[MiNT] Wheel support in XaAES

[Odd Skancke <ozk@atari.org>]

The below is how I imagine wheel-support can be done in XaAES and is 
already
implemented. However, I think that we need to find a decent value for 
WM_WHEEL,
it is 345 for now. Anyway, test this and let me know how it works.


                      XaAES and wheel mouse handling.

 This has changed a little compared to the original documentation and
implementation. When the wheel is on a window whose owner dont know about
mouse wheels at all, normal WM_ARROWED messages are sent. There is no extra
info added to these messages in this case, as it were in the original
implementation.

 Currently mouse wheel events are sent to the owner of the window 
underneath
the mouse pointer in all cases except when owner of mouse_lock() is waiting
for MU_WHEEL.

 For programmers who want to take advantage of mouse wheels in a better 
way,
here's an overview;

 wind_set(handle, WF_WHEEL, mode, wheel_mode, 0, 0);

 handle      Window handle, or 0 if one wants settings to apply to all 
windows
             opened hereafter by the application.

 mode        0 = Turn extended wheel awareness off, 1 = Turn on.

 wheel_mode
          XWHL_REALWHEEL ( 0 )
             When wheel_mode is set to 0 (XWHL_REALWHEEL), XaAES will send
             real wheel messages, constructed as follows;

             msg[0] = WM_WHEEL ( 345 )
             msg[1] = ID of sender
             msg[2] = ...
             msg[3] = window handle
             msg[4] = orient
             msg[5] = wheel ID
             msg[6] = wheel amount
             msg[7] = Not used, always 0

             'orient' is a bitmask where bit 0 indicates direction, and
             bit 1 indicates orientation;

              bit 0  -  0 = up or left
                        1 = down or right
              bit 1  -  0 = vertical (bit 0 indicates UP/DOWN)
                        1 = horizontal (bit 0 indicates LEFT/RIGHT)

             'wheel ID' contains the wheel number. 0 is wheel #1, etc..
         'wheel amount' holds the number of wheel-turns.
         
          XWHL_AROWWHEEL ( 1 ) This is the default wheel_mode set if the
             value passed is outside the available range. When this mode is
             selected, normal WM_ARROWED messages are sent upon each wheel
             turn. With this mode, WM_ARROWED messages are send even when
             the window has no ARROW gadgets.

          XWHL_SLDRWHEEL ( 2 )
             When wheel_mode is set to 2 (XHWL_SLDRWHEEL), XaAES converts
             wheel turns into slider movements. XaAES sends standard
             WM_VSLID/WM_HSLID messages reflecting the wheel turns.
             For this to work, WF_VSLIDE/WF_HSLIDE wind_get/set() modes 
have
             been extended. When the application gets the WM_xSLIDE 
message,
             it must pass back the position from the message unmodified
             together with your modified position;

             wind_set(handle, WF_[V,H]SLIDE, postion, unmodified, 0, 0);

             Even if the application snaps slider movements and finds that
             the slider does not move, it has to pass back the unmodified
             slider position via wind_set(). In cases where the original
             slider position match the prevsiously set position, XaAES does
             not set or redraw the slider. But it needs to collect the 
'real'
             position of the slider for wheel -> slider calculations to 
work.

--
Odd Skancke