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    <p>This is deliberate behavior of the <code>FastScroller</code>. When you call <code>setAdapter</code> on your <code>ListView</code>, the adapter is wrapped in a <code>HeaderViewListAdapter</code> if there are any headers set; this is why you must call <code>addHeaderView</code> before <code>setAdapter</code>. Then, in the <code>FastScroller</code> code, we see:</p> <pre><code> if (adapter instanceof HeaderViewListAdapter) { mListOffset = ((HeaderViewListAdapter)adapter).getHeadersCount(); adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter(); } </code></pre> <p>That is, get an offset and use the underlying adapter. <code>mListOffset</code> is then used to set the top position to scroll to with the fast scroller. So where does this wrapping actually happen? Up to, as expected, <code>ListView.addHeaderView</code>, where we see:</p> <pre><code> if (mHeaderViewInfos.size() &gt; 0|| mFooterViewInfos.size() &gt; 0) { mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); } else { mAdapter = adapter; } </code></pre> <p>So we're definitely looking around the right place. Now, it sounds like your goal is to NOT have the offset behavior for list headers for your fast thumb, but otherwise have a normal list with header. To do this, it's sufficient (based on what we've seen of the code) to have <code>FastScroller.mListOffset = 0</code>. This is set only in <code>getSectionsFromIndexer</code>, which is called unconditionally in <code>init</code>, and conditionally in several other functions only when <code>mListAdapter == null</code>. <code>mListAdapter</code> is only null if <code>onSectionsChanged</code> gets called, so let's ignore that path for now.</p> <p>After a lot of digging around, and playing with various reflection hooks, I can say that there's no way to do this that will be even slightly future-compatible. You can use reflection to swap out the HeaderViewListAdapter for one that lies about its header count, etc; but that's quite fragile. Similarly, you can subclass the (package visible) FastScroller with one with your own behavior; but <code>mListOffset</code> is referenced widely and not through a getter, so this is even uglier than usual. Basically, you're running up against the fact that the system doesn't work quite the way you want.</p> <p>I hesitate to call this a bug, since it's so clear from the code that it's deliberate behavior. Have you considered making the first element of the list just a special first element (possibly using a custom <code>WrapperListAdapter</code> much like <code>HeaderViewListAdapter</code> if desired for book-keeping), rather than using the header mechanism?</p>
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