How do I know if GUI is selected?

Hello,

Unity's GUI is very crappy and should only get used for prototyping (at least until 4.2 is released). On that note, there is no built in way of finding out the buttons state like there is (and should be) in any modern GUI modules.

There is however, a workaround:
Instead of finding out the buttons state, you calculate for yourself if the mouse is over the button:

 //finding wether mouse is in rectangle
 function InRect(rectangle:Rect) {
     return Input.mousePosition.x > rectangle.x &&
         Input.mousePosition.x < rectangle.x + rectangle.width &&
         Input.mousePosition.y > rectangle.y &&
         Input.mousePosition.y < rectangle.y = rectangle.height;
 }
 
 //using GUI
 var rect:Rect = Rect(0, 0, 100, 200);
 function OnGUI() {
     GUI.Button(rect, /*content*/);
     if (InRect(rect)) {
         //we are over the button
     }
 }
 
 //using GUILayout
 function OnGUI() {
     GUILayout.Button(/*content*/)
     if (InRect(GUILayoutUtility.GetLastRect())) {
         //we are over the button
     }
 }

Note that this code is untested, so there might be some bugs :)

Hope this helps,
Benproductions1