scrolling for the osx shadow server

[totaam]

Issue migrated from trac ticket # 1321

component: platforms | priority: major | resolution: wontfix | keywords: osx shadow scrolling

2016-09-22 09:46:06: antoine created the issue

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Follow up from #1232, osx has an API to give us those rectangles: CGScreenUpdateMoveCallback.
It shouldn't be too hard to add this callback to the osx shadow server, it will be a little bit more difficult to bypass most of the screen damage logic to go straight to the "scrolling" encoder.

[totaam]

2017-02-15 09:10:33: antoine uploaded file osx-shadow-scrolling.patch (5.5 KiB)

attempt to use CGScreenRegisterMoveCallback

[totaam]

2017-02-15 09:14:27: antoine changed status from new to assigned

[totaam]

2017-02-15 09:14:27: antoine commented

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The patch above fails with a cryptic error message: SystemError: error return without exception set.

Maybe we'll need to use Cython to get this to work. PITA.

[totaam]

2019-03-20 05:06:15: antoine commented

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Milestone renamed

[totaam]

2020-02-29 07:14:52: antoine uploaded file osx-shadow-scrolling-v2.patch (5.6 KiB)

updated patch

[totaam]

2020-02-29 07:18:04: antoine changed status from assigned to closed

[totaam]

2020-02-29 07:18:04: antoine set resolution to wontfix

[totaam]

2020-02-29 07:18:04: antoine commented

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Even with the latest pyobjc 6.1 and the refreshed patch, registering for the callback fails:

Traceback (most recent call last):
  File "/Users/antoine/Desktop/Xpra.app/Contents/Resources/lib/python/xpra/server/shadow/shadow_server_base.py", line 431, in _process_map_window
    self.start_refresh(wid)
  File "/Users/antoine/Desktop/Xpra.app/Contents/Resources/lib/python/xpra/platform/darwin/shadow_server.py", line 162, in start_refresh
    err = CG.CGScreenRegisterMoveCallback(self.screen_move_callback, None)
SystemError: <built-in function CGScreenRegisterMoveCallback> returned NULL without setting an error

And this API is deprecated anyway, in favour of the Quartz Display Streaming API