trouble with ViewFlipper

I got totally side-tracked in my Android app trying to do a quick implementation of onFling. The intent was to not have to worry about my GridView filling up with buckets - I thought I could just max out the current view at 9 and implement onFling to take in the swipe gesture from the user to move over and look at the next (or previous) 9 buckets.

My first surprise was that it was harder than I expected! I shouldn't have been surprised :) Seriously, I thought that I could just wrap my existing view with the ViewFlipper and provide an index for 'paging'. I ended up implementing (hard-coding) 3 static pages with the intention of just ignoring the swipe if there weren't any next / previous screens. My second surprise was that I couldn't get the onFling / GestureDetector to fire. I thought I had grown a solid understanding of Android but sheesh - this should be trivial stuff.

Added to onCreate

        mViewFlipper = (ViewFlipper) findViewById(R.id.main_flipper);
        mGestureDetector = new GestureDetector(new FlingGestureDetector());
        mGestureListener = new OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                Log.d(getClass().getSimpleName(), "HERE onTouch");
                if (mGestureDetector.onTouchEvent(event)) {
                    return true;
                }
                return false;
            }
        };

Then I added this inner class. Just a quick reminder, this doesn't currently work - I'm just recording the notes here.

    class FlingGestureDetector extends SimpleOnGestureListener {
        @Override
        public boolean onFling(MotionEvent eventStart, MotionEvent eventEnd, float velocity, float unusedVelocity) {
            Log.i(getClass().getSimpleName(), "onFling (" + eventStart + ", " + eventEnd + ", " + velocity + ")");

            try {
                if (Math.abs(eventStart.getY() - eventEnd.getY()) > FLING_MAX_DEVIATION) {
                    Log.d(MainActivity.class.getSimpleName(), "onFling too much Y in motion, not fling");
                    return false;
                }
                if (eventStart.getX() - eventEnd.getX() > FLING_MIN_DISTANCE && Math.abs(velocity) > FLING_MIN_VELOCITY) {
                    mViewFlipper.setInAnimation(AnimationUtils.makeInAnimation(MainActivity.this, true));
                    mViewFlipper.setOutAnimation(AnimationUtils.makeOutAnimation(MainActivity.this, true));
                    mViewFlipper.showNext();
                } else if (eventEnd.getX() - eventStart.getX() > FLING_MIN_DISTANCE && Math.abs(velocity) > FLING_MIN_VELOCITY) {
                    mViewFlipper.setInAnimation(AnimationUtils.makeInAnimation(MainActivity.this, false));
                    mViewFlipper.setOutAnimation(AnimationUtils.makeOutAnimation(MainActivity.this, false));
                    mViewFlipper.showPrevious();
                }
            } catch (Exception e) {
                Log.w(MainActivity.class.getSimpleName(), "onFling ignoring unexpected exception: " + e);
            }
            return false;
        }
    }

    OnTouchListener mGestureListener;

    /**
     * Most people will probably just have the 1 page of buckets but for the
     * people lucky enough to have more than 9 / 12 / whatever the number is,
     * they can fling thru the pages.
     */
    private int mViewIndex = 0;

Blah blah blah - just a distraction. I need to get back to fixing sync'ing and adding buckets.