[Mac-emacs-devel] set-mouse-position patch for Mac OS X

[Steven T. <ste...@ma...>]

After much digging I found a way to move the mouse cursor around 
programmatically in Mac OS X, despite the documentation of 
CursorDeviceMoveTo saying you could not.  In Quartz 2D, they added the 
ability to directly modify the screen, including setting the position of 
the cursor.  The documentation can be found in a technote here 
http://developer.apple.com/technotes/tn/tn2007.html  I'm running 10.1.5, 
so that's all I can vouch for.

To try it out you can simple eval (set-mouse-position (selected-frame) 
10 10) and it should jump the cursor 10 lines down and 10 characters 
over.  If you remove the call to ObscureCursor in XTread_socket it will 
be more dramatic.  mouse-avoidance-mode is even more clever.

Replace the implementation of x_set_mouse_pixel_position in macterm.c 
(around line 9923 in my version) to be this...


void
x_set_mouse_pixel_position (f, pix_x, pix_y)
      struct frame *f;
      int pix_x, pix_y;
{
#if MAC_OSX
   CGPoint point;
   Point pt;
   Rect r;
   GrafPtr savePort;

   BLOCK_INPUT;

   GetPort(&savePort);
#if TARGET_API_MAC_CARBON
   SetPort (GetWindowPort (FRAME_MAC_WINDOW (f)));
#else
   SetPort (FRAME_MAC_WINDOW (f));
#endif

   GetWindowPortBounds (FRAME_MAC_WINDOW (f), &r);
   SetPt(&pt, r.left, r.top);

   LocalToGlobal(&pt);
   SetPort (savePort);

   /* Use Quartz 2d Direct Display API to move cursor.  Not sure if this
      works on OS X 10.0 */
   point = CGPointMake(pt.h+pix_x, pt.v+pix_y);
   CGDisplayMoveCursorToPoint(kCGDirectMainDisplay, point);

   UNBLOCK_INPUT;
#endif /* MAC_OSX */
}

Thanks for reading,
-Steven