Widget missing when executing a redo on a custom node

[doble_de]

Hi,

I'm working on a custom node. It modifies the timeline color, setting a custom widget created in the postConstructor call.

This widget is deleted when the node is "deleted" using the following callbacks:

MSceneMessage.kBeforeNew

MSceneMessage.kBeforeImport

MSceneMessage.kBeforeOpen

MNodeMessage.addNodePreRemovalCallback

MDGMessage.addNodeRemovedCallback

All those callbacks run a function that deletes the widget and all the callbacks the node created.

When I delete the node, the callbacks and the widget are removed. But if I do a redo, I can see the callbacks are up again, but not the widget.

Wondering how can I create the widget again after a redo of the node happens, as the constructor and the postConstructor are not called.

Thanks,

David

[jmreinhart]

Could you run"MDGMessage::addNodeAddedCallback" in registerPlugin? and have that callback take care of triggering the creation of those callbacks, rather than having the postConstructor do it? That seems safer, since construction/destruction may not always line up with deletion and creation. 

[doble_de]

Hi,

thanks for the reply. The problem with the callback is that I delete all the callbacks when the node is deleted. So when I do an undo, that callback is not called.

[jmreinhart · Accepted solution]

To clarify, this is what I was imagining.

When Node is Created

When Node is deleted

When delete is undone

This would work differently than what you have now because the constructor doesn't get called again when you "undo" since the C++ object remains constructed when you undo. But the nodeAddedCallback would get triggered on the initial node creation and on the redo.

[doble_de]

Oh, sorry I didn’t read it properly and I was creating the nodeAdded callback inside the node, and not in the load plugin part.

That worked great, thanks a lot! And thank you for doing the diagram!

[jmreinhart]

Yeah, it's a bit hard to convey in words. Glad it worked!