Android Swipe on List

Question

Does anyone have a simple example of a ListActivity displaying Textviews in a column and when you swipe left to right you see that row in a new view? This would be to say edit the data for that row or show more detailed info on that row. Please do not reference code shogun or other sites as I have googled and have not seen this answered.

Answer 1

I had the same problem and I didn't find my answer here.

I wanted to detect a swipe action in ListView item and mark it as swiped, while continue to support OnItemClick and OnItemLongClick.

Here is me solution:

1st The SwipeDetector class:

import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class SwipeDetector implements View.OnTouchListener {

    public static enum Action {
        LR, // Left to Right
        RL, // Right to Left
        TB, // Top to bottom
        BT, // Bottom to Top
        None // when no action was detected
    }

    private static final String logTag = "SwipeDetector";
    private static final int MIN_DISTANCE = 100;
    private float downX, downY, upX, upY;
    private Action mSwipeDetected = Action.None;

    public boolean swipeDetected() {
        return mSwipeDetected != Action.None;
    }

    public Action getAction() {
        return mSwipeDetected;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            downX = event.getX();
            downY = event.getY();
            mSwipeDetected = Action.None;
            return false; // allow other events like Click to be processed
        case MotionEvent.ACTION_UP:
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // horizontal swipe detection
            if (Math.abs(deltaX) > MIN_DISTANCE) {
                // left or right
                if (deltaX < 0) {
                    Log.i(logTag, "Swipe Left to Right");
                    mSwipeDetected = Action.LR;
                    return false;
                }
                if (deltaX > 0) {
                    Log.i(logTag, "Swipe Right to Left");
                    mSwipeDetected = Action.RL;
                    return false;
                }
            } else if (Math.abs(deltaY) > MIN_DISTANCE) { // vertical swipe
                                                            // detection
                // top or down
                if (deltaY < 0) {
                    Log.i(logTag, "Swipe Top to Bottom");
                    mSwipeDetected = Action.TB;
                    return false;
                }
                if (deltaY > 0) {
                    Log.i(logTag, "Swipe Bottom to Top");
                    mSwipeDetected = Action.BT;
                    return false;
                }
            }
            return false;
        }
        return false;
    }
}

2nd I use the swipe detector class in the list view:

    final ListView lv = getListView();
    final SwipeDetector swipeDetector = new SwipeDetector();
    lv.setOnTouchListener(swipeDetector);
    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if (swipeDetector.swipeDetected()){
                    // do the onSwipe action 
                } else {
                    // do the onItemClick action
                }
            }
    });
    lv.setOnItemLongClickListener(new OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view,int position, long id) {
            if (swipeDetector.swipeDetected()){
                // do the onSwipe action 
            } else {
                // do the onItemLongClick action
            }
        }
    });

This way I can support 3 actions - swipe, click, long click and I can use the ListView item info.

ADDED LATER:

Since ListView catches a scrolling action, it is sometimes hard to swipe. To fix it, I made the following change to SwipeDetector.onTouch:

public boolean onTouch(View v, MotionEvent event) {
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            mSwipeDetected = Action.None;
            return false; // allow other events like Click to be processed
        }
        case MotionEvent.ACTION_MOVE: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // horizontal swipe detection
            if (Math.abs(deltaX) > HORIZONTAL_MIN_DISTANCE) {
                // left or right
                if (deltaX < 0) {
                    Log.i(logTag, "Swipe Left to Right");
                    mSwipeDetected = Action.LR;
                    return true;
                }
                if (deltaX > 0) {
                    Log.i(logTag, "Swipe Right to Left");
                    mSwipeDetected = Action.RL;
                    return true;
                }
            } else 

            // vertical swipe detection
            if (Math.abs(deltaY) > VERTICAL_MIN_DISTANCE) {
                // top or down
                if (deltaY < 0) {
                    Log.i(logTag, "Swipe Top to Bottom");
                    mSwipeDetected = Action.TB;
                    return false;
                }
                if (deltaY > 0) {
                    Log.i(logTag, "Swipe Bottom to Top");
                    mSwipeDetected = Action.BT;
                    return false;
                }
            } 
            return true;
        }
    }
    return false;
}