Add signals to Camera nodes triggered when they gain or lose "current" status

[mrkdji]

I am working on a point & click game with multiple cameras and it would have been convenient to have something like current_status_changed(value) to activate / deactivate input processing.

[AThousandShips]

When does camera switching happen automatically? If it's controlled by code you can just signal when you change it, no need for a signal, signals are meant for things that happen outside of your control

I'd instead suggest a notification, internally Camera3D already has one, so adding one for the 2D case and also exposing them both would solve this without the complexity of a signal, and it'd be more appropriate as it's the camera that should respond to this change IMO, not some other node

[mrkdji]

A notification is perfectly fine for what I want to achieve, and it would be much better than nothing, but I still believe that a signal would be more beginner friendly.

[Mickeon]

To be fair exposing a notification would be ok, but if one were to expose the notification I cannot see the downsides of exposing a new signal, it'd pretty much work like Control nodes focus_entered focus_exited.

Signals do not come for free. Even if the signal is not connected to anything there's always a base performance cost, albeit relatively small. The same goes for notifications, but those are often very much necessary internally.
However, I don't necessarily disagree. It's not like switching cameras happens ridiculously often. The important question is always "how often will developers make use of this". So, good call opening a discussion about this. I would recommend making a full proposal to catch more eyes, as well.

[AThousandShips]

If we add a signal I'd add it to viewport instead and have it convey the new current camera, that seems more useful for a signal, having a local signal on each camera means a notification works just as well and I'd say that would be the most appropriate change

[Mickeon]

Yeah that's sound to me. If there's no camera available at all the Viewport signal would just emit the signal and pass null.
Perhaps the signal should instead pass the previously active camera, instead? Just food for thought. It's why it'd be nice to think of a good proposal.

[AThousandShips]

I'd say to pass both camera_2d/3d_changed(old, new)