How to set selection for treeviewer without firing selectionChanged()?

Question

I am working on an eclipse RCP project. It has several views with TreeViewer and I use selectionChanged() method to handle selection events. However, at times I need to set selection programmatically.For this, in selectionChanged() method, I invoke setSelection() method of TreeViewer to set the desired selection. This method fires selectionChanged() method of all views thus resulting in cyclic calls to selectionChanged().

How can I select an item from the TreeViewer or StructuredViewer without firing selectionChanged() for other views?

@Baz Good to know there are people facing similar problems. I thought I am doing something wrong. I have used similar structure in my application. Since it has many views handling selections using booleans becomes quite unmanageable. Eclipse should take a note of this. — SaurabhJinturkar, Jun 20 '14 at 04:58

score 3 · Accepted Answer · answered Jun 16 '14 at 14:08

3

Well, creating an event that triggers the Listener you're currently in is always a tricky situation. What I usually do is something along those lines:

Listener listener = new Listener()
{
    private boolean ignore = false;

    @Override
    public void handleEvent(Event e)
    {
        if(ignore)
            return;

        ignore = true;
        doPotentiallyCyclicStuff();
        ignore = false;
    }
};

It's not a very pretty solution, but it does work.

Looking forward to alternative solutions here, since this has been bothering me for a while now.

answered Jun 16 '14 at 14:08

Baz

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I have not seen anything better. In fact the TreeViewer code does exactly this to avoid cycles internally. – greg-449 Jun 16 '14 at 14:12
Who is updating ignore value in this case? It will always be false how come it reaches to doPotentiallyCyclicStuff(); ? – Prasad S Deshpande Jun 17 '14 at 07:47
@PrasadSDeshpande Read the if check again and think for a second ;) – Baz Jun 17 '14 at 07:59
@Baz got it mymistake – Prasad S Deshpande Jun 17 '14 at 09:51

How to set selection for treeviewer without firing selectionChanged()?

1 Answers1