Bug 25507 - [Android][iOS] Xamarin.Forms LayoutTo view not remaining visible
Summary: [Android][iOS] Xamarin.Forms LayoutTo view not remaining visible
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 1.3.0
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2014-12-18 12:34 UTC by Dominic N [MSFT]
Modified: 2015-01-12 17:14 UTC (History)
6 users (show)

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

Test project demonstrating issue. (25.29 KB, application/zip)
2014-12-18 12:34 UTC, Dominic N [MSFT]

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Description Dominic N [MSFT] 2014-12-18 12:34:55 UTC
Created attachment 9130 [details]
Test project demonstrating issue.

## Overview:

There is a report of an issue using LayoutTo to display a view in Xamarin.Forms iOS and Android (Windows Phone works fine). In the customer's app, there is a view on the page for displaying the current location (longitude and latitude). The viewmodel bound to its context refreshes its properties every few seconds and when the UI updates the new coordinates, the SideMenu disappears. The test project attached simulates the UI update with a timer, updating a label every 5 seconds (test project is a X.Forms project with Android code).

## Steps to reproduce:

1. Download the sample app
2. Run on Android device
3. Click on the header label (“Click to open the menu”)
4. Wait for timer to update label
5. Observe results

## Expected results:

A yellow ContentView slides from the right side of the page and stays visible.

## Actual results:

The ContentView disappears when the label is updated.

## Other information:

The customer has found a workaround to the problem by removing the GPSView binding before the menu slides in/ restoring the binding after the menu slides out so no UI updates happen while the menu is visible.
Comment 2 Rajneesh Kumar 2014-12-19 01:36:21 UTC
I have checked this issue and I am also observing the same behavior as described in bug description. To reproduce this issue I have followed the steps provided in bug description. After deploying the application, I clicked on header label, I observed that a yellow ContentView slides from the right side of the page and it disappears when the label is updated. Please refer the screencast.

Additional Information: Observing the same behavior on device and emulator.

===Supplement info=== 
Screencast: http://www.screencast.com/t/vwW7Eq2BK
Ide Logs: http://www.screencast.com/t/Z7HaJV6X
Application Output: https://gist.github.com/Rajneesh360Logica/6101720ce605aa7b4032
Build Output: https://gist.github.com/Rajneesh360Logica/1c6da530864e2b8615e6
Device Log: https://gist.github.com/Rajneesh360Logica/590d83177963bc3f3a9f

Environment Info:

=== Xamarin Studio ===

Version 5.5.4 (build 15)
Installation UUID: 011d70a5-dede-428b-ab04-ef451c2e539d
	Mono 3.10.0 ((detached/92c4884)
	GTK+ 2.24.23 (Raleigh theme)

	Package version: 310000031

=== Xamarin.Android ===

Version: (Business Edition)
Android SDK: /Users/MM/Desktop/android-sdk-macosx
	Supported Android versions:
		2.1    (API level 7)
		2.2    (API level 8)
		2.3    (API level 10)
		3.1    (API level 12)
		3.2    (API level 13)
		4.0    (API level 14)
		4.0.3  (API level 15)
		4.1    (API level 16)
		4.2    (API level 17)
		4.3    (API level 18)
		4.4    (API level 19)
		4.4.87 (API level 20)
		5.0    (API level 21)
Java SDK: /usr
java version "1.7.0_65"
Java(TM) SE Runtime Environment (build 1.7.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

=== Apple Developer Tools ===

Xcode 6.1 (6604)
Build 6A1052d

=== Xamarin.iOS ===

Version: (Business Edition)
Hash: 7244769
Build date: 2014-12-11 14:54:30-0500

=== Xamarin.Mac ===

Version: (Business Edition)

=== Build Information ===

Release ID: 505040015
Git revision: f93940a35458a18052f1a25e106e62ca970d9c40
Build date: 2014-11-19 15:32:41-05
Xamarin addins: dc23cbd91a3a0e1d326328e1229e86c942a49ec8

=== Operating System ===

Mac OS X 10.9.5
Darwin MacMini.local 13.4.0 Darwin Kernel Version 13.4.0
    Sun Aug 17 19:50:11 PDT 2014
    root:xnu-2422.115.4~1/RELEASE_X86_64 x86_64
Comment 3 Dominic N [MSFT] 2014-12-19 11:14:34 UTC
Edit to original post: The customer indicated that he does see the same error on Windows Phone (I am unable to test on Windows Phone).

Thank you.
Comment 4 Jason Smith [MSFT] 2015-01-12 17:14:23 UTC
Use the translation properties and not LayoutTo. LayoutTo should only be used inside of Layout subclasses to perform layout transitions. Translation is a post layout shift of a View, LayoutTo calls Layout itself which the parent Layout also calls to perform layouting.