Trouble with detecting gestures over ListView

Andrew picture Andrew · Jan 13, 2011 · Viewed 8.5k times · Source

I have an Activity that contains a ViewFlipper. The ViewFlipper includes 2 layouts, both of which are essentially just ListViews.

So the idea here is that I have two lists and to navigate from one to the other I would use a horizontal swipe.

I have that working. However, what ever list item your finger is on when the swipe begins executing, that item will also be long-clicked.

Here is the relevant code I have:

public class MyActivity extends Activity implements OnItemClickListener, OnClickListener {

    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 mGestureDetector;
    View.OnTouchListener mGestureListener;

    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) {
                    if (mCurrentScreen != SCREEN_SECONDLIST) {
                        mCurrentScreen = SCREEN_SECONDLIST;
                        mFlipper.setInAnimation(inFromRightAnimation());
                        mFlipper.setOutAnimation(outToLeftAnimation());
                        mFlipper.showNext();
                        updateNavigationBar();
                    }
                }
                else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                    if (mCurrentScreen != SCREEN_FIRSTLIST) {
                        mCurrentScreen = SCREEN_FIRSTLIST;
                        mFlipper.setInAnimation(inFromLeftAnimation());
                        mFlipper.setOutAnimation(outToRightAnimation());
                        mFlipper.showPrevious();
                        updateNavigationBar();
                    }
                }
            } catch (Exception e) {
                // nothing
            }
            return true;
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (mGestureDetector.onTouchEvent(event))
            return true;
        else
            return false;
    }





    ViewFlipper mFlipper;

    private int mCurrentScreen = SCREEN_FIRSTLIST;

    private ListView mList1;
    private ListView mList2;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.layout_flipper);

        mFlipper = (ViewFlipper) findViewById(R.id.flipper);

        mGestureDetector = new GestureDetector(new MyGestureDetector());
        mGestureListener = new View.OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                if (mGestureDetector.onTouchEvent(event)) {
                    return true;
                }
                return false;
            }
        };

        // set up List1 screen

        mList1List = (ListView)findViewById(R.id.list1);
        mList1List.setOnItemClickListener(this);
        mList1List.setOnTouchListener(mGestureListener);

        // set up List2 screen
        mList2List = (ListView)findViewById(R.id.list2);
        mList2List.setOnItemClickListener(this);
        mList2List.setOnTouchListener(mGestureListener);

    }

    …
}

If I change the "return true;" statement from the GestureDetector to "return false;", I do not get long-clicks. Unfortunately, I get regular clicks.

Does anyone know how I can get around this?

Answer

jsonfry picture jsonfry · Jan 18, 2011

Just to throw in a completely different answer with a completely different approach...

I've made a custom view called SwipeView, it's open source etc etc blah blah blah. It should let you do what you want to do as simply as going:

mSwipeView.addChild(myList1);
mSwipeView.addChild(myList2);

You won't have to mess about with gesture detectors or anything, and the the swipe should follow your finger as you do it...

(This reads like a terrible terrible advert, please excuse me. It's been a long day ;)

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