ViewPager & RelativeLayout issues (Android)

[NickIliev]

From @manijak on October 31, 2016 18:36

Did you verify this is a real problem by searching [Stack Overflow]

Yes.
Tried at first on the "next" versions of core-modules. But managed to get the same result on 2.3.0.

Tell us about the problem

I'm trying to add the android version to my Carousel plugin. Playing with the ViewPager and Layouts. If I return the ViewPager as _nativeView it works fine, but if I return the RelativeLayout as the _nativeView it fails.

java.lang.ClassCastException: android.support.v4.view.ViewPager$LayoutParams cannot be cast to android.widget.RelativeLayout$LayoutParams
	at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:476)
	at android.view.View.measure(View.java:18788)
	at org.nativescript.widgets.CommonLayoutParams.measureChild(CommonLayoutParams.java:229)
	at org.nativescript.widgets.StackLayout.onMeasure(StackLayout.java:83)
	at android.view.View.measure(View.java:18788)
	at org.nativescript.widgets.CommonLayoutParams.measureChild(CommonLayoutParams.java:229)
	at org.nativescript.widgets.MeasureHelper.measureChildFixedColumnsAndRows(GridLayout.java:1059)
	at org.nativescript.widgets.MeasureHelper.measure(GridLayout.java:869)
	at org.nativescript.widgets.GridLayout.onMeasure(GridLayout.java:279)
	at android.view.View.measure(View.java:18788)
	at org.nativescript.widgets.CommonLayoutParams.measureChild(CommonLayoutParams.java:229)
	at org.nativescript.widgets.ContentLayout.onMeasure(ContentLayout.java:32)
...

Which platform(s) does your issue occur on?

Android

Please provide the following version numbers that your issue occurs with:

• CLI: 2.3.0
• Cross-platform modules: 2.3.0
• Runtime(s): 2.3.0

Please tell us how to recreate the issue in as much detail as possible.

Here is a sample app that will reproduce the issue (android only)
https://dl.dropboxusercontent.com/u/33168380/pager-test.zip

Copied from original issue: NativeScript/NativeScript#3001

[petekanev]

@manijak You could try getting rid of the RelativeLayout and adding views (CarouselItems) only to the ViewPager as that will help simplify logic.

[manijak]

Yeah you are correct, I have moved away from the RelativeLayout idea altogether. The only reason I decided to wrap ViewPager innside the RelativeLayout is because I wanted to present the pageIndicator on top of the viewpager (like an overlay). From the examples online, relativeLayout was recomended.
The {N} TabView does something similar with the GridLayout. Packing a viewPager and TabStrip.

If I only add the indicator to the relativeLayout, it worked, but if I add the viewPager, it didn't.

So my solution (not a very good one), is to add the indicator to the parent view of the viewPager. Wrapping this plugin in a GridLayout in the xml, makes it work (indicator overlays viewPager, otherwise it's added below).

I've also managed to get it working innside a TabView (they both extend ViewPager).

@Pip3r4o Thanks for the time you took to look at this. 👍 Think we can close this one.