Entry | |
---|---|
R0 | AutoScroll Entry Flags or 0 to cancel autoscrolling |
R1 | Pointer to AutoScroll Block ignored if R0 = 0 |
Exit | |
---|---|
R0 | AutoScroll Exit Flags |
The purpose of this call is to control how the Wimp automatically scrolls an application’s windows.
Typical use is to handle the window scrolling whilst dragging in a window either as part of the drag and drop protocol or when dragging one end of a text selection.
In the latter case after a drag button Mouse_Click event you start a drag with Wimp_DragBox, call Wimp_AutoScroll 3,autoscrollblk and when you get a User_Drag_Box event after the mouse button is released you call Wimp_AutoScroll 0.
The flags returned from AutoScroll inform you of its current status. If you need to monitor this during the drag you need to call AutoScroll 7,autoscrollblk where autoscrollblk has the same information as your original Autoscroll call. If bit 7 is set other entry flags are ignored.
This call is application specific, and not system wide.
The window handle in the block passed in R1 must be owned by the calling task.
Only 1 window can use autoscroll at a time so when you are finished with it you should cancel it.