UI Controls don't receive Update event

[mtszkarbowiak]

Issue description:

Custom UI controls don't receive invokes on override void Update(float deltaTime) event method. This breaks existing controls.

Steps to reproduce:

1. Create a custom control.
2. Declare aforementioned overriding method.

Flax version:

1.8, I think it was NOT in 1.7

[Tryibion]

Works fine for me... even runs while not in play mode. Do you have any code that can reproduce this issue?

[mtszkarbowiak]

I was preparing the code when it clicked it my brain: Update is not invoked if the checkbox Receives Events for the canvas is checked off. The comment for this checkbox says though that it should be used to disable input events.

[Tryibion]

I see. I guess the question is, should it call update if that is uncheck marked? there could be inputs firing in the update loop....

[mtszkarbowiak]

I think it should. My understanding is the following:

1. Creating a canvas which does not receive input is useful. It may be used for Player's HUD which never interacts with mouse, just displays info.
2. Such canvas should still be update-able. For example health bars, map markers, etc. Time dependence allows for animations. That's why it takes delta time as a param.
3. Control has separate Update and Draw to distinguish the process of drawing and updating state, meaning that the engine may draw the control multiple times between updates, and vice versa. (As I remember Unity can do that.)
4. Ultimately, to modify if a script is updating, the engine uses Enabled. If so, the controls should follow it.