ValueTree::setPropertyExcludingListener & Redo/Undo

General JUCE discussion
#1

I have a ValueTree object, which I use with an UndoManager. It has a strange Undo/Redo behaviour, when using ValueTree::setPropertyExcludingListener

I set the properties of my ValueTree using ValueTree::setPropertyExcludingListener. Because I do not want a certain listener to get informed. But I still want my ValueTree::Listener to get notified, when Undo or Redo happens.

So here is the thing: Undo is working fine - my listener gets informed. But Redo is not good. If I execute Redo, my listener is not informed.

The reason for this is in the ValueTree::SetPropertyAction class.
It behaves differently for Undo and for Redo. For Undo it will do a normal setProperty. But for Redo it is doing a setProperty, with Listener excluded.

Here is a code excerpt from ValueTree::SetPropertyAction :

        bool perform() override
        {
            jassert (! (isAddingNewProperty && target->hasProperty (name)));

            if (isDeletingProperty)
                target->removeProperty (name, nullptr);
            else
                target->setProperty (name, newValue, nullptr, excludeListener);

            return true;
        }

        bool undo() override
        {
            if (isAddingNewProperty)
                target->removeProperty (name, nullptr);
            else
                target->setProperty (name, oldValue, nullptr);

            return true;
        }

(Note that “Redo” will isue a call to “perform”).

On first glance, this seems inconsistent to me. Could it be a bug?
Why should it exclude the listener for Redo, but not for Undo?
And more so, why only if you set a property, but not if you remove one?
Or is there a good explanation for this?

Ideally, I would like it to not exclude any listeners att all. Neither for Undo nor for Redo.

I am working on JUCE 5.4.2, develop branch from last week.

#2

Hey @t0m or any one else from the JUCE team.
Kind of interested to hear your point on this behaviour.

#3

I have the same problem. I only want to exclude a listener for a single call (to avoid convert to var and then from var a big block), but I don’t want to exclude it for undo/redo.

Since these listener are synchronous I placed a temporal bool flag to exclude instead using setPropertyExcludingListener. It seems it works fine.

My set function:

            avoidCallbackThisTime = true;
            parentTree.setProperty(id, ruleSetter.toVar(newVal), undoManager);

My valueTreePropertyChanged function:

     if (avoidCallbackThisTime == false)
     {
        // I do my data conversion / calls, here
     }
     else
     {
        avoidCallbackThisTime = false;
     }