control id question

What is the purpose of the control ids?
When I add a new control can I pick an arbitraty number for the id? Does it have to be unique in that one window, or across the whole application?

I'm diving into making a touchscreen friendly version of the MCE skin, so i think you can expect a whole bunch of questions from me. I'll be a guru soon enough though.

[frodo]

control id's are used by mediaportal to make a connection
between the layout (defined in the xml files) and the
functionality (defined in the sourcecode)

Say you have a play button with id = 4
then in the source code i know that if a button with id=4 is pressed
that we should start playing the file

When I add a new control can I pick an arbitraty number for the id?

Yes you can since a 'new control' has no functionality yet in the sourcecode.
However make sure you dont use an id which already is used in the xml file

Does it have to be unique in that one window

In general yes. The idea is that id's are unique in one window
However not all controls have functionality behind it
(think of the background image) so you'll see that those ids
can be used more then once

Frodo

and for the controls for actions such as play and stop etc... Does the id for the control matter? Isn't it the action that is used to decide to play or stop etc..?

[MrMario64]

yes it matters.
Each button needs it's own ID to make it possible to make the Onleft, Onright Onup and Ondown items.
YO\ou tell MP to wich button or controll you wanna go to when going up,down.left or right.
This needs each button to be unique