Trackbar (slider) wierdness
-
I'm hoping someone knows enough about the history of Windows to explain some things. First, why would trackbars send WM_SCROLL messages? Even if they were going for a sort of backward compatibility that would have allowed programs that used scrollbars as trackbars to be upgraded just from resource changes, it seems to me that trackbars could have supported a mode that would have allowed them to send messages of a type that frameworks wouldn't already use for scrolling. Why did they make it so hard to use? Also, the MSDN documentation says that TB_THUMBPOSITION is "WM_LBUTTONUP following a TB_THUMBTRACK notification message." This message would actually be useful if it were sent when the trackbar's position were updated by the keyboard. Instead, I have to check for every message except TB_THUMBTRACK and see if the position is different from my last recorded position to decide when a lasting adjustment to a thumb position is made. Why didn't they make TB_THUMBPOSITION work for that? Nathan Holt