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POCustom filtering in Android using ArrayAdapter
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  1. POCustom filtering in Android using ArrayAdapter
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    copied!<p>I'm trying to filter my ListView which is populated with this ArrayAdapter:</p> <pre><code>package me.alxandr.android.mymir.adapters; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.Set; import me.alxandr.android.mymir.R; import me.alxandr.android.mymir.model.Manga; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.SectionIndexer; import android.widget.TextView; public class MangaListAdapter extends ArrayAdapter&lt;Manga&gt; implements SectionIndexer { public ArrayList&lt;Manga&gt; items; public ArrayList&lt;Manga&gt; filtered; private Context context; private HashMap&lt;String, Integer&gt; alphaIndexer; private String[] sections = new String[0]; private Filter filter; private boolean enableSections; public MangaListAdapter(Context context, int textViewResourceId, ArrayList&lt;Manga&gt; items, boolean enableSections) { super(context, textViewResourceId, items); this.filtered = items; this.items = filtered; this.context = context; this.filter = new MangaNameFilter(); this.enableSections = enableSections; if(enableSections) { alphaIndexer = new HashMap&lt;String, Integer&gt;(); for(int i = items.size() - 1; i &gt;= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) &gt; 'Z' || firstChar.charAt(0) &lt; 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set&lt;String&gt; keys = alphaIndexer.keySet(); Iterator&lt;String&gt; it = keys.iterator(); ArrayList&lt;String&gt; keyList = new ArrayList&lt;String&gt;(); while(it.hasNext()) keyList.add(it.next()); Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); } } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if(v == null) { LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.mangarow, null); } Manga o = items.get(position); if(o != null) { TextView tt = (TextView) v.findViewById(R.id.MangaRow_MangaName); TextView bt = (TextView) v.findViewById(R.id.MangaRow_MangaExtra); if(tt != null) tt.setText(o.getName()); if(bt != null) bt.setText(o.getLastUpdated() + " - " + o.getLatestChapter()); if(enableSections &amp;&amp; getSectionForPosition(position) != getSectionForPosition(position + 1)) { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setText(sections[getSectionForPosition(position)]); h.setVisibility(View.VISIBLE); } else { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setVisibility(View.GONE); } } return v; } @Override public void notifyDataSetInvalidated() { if(enableSections) { for (int i = items.size() - 1; i &gt;= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) &gt; 'Z' || firstChar.charAt(0) &lt; 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set&lt;String&gt; keys = alphaIndexer.keySet(); Iterator&lt;String&gt; it = keys.iterator(); ArrayList&lt;String&gt; keyList = new ArrayList&lt;String&gt;(); while (it.hasNext()) { keyList.add(it.next()); } Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); super.notifyDataSetInvalidated(); } } public int getPositionForSection(int section) { if(!enableSections) return 0; String letter = sections[section]; return alphaIndexer.get(letter); } public int getSectionForPosition(int position) { if(!enableSections) return 0; int prevIndex = 0; for(int i = 0; i &lt; sections.length; i++) { if(getPositionForSection(i) &gt; position &amp;&amp; prevIndex &lt;= position) { prevIndex = i; break; } prevIndex = i; } return prevIndex; } public Object[] getSections() { return sections; } @Override public Filter getFilter() { if(filter == null) filter = new MangaNameFilter(); return filter; } private class MangaNameFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence constraint) { // NOTE: this function is *always* called from a background thread, and // not the UI thread. constraint = constraint.toString().toLowerCase(); FilterResults result = new FilterResults(); if(constraint != null &amp;&amp; constraint.toString().length() &gt; 0) { ArrayList&lt;Manga&gt; filt = new ArrayList&lt;Manga&gt;(); ArrayList&lt;Manga&gt; lItems = new ArrayList&lt;Manga&gt;(); synchronized (items) { Collections.copy(lItems, items); } for(int i = 0, l = lItems.size(); i &lt; l; i++) { Manga m = lItems.get(i); if(m.getName().toLowerCase().contains(constraint)) filt.add(m); } result.count = filt.size(); result.values = filt; } else { synchronized(items) { result.values = items; result.count = items.size(); } } return result; } @SuppressWarnings("unchecked") @Override protected void publishResults(CharSequence constraint, FilterResults results) { // NOTE: this function is *always* called from the UI thread. filtered = (ArrayList&lt;Manga&gt;)results.values; notifyDataSetChanged(); } } } </code></pre> <p>However, when I call filter('test') on the filter nothing happens at all (or the background-thread is run, but the list isn't filtered as far as the user conserns). How can I fix this?</p>
 

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