content: package antistatic.spinnerwheel.demo;
  
  import java.text.Collator;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import android.app.ListActivity;
  import android.content.Intent;
  import android.content.pm.PackageManager;
  import android.content.pm.ResolveInfo;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.ListView;
  import android.widget.SimpleAdapter;
  
  public class WheelDemo extends ListActivity {
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          
          Intent intent = getIntent();
          String path = intent.getStringExtra("com.example.android.apis.Path");
          
          if (path == null) {
              path = "";
          }
  
          setListAdapter(new SimpleAdapter(this, getData(path),
                  android.R.layout.simple_list_item_1, new String[] { "title" },
                  new int[] { android.R.id.text1 }));
      }
  
      protected List getData(String prefix) {
          List<Map> myData = new ArrayList<Map>();
  
          Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
          mainIntent.addCategory("antistatic.spinnerwheel.WHEEL_SAMPLE");
  
          PackageManager pm = getPackageManager();
          List<ResolveInfo> list = pm.queryIntentActivities(mainIntent, 0);
  
          if (null == list)
              return myData;
  
          String[] prefixPath;
          
          if (prefix.equals("")) {
              prefixPath = null;
          } else {
              prefixPath = prefix.split("/");
          }
          
          int len = list.size();
          
          Map<String, Boolean> entries = new HashMap<String, Boolean>();
  
          for (int i = 0; i < len; i++) {
              ResolveInfo info = list.get(i);
              CharSequence labelSeq = info.loadLabel(pm);
              String label = labelSeq != null
                      ? labelSeq.toString()
                      : info.activityInfo.name;
              
              if (prefix.length() == 0 || label.startsWith(prefix)) {
                  
                  String[] labelPath = label.split("/");
  
                  String nextLabel = prefixPath == null ? labelPath[0] : labelPath[prefixPath.length];
  
                  if ((prefixPath != null ? prefixPath.length : 0) == labelPath.length - 1) {
                      addItem(myData, nextLabel, activityIntent(
                              info.activityInfo.applicationInfo.packageName,
                              info.activityInfo.name));
                  } else {
                      if (entries.get(nextLabel) == null) {
                          addItem(myData, nextLabel, browseIntent(prefix.equals("") ? nextLabel : prefix + "/" + nextLabel));
                          entries.put(nextLabel, true);
                      }
                  }
              }
          }
  
          Collections.sort(myData, sDisplayNameComparator);
          
          return myData;
      }
      
      private final static Comparator<Map> sDisplayNameComparator = new Comparator<Map>() {
          private final Collator collator = Collator.getInstance();
  
          public int compare(Map map1, Map map2) {
              return collator.compare(map1.get("title"), map2.get("title"));
          }
      };
  
      protected Intent activityIntent(String pkg, String componentName) {
          Intent result = new Intent();
          result.setClassName(pkg, componentName);
          return result;
      }
      
      protected Intent browseIntent(String path) {
          Intent result = new Intent();
          result.setClass(this, WheelDemo.class);
          result.putExtra("com.example.android.apis.Path", path);
          return result;
      }
  
      protected void addItem(List<Map> data, String name, Intent intent) {
          Map<String, Object> temp = new HashMap<String, Object>();
          temp.put("title", name);
          temp.put("intent", intent);
          data.add(temp);
      }
  
      @Override
      protected void onListItemClick(ListView l, View v, int position, long id) {
          Map map = (Map) l.getItemAtPosition(position);
  
          Intent intent = (Intent) map.get("intent");
          startActivity(intent);
      }
  }
  