List view not scrolling in fragment using view pager inside NestedScrollView

Question

Hi there i needed to create layout like whatsapp, which scrolls the actionbar but not tabLayout. I used viewpager for loads fragment in it. In fragment i added listview but on Listview scroll that action bar not scrolling there. Using some tutorials on stackoverflow i got that for this purpose needed to use nestedScrollView and it works for me. But it stops scrolling listview. I used this code for that.

activity_my.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"></android.support.design.widget.CollapsingToolbarLayout>

</android.support.design.widget.AppBarLayout>

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:layout_gravity="bottom"
    app:layout_anchor="@+id/appbar"
    app:layout_anchorGravity="bottom"
    app:layout_collapseMode="none">

    <ImageView
        android:id="@+id/tabBg"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/primary"
        android:scaleType="fitXY" />

    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:layout_gravity="bottom"
        android:background="#00000000"
        app:layout_anchor="@+id/appbar"
        app:layout_anchorGravity="bottom"
        app:layout_collapseMode="none"
        app:tabGravity="fill"
        app:tabIndicatorColor="#fff"
        app:tabIndicatorHeight="2dp"
        app:tabMode="scrollable"
        app:tabSelectedTextColor="#fff"
        app:tabTextColor="#fff" />

</FrameLayout>
<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="?attr/actionBarSize"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:minHeight="1000dp"
        android:orientation="vertical">

        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"/>
    </LinearLayout>
</android.support.v4.widget.NestedScrollView>

<!--<android.support.v4.view.ViewPager
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="?attr/actionBarSize"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />-->
</android.support.design.widget.CoordinatorLayout>

MyActivity.java

public class MyActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
ArrayList<Fragment> fragmentArrayList;
TabAdapter tabAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
    /*Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(false);*/

    viewPager = (ViewPager) findViewById(R.id.pager);
    setupViewPager(viewPager);

    tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(viewPager);
}

private void setupViewPager(ViewPager viewPager) {
    TabAdapter adapter = new TabAdapter(getSupportFragmentManager());
    adapter.addFragment(new OneFragment(), "ONE");
    adapter.addFragment(new OneFragment(), "TWO");
    adapter.addFragment(new OneFragment(), "THREE");
    viewPager.setAdapter(adapter);
   }

 }

FragmentOne.java

public class OneFragment extends Fragment {
ListView listTest;
ArrayList<String> itemList;
ArrayAdapter<String> adapter;

public OneFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_one, container, false);
    listTest = (ListView) view.findViewById(R.id.listTest);
    itemList = new ArrayList<>();
    for (int i = 0; i < 50; i++) {
        itemList.add("Item : " + i);
    }
    adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, itemList);
    listTest.setAdapter(adapter);
    return view;
   }
}

fragment_one.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ListView
        android:id="@+id/listTest"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></ListView>
</RelativeLayout>

I used LinearLayout monHeight = 1000dp because if i use android:fillViewPort="true" in nestedScrollView and remove minHeight from LinearLayout then listview shows but not scroll. Now it scrolls but till 1000dp then the other items are not shown.

Answer 1

Okey first of all You warped ViewPager inside NestedScrollView, this is not necessary.

so change,

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="?attr/actionBarSize"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:minHeight="1000dp"
        android:orientation="vertical">

        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"/>
    </LinearLayout>
</android.support.v4.widget.NestedScrollView>

to,

<android.support.v4.view.ViewPager
     android:id="@+id/pager"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:layout_weight="1"
     app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

Now Your are taking ListView, which is not working good with AppBarLayout, so I suggest you use RecyclerView instead.

Note: if you still want to use ListView you can use NonScrollListview wraping it under NestedScrollView.

NonScrollListView

public class NonScrollListView extends ListView {

    public NonScrollListView(Context context) {
         super(context);
    }

    public NonScrollListView(Context context, AttributeSet attrs) {
         super(context, attrs);
    }

    public NonScrollListView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         int heightMeasureSpec_custom = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
         super.onMeasure(widthMeasureSpec, heightMeasureSpec_custom);
         ViewGroup.LayoutParams params = getLayoutParams();
         params.height = getMeasuredHeight();
    }
}

And just change your fragment_one liske this.

<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <packagename.NonScrollListView
        android:id="@+id/listTest"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></packagename.NonScrollListView>
</android.support.v4.widget.NestedScrollView>

I hope this will help you out. Happy coding..