#5344 HIGH Update.: Frame is very slow to respond to the frame button in specific situations

[Zarro Boogs per Child]

#5344: Frame is very slow to respond to the frame button in specific situations
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  Reporter:  AlexL   |       Owner:  rwh     
      Type:  defect  |      Status:  new     
  Priority:  high    |   Milestone:  Update.1
 Component:  sugar   |     Version:          
Resolution:          |    Keywords:          
  Verified:  0       |    Blocking:          
 Blockedby:          |  
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Comment(by rwh):

 On closer inspection it seems that getting the preview takes about 0.5sec,
 and that happens before the frame is hidden. Writing to the DS also occurs
 before hiding the frame, but takes only in the order of ~0.01sec.

 I broke down the time in Activity._get_preview():
  * get pixbuf: 0.08s
  * scale: 0.16s
  * encode png and write: 0.15s

 BTW: The implementation was really ugly with writing to a temp file. I
 have a patch to use gtk.gdk.Pixbuf.save_to_callback to avoid this.

 Seems like we have to scale and encode somewhere else: doing it async in
 parts while also animating the frame will result in a bad user experience
 due to the big time blocks. I guess scaling isn't done when taking the
 screenshot because it the preview is usually not necessary.
 I think we could defer the safe until after the animation, perhaps in
 combination with chopping the function in async pieces.

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Ticket URL: <http://dev.laptop.org/ticket/5344#comment:8>
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