Get maximum HorizontalScrollView scroll amount
<p>I'm adding floating arrows to my <code>HorizontalScrollView</code> which will let the user know that there are more item's outside of the current view.</p>

<p>What I need is how to tell if the View has been scrolled to it's maximum. You would have thought the method <code>getMaxScrollAmount()</code> would give you this - it doesn't, in my code it gives me the width of the View. Go figure why. Here's my code - nice and simple:</p>

<pre><code>    final ImageView leftArrow = (ImageView) toReturn.findViewById(R.id.leftArrow);
    final ImageView rightArrow = (ImageView) toReturn.findViewById(R.id.rightArrow);

    final HorizontalScrollView scrollView = (HorizontalScrollView) toReturn.findViewById(R.id.actionBarHoriztonalScroll);


    final GestureDetector gd = new GestureDetector(new SimpleOnGestureListener() {
        @Override
        public boolean onScroll(MotionEvent e1, 
                                MotionEvent e2, 
                                float distanceX, 
                                float distanceY) {
            if(scrollView.getScrollX() == 0) {
                leftArrow.setVisibility(View.GONE);
            } else {
                leftArrow.setVisibility(View.VISIBLE);
            }
            if(scrollView.getScrollX() == scrollView.getMaxScrollAmount() ||
                scrollView.getMaxScrollAmount() == 0) {
                rightArrow.setVisibility(View.GONE);
            } else {
                rightArrow.setVisibility(View.VISIBLE);
            }

            Log.v(ClientDetailsFragment.class.getSimpleName(), "max: " + scrollView.getMaxScrollAmount() +
                                                            "current: " + scrollView.getScrollX());
            return super.onScroll(e1, e2, distanceX, distanceY);
        }
    });

    scrollView.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View arg0, MotionEvent ev) {
            gd.onTouchEvent(ev);
            return false;
        }
    });
</code></pre>

<p>Output from the above debugging:</p>

<pre><code>10-03 14:36:16.343: VERBOSE/(20508): max: 240 current: 126
10-03 14:36:16.363: VERBOSE/(20508): max: 240 current: 127
10-03 14:36:16.386: VERBOSE/(20508): max: 240 current: 132
10-03 14:36:16.398: VERBOSE/(20508): max: 240 current: 143
10-03 14:36:16.417: VERBOSE/(20508): max: 240 current: 149
10-03 14:36:16.433: VERBOSE/(20508): max: 240 current: 152
10-03 14:36:16.449: VERBOSE/(20508): max: 240 current: 152
10-03 14:36:16.468: VERBOSE/(20508): max: 240 current: 152
</code></pre>

<p>(152 is the Max in this case)</p>
