Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!hplabs!hp-pcd!hpcvlo!markc
From: markc@hpcvlo.HP.COM (Mark F. Cook)
Newsgroups: comp.windows.x
Subject: Re: Keeping the mouse within a window
Message-ID: <3940048@hpcvlo.HP.COM>
Date: Tue, 24-Nov-87 14:31:06 EST
Article-I.D.: hpcvlo.3940048
Posted: Tue Nov 24 14:31:06 1987
Date-Received: Sat, 28-Nov-87 18:45:11 EST
References: <6908@ut-ngp.UUCP>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 37

>I have an application where I am using mouse movement within a window to 
>control a cursor on another (graphics) display.  I use LeaveWindow
>events to detect when the mouse has gone out of the window bounds and
>then warp it back inside the window.  This works, but tends to be jittery,
>etc.  Is there a better way to constrain mouse movements, that doesn't 
>rely on interaction with the user program?  
>
>Rick Watson
>University of Texas Computation Center
> arpa:   ccaw001@utadnx.cc.utexas.edu
> uucp:   ...seismo!ut-sally!ut-ngp!rick
> bitnet: ccaw001@utadnx     span:  utspan::watson
> phone:  512/471-8220 512/471-3241
>----------

    One way that I have used to do this is detection of MouseMoved events
followed by 4 XCondWarpMouse() calls (1 for each border).  You could specify
some reasonable zone of sensitivity near each border (perhaps just a wide
border itself would do).  Then, if the mouse gets too close to the window
border, you can, for example, warp it back to the window center.
    You will probably still want to check for LeaveWindow events, since it
is possible, on some computers, to move the mouse fast enough to get across
the sensitive border region between mouse polling intervals (the amount of
time between to checks on the current mouse position).  This is the only
situation I'm aware of the the MouseMoved/XCondWarpMouse() combination doesn't
take care of, and the LeaveWindow detection should cover that.

Regards,

Mark F. Cook - CWO Tech. Support

USMail: Technical Support
	Hewlett-Packard - Corvallis Workstation Operation
	1000 NE Circle Blvd.  Corvallis, OR 97330

ARPA: markc@hpcvlo.HP.COM
UUCP: {cmcl2, harpo, hplabs, rice, tektronix}!hp-pcd!markc