NetBeans: How to create a context aware action with an icon for the context menu

Here a small sample how to create a context aware action with icons for a NetBeans Platform RCP application or even the NB IDE. You may wonder and questions like “Why the heck he is doing this” or “Why he won’t use the standard action wizard?” may pop up.

Assigning icons to actions is easy. BUT the icons do will not be displayed in the context menu (by default). It is possible but not best practice in NB RCP. Keep in mind that icons in menus are not supported for MacOS. So use it wisely.

The important points are:

  • extend from AbstractAction to get access to putValue (you loose the standard context aware features, so you have to implement them yourself via keeping a proxy to the global lookup and enabling the action depending on the content of the lookup)
  • implement Presenter.Popup and return a JMenuItem instance for the current action (see [1], [2])
  • set the icon via putValue(javax.swing.Action.SMALL_ICON, ...)
package de.markiewb.netbeans.sample.contextmenu;

import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import static javax.swing.Action.SMALL_ICON;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import org.netbeans.api.annotations.common.StaticResource;
import org.netbeans.api.project.Project;
import org.openide.awt.ActionID;
import org.openide.awt.ActionReference;
import org.openide.awt.ActionReferences;
import org.openide.awt.ActionRegistration;
import org.openide.util.ImageUtilities;
import org.openide.util.Lookup;
import org.openide.util.NbBundle.Messages;
import org.openide.util.Utilities;
import org.openide.util.actions.Presenter;

        category = "Build",
        id = "de.markiewb.netbeans.sample.contextmenu.HelloIconAction")
    @ActionReference(path = "Menu/File", position = 0),
    @ActionReference(path = "Loaders/Languages/Actions", position = 0),
        displayName = "#CTL_HelloIconAction")

@Messages("CTL_HelloIconAction=Hello Icon Action")
public final class HelloIconAction extends AbstractAction implements Presenter.Popup {

    private static final String ICON = "de/markiewb/netbeans/sample/contextmenu/sample.gif";
    private static final long serialVersionUID = 1L;
    private final Lookup context;

    public HelloIconAction() {
        context = Utilities.actionsGlobalContext();
        putValue(SMALL_ICON, ImageUtilities.loadImageIcon(ICON, false));
        putValue(NAME, Bundle.CTL_HelloIconAction());

    public boolean isEnabled() {
        return null != context.lookup(Project.class);

    public void actionPerformed(ActionEvent ev) {
        JOptionPane.showMessageDialog(null, "Hello colorful project.\n" + context.lookup(Project.class).toString());

    public JMenuItem getPopupPresenter() {
        return new JMenuItem(this);



The result:
Shows the result

See sample code at


NetBeans: Quicktip: Open project for open file

A very useful feature of NetBeans is to the project for an opened file.


Imagine the following scenario: You searched for content in java files using the file explorer (or other indexing tool) — instead of opening all projects and using the file search of NB. You open the file directly in NetBeans by copying its full absolute path and pasting it into the “File-> Open File” dialog.

Now you want to open the surrounding project for several reasons.

  • You could open the project manually OR
  • even easier invoke the action “Navigate->Select in Projects” from the menu bar (or the corresponding shortcut). Now a dialog opens (if a project can be found for the file) and asks for permission to open the project.

Very neat and useful.

New NetBeans-plugin: “Toggle line wrap”

I implemented another easy plugin, which adds a status bar button and an action which allows to toggle the line wrap setting. You do not have to use the options dialog and you can assign a shortcut for it. It is compatible to NetBeans >7.0


More details and download at (sourcecode is also available).

In a few days it will also be available the at NetBeans IDE Update Center and you can install it from within your IDE. Stay tuned.