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androidandroid-layoutandroid-listviewandroid-gesture

Swipe to delete listitem


I would like to implement a swipe gesture to delete rows in a ListView similar to the android notifications.

Right now all I have is a ListView with an onTouchListener - that said, I already have swipe detection working.

gestureDetector = new GestureDetector(this, new GestureListener());
onTouchListener = new TouchListener();  
listview.setOnTouchListener(onTouchListener);  

My GestureListener class:

protected class GestureListener extends SimpleOnGestureListener
{
    private static final int SWIPE_MIN_DISTANCE = 150;
    private static final int SWIPE_MAX_OFF_PATH = 100;
    private static final int SWIPE_THRESHOLD_VELOCITY = 100;

    private MotionEvent mLastOnDownEvent = null;

    @Override
    public boolean onDown(MotionEvent e)
    {
        mLastOnDownEvent = e;
        return super.onDown(e);
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
    {
        if(e1 == null){
            e1 = mLastOnDownEvent;
        }
        if(e1==null || e2==null){
            return false;
        }

        float dX = e2.getX() - e1.getX();
        float dY = e1.getY() - e2.getY();

        if (Math.abs(dY) < SWIPE_MAX_OFF_PATH && Math.abs(velocityX) >= SWIPE_THRESHOLD_VELOCITY && Math.abs(dX) >= SWIPE_MIN_DISTANCE ) {
            if (dX > 0) {
                Toast.makeText(getApplicationContext(), "Right Swipe", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(getApplicationContext(), "Left Swipe", Toast.LENGTH_SHORT).show();
            }
            return true;
        }
        else if (Math.abs(dX) < SWIPE_MAX_OFF_PATH && Math.abs(velocityY)>=SWIPE_THRESHOLD_VELOCITY && Math.abs(dY)>=SWIPE_MIN_DISTANCE ) {
            if (dY>0) {
                Toast.makeText(getApplicationContext(), "Up Swipe", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(getApplicationContext(), "Down Swipe", Toast.LENGTH_SHORT).show();
            }
            return true;
        }
        return false;
    }
}

My TouchListener class:

protected class TouchListener implements View.OnTouchListener
{
    @Override
    public boolean onTouch(View v, MotionEvent e)
    {
        if (gestureDetector.onTouchEvent(e)){
            return true;
        }else{
            return false;
        }
    }
}

Are there some tutorials / examples on that?

thanks


Solution

  • If you have your swipe detection working, all that is left is to delete the item. For that, the following code will delete the item off screen.

    yourListViewAdapter.yourListItems.remove(position);
    yourListViewAdapter.notifyDataSetChanged();