AnimatedLayout part 3: update onTouch() method

AnimatedLayout.java

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        isTouching = true;
        mFling.cancel();
        switch (event.getActionMasked()) {
            case MotionEvent.ACTION_DOWN:
                mPreviousTouchX = event.getX();
                if (mVelocityTracker == null) {
                    // Retrieve a new VelocityTracker object to watch the velocity
                    // of a motion.
                    mVelocityTracker = VelocityTracker.obtain();
                } else {
                    // Reset the velocity tracker back to its initial state.
                    mVelocityTracker.clear();
                }
                mVelocityTracker.addMovement(event);
                return true;
            case MotionEvent.ACTION_MOVE:
                mVelocityTracker.addMovement(event);
                ...
                return true;
            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                if (needToFling()) {
                    mVelocityTracker.addMovement(event);
                    mVelocityTracker.computeCurrentVelocity(1000);
                    float velocityX = mVelocityTracker.getXVelocity();

                    if (Math.abs(velocityX) < mCurrentMinFlingVelocityPx) {
                        if (mOffsetValue < getWidth() / 2f) {
                            velocityX = -mCurrentMinFlingVelocityPx;
                        } else {
                            velocityX = +mCurrentMinFlingVelocityPx;
                        }
                    }
                    mFling.setStartVelocity(velocityX)
                            .setMinValue(0)
                            .setMaxValue(getWidth())
                            .setFriction(0.1f)
                            .start();
                    mPreviousTouchX = -1;
                } else {
                    applyIdleState();
                    invalidate();
                }
                if (mVelocityTracker != null) {
                    mVelocityTracker.recycle();
                    mVelocityTracker = null;
                }
                isTouching = false;
                return true;
            default:
                return false;
        }
    }

    private boolean needToFling() {
        return 0 < mOffsetValue && mOffsetValue < getWidth();
    }

    private void applyIdleState() {
        mCurrentAnimation = IDLE_ANIMATION_STATE;
        mPreviousTouchX = -1;
        if (mOffsetValue < getWidth() / 2f) {
            mIdleState = WINTER_STATE;
            updateOffset(0);
            applyWinter();
        } else {
            mIdleState = SUMMER_STATE;
            updateOffset(getWidth());
            applySummer();
        }
    }