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PORefreshing a ListView with a custom adapter
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  1. PORefreshing a ListView with a custom adapter
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    copied!<p>I am writing a small google talk client for android and I am having trouble refreshing my ListView correcty.</p> <p>This list contains the contact list and is showing the name and the presence of the contact. My listener works fine and I can see the presence changes of each contact in the log cat window, but my ListView is not refreshing... here is some code:</p> <pre><code>package de.marc.messenger; // ofc here are the imports public class RosterActivity extends Activity { private Roster _roster; private XMPPConnection _connection; private List&lt;HashMap&lt;String, String&gt;&gt; _buddies; private BuddyAdapter _adapter; private ListView _list; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.roster); _buddies = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;(); _connection = LoginActivity.CONNECTION; makePauseForRoster(); _roster = _connection.getRoster(); addRosterListener(); fillBuddyList(); sortBuddyList(); initializeListView(); } /** * Lets the thread sleep for a second to ensure that the presence of every * user will be available */ private void makePauseForRoster() { try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } } /** * Adds a listener to the roster, primarily for changes of presence */ private void addRosterListener() { _roster.addRosterListener(new RosterListener() { public void presenceChanged(Presence presence) { String user = presence.getFrom().split("/")[0]; HashMap&lt;String, String&gt; buddy = findBuddyInRoster(user); String p = getPresenceString(user); buddy.put("presence", p); System.out.println(buddy.values().toString()); // this works _adapter.notifyDataSetChanged(); // this doesn't _list.invalidate(); // this neither } }); } /** * Fills the list view with the roster entries */ private void initializeListView() { _adapter = new BuddyAdapter(this, R.layout.roster_item, _buddies); _list = (ListView) findViewById(R.id.list_roster); _list.setAdapter(_adapter); } /** * Fills the buddy list with relevant data from a RosterEntry. Relevant data * is the users' name, email and presence */ private void fillBuddyList() { // this just fills my list of hashmaps (_buddies) } /** * Get a predefined String depending on the presence of a user */ private String getPresenceString(String user) { // something like "available: away ()" -&gt; "away" } /** * Sorts the buddy list. Only criterion is the presence of the user, because * we have linear algorithms for this kind of problem. */ private void sortBuddyList() { // move all offline contacts to the end // move all online contacts to the beginning // all other kind of contacts will stay in the middle } /** * Finds a specific buddy object for a user via his hashed email */ private HashMap&lt;String, String&gt; findBuddyInRoster(String user) { for (HashMap&lt;String, String&gt; buddy : _buddies) { if (user.equals(buddy.get("user"))) { return buddy; } } return null; } </code></pre> <p>}</p> <p>This works fine, everything is shown correctly.. only trouble seems to be in the addRosterListener() method, where the onPresenceChanged() is implemented.. </p> <p>Here is my adapter:</p> <pre><code>package de.marc.messenger; // as well some imports public class BuddyAdapter extends ArrayAdapter&lt;HashMap&lt;String, String&gt;&gt; { private Context _context; private List&lt;HashMap&lt;String, String&gt;&gt; _map; private LayoutInflater _inflater; public BuddyAdapter(Context context, int id, List&lt;HashMap&lt;String, String&gt;&gt; map) { super(context, id, map); _context = context; _map = map; _inflater = (LayoutInflater) _context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); } @Override public View getView(int position, View convertView, ViewGroup parent) { // find view of a single row in a listview View row = convertView; if (convertView == null) { row = _inflater.inflate(R.layout.roster_item, null); } // get data for a specific row String name = _map.get(position).get("name"); String user = _map.get(position).get("user"); String presence = _map.get(position).get("presence"); // extract views from the row view TextView nameText = (TextView) row.findViewById(R.id.text_name); TextView userText = (TextView) row.findViewById(R.id.text_id); ImageView presenceImg = (ImageView) row .findViewById(R.id.image_presence); // set data in extracted views nameText.setText(name); userText.setText(user); int resource = 0; // something is done with this variable presenceImg.setImageResource(resource); return row; } </code></pre> <p>}</p> <p>Is there anything I am missing?</p> <p><strong>Edit:</strong> I changed my onPresenceChanged method like this:</p> <pre><code>public void presenceChanged(Presence presence) { String user = presence.getFrom().split("/")[0]; HashMap&lt;String, String&gt; buddy = findBuddyInRoster(user); _adapter.remove(buddy); String p = getPresenceString(user); buddy.put("presence", p); _adapter.add(buddy); _adapter.notifyDataSetChanged(); } </code></pre> <p>It works to some extend: After swiping a bit on the screen, the contact that changed his presence is now out of the list :/</p>
 

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