title: Is a mouse click a WM_* message or a combination of up & down messages?
body: <p>I'm used to working with a Windows framework that provides events for things like a mouse click or a mouse double click.  Are click events a Windows construct (i.e. does Windows send a WM_DOUBLECLICK or similar message) or does it send WM_MOUSEDOWN and WM_MOUSEUP to applications which then do some math to decide if the event was a click or otherwise?</p>