new LastNameProperty("Lincoln"));
    return s;
}
FAQ77
FAQ: How do I Get All Methods/Fields/Constructors of a Class?
protected void performAction(Node[] activatedNodes) {
    DataObject dataObject = (DataObject) activatedNodes[0].getLookup().lookup(DataObject.class);
    JavaSource js = JavaSource.forFileObject(dataObject.getPrimaryFile());
    try {
        js.runUserActionTask(new Task<CompilationController>() {
            public void run(CompilationController parameter) throws IOException {
                parameter.toPhase(Phase.ELEMENTS_RESOLVED);
                new MemberVisitor(parameter).scan(parameter.getCompilationUnit(), null);
            }
        }, true);
    } 
    catch (IOException e) {
        Logger.getLogger("global").log(Level.SEVERE, e.getMessage(), e);
    }
}
private static class MemberVisitor extends TreePathScanner<Void, Void> {
    private CompilationInfo info;
    public MemberVisitor(CompilationInfo info) {
        this.info = info;
    }
    @Override
    public Void visitClass(ClassTree t, Void v) {
        Element el = info.getTrees().getElement(getCurrentPath());
        if (el == null) {
            System.err.println("Cannot resolve class!");
        } 
        else {
            TypeElement te = (TypeElement) el;
            System.err.println("Resolved class: " + te.getQualifiedName().toString());
            //XXX: only as an example, uses toString on element, which should be used only for debugging
            System.err.println("enclosed methods: " + ElementFilter.methodsIn(te.getEnclosedElements()));
            System.err.println("enclosed types: " + ElementFilter.typesIn(te.getEnclosedElements()));
        }
        return null;
    }
}
FAQ78
FAQ: How do I obtain a source file for a Java class and open it in the editor?
String classResource = "javax/swing/JComponent.java";
for (FileObject curRoot : GlobalPathRegistry.getDefault().getSourceRoots()) {
    FileObject fileObject = curRoot.getFileObject(classResource);
    if (fileObject != null) {
        // source file object found
        // do something, e.g. openEditor(fileObject, lineNumber);
        return;
    }
}
FAQ79
FAQ: How can I scan a classpath to find all classes of a particular type?
private Set<ElementHandle<TypeElement>> findAllSubTypes(ClassPath on, ElementHandle<TypeElement> of) {
    ClasspathInfo cpInfo = ClasspathInfo.create(ClassPath.EMPTY, ClassPath.EMPTY, on);
    List<ElementHandle<TypeElement>> todo = new LinkedList<ElementHandle<TypeElement>>(of);
    Set<ElementHandle<TypeElement>> result = new HashSet<ElementHandle<TypeElement>>();
    while (!todo.isEmpty()) {
        //TODO: if cancellable, check for cancel here
        ElementHandle<TypeElement> curr = todo.remove(0);
        result.add(curr);
        Set<ElementHandle<TypeElement>> typeElements = cpInfo.getClassIndex().getElements(eh, EnumSet.of(ClassIndex.SearchKind.IMPLEMENTORS), EnumSet.of(ClassIndex.SearchScope.SOURCE));
        if (typeElements != null) { //can be null for cancellable tasks
            todo.addAll(typeElements);
        }
    }
    return result;
}
FAQ80
FAQ: FAQ What is a document partition?
   IPartitionTokenScanner createScanner() {
      IToken cmt = new Token(HTMLConfiguration.HTML_COMMENT);
      IToken tag = new Token(HTMLConfiguration.HTML_TAG);
      IPredicateRule[] rules = new IPredicateRule[2];
      rules[0] = new MultiLineRule("", cmt);
      rules[1] = new TagRule(tag);
      RuleBasedPartitionScanner scanner = 
         new RuleBasedPartitionScanner();
      scanner.setPredicateRules(rules);
      return sc;
   }
FAQ81
FAQ: FAQ How do I create a repeating background task?
   public class RepeatingJob extends Job {
      private boolean running = true;
      public RepeatingJob() {
         super("Repeating Job");
      }
      protected IStatus run(IProgressMonitor monitor) {
         schedule(60000);
         return Status.OK_STATUS;
      }
      public boolean shouldSchedule() {
         return running;
      }
      public void stop() {
         running = false;
      }
   }
/*
Sample  Code by Parvez Hakim
www.abobjects.com
*/
RepeatingJob job = new RepeatingJob("BackupScheduler"+jobNumber++,nextDelay) {   
   protected IStatus run(IProgressMonitor monitor){ 
      schedule(repeatDelay-cpuTimeTakenbyJob);
      return org.eclipse.core.runtime.Status.OK_STATUS;
   }
  };
  job.schedule(delay); // start after 20 seconds  
  return job;
}
public abstract class RepeatingJob extends Job{
    private boolean running = true;
    protected long repeatDelay = 0; 
    public RepeatingJob(String jobName,long repeatPeriod){ 
     super(jobName);
       repeatDelay = repeatPeriod;
    }/**
    protected IStatus run(IProgressMonitor monitor) {
       schedule(repeatDelay);
       return Status.OK_STATUS;
    }
    */ 
    public boolean shouldSchedule() {
       return running;
    }
    public void stop() {
       running = false;
    }
 }
FAQ82
FAQ: FAQ How do I implement an incremental project builder?
   public class Builder extends IncrementalProjectBuilder {   
      protected IProject[] build(int kind, Map args, 
       IProgressMonitor monitor) {
         if (kind == IncrementalProjectBuilder.FULL_BUILD) {
            fullBuild(monitor);
         } else {
            IResourceDelta delta = getDelta(getProject());
            if (delta == null) {
               fullBuild(monitor);
            } else {
               incrementalBuild(delta, monitor);
            }
         }
         return null;
      }   
      private void incrementalBuild(IResourceDelta delta, 
       IProgressMonitor monitor) {
         System.out.println("incremental build on "+delta);
         try {
            delta.accept(new IResourceDeltaVisitor() {
               public boolean visit(IResourceDelta delta) {
                  System.out.println("changed: "+
                   delta.getResource().getRawLocation());
                  return true; // visit children too
               }
            });
         } catch (CoreException e) {
            e.printStackTrace();
         }
      }
      private void fullBuild(IProgressMonitor monitor) {
         System.out.println("full build");
      }
   }
FAQ83
FAQ: FAQ How do I add Content Assist to my language editor?
   class CompletionProcessor implements IContentAssistProcessor { 
      private final IContextInformation[] NO_CONTEXTS = { };
      private final char[] PROPOSAL_ACTIVATION_CHARS = { 's','f','p','n','m', };
      private ICompletionProposal[] NO_COMPLETIONS = { };
      public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
         try {
            IDocument document = viewer.getDocument();
            ArrayList result = new ArrayList();
            String prefix = lastWord(document, offset);
            String indent = lastIndent(document, offset);
            EscriptModel model = EscriptModel.getModel(document, null);
            model.getContentProposals(prefix, indent, offset, result);
            return (ICompletionProposal[]) result.toArray(new ICompletionProposal[result.size()]);
         } catch (Exception e) {
            // ... log the exception ...
            return NO_COMPLETIONS;
         }
      }
      private String lastWord(IDocument doc, int offset) {
         try {
            for (int n = offset-1; n >= 0; n--) {
              char c = doc.getChar(n);
              if (!Character.isJavaIdentifierPart(c))
                return doc.get(n + 1, offset-n-1);
            }
         } catch (BadLocationException e) {
            // ... log the exception ...
         }
         return "";
      }
      private String lastIndent(IDocument doc, int offset) {
         try {
            int start = offset-1; 
            while (start >= 0 && doc.getChar(start)!= '\n') start--;
            int end = start;
            while (end < offset && Character.isSpaceChar(doc.getChar(end))) end++;
            return doc.get(start+1, end-start-1);
         } catch (BadLocationException e) {
            e.printStackTrace();
         }
         return "";
      }
      public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) { 
         return NO_CONTEXTS;
      }
      char[] getCompletionProposalAutoActivationCharacters() {
         return PROPOSAL_ACTIVATION_CHARS;
      }
      // ... remaining methods are optional ...
   }
FAQ84
FAQ: FAQ How do I create and examine an AST?
   class ASTPrinter extends ASTVisitor {
      StringBuffer buffer = new StringBuffer();
      public void preVisit(ASTNode node) {
         //write the name of the node being visited
         printDepth(node);
         String name = node.getClass().getName();
         name = name.substring(name.lastIndexOf('.')+1);
         buffer.append(name);
         buffer.append(" {\r\n");
      }
      public void postVisit(ASTNode node) {
         //write a closing brace to indicate end of the node
         printDepth(node);
         buffer.append("}\r\n");
      }
      void printDepth(ASTNode node) {
         //indent the current line to an appropriate depth
         while (node != null) {
            node = node.getParent();
            buffer.append("  ");
         }
      }
   }
   ...
   //java model handle for selected file
   ICompilationUnit unit = ...;
   ASTParser parser = ASTParser.newParser(AST.JLS2);
   parser.setKind(ASTParser.K_COMPILATION_UNIT);
   CompilationUnit ast = 
                  (CompilationUnit)parser.createAST(null);
   ASTPrinter printer = new ASTPrinter();
   ast.accept(printer);
   MessageDialog.openInformation(shell, "AST for: " + 
      unit.getElementName(), printer.buffer.toString());
FAQ85
FAQ: FAQ How does a view persist its state between sessions?
   private static final String STORE_SELECTION = "ShoppingList.SELECTION";
   public void saveState(IMemento memento) {
      super.saveState(memento);
      ISelection sel = viewer.getSelection();
      IStructuredSelection ss = (IStructuredSelection) sel;
      StringBuffer buf = new StringBuffer();
      for (Iterator it = ss.iterator(); it.hasNext();) {
         buf.append(it.next());
         buf.append(',');
      }
      memento.putString(STORE_SELECTION, buf.toString());
   }
FAQ86
FAQ: FAQ How do I create a Rich Client application?
   public class MinimalRCPApp extends WorkbenchAdvisor
      implements IPlatformRunnable {
      public String getInitialWindowPerspectiveId() {
         return "org.eclipse.faq.minimalperspective";
      }
      public void preWindowOpen(
                     IWorkbenchWindowConfigurer wwc) {
         configurer.setShowMenuBar(false);
         configurer.setShowFastViewBars(false);
         configurer.setShowStatusLine(false);
         configurer.setShowCoolBar(false);
      }
      public Object run(Object args) throws Exception {
         Display d = PlatformUI.createDisplay();
         int ret = PlatformUI.createAndRunWorkbench(d, this);
         if (ret == PlatformUI.RETURN_RESTART)
            return EXIT_RESTART;
         return EXIT_OK;
      }
   }
FAQ87
FAQ: FAQ How do I load and save plug-in preferences?
private void savePluginSettings() {
  // saves plugin preferences at the workspace level
  Preferences prefs =
    //Platform.getPreferencesService().getRootNode().node(Plugin.PLUGIN_PREFEERENCES_SCOPE).node(MY_PLUGIN_ID);
    InstanceScope.INSTANCE.getNode(MY_PLUGIN_ID); // does all the above behind the scenes
  prefs.put(KEY1, this.someStr);
  prefs.put(KEY2, this.someBool);
  try {
    // prefs are automatically flushed during a plugin's "super.stop()".
    prefs.flush();
  } catch(BackingStoreException e) {
    //TODO write a real exception handler.
    e.printStackTrace();
  }
}
private void loadPluginSettings() {
  Preferences prefs = new InstanceScope().getNode(MY_PLUGIN_ID);
  // you might want to call prefs.sync() if you're worried about others changing your settings
  this.someStr = prefs.get(KEY1);
  this.someBool= prefs.getBoolean(KEY2);
}
FAQ88
FAQ: FAQ How to decorate a TableViewer or TreeViewer with Columns?
/**
 *  Class that supports Decoration of TableViewer and TreeViewer with TreeColumns
 */
package decorators;
import org.eclipse.jface.viewers.DecoratingLabelProvider;
import org.eclipse.jface.viewers.ILabelDecorator;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.swt.graphics.Image;
/**
 * @author Annamalai Chockalingam
 *
 */
public class TableDecoratingLabelProvider extends DecoratingLabelProvider
    implements ITableLabelProvider {
ITableLabelProvider provider;
ILabelDecorator decorator;
/**
* @param provider
* @param decorator
*/
public TableDecoratingLabelProvider(ILabelProvider provider,
    ILabelDecorator decorator) {
  super(provider, decorator);
  this.provider = (ITableLabelProvider) provider;
  this.decorator = decorator;
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITableLabelProvider#getColumnImage(java.lang.Object, int)
*/
public Image getColumnImage(Object element, int columnIndex) {
  Image image = provider.getColumnImage(element, columnIndex);
  if (decorator != null) {
    Image decorated = decorator.decorateImage(image, element);
    if (decorated != null) {
      return decorated;
    }
  }
  return image;
}
/* (non-Javadoc)
* @see org.eclipse.jface.viewers.ITableLabelProvider#getColumnText(java.lang.Object, int)
*/
public String getColumnText(Object element, int columnIndex) {
  String text = provider.getColumnText(element, columnIndex);
  if (decorator != null) {
    String decorated = decorator.decorateText(text, element);
    if (decorated != null) {
      return decorated;
    }
  }
  return text;
}
FAQ89
FAQ: FAQ How do I open an editor on something that is not a file?
class StringStorage implements IStorage {
  private String string;
  StringStorage(String input) {
    this.string = input;
  }
  public InputStream getContents() throws CoreException {
    return new ByteArrayInputStream(string.getBytes());
  }
  public IPath getFullPath() {
    return null;
  }
  public Object getAdapter(Class adapter) {
    return null;
  }
  public String getName() {
    int len = Math.min(5, string.length());
    return string.substring(0, len).concat("..."); //$NON-NLS-1$
  }
  public boolean isReadOnly() {
    return true;
  }
}
FAQ90
FAQ: FAQ How do I write an editor for my own language?
   class Scanner extends RuleBasedScanner {
      public Scanner() {
         WordRule rule = new WordRule(new IWordDetector() {
            public boolean isWordStart(char c) { 
          return Character.isJavaIdentifierStart(c); 
            }
            public boolean isWordPart(char c) {   
             return Character.isJavaIdentifierPart(c); 
            }
         });
         Token keyword = new Token(new TextAttribute(Editor.KEYWORD, null, SWT.BOLD));
         Token comment = new Token(new TextAttribute(Editor.COMMENT));
         Token string = new Token(new TextAttribute(Editor.STRING));
         //add tokens for each reserved word
         for (int n = 0; n < Parser.KEYWORDS.length; n++) {
            rule.addWord(Parser.KEYWORDS[n], keyword);
         }
         setRules(new IRule[] {
            rule,
            new SingleLineRule("#", null, comment),
            new SingleLineRule("\"", "\"", string, '\\'),
            new SingleLineRule("'", "'", string, '\\'),
            new WhitespaceRule(new IWhitespaceDetector() {
               public boolean isWhitespace(char c) {
                  return Character.isWhitespace(c);
               }
            }),
         });
      }
   }
FAQ91
FAQ: FAQ How do I create an Outline view for my own language editor?
   public Object getAdapter(Class required) {
      if (IContentOutlinePage.class.equals(required)) {
         if (myOutlinePage == null) {
            myOutlinePage = new CoolLanguageContentOutlinePage(
                           getDocumentProvider(), this);
            myOutlinePage.setInput(getEditorInput());
         }
         return myOutlinePage;
      }
      return super.getAdapter(required);
   }
FAQ92
FAQ: FAQ What is the Java model?
   IWorkspace workspace = ResourcesPlugin.getWorkspace();
   IJavaModel javaModel = JavaCore.create(workspace.getRoot());
   IJavaProject projects[] = javaModel.getJavaProjects();
   for (int n = 0; n < projects.length; n++) {
      IJavaProject project = projects[n];
      IPackageFragmentRoot[] roots = project.getAllPackageFragmentRoots();
      int nClasses = 0;
      for (int k = 0; k < roots.length; k++) {
         IPackageFragmentRoot root = roots[k];
         IJavaElement[] elements = root.getChildren();
         for (int i = 0; i < elements.length; i++) {
            IJavaElement element = elements[i];
            PackageFragment fragment = (PackageFragment) element.getAdapter(PackageFragment.class);
            if (fragment == null) continue;
            IJavaElement fes[] = fragment.getChildren();
            for (int j = 0; j < fes.length; j++) {
               String className = fes[j].getElementName();
               nClasses++;
            }
         }
      }
      String projectName = projects[n].getElementName();
      System.out.println("Classpath for project "+ projectName +" contains "+nClasses+" classes.");
   }
FAQ93
FAQ: FAQ How do I switch from using a Progress dialog to the Progress view?
   IRunnableWithProgress op = new IRunnableWithProgress() {
      public void run(IProgressMonitor monitor) {
         runDecathlon(monitor);
      }
   };
   IWorkbench wb = PlatformUI.getWorkbench();
   IWorkbenchWindow win = wb.getActiveWorkbenchWindow();
   Shell shell = win != null ? win.getShell() : null;
   new ProgressMonitorDialog(shell).run(true, true, op);
FAQ94
FAQ: FAQ How do I make a view respond to selection changes in another view?
   public class ChaptersView extends ViewPart {
      private TableViewer viewer;
      ISelectionListener listener = new ISelectionListener() {
         public void selectionChanged(IWorkbenchPart part, ISelection sel) {
            if (!(sel instanceof IStructuredSelection))
               return;
            IStructuredSelection ss = (IStructuredSelection) sel;
            Object o = ss.getFirstElement();
            if (o instanceof Book)
               viewer.setInput(ss.size()==1 ? o : null);
         }
      };
      public void createPartControl(Composite parent) {
         getSite().getPage().addSelectionListener(listener);
      }
      public void dispose() {
         getSite().getPage().removeSelectionListener(listener);
      }
   }
FAQ95
FAQ: FAQ How do I enable the Save and Revert actions?
   public class MinimalEditor extends EditorPart {
      protected boolean dirty = false;
      ...
      public boolean isDirty() {
         return dirty;
      }
      protected void setDirty(boolean value) {
         dirty = value;
         firePropertyChange(PROP_DIRTY);
      }
   }
FAQ96
FAQ: FAQ How do I implement a search operation?
   class SearchSizePage extends DialogPage 
    implements ISearchPage {
      private ISearchPageContainer container;
      public boolean performAction() {
         // ... validate input ...
         IRunnableWithProgress query = ...;//the query object
         container.getRunnableContext().run(true, true, query);
         return true;
      }
      public void setContainer(ISearchPageContainer spc) {
         this.container = spc;
      }
   }
FAQ97
FAQ: FAQ How do I create a Compare dialog?
   class CompareItem implements IStreamContentAccessor,
            ITypedElement, IModificationDate {
      private String contents, name;
      private long time;
      CompareItem(String name, String contents, long time) {
         this.name = name;
         this.contents = contents;
         this.time = time;
      }
      public InputStream getContents() throws CoreException {
         return new ByteArrayInputStream(contents.getBytes());
      }
      public Image getImage() {return null;}
      public long getModificationDate() {return time;}
      public String getName() {return name;}
      public String getString() {return contents;}
      public String getType() {return ITypedElement.TEXT_TYPE;}
   }
FAQ98
FAQ: FAQ How do I create a dialog with a details area?
   Date date = new Date();
   SimpleDateFormat format = new SimpleDateFormat();
   String[] patterns = new String[] {
      "EEEE", "yyyy", "MMMM", "h 'o''clock'"};
   String[] prefixes = new String[] {
      "Today is ", "The year is ", "It is ", "It is "};
   String[] msg = new String[patterns.length];
   for (int i = 0; i < msg.length; i++) {
      format.applyPattern(patterns[i]);
      msg[i] = prefixes[i] + format.format(date);
   }
   final String PID = ExamplesPlugin.ID;
   MultiStatus info = new MultiStatus(PID, 1, msg[0], null);
   info.add(new Status(IStatus.INFO, PID, 1, msg[1], null));
   info.add(new Status(IStatus.INFO, PID, 1, msg[2], null));
   info.add(new Status(IStatus.INFO, PID, 1, msg[3], null));
   ErrorDialog.openError(window.getShell(), "Time", null, info);
FAQ99
FAQ: FAQ How do I open an editor programmatically?
import java.io.File;
import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.ide.IDE;
File fileToOpen = new File("externalfile.xml");
if (fileToOpen.exists() && fileToOpen.isFile()) {
    IFileStore fileStore = EFS.getLocalFileSystem().getStore(fileToOpen.toURI());
    IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
    try {
        IDE.openEditorOnFileStore( page, fileStore );
    } catch ( PartInitException e ) {
        //Put your exception handler here if you wish to
    }
} else {
    //Do something if the file does not exist
}
FAQ100
FAQ: FAQ What is the difference between a path and a location?
   IPath location = ...;
   IFile[] files = root.findFilesForLocation(location);
   IFolder[] folders = root.findContainersForLocation(location);
   if (files.length > 0) {
      for (int i = 0; i < files.length; i++)
         path = files[i].getLocation();
   } else {
      for (int i = 0; i < folders.length; i++)
         path = folders[i].getLocation();
   }
FAQ101
FAQ: FAQ How do I display a Web page in SWT?
   Display display = new Display();
   final Shell shell = new Shell(display, SWT.SHELL_TRIM);
   shell.setLayout(new FillLayout());
   Browser browser = new Browser(shell, SWT.NONE);
   browser.addTitleListener(new TitleListener() {
      public void changed(TitleEvent event) {
         shell.setText(event.title);
      }
   });
   browser.setBounds(0,0,600,400);
   shell.pack();
   shell.open();
   browser.setUrl("http://eclipsefaq.org");
   while (!shell.isDisposed())
      if (!display.readAndDispatch())
         display.sleep();
FAQ102
FAQ: FAQ How do I open an editor on a file outside the workspace?
IWorkspace ws = ResourcesPlugin.getWorkspace();
IProject project = ws.getRoot().getProject("External Files");
if (!project.exists())
    project.create(null);
if (!project.isOpen())
    project.open(null);
Shell shell = window.getShell();
String name = new FileDialog(shell, SWT.OPEN).open();
if (name == null)
    return;
IPath location = new Path(name);
IFile file = project.getFile(location.lastSegment());
file.createLink(location, IResource.NONE, null);
IWorkbenchPage page = window.getActivePage();
if (page != null)
    page.openEditor(file);
FAQ103
FAQ: FAQ How do I add a builder to a given project?
   private void addBuilder(IProject project, String id) {
      IProjectDescription desc = project.getDescription();
      ICommand[] commands = desc.getBuildSpec();
      for (int i = 0; i < commands.length; ++i)
         if (commands[i].getBuilderName().equals(id))
            return;
      //add builder to project
      ICommand command = desc.newCommand();
      command.setBuilderName(id);
      ICommand[] nc = new ICommand[commands.length + 1];
      // Add it before other builders.
      System.arraycopy(commands, 0, nc, 1, commands.length);
      nc[0] = command;
      desc.setBuildSpec(nc);
      project.setDescription(desc, null);
   }
FAQ104
FAQ: FAQ How do I add hover support to my text editor?
   public class TextHover implements ITextHover {
      public IRegion getHoverRegion(ITextViewer tv, int off) {
         return new Region(off, 0);
      }
      public String getHoverInfo(ITextViewer tv, IRegion r) {
         try {
            IDocument doc = tv.getDocument();
            EscriptModel em = EscriptModel.getModel(doc, null);
            return em.getElementAt(r.getOffset()).
               getHoverHelp();
         }
         catch (Exception e) {            
            return ""; 
         }
      }
   }
FAQ105
FAQ: FAQ How do I launch a Java program?
   void launch(IJavaProject proj, String main) {
      IVMInstall vm = JavaRuntime.getVMInstall(proj);
      if (vm == null) vm = JavaRuntime.getDefaultVMInstall();
      IVMRunner vmr = vm.getVMRunner(ILaunchManager.RUN_MODE);
      String[] cp = JavaRuntime.
         computeDefaultRuntimeClassPath(proj);
      VMRunnerConfiguration config = 
         new VMRunnerConfiguration(main, cp);
      ILaunch launch = new Launch(null, 
         ILaunchManager.RUN_MODE, null);
      vmr.run(config, launch, null);
   }
FAQ106
FAQ: FAQ How do I find out what object is selected?
   IWorkbenchPage page = ...;
   //the current selection in the entire page
   ISelection selection = page.getSelection();
   //the current selection in the navigator view
   selection = page.getSelection(IPageLayout.ID_RES_NAV);
   //add a listener
   ISelectionListener sl = new ISelectionListener() {
      public void selectionChanged(IWorkbenchPart part, ISelection sel) {
         System.out.println("Selection is: " + sel);
      }
   };
   page.addSelectionListener(sl);
   //add a listener to selection changes only
   //in the navigator view
   page.addSelectionListener(sl, IPageLayout.ID_RES_NAV);
FAQ107
FAQ: FAQ How do I make my view appear in the Show In menu?
   public boolean show(ShowInContext context) {
      if (viewer == null || context == null)
         return false;
      ISelection sel = context.getSelection();
      if (sel instanceof IStructuredSelection) {
         IStructuredSelection ss = (IStructuredSelection)sel;
         Object first = ss.getFirstElement();
         if (first instanceof Book) {
            viewer.setInput(first);
            return true;
         }
      }
      return false;
   }
FAQ108
FAQ: FAQ How do I create my own editor?
   public class MinimalEditor extends EditorPart {
      private Label contents;
      public void createPartControl(Composite parent) {
         contents = new Label(parent, SWT.NONE);
         contents.setText("Minimal Editor");
      }
      public void init(IEditorSite site, IEditorInput input) {
         setSite(site);
         setInput(input);
      }
      public void setFocus() {
         if (contents != null)
            contents.setFocus();
      }
   }
FAQ109
FAQ: FAQ How do I create a compare editor?
 class CompareInput extends CompareEditorInput {
      public CompareInput() {
         super(new CompareConfiguration());
      }
      protected Object prepareInput(IProgressMonitor pm) {
         CompareItem ancestor = 
            new CompareItem("Common", "contents");
         CompareItem left = 
            new CompareItem("Left", "new contents");
         CompareItem right = 
            new CompareItem("Right", "old contents");
         return new DiffNode(null, Differencer.CONFLICTING, 
            ancestor, left, right);
      }
   }
FAQ110
FAQ: FAQ How can I change the name or tooltip of my action?
class ToggleAction 
         implements IWorkbenchWindowActionDelegate {
      private boolean state = false;
      public void run(IAction action) {
         state = !state;
         String name = state ? "True Action" : "False Action";
         action.setText(name);
         action.setToolTipText(name);
      }
   }
FAQ111
FAQ: FAQ How do I support multiple natural languages in my plug-in messages?
 String translate(String key, String[] parms) {
      try {
         ResourceBundle bundle = 
            ResourceBundle.getBundle("messages");
         String msg = bundle.getString(key);
         return MessageFormat.format(msg, parms);
      } catch (MissingResourceException e) {
         return key;
      }
   }
FAQ112
FAQ: FAQ How do I prevent builds between multiple changes to the workspace?
 final IFolder folder1 = ..., folder2 = ...;
   Job job = new WorkspaceJob("Creating folders") {
      public IStatus runInWorkspace(IProgressMonitor monitor) 
         throws CoreException {
         folder1.create(IResource.NONE, true, null);
         folder2.create(IResource.NONE, true, null);
         return Status.OK_STATUS;
      }
   };
   job.schedule();
FAQ113
FAQ: FAQ How do I open a Property dialog?
ISelection sel = ... obtain the current selection
   PropertyPage page = new MyPropertyPage();
   PreferenceManager mgr = new PreferenceManager();
   IPreferenceNode node = new PreferenceNode("1", page);
   mgr.addToRoot(node);
   PropertyDialog dialog = new PropertyDialog(shell, mgr, sel);
   dialog.create();
   dialog.setMessage(page.getTitle());
   dialog.open();
FAQ114
FAQ: FAQ How do I support formatting in my editor?
  MultiPassContentFormatter formatter= 
      new MultiPassContentFormatter(
      getConfiguredDocumentPartitioning(viewer), 
      IDocument.DEFAULT_CONTENT_TYPE);
   formatter.setMasterStrategy(
      new JavaFormattingStrategy());
   formatter.setSlaveStrategy(
      new CommentFormattingStrategy(...), 
      IJavaPartitions.JAVA_DOC);
FAQ115
FAQ: FAQ How do I insert text in the active text editor?
   IWorkbenchPage page = ...;
   IEditorPart part = page.getActiveEditor();
   if (!(part instanceof AbstractTextEditor)
      return;
   ITextEditor editor = (ITextEditor)part;
   IDocumentProvider dp = editor.getDocumentProvider();
   IDocument doc = dp.getDocument(editor.getEditorInput());
   int offset = doc.getLineOffset(doc.getNumberOfLines()-4);
   doc.replace(offset, 0, pasteText+"\n");
FAQ116
FAQ: FAQ How do activities get enabled?
String id = ...
IWorkbench wb = PlatformUI.getWorkbench();
IWorkbenchActivitySupport as = wb.getActivitySupport();
IActivityManager am = as.getActivityManager();
IIdentifier identifier = am.getIdentifier(id);
Set activities = new HashSet(am.getEnabledActivityIds());
if (activities.addAll(identifier.getActivityIds())) {
   as.setEnabledActivityIds(activities);
}
FAQ117
FAQ: FAQ How do I distinguish between internal and external JARs on the build path?
IClasspathEntry entry = ...
   IPath path = entry.getPath();
   IWorkspace workspace = ResourcesPlugin.getWorkspace();
   IResource jarFile= workspace.getRoot().findMember(path);
   if (jarFile != null) {
      return jarFile.getLocation();
   } else {
      // must be an external JAR (or invalid classpath entry)
   }
FAQ118
FAQ: FAQ How do I use the context class loader in Eclipse?
 Thread current = Thread.currentThread();
   ClassLoader oldLoader = current.getContextClassLoader();
   try {
      current.setContextClassLoader(getClass().getClassLoader());
      //call library code here
   } finally {
      current.setContextClassLoader(oldLoader);
   }
FAQ119
FAQ: FAQ How do I launch the preference page that belongs to my plug-in?
IPreferencePage page = new MyPreferencePage();
PreferenceManager mgr = new PreferenceManager();
IPreferenceNode node = new PreferenceNode("1", page);
mgr.addToRoot(node);
PreferenceDialog dialog = new PreferenceDialog(shell, mgr);
dialog.create();
dialog.setMessage(page.getTitle());
dialog.open();
FAQ120
FAQ: FAQ How do I use progress monitors?
try {
      monitor.beginTask("Performing decathlon: ", 10);
      monitor.subTask("hammer throw");
      //perform the hammer throw
      monitor.worked(1);
      //... repeat for remaining nine events
   } finally {
      monitor.done();
   }
FAQ121
FAQ: FAQ How do I use a SubProgressMonitor?
 public void move(File a, File b, IProgressMonitor pm) {
      try {
         pm.beginTask("Moving", 10);
         copy(a, b, new SubProgressMonitor(pm, 8));
         delete(a, new SubProgressMonitor(pm, 2));
      } finally {
         pm.done();
      }
   }
FAQ122
FAQ: FAQ How do I use IAdaptable and IAdapterFactory?
 Object input = ...;
   IResource resource = null;
   if (input instanceof IResource) {
      resource = (IResource)input;
   } else if (input instanceof IAdaptable) {
      IAdaptable a = (IAdaptable)input;
      resource = (IResource)a.getAdapter(IResource.class);
   }
FAQ123
FAQ: FAQ How do I react to changes in source files?
 IResourceChangeListener rcl = new IResourceChangeListener() {
      public void resourceChanged(IResourceChangeEvent event) {
         IResource resource = event.getResource();
         if (resource.getFileExtension().equals("escript")) {
            // run the compiler
         }
      }
   };
   ResourcesPlugin.getWorkspace().addResourceChangeListener(rcl);
FAQ124
FAQ: FAQ How do I create Java elements?
 IType type = ...;
   String body = "public String toString() {"+
      "return super.toString();}";
   IMethod method = type.'''getMethod'''("toString", new String[0]);
   if (!method.exists())
      method = type.createMethod(body, null, false, null);
FAQ125
FAQ: FAQ How do I make key bindings work in an RCP application?
  public void fillActionBars(IWorkbenchWindow window,
      IActionBarConfigurer configurer, int flags) {
      ...
      if (maximizeAction == null) {
         maximizeAction = ActionFactory.MAXIMIZE.create(window);
         configurer.registerGlobalAction(maximizeAction);
      }
      menu.add(maximizeAction);
   }
FAQ126
FAQ: FAQ How do I use the platform logging facility?
import org.eclipse.core.runtime.Status;
   ...
   public void log(String msg) {
      log(msg, null);
   }
   public void log(String msg, Exception e) {
      getLog().log(new Status(Status.INFO, myPluginID, Status.OK, msg, e));
   }
FAQ127
FAQ: FAQ How do I prevent two jobs from running at the same time?
public class MutexRule implements ISchedulingRule {
      public boolean isConflicting(ISchedulingRule rule) {
         return rule == this;
      }
      public boolean contains(ISchedulingRule rule) {
         return rule == this;
      }
   }