[TIMOB-17491] Android: contentOffset property of UI.ScrollView not accessible

GitHub Issue	n/a
Type	Bug
Priority	High
Status	Closed
Resolution	Fixed
Resolution Date	2014-11-04T22:42:44.000+0000
Affected Version/s	Release 3.4.0
Fix Version/s	Release 3.4.2, Release 3.5.0, Release 4.0.0
Components	Android
Labels	android, contentOffset, parity, scrollview
Reporter	Kevin Frugier
Assignee	Hieu Pham
Created	2014-08-11T13:59:17.000+0000
Updated	2015-04-19T16:07:09.000+0000

Description

The contentOffset property (reflecting what's currently visible in a ScrollView), is undefined on Android. Documentation of [UI.ScrollView|(http://docs.appcelerator.com/titanium/latest/#!/api/Titanium.UI.ScrollView-property-contentOffset] says it's available on Android since 0.9, however in version 3.3.0 GA it (still?) doesn't work.

Notes

* contentOffset is not set manually anywhere in the test code * I'm talking about UI.ScrollView, not tableview or listview

How to reproduce

Create a ScrollView

<Alloy>
	<ScrollView id="myscrollview" />
</Alloy>

In the controller, try to get the value of the property :

alert($.myscrollview.contentOffset.x);

Actual result

On iOS : the value is properly displayed and reflects any scrolling (manual or not) done on the ScrollView On Android : a runtime error occurs with the following message : {panel:title=Runtime Error} Message: Uncaught TypeError: Cannot read property 'x' of undefined Source: alert($.myscrollview.contentOffset.x); {panel}

Expected result

Both iOS & Android should produce the same result. Looking at the source of [TiUIScrollView.java](https://github.com/appcelerator/titanium_mobile/blob/master/android/modules/ui/src/java/ti/modules/titanium/ui/widget/TiUIScrollView.java) we see that indeed the property is supposed to be updated upon scrolling. However the property is not accessible from JavaScript on Android. (Could it be a problem in the proxy?)

Comments

Shuo Liang 2014-08-12

Can reproduce with SDK 3.2.3 GA and 3.3.0 GA on Android 4.2.2. Here is a simple test case.

   var win = Ti.UI.createWindow({
     backgroundColor: 'white',
     exitOnClose: true,
     fullscreen: false,
     title: 'ScrollView Demo'
   });
   
   var scrollView = Ti.UI.createScrollView({
     contentWidth: 'auto',
     contentHeight: 'auto',
     showVerticalScrollIndicator: true,
     showHorizontalScrollIndicator: true,
     height: '80%',
     width: '80%'
   });
   var view = Ti.UI.createView({
     backgroundColor:'#336699',
     borderRadius: 10,
     //top: 10,
     height: 2000,
     width: 1000
   });
   
   // output the contentOffset value
   Ti.API.info(scrollView.contentOffset.x);
   
   scrollView.add(view);
   win.add(scrollView);
   win.open();

Hieu Pham 2014-10-30

master PR: https://github.com/appcelerator/titanium_mobile/pull/6292 3.4.X PR: https://github.com/appcelerator/titanium_mobile/pull/6313
Satyam Sekhri 2014-11-25

The contentOffset property for ScrollView is accessible now and does not show any error. Tested with both the alloy and classic code provided. Verified on: SDK: 3.5.0.v20141124155715 Studio: 3.4.1.201410281743 CLI: 3.4.1 Alloy: 1.5.1 Device: Samsung Galaxy S5 (v4.4.2)
Rainer Schleevoigt 2015-04-19

It doesn't work with SDK3.5.1.GA

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