Bug 60210 - 3D touch peek pop intermittently causing UI to freeze
Summary: 3D touch peek pop intermittently causing UI to freeze
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 2.3.4
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2017-10-16 15:32 UTC by odawson
Modified: 2017-12-14 13:33 UTC (History)
3 users (show)

Is this bug a regression?: ---
Last known good build:

peek testbed (244.01 KB, application/x-zip-compressed)
2017-10-16 15:32 UTC, odawson
full env info (4.31 KB, text/plain)
2017-10-30 17:00 UTC, odawson

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Description odawson 2017-10-16 15:32:26 UTC
Created attachment 25320 [details]
peek testbed

The peek/pop functionality exposed via xamarin forms UIViewControllerPreviewingDelegate sometimes stops the UI from being updated.
No errors specific to this issue are appear to be logged in the debug output

I have attached a simple testbed to repro the problem.

repro steps:
- build and deploy testbed app on iPhone supporting 3D touch
- repeatedly apply pressure to the screen to reveal the "peek" view
- as soon as peek view is displayed remove finger then immediately try again
- after around 20 - 40 reps the UI will freeze in the popped state (e.g peek view displayed with blurred background)

- looking at debug messages the app seems to still be responsive but the display is no longer updated
- this only seems to happen when running on a device and not in the simulator

This seems to be due to 2 factors:
- excessive time taken in the GetViewControllerForPreview method (e.g. view model contruction )
-- the testbed uses a Task.Delay to simulate work done in the contruction of the view / view model
- complexity of form to be rendered in the peek view
Comment 1 Manuel de la Peña [MSFT] 2017-10-23 11:47:10 UTC
This seems to be an issue in the Forms code. Can you please provide the full environment information so that we can correctly assign the bug?
Comment 2 odawson 2017-10-23 12:10:24 UTC
- We debug on Windows 7 with visual studio 2015
- Visual studio connects to Mac to build app on device
- Xamarin forms version="" targetFramework="portable45-net45+win8+wpa81"
- Using Xamarin 10.12
Comment 3 odawson 2017-10-24 08:22:35 UTC
Product is forms, but I've set the component to iOS as its an iPhone specific issue, is that correct?
Also, let me know if you require any further environment details.
Comment 4 Manuel de la Peña [MSFT] 2017-10-30 16:56:59 UTC
Make sense. The best way to get the full information of you environment on Windows VS is -> "Help menu", "About Microsoft Visual Studio" item.
Then copy/paste the version information (you can use the "Copy Information" button).

That contains all the information. The bug has been confirmed. Someone in the forms team should reach you about any other possible information.
Comment 5 odawson 2017-10-30 17:00:55 UTC
Created attachment 25506 [details]
full env info

full environment info attached
Comment 6 odawson 2017-10-30 17:02:07 UTC
thanks - I've attached the full env as a file as its rather large.
Comment 7 odawson 2017-11-30 16:13:37 UTC
any ideas about this issue?
Comment 8 Manuel de la Peña [MSFT] 2017-12-14 13:33:12 UTC
Let me ping someone from the Forms team. They should have taken a look at it.