listview - Android - view tag isn't correct on view:null (CursorAdapter and DataBinding)

Question

So yesterday I have finally found some time to try new DataBinding library. I have tried to use it with CursorAdapter but with no success.

As Androidguys written on their page:

If you are using data binding items inside a ListView or RecyclerView adapter, you may prefer to use:

ListItemBinding binding = ListItemBinding.inflate(layoutInflater, viewGroup, false);
//or
ListItemBinding binding = DataBindingUtil.inflate(layoutInflater, R.layout.list_item, viewGroup, false);

But in CursorAdapter I have to separate Inflating and Binding into 2 methods. So How correctly implement it? Mostly I got an Exception: view tag isn't correct on view:null

private class BookCursorAdapter extends CursorAdapter {

    public BookCursorAdapter(Context context) {
        super(context, null, 0);
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        BookListItemBinding binding = DataBindingUtil.inflate(getLayoutInflater(), R.layout.book_list_item, parent, false);
        return binding.getRoot();

        // or just
        // return getLayoutInflater().inflate(R.layout.book_list_item, parent, false);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // here it fails (and i cannot see source code of bind method)
        BookListItemBinding.bind(view).setBook(new Book(cursor));
    }
}

How to correctly implement binding with CursorAdapter?

10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: FATAL EXCEPTION: main 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: Process: kandrac.xyz.library, PID: 6231 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: java.lang.RuntimeException: view tag isn't correct on view:null 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at kandrac.xyz.library.databinding.BookListItemBinding.bind(BookListItemBinding.java:135) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at kandrac.xyz.library.MainActivity$BookCursorAdapter.bindView(MainActivity.java:95) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.CursorAdapter.getView(CursorAdapter.java:254) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.AbsListView.obtainView(AbsListView.java:2347) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.ListView.makeAndAddView(ListView.java:1864) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.ListView.fillDown(ListView.java:698) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.ListView.correctTooLow(ListView.java:1474) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.ListView.fillGap(ListView.java:672) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.AbsListView.trackMotionScroll(AbsListView.java:4991) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.AbsListView.scrollIfNeeded(AbsListView.java:3418) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.AbsListView.onTouchMove(AbsListView.java:3801) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.widget.AbsListView.onTouchEvent(AbsListView.java:3632) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.View.dispatchTouchEvent(View.java:8471) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2399) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2092) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2369) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1719) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.app.Activity.dispatchTouchEvent(Activity.java:2742) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.support.v7.internal.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2330) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.View.dispatchPointerEvent(View.java:8666) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4123) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3989) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3597) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3563) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3680) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3571) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3737) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3597) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3563) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3571) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5807) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5781) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5752) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5897) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method) 10-14 06:25:43.847 6231-6231/kandrac.xyz.library E/AndroidRuntime: at android.view.InputEven

Answer 1

Based on Android developers video about databinding It looks like ItemBinding is set as tag for view (in their case it is passed inside ViewHolder) and retrieved later. Thats where I found idea to find binding inside views:

So the Solution is:

private class BookCursorAdapter extends CursorAdapter {

    ...

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        BookListItemBinding binding = BookListItemBinding.inflate(getLayoutInflater(), parent, false);
        return binding.getRoot();
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        Book book = new Book(cursor);
        BookListItemBinding binding = DataBindingUtil.getBinding(view);
        binding.setBook(book);
    }

}