Android: How to handle right to left swipe gestures

Question

I want my app to recognize when a user swipes from right to left on the phone screen.

How to do this?

Answer 1

@Edward Brey's method works great. If someone would also like to copy & paste the imports for the OnSwipeTouchListener, here they are:

 import android.content.Context;
 import android.view.GestureDetector;
 import android.view.GestureDetector.SimpleOnGestureListener;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnTouchListener;

Answer 2

Use SwipeListView and let it handle the gesture detection for you.

Answer 3

My solution is similar to those above but I have abstracted the gesture handling into an abstract class OnGestureRegisterListener.java, which includes swipe, click and long click gestures.

OnGestureRegisterListener.java

public abstract class OnGestureRegisterListener implements View.OnTouchListener {

    private final GestureDetector gestureDetector;
    private View view;

    public OnGestureRegisterListener(Context context) {
        gestureDetector = new GestureDetector(context, new GestureListener());
    }

    @Override
    public boolean onTouch(View view, MotionEvent event) {
        this.view = view;
        return gestureDetector.onTouchEvent(event);
    }

    public abstract void onSwipeRight(View view);
    public abstract void onSwipeLeft(View view);
    public abstract void onSwipeBottom(View view);
    public abstract void onSwipeTop(View view);
    public abstract void onClick(View view);
    public abstract boolean onLongClick(View view);

    private final class GestureListener extends GestureDetector.SimpleOnGestureListener {

        private static final int SWIPE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;

        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            onLongClick(view);
            super.onLongPress(e);
        }

        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            onClick(view);
            return super.onSingleTapUp(e);
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            boolean result = false;
            try {
                float diffY = e2.getY() - e1.getY();
                float diffX = e2.getX() - e1.getX();
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffX > 0) {
                            onSwipeRight(view);
                        } else {
                            onSwipeLeft(view);
                        }
                        result = true;
                    }
                }
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeBottom(view);
                    } else {
                        onSwipeTop(view);
                    }
                    result = true;
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }

    }
}

And use it like so. Note that you can also easily pass in your View parameter.

OnGestureRegisterListener onGestureRegisterListener = new OnGestureRegisterListener(this) {
    public void onSwipeRight(View view) {
        // Do something
    }
    public void onSwipeLeft(View view) {
        // Do something
    }
    public void onSwipeBottom(View view) {
        // Do something
    }
    public void onSwipeTop(View view) {
        // Do something
    }
    public void onClick(View view) {
        // Do something
    }
    public boolean onLongClick(View view) { 
        // Do something
        return true;
    }
};

Button button = findViewById(R.id.my_button);
button.setOnTouchListener(onGestureRegisterListener);

Answer 4

This issue still exists. An OnTouchListener with an OnSwipeTouchListener solves it in a simple way:

myView.setOnTouchListener(
    new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            if(!swipe.onTouch(v, event)) {
                if (event.getAction() == MotionEvent.ACTION_UP) {
                    // your code here

                    return true;
                } else if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    // your code here

                    return true;
                }
            }
            return false;
        }

    }
);

where swipe refers to a class which records whether swipe methods have been invoked, then forwards events to the delegate OnSwipeTouchListener.

private class DirtyOnSwipeTouchListener extends OnSwipeTouchListener {
    private boolean dirty = false;
    private OnSwipeTouchListener delegate;

    public DirtyOnSwipeTouchListener(Context ctx, OnSwipeTouchListener delegate) {
        super(ctx);

        this.delegate = delegate;
    }

    private void reset() {
        dirty = false;
    }

    public void onSwipeTop() {
        dirty = true;
        delegate.onSwipeTop();
    }

    public void onSwipeRight() {
        dirty = true;
        delegate.onSwipeRight();
    }

    public void onSwipeLeft() {
        dirty = true;
        delegate.onSwipeLeft();
    }

    public void onSwipeBottom() {
        dirty = true;
        delegate.onSwipeBottom();
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        try {
            super.onTouch(v, event);

            return dirty;
        } finally {
            dirty = false;
        }

    }
};