CODEWITHSUNDEEP
javaandroidmulti-touch
WWaldo
WWaldo

Reputation: 177

Android Multitouch Issues

This is a fairly simple question I am sure, but I can't seem to figure out a way around this little thing. First, here is my code:

switch (event.getAction() & MotionEvent.ACTION_MASK) {

        case MotionEvent.ACTION_DOWN:
            Log.w("Platformer", "primary down");
            break;

        case MotionEvent.ACTION_UP:
            Log.w("Platformer", "primary up");
            break;

        case MotionEvent.ACTION_POINTER_1_DOWN:
            Log.w("Platformer", "secondary down");
            break;

        case MotionEvent.ACTION_POINTER_1_UP:
            Log.w("Platformer", "secondary up");
            break;
        }

All I wanted it to do was when I pressed down, it would show me in the log whether the primary or secondary pointer was down, and when I release, do the same thing. The problem is, it always works on the down, but on up, whatever the 1st finger that comes up is, regardless of if it was the primary or secondary pointer originally, it returns that the secondary pointer was removed. Any idea around this? I am guessing it is something simple, but I don't know where to look truthfully. Thanks in advance.

WWaldo

Upvotes: 2

Views: 1642

Answers (2)

Michael
Michael

Reputation: 836

ACTION_UP means that the gesture is over, that is, all pointers are up.

ACTION_POINTER_UP means that a non-primary pointer is up, you'll have to check the event to figure out which, i.e.:

int pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> 
     MotionEvent.ACTION_POINTER_INDEX_SHIFT;
int pointerId = event.getPointerId(pointerIndex)

ACTION_POINTER_1_UP and ACTION_POINTER_2_UP are deprecated now.

You should note that this is extremely buggy on Android versions less than Gingerbread. I find that if I lift the first of two touches and place it back down, the pointers swap index and ID. Very frustrating.

Upvotes: 3

Amandeep Grewal
Amandeep Grewal

Reputation: 1821

Use getPointerId to get which pointer is being selected.

Edit

To answer the question in the comment, try:

    for (int i = 0; i < ev.getPointerCount(); i++) {
        switch (ev.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_POINTER_DOWN:
            Log.d(TAG,"down "+ ev.getPointerId(i));
            break;
        case MotionEvent.ACTION_MOVE:
            Log.d(TAG,"move "+ ev.getPointerId(i));
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_POINTER_UP:
            Log.d(TAG,"up "+ ev.getPointerId(i));
            break;  
        }
    }

Upvotes: 0

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