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copied!<pre><code>Charsequence alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; </code></pre> <p>Here</p> <pre><code>A = 0 B = 1 C = 2 D = 3 E = 4 F = 5 . . . Z = 25 </code></pre> <p>Create a new AlphabetIndexer</p> <pre><code>AlphabetIndexer alphabetIndexer = new AlphabetIndexer(cursor, sortedColumnIndex, alphabets); </code></pre> <p>getSections() retreives the String[] of the alphabets that is provided to the alphabetIndexer</p> <pre><code>String[] sections = (String[]) alphabetIndexer.getSections(); </code></pre> <p>alphabetIndexer.getSectionForPosition(position) retreives the section for the current position</p> <p>Consider the given case</p> <pre><code>position Data getSectionForPosition(position) ________ _________ __________ 0 Ajdhfj j 0 1 Aadf hdsf 0 2 Ajfkldsahf 0 3 Asdhfa df 0 4 Badhf 1 5 Bdfj sadif 1 6 Bghoi ij 1 7 Bjkojg o 1 8 Cadj fkljsdf 2 9 Cgjds kfja 2 10 Cn khdfaj 2 11 Cph iohsdf 2 12 Czjfa sh 2 13 Dfgoa hjoifaj 3 14 Dzfjdak sfh 3 15 Fhf adhf 5 16 Zdfh ajdf 25 </code></pre> <p>To get the section for the position </p> <pre><code>String section = sections[getSectionForPosition(position)]; </code></pre> <p>alphabetIndexer.getPositionForSection(section) retreives the first position at which the data starts with that section</p> <pre><code>section getPositionForSection(section) _________ ____________________ 0 0 1 4 2 8 3 13 4 13 5 15 6 15 7 15 8 15 . . . . . . 23 15 24 15 25 16 </code></pre> <p>Hope this helps you.</p> <p>An example of using alphabetIndexer</p> <pre><code>public abstract class SectionedListAdapter extends ResourceCursorAdapter { private SparseIntArray sections; private SparseIntArray cursorPositions; private Context mContext; private int sortedColumnIndex; private static final int NORMAL_LIST_VIEW = 0; private static final int SECTION_LIST_VIEW = 1; private static final int NULL_LIST_VIEW = 2; public SectionedListAdapter(Context context, int layout, Cursor c, boolean autoRequery, int sortedColumnIndex, int defaultBitmapResId) { super(context, layout, c, autoRequery); this.mContext = context; this.sortedColumnIndex = sortedColumnIndex; setSortedCursorColumn(c); } public void setSortedCursorColumn(Cursor cursor){ if (cursor == null){ return; } AlphabetIndexer alphabetIndexer = new AlphabetIndexer(cursor, sortedColumnIndex, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"); sections = new SparseIntArray(); int m=0; int t = 'A'; for (int i=0; i < 26; i++){ if ((i+1) < 26) { int position = alphabetIndexer.getPositionForSection(i); int temp = alphabetIndexer.getPositionForSection(i + 1); if (temp != position){ sections.put(position + m, t+i); m++; } } else { int position = alphabetIndexer.getPositionForSection(i); int temp = alphabetIndexer.getPositionForSection(i-1); if (position != temp){ sections.put(position + m, t+i); } } } int temp = 0; cursorPositions = new SparseIntArray(); for (int i=0; i<cursor.getCount() + sections.size(); i++){ if (sections.get(i, -1) != -1){ temp ++; cursorPositions.put(i, -1); } else { cursorPositions.put(i, i - temp); } } } @Override public View getView(int position, View view, ViewGroup parent) { if (getItemViewType(position) == NORMAL_LIST_VIEW){ if (view == null){ view = newView(mContext, getCursor(), parent); } getCursor().moveToPosition(cursorPositions.get(position)); bindView(view, mContext, getCursor(), position); } else if (getItemViewType(position) == SECTION_LIST_VIEW) { if (view == null){ view = newSectionView(mContext, getCursor(), parent); } bindSectionView(view, mContext, (char)sections.get(position)); } else { if (view == null){ } else { view = new ViewStub(mContext); } } return view; } public abstract View newSectionView(Context context, Cursor cursor, ViewGroup parent); public abstract void bindSectionView(View view, Context context, char text); public abstract void bindView(View view, Context context, Cursor cursor, int position); @Override public boolean areAllItemsEnabled() { return false; } @Override public boolean isEnabled(int position) { return cursorPositions.get(position) >= 0; } @Override public int getItemViewType(int position) { if (cursorPositions.get(position) >= 0){ return NORMAL_LIST_VIEW; }else if (cursorPositions.get(position) == -1){ return SECTION_LIST_VIEW; } else { return NULL_LIST_VIEW; } } @Override public int getViewTypeCount() { return 3; } private void putCursorExclusion(int position, boolean isActualPosition){ if (isActualPosition) { cursorPositions.put(position, -cursorPositions.get(position)); } else { int actualPosition = cursorPositions.keyAt(cursorPositions.indexOfValue(position)); cursorPositions.put(actualPosition, -position); } } private void removeCursorExclusion(int position, boolean isActualPosition){ if (isActualPosition){ cursorPositions.put(position, -cursorPositions.get(position)); } else { int actualPosition = cursorPositions.keyAt(cursorPositions.indexOfValue(-position)); cursorPositions.put(actualPosition, position); } } @Override public int getCount() { return cursorPositions == null ? 0 : cursorPositions.size(); } public SparseIntArray getSections() { return sections; } public SparseIntArray getCursorPositions() { return cursorPositions; } @Override public void bindView(View view, Context context, Cursor cursor) { //do nothing here } @Override public Cursor swapCursor(Cursor newCursor) { return super.swapCursor(newCursor); } @Override public void notifyDataSetChanged() { super.notifyDataSetChanged(); } @Override public void changeCursor(Cursor cursor) { setSortedCursorColumn(cursor); super.changeCursor(cursor); } } </code></pre> <p>To use this just create a new class extends SectionedListAdapter and then provide required details.</p>

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