How to subscribe to an OpenProject event in Eclipse?

Question

I'm developing an Eclipse plugin.

I have been reading how to subscribe get notification when a project is about to be closed, using the interface IResourceChangeListener, and using the PRE_CLOSE event type. The following text has been taken from the Eclipse help:

Notifies listeners that a project is about to be closed. This event can be used to extract and save necessary information from the in-memory representation (e.g., session properties) of a project before it is closed. (When a project is closed, the in-memory representation is disposed). The workspace is locked (no resources can be updated) during this event. The event contains the project that is being closed.

I didn't found how to be notified when a project is about to be opened.

Answer 1

You can create your own IResourceChangeListener and filter the kind of delta by IResourceDelta.OPEN, which only affects to IProjects, and it's fired both when opening and closing a project:

public void resourceChanged(IResourceChangeEvent event) {
    if (event == null || event.getDelta() == null)
        return;
    event.getDelta().accept(new IResourceDeltaVisitor() {
        public boolean visit(IResourceDelta delta) throws CoreException {
            if (delta.getKind() == IResourceDelta.OPEN)
                final IResource resource = delta.getResource();
                if (!(resource instanceof IProject))
                    return;
               //do your stuff and check the project is opened or closed
        }
}

Useful link: http://www.eclipse.org/articles/Article-Resource-deltas/resource-deltas.html

Answer 2

I know this question has been long answered, but I want to update it with a working code snippet, just in case anybody will need it. I tested it on Eclipse Luna, Indigo, and Kepler.

public void resourceChanged(final IResourceChangeEvent event) {
    if (event == null || event.getDelta() == null) {
        return;
    }

    try {
        event.getDelta().accept(new IResourceDeltaVisitor() {
            public boolean visit(final IResourceDelta delta) throws CoreException {
                IResource resource = delta.getResource();
                if (((resource.getType() & IResource.PROJECT) != 0)
                        && resource.getProject().isOpen()
                        && delta.getKind() == IResourceDelta.CHANGED
                        && ((delta.getFlags() & IResourceDelta.OPEN) != 0)) {

                    IProject project = (IProject)resource;
                    projectOpened(project);
                }
                return true;
            }
        });
    } catch (CoreException e) {
        e.printStackTrace();
    }
}

Answer 3

IResourceChangeEvent is POST_CHANGE and related IResourceDelta kind is IResourceDelta.CHANGED and flags include IResourceDelta.OPEN.