How do I determine if the player is opening a GUI in client side?

[WeAthFolD]

I have written some custom keys that provides specific functions for the player. For example, open the armor flashlight while equipped, but I met with some problems.

Using Minecraft's KeyHandler, the keyDown(...) function is fired regardless of the world presentation, or player is opening GUIs or not.

This is defintely not what I'm looking for. I know I can skip the process with if(Minecraft.getMinecraft().thePlayer != null)check, but I want the key not to fire when player is chatting/opening a GUI, however I didn't see similar functions in EntityPlayerSP, nor Minecraft class itself.

Any Ideas ?

[hydroflame]

check that Minecraft.getMinecraft().thePlayer.currentScreen == null (or is equal to the in game gui