Scrollbars are stealing the WM_MOUSEWHEEL message

["Harold Hunt" <huntharo at msu dot edu>]

I just discovered a problem with using scrollbars in Cygwin/XFree86:

1) Pass the -scrollbars parameter to XWin.exe

2) Launch Cygwin/XFree86 via startxwin.bat, with the -scrollbars parameter
as in (1).  Scrollbars should not be displayed be default.  If they are,
remove any -screen parameters and try again.

3) In your xterm, run ``ls'' a few times to generate enough output to be
able to scroll up.

4) Roll the mouse wheel up, notice that the xterm content scrolls up.

5) Roll the mouse wheel down, notice that the xterm content scrolls down.

6) Leave the xterm window scrolled to about the middle of the displayed
content.

7) Shrink the size of the Cygwin/XFree86 window using the double-headed
arrow at the upper-right hand corner of the Cygwin/XFree86 window (right
above the X that closes the window).  Scrollbars should now be displayed,
and the right-hand scrollbar should have the thumb at the top of the
scrollbar (i.e., you can only scroll down).

8) Roll the mouse wheel up, notice that the xterm content scrolls up.  When
you reach the top of the content, xterm will stop scrolling.

9) Roll the mouse wheel down.  You will see that xterm scrolls down one
segment, then the WM_MOUSEWHEEL messages start getting stolen by the
right-hand scrollbar.

10) The whole Cygwin/XFree86 window now scrolls up or down when you roll the
mouse wheel up or down.

11) Minimizing/restoring/clicking the scrollbar/clicking the client area/
all do nothing to stop the scrollbar from stealing the mouse wheel messages.

12) There does not appear to be a simple way to keep the scrollbar from
stealing the mouse wheel messages.


Any suggestions?

Harold