The standard reference for "pointer warping" for [Tk] has been the "usage FAQ" [http://www.hobbs.wservice.com/tcl/faqs/tk/tkfaq.html] (2004-12-19: link dead)
[[oooo; we ''do'' need to fix that link ...]].
It briefly mentions that pointer warping is a bad idea ([don't do that]), supplies source for an extension
which implements warping, and also points to [[fill in the details here ...]], with its implementation of the same as ...  The FAQ doesn't seem to be current ...

As "[Changes in Tcl/Tk 8.3]" hints, release 8.3's [event] command builds in pointer warping.

Here is a simple example of pointer warping:

 event generate . <Motion> -warp 1 -x 50 -y 50.

(Move the cursor to the '.' window, inset 50 pixels from top left corner)

Among the legitimate uses of pointer warping are test automations, including [Android], and for pedagogic purposes (Android can also
help build demonstrations).

Another legitimate use of pointer warping was the GUI design of Interleaf Version <= 5. The GUI was mainly context-menu driven and remembered the last menu choice in the cascading tree of sub-menus. With a delay of about 300ms, the next cascade opened with mouse pointer on appropriate entry. It was not the worst GUI I've worked with. ([wdb])

[Larry Smith] Open Look also would warp the mouse if it improved the GUI. As I recall, choosing the "resize" entry from the window control menu would not only put you in resize mode, it would warp the point to the handle at the lower right.

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[kroc] - Here's a trick to move the mouse cursor with keyboard arrows. It could be useful when mouse is broken. Someone should add mouse click with spacebar or enter.

 bind . <Up> { event generate . <Motion> -warp 1 -x [expr %x+0] -y [expr %y-10] }
 bind . <Down> { event generate . <Motion> -warp 1 -x [expr %x+0] -y [expr %y+10] }
 bind . <Left> { event generate . <Motion> -warp 1 -x [expr %x-10] -y [expr %y+0] }
 bind . <Right> { event generate . <Motion> -warp 1 -x [expr %x+10] -y [expr %y+0] }

[Larry Smith] This is ''just'' a handy trick, this is something ''every'' program should have if it relied on positioning with the mouse. Change the 10 to a 1 to get the kind of "nudge" functionality every graphical editor really should have.
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Also see "[Moving the mouse]".

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