View Pager Scrolling not working inside Scroll view in Android

Question

I use an View Pager with Tab Layout and each tab has Fragment (Fragment with Listview). Scrolling inside view Pager not working .I want to just enable scrolling facility inside View Pager. Please give me suggestion. Here,I also want to inform you that Listview size can't be fix.

       <ScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="@dimen/_25sdp"
            android:fillViewport="true"
            android:paddingHorizontal="@dimen/_10sdp"
            android:paddingTop="@dimen/_15sdp"
            android:scrollbars="none">

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

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginBottom="@dimen/_10sdp"
                    android:paddingLeft="@dimen/_5sdp"
                    android:text="@string/dashboard"
                    android:textColor="@color/black"
                    android:textSize="@dimen/_14ssp" />

                <GridView
                    android:id="@+id/gv_dashboard"
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/_175sdp"
                    android:horizontalSpacing="@dimen/_5sdp"
                    android:listSelector="@android:color/transparent"
                    android:numColumns="2"
                    android:scrollbars="none"
                    android:verticalSpacing="@dimen/_5sdp" />

                <com.google.android.material.tabs.TabLayout
                    android:id="@+id/tl_comp_category"
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/_25sdp"
                    android:layout_gravity="center"
                    android:layout_marginHorizontal="@dimen/_4sdp"
                    android:layout_marginVertical="@dimen/_10sdp"
                    app:tabBackground="@drawable/tab_background"
                    app:tabIndicator="@android:color/transparent"
                    app:tabMode="auto"
                    app:tabPaddingEnd="@dimen/_5sdp"
                    app:tabPaddingStart="@dimen/_5sdp"
                    app:tabTextAppearance="@style/ComCatTabText" />

                <androidx.viewpager.widget.ViewPager
                    android:id="@+id/vp_tab"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" />
            </LinearLayout>
        </ScrollView>

Answer 1

This solution work for me.

STEP 1 : Create an Class which extends viewPager.

STEP 2 : Use this class in your XML

STEP 3 : use setPrimaryItem() function in your ViewPager Adapter Class which extends FragmentPagerAdapter

STEP - 1

public class CustomViewPager extends ViewPager {
private View mCurrentView;
public CustomViewPager(@NonNull Context context) {
    super(context);
}

public CustomViewPager(@NonNull Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (mCurrentView == null) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        return;
    }
    int height = 0;
    mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, 
    MeasureSpec.UNSPECIFIED));
    int h = mCurrentView.getMeasuredHeight();
    if (h > height) height = h;
    heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 }
  public void measureCurrentView(View currentView) {
     mCurrentView = currentView;
     requestLayout();
 }

 public int measureFragment(View view) {
    if (view == null)
        return 0;
    view.measure(0, 0);
    return view.getMeasuredHeight();
 }
}

STEP - 2

   <com.appName.widget.CustomViewPager
                    android:id="@+id/vp_tab"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:scrollbars="none"
                    android:overScrollMode="never"/>

STEP - 3

  public class VPAdapter extends FragmentPagerAdapter {

 //   YOUR OTHER CODE 

 @Override
    public void setPrimaryItem(ViewGroup container, int position, Object object) {
         super.setPrimaryItem(container, position, object);
      if (position != mCurrentPosition) {
        Fragment fragment = (Fragment) object;
        CustomViewPager pager = (CustomViewPager) container;
        if (fragment != null && fragment.getView() != null) {
            mCurrentPosition = position;
            pager.measureCurrentView(fragment.getView());
        }
    }
  }
}

Answer 2

Scroll View must be used with just a child. Try removing the Linear above Scroll

Documentation about Scroll View