🚀 go-pugleaf

patl@bodacia.eng.sun.com writes:
| In article 965@modular.UUCP, earley@modular.com (Joe Earley) writes:
| >I can't figure
| >out how to track the mouse movement in a TNT 3.0 canvas without making
| >the user press the select or adjust button.
|
| How are you supposed to tell whether you are drawing or not if you
| don't have a button down?
| 
| Assuming that you have a good answer for that...
| 
| What you want is the MotionService.  It was implemented in 3.0, but
| too late to get into the documentation.

 [details of MotionService mostly omitted]

| Legal values for /setwatchmotion:
| 
| 	/None		Ignore mouse motion
| 			(Except with button down - via TrackService)
| 	/Local		Call /HandleMotion for each mouse motion event
| 			within this canvas.
| 	/All		Call /HandleMotion for each mouse motion event
| 			anywhere on the screen.

A few minor corrections:

- Motion tracking was indeed implemented late in 3.0; I believe it is
  mentioned somewhere in the Release Notes even though it got it too
  late to be in the mainline documentation.

- Instead of calling /setwatchmotion, you can override the class
  variable /WatchMotion.  (Usual class-vs-instance tradeoffs apply.)

- The /Local mode calls /HandleMotion for mouse motion events within
  the canvas, and also for enter/exit events to/from the canvas.

- There is another possible value for /WatchMotion:  /Crossing.  This
  calls /HandleMotion *only* for enter/exit events.
--
--	-- Don Woods.				[*** Generic Disclaimer ***]
--				    ...!sun!woods.eng -or- Woods@Eng.Sun.com