Creating new GUI Controls

Unity Engine
1

I got a weird question…

How do you create a new GUI Control from scratch?

Here’s the idea, I want a checkbox - I know it already exist - that support a third states - that doesn’t exist.

So, I thought of creating a new checkbox method by drawing textures depending of the different state… But that doesn’t make it “a control” that can be focused on, just a texture with a collection of mouse event. Worse, the texture doesn’t appear to be redrawn on MouseDrag. Would that be something flagged by a proper control?

Or imagine I would like to make a new Button, one that would have the following states;

  • Idle
  • Hovered
  • Pressed
  • Pressed but with the mouse away
  • Clicked
  • Focused

For that, I would probably want to handle the mouse event myself as the GUI.Button is sealed to any change.

What is going on behind the scene in that GUI.Button?? How to make a real control visible to GUI?

2

So far as I know, GUI isn’t object based at all. Button is just a static method that returns a bool stating whether it’s being clicked or not. The manual entry on GUI extensions would seem to point to a similar pattern. You make a method (static or not) that takes a Rect and whatever else you need. My guess is the best you could do is some hacky style swapping to support states not included out of the box.

3

I know that… But how do you select a control? The Inspector’s control have a selection focus. When you call “SetNextControlName” (http://docs.unity3d.com/Documentation/ScriptReference/GUI.SetNextControlName.html) it attributes a name to a specific control. How do you tell that system what a “control” is?

All the example they do in their tutorial is to compound existing “control”, they never create a new one from scratch. I would like to see the code behind “Button” or “Toggle”. Does anybody decompiled that?

4

I checked UnityEngine.dll with a .NET Reflector, and sadly, everything that would define a Control appear to be native.

So, creating a control from scratch that uses the same interactions as native Control is just impossible. :frowning:
Even a button’s behaviour is an internal call.