如何在 eclipse 插件中添加 IResourceChangeListener？

Question

I am trying to add IResourceChangeListener in my eclipse plugin, using following tutorial:

https://eclipse.org/articles/Article-Resource-deltas/resource-deltas.html

However, I never found anywhere, where should I add these listener code. I found that they are just creating a new class where they added the listener code. If I add it just in any java class, then how eclipse will know, which class to trigger when the events occur? I tried to put the code in activator.java as following (I added it there because it maintains the plugin life cycle).

I modified the start and stop method.

package testPlugin;

import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.BundleContext;

/**
 * The activator class controls the plug-in life cycle
 */
public class Activator extends AbstractUIPlugin {

    // The plug-in ID
    public static final String PLUGIN_ID = "testPlugin"; //$NON-NLS-1$

    /** the resource listener on URI changes */
    IWorkspace workspace = ResourcesPlugin.getWorkspace();
    IResourceChangeListener listener;

    // The shared instance
    private static Activator plugin;

    /**
     * The constructor
     * 
     */

    public Activator() {

    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext
     * )
     */
    public void start(BundleContext context) throws Exception {
        super.start(context);
        plugin = this;
        listener = new IResourceChangeListener() {
            public void resourceChanged(IResourceChangeEvent event) {
                System.out.println("Something changed!");
            }
        };

        workspace.addResourceChangeListener(listener);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext
     * )
     */
    public void stop(BundleContext context) throws Exception {
        if (workspace != null) {
            workspace.removeResourceChangeListener(listener);
        }
        plugin = null;
        super.stop(context);
    }

    /**
     * Returns the shared instance
     *
     * @return the shared instance
     */
    public static Activator getDefault() {

        return plugin;
    }

    /**
     * Returns an image descriptor for the image file at the given plug-in
     * relative path
     *
     * @param path
     *            the path
     * @return the image descriptor
     */
    public static ImageDescriptor getImageDescriptor(String path) {
        return imageDescriptorFromPlugin(PLUGIN_ID, path);
    }
}

But its not working. When I change my current editor by external MKS check out, its not printing "Something has changed" to consol, or simply its not working.

How can I make it working? Where should I add the code actually? I want to modify the working editor (can be default java editor) in eclipse without creating any new editor with this listener.

Thanks a lot in advance.

Answer 1

There are 2 ways to do this.

1. Write your own class by implementing IResourceChangeListener. This will provide fine control.
2. Use below code

workspace.addResourceChangeListener(listener,IResourceChangeEvent.POST_CHANGE|IResourceChangeEvent.PRE_BUILD);