View.OnTouchListener() does not work on parent layout

Question

I've set a View.OnTouchListener on a parent layout, but it doesn't appear to work.

Here is the XML for the UI:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:orientation="vertical"
    android:id="@+id/mainActivityLinearLayout"
    android:background="@drawable/listviewborder"
    tools:context=".MainActivity" >

    <View
        android:id="@+id/lineView"
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:background="@color/gray" />

    <ListView
        android:id="@+id/gameListView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="2"
        android:dividerHeight="2dp" />

</LinearLayout>

Here is the OnTouchListener set on the parent layout:

mainActivityView = this.findViewById(R.id.mainActivityLinearLayout);
mainActivityView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            System.out.println("Touch test activity");
            return true;
        }
    });

onTouch() is never called and the string never prints.

Not that I have implemented OnItemClick for the ListView and I just want to be able to detect touches on the whole layout.

I've also tried

gameListView = (ListView) findViewById(R.id.gameListView);
gameListView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            System.out.println("Touch test list");
            return true;
        }
    });

although this didn't work either.

Why is the parent layout not getting touch events? How can I get it working?

Answer 1

By returning true in onTouch(), you consume the touch event; the parent view's OnTouchListener will not be invoked. The documentation states:

public abstract boolean onTouch (View v, MotionEvent event)

[...]

Returns
True if the listener has consumed the event, false otherwise.

You may instead be interested in having the parent ViewGroup intercept touch events from its children through onInterceptTouchEvent(), as detailed in this guide.

Answer 2

I encountered same problem just now. I think it's because the touch event never reaches LinearLayout. What I did to solve this problem is to intercept the touch event for a cutom view

public class MyPager extends ViewPager {

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

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

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        // Do not allow swiping to switch between child pager pages
        return false;
    }
}

when you want to catch the touch, return true. if return false, touch event will pass down to children views.

Hope this helps for whoever searching for it.

EDIT: You can also try to add attribute android:clickable="true" for parent layout. This may affect the clicking on child views though (I use it in some cases but not sure it works for all)

Answer 3

1. Make this class to detect gesture listener

      class MyGestureDetector extends SimpleOnGestureListener {
   
       @Override
       public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
               float velocityY) {
           try {
               if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                   return false;
               // right to left swipe
               if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                       && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                   Log.d("asdsa", "left");
                   // Toast.makeText(SelectFilterActivity.this, "Left Swipe",
                   // Toast.LENGTH_SHORT).show();
               } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                       && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                   Log.d("asdsa", "right");
                   Fragment fr = getActivity().getSupportFragmentManager()
                           .findFragmentByTag("list_items");
                   if (fr != null) {
                       Log.d("asdsa", "not null");
                       if (fr.isVisible()) {
                           Log.d("asdsa", "visible");
                           getActivity().getSupportFragmentManager()
                                   .beginTransaction()
                                   .setCustomAnimations(0, R.anim.right_out)
                                   .remove(fr).commit();
                       }
                   }
                   // Toast.makeText(SelectFilterActivity.this, "Right Swipe",
                   // Toast.LENGTH_SHORT).show();
               }
           } catch (Exception e) {
               // nothing
           }
   
           return false;
       }
   

2. Declare this variables in activity:

   private static final int SWIPE_MIN_DISTANCE = 120;
   
   private static final int SWIPE_MAX_OFF_PATH = 250;
   private static final int SWIPE_THRESHOLD_VELOCITY = 200;
   private GestureDetector gestureDetector;
   View.OnTouchListener gestureListener;
   

3. Now inside your activity onCreate do this:

   gestureDetector = new GestureDetector(getActivity(), new MyGestureDetector());
   gestureListener = new View.OnTouchListener() {
       public boolean onTouch(View v, MotionEvent event) {
           return gestureDetector.onTouchEvent(event);
       }
   };
   listView.setOnTouchListener(gestureListener);
   

4. Finally check the gestures if occurring or not , for me it worked perfect.