Develop Reference

Listview does not automatically refresh after getting list data from DataStore

I have a ListView which I populate with data from DataStore or from my local database.
I am checking some condition that will determine whether I will fetch data from the DataStore or database. When I fetch from the database the ListView automatically refreshes itself, but when I fetch from the DataStore it does not. I then have to click my TextView, which is below ListView, and when I click it the soft keyboard appears and then my ListView is populated with data from DataStore.
My activity that has the ListView:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_xyz);
list_View = (ListView) findViewById(R.id.data_listView);
list_View.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
list_View.setMultiChoiceModeListener(new Selector());
adapter = new MyAdapter(context,Long.valueOf(id),isOnline());
list_View.setAdapter(adapter);
list_View.setSelection(adapter.getCount() - 1);
adapter.registerDataSetObserver(new DataSetObserver() {
#Override
public void onChanged() {
super.onChanged();
list_View.setSelection(adapter.getCount() - 1);
}
LoadDataTask ldt = new LoadDataTask();
ldt.execute("123456789");
}
private void loadDataFromDataStore(final Long contactId){
final ArrayList<Data> data = new ArrayList<>();;
d("loadingdataFromDatasore");
GetDataTask task = new GetDataTask(new ApiTask.ResultListener() {
#Override
public void successHook(Object o) {
if (o instanceof GetDataResponse) {
GetDataResponse res = (GetDataResponse) o;
if (res.getData() != null && res.getData().getItems() != null) {
for (ListDataItem i : res.getData().getItems()) {
Data dp = new Data(i.getPosition(), i.getMessage(), i.getDateCreated(),i.getMessageId(),1);
adapter.addFromOtherThread(dp);
}
}
d("Messages loaded from server: " + adapter.getCount());
}
}
}
public class LoadDataTask extends AsyncTask<String,String,Void> {
#Override
protected Void doInBackground(String... params){
if(isOnline && isFirstTime){
loadDataFromDataStore(Long.valueOf(params[0]));
}else{
//load from database
}
return null;
}
#Override
protected void onPostExecute(Void v){
adapter.notifyDataSetChanged();
}
}
My adapter class that extends BaseAdapter (I have removed unnecessary code for this question):
public class DataAdapter extends BaseAdapter {
private ArrayList<Data>data_list;
public DataAdapter(){
data_list = new ArrayList<>();
}
public void addFromOtherThread(Data object) {
data_list.add(object);
}
What am I missing that is making listview not to automatically refresh itself even after calling notifyDatasetChanged()?

change :
#Override
protected void onPostExecute(Void v){
adapter.notifyDataSetChanged();
}
}
to:
#Override
protected void onPostExecute(Void v){
adapter.notifyDataSetChanged();
list_View.setAdapter(adapter);
}
}
Let me know if more clarification is required by commenting below.

#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_xyz);
list_View = (ListView) findViewById(R.id.data_listView);
list_View.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
list_View.setMultiChoiceModeListener(new Selector());
adapter = new MyAdapter(context,Long.valueOf(id),isOnline());
list_View.setAdapter(adapter);
list_View.setSelection(adapter.getCount() - 1);
adapter.registerDataSetObserver(new DataSetObserver() {
#Override
public void onChanged() {
super.onChanged();
list_View.setSelection(adapter.getCount() - 1);
}
loadDataFromDataStore("123456789")
}
private void loadDataFromDataStore(final Long contactId){
final ArrayList<Data> data = new ArrayList<>();;
d("loadingdataFromDatasore");
new GetDataTask(new ApiTask.ResultListener() {
#Override
public void successHook(Object o) {
if (o instanceof GetDataResponse) {
GetDataResponse res = (GetDataResponse) o;
if (res.getData() != null && res.getData().getItems() != null) {
for (ListDataItem i : res.getData().getItems()) {
Data dp = new Data(i.getPosition(), i.getMessage(), i.getDateCreated(),i.getMessageId(),1);
adapter.addFromOtherThread(dp);
}
}
d("Messages loaded from server: " + adapter.getCount());
adapter.notifyDatasetChanges();
}
}
}.execute();
}
GetDataTask should work on background internally you don't need to starts a AsyncTask from here.
If you want to use AsyncTask then your AsyncTask should wait for the result from GetDataTask which it is not doing in your code implementation.
I don't know which kind of framework you are using to making api call but your implementation seems to look wrong.
I have write the code on assumption bases if your GetDataTask is a AsyncTask or some background processor it will work perfectly.

How to update a ListView inside a message listener?

I'm building a chat application, so I'm using two ListViews: one that shows the online friends and one for the chat itself, that receives the messages and so on. I'm using the XMPP protocol and the Smack Library for Android.
The Smack Library give me Listeners which are activated every time a friend status changes(online/offline) and the other one when the user receives a message. Here's how I declare the adapter and call an AsyncTask when the user press a button:
peopleList = (ListView) findViewById(R.id.peopleList);
adapter = new MyAdapter(this, people);
peopleList.setAdapter(adapter);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new ConnectAndLoad(MainActivity.this).execute();
}
});
Inside the AsyncTask, I connect to the server inside the doInBackground method and inside the onPostExecute I create the listener which adds the user to the array list of the listview and call adapter.notifyDataSetChanged();
public class ConnectAndLoad extends AsyncTask<String, Integer, Boolean> {
private ProgressDialog dialog;
public ConnectAndLoad(Activity activity)
{
this.dialog = new ProgressDialog(activity);
this.dialog.setTitle("Loading..");
this.dialog.setMessage("Connecting to the server..");
dialog.show();
}
#Override
protected Boolean doInBackground(String... arg0) {
MyConnectionManager.getInstance().setConnectionConfiguration(getApplicationContext());
MyConnectionManager.getInstance().connect();
MyConnectionManager.getInstance().login();
return true;
}
protected void onPostExecute(Boolean boo)
{
MyConnectionManager.getInstance().bored();
Roster roster = Roster.getInstanceFor(MyConnectionManager.getInstance().getConnection());
try
{
if (!roster.isLoaded()) roster.reloadAndWait();
}
catch (Exception e)
{
Log.e(TAG, "reload");
}
roster.addRosterListener(new RosterListener() {
public void entriesDeleted(Collection<String> addresses) {
}
public void entriesUpdated(Collection<String> addresses) {
}
public void entriesAdded(Collection<String> addresses) {
}
#Override
public void presenceChanged(Presence presence) {
people.add(new People(presence.getFrom(), presence.getStatus()));
adapter.notifyDataSetChanged();
}
});
dialog.dismiss();
}
}
And below is my Custom Adapter:
public class PeopleAdapter extends ArrayAdapter<People> {
private ArrayList<People> events_list = new ArrayList<>();
Context context;
public PeopleAdapter(Context context, ArrayList<People> users) {
super(context, 0, users);
this.context = context;
this.events_list = users;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
People user = getItem(position);
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.people_list, parent, false);
}
TextView tvName = (TextView) convertView.findViewById(R.id.name);
TextView tvStatus = (TextView) convertView.findViewById(R.id.status);
tvName.setText(user.name);
tvStatus.setText(user.status);
convertView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "You Clicked " + events_list.get(position).name, Toast.LENGTH_SHORT).show();
Intent i = new Intent(context, ConversationActivity.class);
i.putExtra("user", events_list.get(position).name);
context.startActivity(i);
}
});
return convertView;
}
}
I mean what I want to do I think it's a simple thing, every single chat app does it, is basically update the list view automatically but I'm having two problems:
The listview ONLY updates after I click on it. So it basically works
but I have to click on the listview..
I receive this error every time the list view updates (the app keeps working though):
Exception in packet listener: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

I can give you a simple solution. Make local Activity variable in the ConnectAndLoad class
private Activity activity;
public ConnectAndLoad(Activity activity)
{
...
activity.activity= activity;
}
Instead on directly calling adapter.notifyDataSetChanged(); use
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
adapter.notifyDataSetChanged();
}
});
It seems like presenceChanged() called in another thread. But be careful and make sure you delete RosterListener when activity gets destroyed or it can lead to the memory leaks i.e activity is already destroyed but you keep getting notifications about presence change.

Android Testing startActivityForResult for Contact

I have one Activity that uses startActivityForResult for Contact by ACTION_PICK. In first, my test is choice the contact and after check the contact selected.
public class ListaMensagemActivity extends ListActivity implements Transacao{
private List<Mensagem> mensagens;
private static final int CONTATO_SELECIONADO=1;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
TransacaoTask task = new TransacaoTask(this, this, R.string.aguarde);
task.execute();
}
#Override
public void executar() throws Exception {
// Busca as mensagens em uma thread
this.mensagens = new MensagemService(this).getMensagem();
}
#Override
public void atualizarView() {
// Atualiza as mensagens na thread principal
if (this.mensagens != null) {
this.setListAdapter(new MensagemAdapter(this, mensagens));
}
}
#Override
public void onListItemClick(ListView parent, View view, int posicao,
long id) {
super.onListItemClick(parent, view, posicao, id);
Intent contactIntent = new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI);
startActivityForResult(contactIntent,CONTATO_SELECIONADO);
}
}

atleast send the code that you wanted to test. this is the structure of unit testing in robotium.
your question is also not clear
public class SimpleActivityTest extends
ActivityInstrumentationTestCase2<SimpleActivity> {
private Solo solo;
public SimpleActivityTest() {
super(SimpleActivity.class);
}
public void setUp() throws Exception {
solo = new Solo(getInstrumentation(), getActivity());
}
#Override
public void tearDown() throws Exception {
solo.finishOpenedActivities();
}
public void testListItemClickShouldDisplayToast() throws Exception {
// check that we have the right activity
solo.assertCurrentActivity("wrong activity", SimpleActivity.class);
// Click a button which will start a new Activity
// Here we use the ID of the string to find the right button
solo.clickOnButton(solo
.getString(de.vogella.android.test.target.R.string.button1));
// assert that the current activity is the SimpleListActivity.class
solo.assertCurrentActivity("wrong activity", SimpleListActivity.class);
solo.clickInList(1);
// searchForText has a timeout of 5 seconds
assertTrue(solo.waitForText("Android")); // Assertion
solo.clickInList(2);
assertTrue(solo.waitForText("iPhone")); // Assertion
solo.clickInList(3);
assertTrue(solo.waitForText("Blackberry")); // Assertion
solo.goBack();
solo.clickOnButton("Button2");
solo.clickOnButton("Button3");
}
public void testListItemClickShouldDisplayToast() throws Exception {
// open the menu
solo.sendKey(Solo.MENU);
solo.clickOnText("Preferences");
solo.clickOnText("User");
solo.clearEditText(0);
Assert.assertTrue(solo.searchText(""));
solo.enterText(0, "http//:www.vogella.com");
Assert.assertTrue(solo.searchText("http//:www.vogella.com"));
solo.goBack();
}
}

The my question is a test to Intent.ACTION_PICK. In case, I have an action pick to choose a contact's number in view of android and get the contact's number.

how to get object reference from other activity [android]

I have two major classes in my project. The first is for creating the connection between the client and the server. The second is for switching between activities.
first:
public class MyActivity extends Activity{
private ListView mList;
private ArrayList<String> arrayList;
private MyCustomAdapter mAdapter;
public TCPClient mTcpClient;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
boolean flag = getIntent().getBooleanExtra("flag",false);
arrayList = new ArrayList<String>();
final EditText editText = (EditText) findViewById(R.id.editText);
Button send = (Button)findViewById(R.id.send_button);
Button menu = (Button)findViewById(R.id.button1);
if (flag == true)
{
//relate the listView from java to the one created in xml
mList = (ListView)findViewById(R.id.list);
mAdapter = new MyCustomAdapter(this, arrayList);
mList.setAdapter(mAdapter);
new connectTask().execute("");
Intent myIntent = new Intent(MyActivity.this,Menu.class);
startActivity(myIntent);
}
send.setOnClickListener(new View.OnClickListener() {
// #Override
public void onClick(View view) {
String message = editText.getText().toString();
//clean the listView to 1 item
if (message.equals("clean"))
{
arrayList.removeAll(arrayList);
mList.removeAllViewsInLayout();
}
//add the text in the arrayList
arrayList.add("c: " + message);
//sends the message to the server
if (mTcpClient != null) {
mTcpClient.sendMessage(message);
}
//refresh the list
mAdapter.notifyDataSetChanged();
editText.setText("");
}
});
//change Activity to live screen mode (live)
menu.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent(MyActivity.this, Menu.class);
startActivity(myIntent);
}
});
}
public class connectTask extends AsyncTask<String,String,TCPClient> {
#Override
protected TCPClient doInBackground(String... message) {
//we create a TCPClient object and
mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() {
// #Override
//print the message as an Item
public void messageReceived(String message) {
//this method calls the onProgressUpdate
publishProgress(message);
}
});
mTcpClient.run();
return null;
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
//in the arrayList we add the messaged received from server
arrayList.add(values[0]);
// notify the adapter that the data set has changed. This means that new message received
// from server was added to the list
mAdapter.notifyDataSetChanged();
}
}
}
the object TCPClient mTcpClient is the major factor in my app. I use it communicate with the server. In addition, even if I switch between activities it is still running properly so I still get info from server even though I am not in that activity.
second:
public class Menu extends Activity
{
public MyActivity myActivity;
public TCPClient mtcp;
protected void onCreate(Bundle savedInstanceState, MyActivity myActivity)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.menu);
ImageView action = (ImageView) findViewById(R.id.imageView1);
action.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event)
{
// here I would like to use mTcpClient object mentioned in the first class
return false;
}
});
}
Basically what I need is a help on how to create in the second class reference to the object mTcpClient that is described in the first class.

You are doing it wrong. If you want to use TcpClient class regardless of context it should NOT be related to first Activity. What you should do is to use singleton pattern:
class TcpClient {
protected static TcpClient mInstance = null;
public TcpClient() {
// your init code...
}
public static TcpClient getInstance() {
if( mInstance == null ) {
mInstance = new TcpClient();
}
return mInstance;
}
...
}
and then, whenever you want to use TcpClient you just do:
TcpClient client = TcpClient.getInstance();

AsyncTask : passing value to an Activity (onCreate method )

Update1
activity:
public Integer _number = 0;
#Override
public void onCreate(Bundle savedInstanceState) {
if (_number >0)
{
Log.d("onSuccessfulExecute", ""+_number);
}
else
{
Log.d("onSuccessfulExecute", "nope empty songs lists");
}
}
public int onSuccessfulExecute(int numberOfSongList) {
_number = numberOfSongList;
if (numberOfSongList >0)
{
Log.d("onSuccessfulExecute", ""+numberOfSongList);
}
else
{
Log.d("onSuccessfulExecute", "nope empty songs lists");
}
return numberOfSongList;
}
end Update1
UPDATE: AsynchTask has its own external class.
How to pass an value from AsyncTask onPostExecute()... to activity
my code does returning value from onPostExecute() and updating on UI but i am looking for a way to set the activity variable (NumberOfSongList) coming from AsynchTask.
AsyncTask class:
#Override
public void onPostExecute(asynctask.Payload payload)
{
AsyncTemplateActivity app = (AsyncTemplateActivity) payload.data[0];
//the below code DOES UPDATE the UI textView control
int answer = ((Integer) payload.result).intValue();
app.taskStatus.setText("Success: answer = "+answer);
//PROBLEM:
//i am trying to populate the value to an variable but does not seems like the way i am doing:
app.NumberOfSongList = payload.answer;
..............
..............
}
Activity:
public Integer NumberOfSongList;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Several UI Code
new ConnectingTask().execute();
Log.d("onCreate", ""+NumberOfSongList);
}

What about using a setter method? e.g.
private int _number;
public int setNumber(int number) {
_number = number;
}
UPDATE:
Please look at this code. This will do what you're trying to accomplish.
Activity class
public class TestActivity extends Activity {
public int Number;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.test);
Button btnDisplay = (Button) findViewById(R.id.btnDisplay);
btnDisplay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast toast = Toast.makeText(v.getContext(), "Generated number: " + String.valueOf(Number), Toast.LENGTH_LONG);
toast.show();
}
});
new TestTask(this).execute();
}
}
AsyncTask class
public class TestTask extends AsyncTask<Void, Void, Integer> {
private final Context _context;
private final String TAG = "TestTask";
private final Random _rnd;
public TestTask(Context context){
_context = context;
_rnd = new Random();
}
#Override
protected void onPreExecute() {
//TODO: Do task init.
super.onPreExecute();
}
#Override
protected Integer doInBackground(Void... params) {
//Simulate a long-running procedure.
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
Log.e(TAG, e.getMessage());
}
return _rnd.nextInt();
}
#Override
protected void onPostExecute(Integer result) {
TestActivity test = (TestActivity) _context;
test.Number = result;
super.onPostExecute(result);
}
}

Just a word of caution: Be very careful when attempting to hold a reference to an Activity instance in an AsyncTask - I found this out the hard way :). If the user happens to rotate the device while your background task is still running, your activity will be destroyed and recreated thus invalidating the reference being to the Activity.

Create a listener.
Make a new class file. Called it something like MyAsyncListener and make it look like this:
public interface MyAsyncListener() {
onSuccessfulExecute(int numberOfSongList);
}
Make your activity implement MyAsyncListener, ie,
public class myActivity extends Activity implements MyAsyncListener {
Add the listener to the constructor for your AsyncTask and set it to a global var in the Async class. Then call the listener's method in onPostExecute and pass the data.
public class MyCustomAsync extends AsyncTask<Void,Void,Void> {
MyAsyncListener mal;
public MyCustomAsync(MyAsyncListener listener) {
this.mal = listener;
}
#Override
public void onPostExecute(asynctask.Payload payload) {
\\update UI
mal.onSuccessfulExecute(int numberOfSongList);
}
}
Now, whenever your AsyncTask is done, it will call the method onSuccessfulExecute in your Activity class which should look like:
#Override
public void onSuccessfulExecute(int numberOfSongList) {
\\do whatever
}
Good luck.