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POAndroid refresh ListView sections-overlay not working in 4.4
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  1. POAndroid refresh ListView sections-overlay not working in 4.4
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    copied!<p>Hi Stackoverflow community,</p> <p>I am currently playing around with Android ListViewsections capabilties, but there seems to be an issue in Android 4.4 API. I have a CursorAdapter which populates the items from a SQLite database. When the adapter gets created, it sections his items. The user has the posssiblity to change the sorting of the ListView items from A-Z to Z-A. When he does this, a new CursorAdapter will be created and set, which of course indexes his items again. I used the following code to set the new Adapter, which seemed to force the Listview to call getSections() and refreshed the sections when fast scrolling:</p> <pre><code>//A new instance of adapter is created here with the new cursor, see code at bottom listView.setFastScrollEnabled(false); listView.setAdapter(adapter); listView.setFastScrollEnabled(true); </code></pre> <p>The above code works great up to Android 4.3, but stopped working in 4.4. In 4.4, the ListView shows the old sections while fast scrolling: So, when the user changed the sorting to Z-A, the ListView still shows this sections-overlay in order A-Z when fast scrolling. I hope you know what I mean.</p> <p>Is this a known bug and is there a workaround for this?</p> <p>Thank you very much.</p> <p>EDIT: This is the code of the adapter I use. It is based on basically 2 cursors. The first one holds the data to show and the second one the indices.</p> <pre><code>public class SectionCheckableCursorAdapter extends CursorAdapter implements SectionIndexer { private LayoutInflater mInflater; private Map&lt;Integer, Object&gt; mSectionIndices = new TreeMap&lt;Integer, Object&gt;(); private Object[] mSections; private Integer[] mSectionPositions; public SectionCheckableCursorAdapter(Context context, Cursor c, Cursor indexCursor) { super(context, c, false); mInflater = LayoutInflater.from(context); buildIndex(indexCursor); } private void buildIndex(Cursor indexCursor) { //init mSectionIndices = new TreeMap&lt;Integer, Object&gt;(); List&lt;Integer&gt; sectionPositionsList = new ArrayList&lt;Integer&gt;(); //get column indices from cursor int indexFirstLetter = indexCursor.getColumnIndex("firstLetter"); int indexCount = indexCursor.getColumnIndex("count"); //build sections int currentCount = 0; while (indexCursor.moveToNext()) { final int count = indexCursor.getInt(indexCount); String firstChar = indexCursor.getString(indexFirstLetter); if (firstChar == null || firstChar.isEmpty()) { firstChar = " "; } if (StringUtils.isNumber(firstChar)) { firstChar = "#"; } if (!mSectionIndices.containsValue(firstChar)) { mSectionIndices.put(currentCount, firstChar); sectionPositionsList.add(currentCount); } currentCount += count; } mSectionPositions = new Integer[sectionPositionsList.size()]; sectionPositionsList.toArray(mSectionPositions); Collection&lt;Object&gt; sections_collection = mSectionIndices.values(); mSections = new Object[sections_collection.size()]; sections_collection.toArray(mSections); } @Override public int getPositionForSection(int section) { if (section &gt; mSectionPositions.length - 1) { if (getCursor() != null) return getCursor().getCount() - 1; return 0; } else { return mSectionPositions[section]; } } @Override public int getSectionForPosition(int position) { for (int i = 0; i &lt; mSectionPositions.length-1; i++) { if (position &gt;= mSectionPositions[i] &amp;&amp; position &lt; mSectionPositions[i+1]) { return i; } } return mSectionPositions.length-1; } @Override public Object[] getSections() { return mSections; } </code></pre> <p>}</p> <p>This is how the Cursors and Adapter are created, before the Adapter gets set like in the code at top:</p> <pre><code>//Query for "real" data and the indices. The indices are created with a query because //this is much faster than iterating through all entries in the "data" cursor mCursor = mDatabase.rawQuery(query, null); mIndexCursor = mDatabase.rawQuery(indexQuery, null); if (mCursor != null) { adapter = new SectionCheckableCursorAdapter(getSherlockActivity(), mCursor, mIndexCursor); } </code></pre>
 

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