Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!cs.utexas.edu!uunet!ingr!b11!myoung
From: myoung@b11.ingr.com (Mark Young)
Newsgroups: comp.windows.x
Subject: Changing Screens/Cursor Warping problem
Keywords: changing screens cursor warping
Message-ID: <5032@b11.ingr.com>
Date: 25 Apr 89 15:45:59 GMT
Organization: Intergraph Corp. Huntsville, AL
Lines: 33

What is the proper behavior for the cursor when a server changes screens?

We have a server implementation that can be traced through the following
sequence of events:

We call NewCurrentScreen from the ddx layer when we detect that the user
wishes us to change screens  We are passing a legitimate cursor location
to NewCurrentScreen, but this cursor location always seems to get ignored.

after tracking the problem, it appeared to be due to the fact that the 
sprite.hot.x and sprite.hot.y were set to -1 in ConfineCursorToWindow
when the screen changes.  In ConfineCursorToWindow, a call is made to 
the function (* pScreen->SetCursorPosition)(pScreen, x, y, generateEvents);
which seems to set the correct cursor position.  It, however, is followed
by a call to CheckPhysLimits which, after determining that the coordinate
specified by sprite.hot.{x,y} is out of bounds (since we it was set to
(-1,-1) in ConfineCursorToWindow, sets the sprite coordinate to (0,0) and
set the cursor position to the same.

We support two logical screens on the same physical screen (this is a useful
side effect of the proprietary window system;  one has four planes and the
other has one plane).  of course, because of this problem, when the user
switches between screens, the hardware cursor always warps to (0,0).

Any and all input would be greatly appreciated.

	...m (tired of cursor chasing) young
--
myoung@ingr.com                       | mark allan young          | where
uunet!ingr!myoung                     | intergraph corp, cr1105   | do I
                                      | one madison industrial pk | put the
"Say, I thought everyone had heard    | huntsville, al  35807     | usual
     of Intergraph?"                  | (205) 772-6094            | disclaimer