[Tab Items] Tab Items does not work with View Binding, throws NPE

Description: Filing this in response to ja…@google.com comment on https://issuetracker.google.com/issues/145687658

a…@tandu.it

I have a view which contains some TabItem with an ID. When I try to generate my binding with .inflate() the app throws an NPE on those views. This happens on both Activity and Fragment.

ja…@google.com :

My working theory is material library is doing something horrific like intercepting TabLayout.addView and not actually putting the views into the hierarchy synchronously.

ja…@google.com :

Indeed, that is the problem.

2019-12-09 15:57:32.859 6425-6425/? I/System.out: FrameLayout ID:16908290 2019-12-09 15:57:32.859 6425-6425/? I/System.out: LinearLayout ID:2131230917 2019-12-09 15:57:32.859 6425-6425/? I/System.out: TabLayout ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: SlidingTabIndicator ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: TabView ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: ImageView ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: TextView ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: TabView ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: ImageView ID:-1 2019-12-09 15:57:32.859 6425-6425/? I/System.out: TextView ID:-1

Please file a bug on the Google Material library that it should consider retaining the IDs if one was supplied.

I’ll repurpose this issue for honoring our tools:viewBindingIgnore attribute on arbitrary XML nodes to at least work around the issue.

Expected behavior: Tab Items working with View Binding without throwing NPEs

Source code: Required source files could be found at https://issuetracker.google.com/issues/145687658

Material Library version:

Android Material dependency: com.google.android.material:material:1.1.0-beta01

[Dreft12]

Still happening, I found a workaround, try this:

Go to your XML and search the ID that is generating the issue and delete its android:id

Use the TabLayout API in your class to access the TabItems.

For example, this is my XML:

<com.google.android.material.tabs.TabItem android:id=“@+id/tbItem” <!-- Delete this line -> android:layout_width=“wrap_content” android:layout_height=“wrap_content” android:layout_gravity=“bottom” android:backgroundTintMode=“screen” android:text=“@string/mosaic” />

Go to your class: And use this:

val tabView: TabLayout = binding.tbType //This is my tab layout tabView.getTabAt(0)!!.text = “Example 1”

[dzzchao]

When will this bug be fixed? Still happening with 1.3.0-rc01