Zippier outliner development environment?

tjw at tjw at
Fri Nov 29 19:06:25 UTC 1996

  How common is this, though?  At a minimum, you could cache a static drag  
image and a list of rectangles in that image that might change from frame to  
frame.  This would presume that there is some way to tell if the morph wants  
to change on each frame.  The implementation for this is quite a bit more  
complicated than a static drag image, but if it is very rare to have a morph  
that wants to display differently on each frame, the savings could be gained  
by only doing the caching if none of the morphs did this.


Begin forwarded message:

Date: Fri, 29 Nov 1996 00:02:31 -0800
From: mario.wolczko at Eng.Sun.COM (Mario Wolczko)
To: tjw at
Cc: randall.smith at Eng.Sun.COM, self-interest at, cam at
Subject: Re: Zippier outliner development environment?

     Err -- not knowing much about how the outliner is implemented, this
   doesn't seem like a hard problem.  When you start a drag, you cache the
   'image' that is being drawn.  Assuming that you have backing-store for the  
   window you are dragging over, this is a very efficient operation.

In general any morph is allowed to change its representation in any
frame, for animation.  For outliners, the values of the slots are
updated even though the outliner is being dragged.  Caching would
defeat this.


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