Initially, after setting up custom listview, no more items are getting added i.e displayed in list view inspite of adding Object item from FirebaseMessagingService.
I have declared listView static so that Object can be added to the list from other classes or services.
Here's my code:
FirebaseMessagingService:
#Override
public void onMessageReceived(final RemoteMessage remoteMessage) {
//Toast.makeText(getApplicationContext(), remoteMessage.getData().get("transaction"),Toast.LENGTH_SHORT).show();
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
#Override
public void run() {
Gson gson = new Gson();
Block b = gson.fromJson(remoteMessage.getData().get("transaction"), Block.class);
OpenChain.arrayList.add(b);
}
});
}
ListView activity code:
public static ArrayList<Block> arrayList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_open_chain);
arrayList = new ArrayList<>();
getSupportActionBar().setTitle("Vote Ledger");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
ListView listView = (ListView) findViewById(R.id.listView);
BlockchainAdap adap = new BlockchainAdap(this, arrayList);
listView.setAdapter(adap);
adap.notifyDataSetChanged();
}
**I am receiving object from cloud in json format
**Also able to add objects from within listview activity but not from FirebaseMessagingSerivce
I have declared listView static so that Object can be added to the
list from other classes or services.
Not, a good solution, you are leaking arrayList here, as it wont be garbage collected when activity gets destroyed.
A better approach would be to use LocalBroadCast in this scenario.
Checkout the link for info
https://developer.android.com/reference/android/support/v4/content/LocalBroadcastManager.html
Now, what you are doing wrong. You, are modifying the arraylist but you are not notifying the adapter about the same.
Try this..
private ArrayList<Block> arrayList = new ArrayList<>();
private BlockchainAdap adap;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_open_chain);
getSupportActionBar().setTitle("Vote Ledger");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
ListView listView = (ListView) findViewById(R.id.listView);
adap = new BlockchainAdap(this, arrayList);
listView.setAdapter(adap);
}
public static void updateList(Block b){
arrayList.add(b);
adap.swap(arrayList);
}
In FirebaseMessagingService
#Override
public void onMessageReceived(final RemoteMessage remoteMessage) {
Gson gson = new Gson();
Block b = gson.fromJson(remoteMessage.getData().get("transaction"), Block.class);
OpenChain.updateList(b);
}
Also, expose a method in your ** BlockchainAdap** for swap.
class BlockchainAdap {
ArrayList<Block> arrayList;
BlockchainAdap(ArrayList<Block> arrayList){
this.arrayList = arrayList;
}
public void swap(ArrayList<Block> arrayList){
this.arrayList = arrayList;
notifydatasetChanged();
}
// other methods
}
This will work, but use
LocalBroadcastReceiver from messaging service to OpenChain activity.
Use RecyclerView instead of ListView.
Related
I wanna add items to my list but it only shows the first one:
public class MainActivity extends Activity {
Server server;
TextView infoip, msg;
TextView usersTitle;
String[] array = {"a"};
ArrayList<String> lst;
ArrayAdapter<String> adapter;
ListView userList;
#Override
public void onCreate(Bundle savedInstanceState) {
lst = new ArrayList<String>(Arrays.asList(array));
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, lst);
userList = (ListView) findViewById(R.id.userList);
userList.setAdapter(adapter);
From this other class method, everytime it is called I want the text to go below the first one. The method certainly runs but it does not put the text below the previous one. It just shows "a"! Anyone knows why?
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
activity.lst.add(message);
activity.adapter.notifyDataSetChanged();
}
});
I have also tried:
adapter.insert(String, int);
lst.add(int, String);
And even added in the onCreate method this:
lst.add(1, "2");
adapter.notifyDataSetChanged();
And still doesnt add the "2"!!
If you are adding items to Arraylist from another class ,you have to declare your Arraylist Static.So that it can hold items in memory.
Replace ArrayList lst with public static ArrayList
Here is the solution to your Problem.I have created an Activity class and Tests java class.
public class MainActivity extends Activity {
String[] array = {"a"};
public static ArrayList<String> lst;
ArrayAdapter<String> adapter;
ListView userList;
Tests tests = new Tests();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
userList = (ListView) findViewById(R.id.userList);
lst = new ArrayList<String>(Arrays.asList(array));
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, lst);
userList.setAdapter(adapter);
tests.callThread();
}
}
Here is the Tests.java Class
public class Tests {
int i = 0;
String message = "";
Thread runOnUiThread;
public void callThread()
{
new Thread(new Runnable() {
#Override
public void run() {
try {
while (i < 10) {
i = i + 1;
message = String.valueOf(i);
//Create a server socket object and bind it to a port
MainActivity.lst.add(message);
}
}catch(Exception e){
e.printStackTrace();
}
}
}).start();
}
}
Just call your service inside this thread where I have incremented variable i and by this way you can populate the list in right order.
Can you tell whether the other class is Activity or Fragment ?
And while adding the data into Arraylist, you don't need the Thread to be run in order to insert new data to Arraylist
Try to make "lst" and "adapter" both static.
I'm suspicious about the runOnUiThread. Can you provide more information why did you use this function? Also i highly recommend using RecyclerView
Also you can refer to this post for adding items to RecyclerView
I want to declare arrayList into this line:
public class tlcity extends Activity {
//ArrayList<String> idArray = null;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
....
and into the other method,for example this method:
protected void onPostExecute(String result) {
//fill the arraylist
...
and into the other method for example this method read arraylist data:
public void readlist(){
//read the arraylist data and show
}
How can i do this?
You can declare ArrayList like this
ArrayList<String> list;
list = new ArrayList<String>();
You can add, remove items in ArrayList Like this
list.add("A");
list.remove(0);
ArrayList<String> abc=new ArrayList<String>();
You can initialize or create an instance of your array list like this
idArray = new ArrayList();
You can perform any operations to it using idArray object.
For example you can add items like this
idArray.add("item1");//In you case its a list of strings.
In the same way you would do that in another Java app / class:
public class tlcity extends Activity {
List<String> idArray;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
idArray = new ArrayList<String>();
}
protected void onPostExecute(String result) {
idArray.add("One");
idArray.add("Two");
idArray.add("Three");
...
}
public void readlist(){
for (final String element : idArray) {
// Use the nth string
}
}
I want to declare arrayList into this line:
ArrayList<String> myList;
and into the other method,for example this method:
myList = new ArrayList<String>;
and into the other method for example this method read arraylist data:
for(int i=0; i<myList.size(); i++)
System.out.println(myList.get(i).toString());
If you want to use ArrayList locally then declare it locally. if you want to use it in all methods then declare it globally in class.
public class tlcity extends Activity {
ArrayList<String> idArray = new ArrayList<>(); // to Use this arraylist globally.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ArrayList<String> localaraaylist = new ArrayList<>(); //to use arraylist in only in oncreate method.
....
According to your post, telling how to declae ArrayList will not enough as you have some methods like onPreExecute() which is a method ofAsyncTask Interface.
Look at this,
public class MainActivity extends ActionBarActivity {
ArrayList<String> arrayList; // declaring ArrayList here
ArrayAdapter<String> adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
arrayList = new ArrayList<String>(); // Initializing arrayList
arrayList.add("initial text"); // adding a data to arrayList
ListView listView = (ListView)findViewById(R.id.listView);
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,arrayList); // setting the arrayList in ArrayAdapter
listView.setAdapter(adapter);
new LongOperation().execute(); // async Task
}
private class LongOperation extends AsyncTask<Void, Void, Void> {
ProgressDialog progressDialog = new ProgressDialog(MainActivity.this);
// progress dialog starts here
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog.setMessage("Loading...");
progressDialog.show();
}
#Override
protected Void doInBackground(Void... voids) {
// for understanding purpose, i made a thread to sleep for 5 sec and later it will add A,B & C to ArrayList.
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// adding few more items to arrayList
arrayList.add("A");
arrayList.add("B");
arrayList.add("C");
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
progressDialog.dismiss(); // dismissing the progress Dialog
adapter.notifyDataSetChanged(); // refreshing listview
readA(); // read the arrayList
}
}
public void readA()
{
for (int i = 0; i<arrayList.size(); i++)
{
Log.d("key",arrayList.get(i));
}
}
}
Output :
If you run the above code, Initially your list view will only contain only one item & after 5 sec loading it will add another 3 items. The below information will print in logcat that reads the ArrayList.
04-13 14:07:32.395 1123-1123/? D/key﹕ initial text
04-13 14:07:32.395 1123-1123/? D/key﹕ A
04-13 14:07:32.395 1123-1123/? D/key﹕ B
04-13 14:07:32.395 1123-1123/? D/key﹕ C
I am programming a messaging app and I want to add users in a group. However, when a list of users pops up and I select one from the list, it doesn't pass the string (the username) to the other activity. All I get is an empty list.
Here is my code:
First Activity = Sending data (usernames from list) through putExtra()
public class ListUsersActivity extends Activity {
private String currentUserId;
private ArrayAdapter<String> namesArrayAdapter;
private ArrayList<String> names;
private ListView usersListView;
private Button logoutButton;
private ProgressDialog progressDialog;
private BroadcastReceiver receiver = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_users);
Parse.initialize(this, "embpZ0spRUv5XwDgI23innll1sgHg0KZNiKzg6kl", "LPsU4UffPeqFXkQB1GfLCIJ4kvg20llPgbOnLise");
currentUserId = ParseUser.getCurrentUser().getObjectId();
names = new ArrayList<>();
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.whereNotEqualTo("objectId", currentUserId);
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> userList, com.parse.ParseException e) {
if (e == null) {
for (int i=0; i<userList.size(); i++) {
names.add(userList.get(i).getUsername().toString());
}
usersListView = (ListView)findViewById(R.id.usersListView);
namesArrayAdapter =
new ArrayAdapter<String>(getApplicationContext(),
R.layout.user_list_item, names);
usersListView.setAdapter(namesArrayAdapter);
usersListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> a, View v, int i, long l) {
Intent goBackToAddPoolIntent = new Intent(ListUsersActivity.this, addNewPoolActivity.class);
addNewPoolActivity checker = new addNewPoolActivity();
checker.checkIfUserIsSelected(usersListView.getItemAtPosition(i).toString());
goBackToAddPoolIntent.putExtra("username", usersListView.getItemAtPosition(i).toString());
startActivity(goBackToAddPoolIntent);
}
});
} else {
Toast.makeText(getApplicationContext(),
"Error loading user list",
Toast.LENGTH_LONG).show();
}
}
});
}
Second Activity = Receiving data from putExtra()
public class addNewPoolActivity extends Activity {
private static ArrayList<String> addedUsers;
private ArrayAdapter <String> addedUserAdapter;
private boolean userIsSelected;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_new_pool);
Button addMembers = (Button) findViewById(R.id.bAddMembers);
addedUsers = new ArrayList<>();
//addedUsers.add("Group Members");
addMembers.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent showUsersToSelect = new Intent(addNewPoolActivity.this, ListUsersActivity.class);
startActivity(showUsersToSelect);
}
});
ListView addedUsersList = (ListView) findViewById(R.id.addedUsersListView);
addedUserAdapter = new ArrayAdapter<>(this, R.layout.user_list_item, addedUsers);
addedUsersList.setAdapter(addedUserAdapter);
if(userIsSelected){
Bundle extras = getIntent().getExtras();
addedUsers.add(extras.getString("username"));
}
}
public void checkIfUserIsSelected(String user){
if (user!=null){
userIsSelected = true;
}else{
userIsSelected = false;
}
}
Since the default value for a boolean is false, the code is never called because
if(userIsSelected){
will always evaluate to false since you have declared the varaible as
private boolean userIsSelected;
and the first snippet here is in onCreate() so it will only run the first time the Activity is created.
Maybe you are wanting to call checkIfUserIsSelected(someUser) before that code but without more context of what you hope to accomplish, it's hard to say.
Possibly, you want to use startActivityForResult() in some way?
In addition to #codeMagic 's answer (Since your boolean value is false, it won't call the statement that you are adding the new data). It's also because of you parse the Data "username" after you setAdapter of your ListView. So basically you are setting the data, and then trying to add the new data you parsed to the list. Either you need to do it before setting your data set to your adapter, or call addedUsersAdapter.notifyDataSetChanged() to refresh your listView's data set.
addedUserAdapter = new ArrayAdapter<>(this, R.layout.user_list_item, addedUsers);
addedUsersList.setAdapter(addedUserAdapter);
Bundle extras = getIntent().getExtras();
// Check if the username has been sent to this Activity.
if(extras != null && extras.containsKey("username")){
addedUsers.add(extras.getString("username"));
// Refresh Your Data Set
addedUserAdapter.notifyDataSetChanged();
}
I have two classes,HomeActivity and CustomListAdapter.THe HomeActivity class extends an activity and then updates a listview.I am populating the data to the listview using a CustomListAdapter class which extends BaseAsapter.Everything is working fine but i want to load the data in a background task.When i do that,an error comes up.
Here is my implementation of the onPostExecute of the AyncTask class.
#Override
protected void onPostExecute(HomeActivity Params){
progressDialog.dismiss();
runOnUiThread(new Runnable(){
public void run(){
final ListView lv1 = (ListView) findViewById(R.id.listings);
lv1.setAdapter(new CustomListAdapter(this, shares));
}
});
}
I get an error telling me that i should change the constructor on CustomListAdapter.But when i change it,everything goes downhill.
I have tried this unsuccessfully too
final ListView lv1 = (ListView) findViewById(R.id.listings);
lv1.setAdapter(new CustomListAdapter(this, shares));
shares is an arraylist of data from the web service.
Here is the constructor in the CustomListAdapter class
public CustomListAdapter(Context context, ArrayList listData) {
this.listData = listData;
layoutInflater = LayoutInflater.from(context);
}
How can go about it?Help will be highly appreciated.
You have to change :
#Override
protected void onPostExecute(HomeActivity Params){
progressDialog.dismiss();
runOnUiThread(new Runnable(){
public void run(){
final ListView lv1 = (ListView) findViewById(R.id.listings);
lv1.setAdapter(new CustomListAdapter(YourActivity.this, shares));
}
});
}
See the below code works for me
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
progressDilaog.dismiss();
itemListAdapter = new ItemListBaseAdapter(
IncidentListActivity.this, Util.arrIncidents);
gridView.setAdapter(itemListAdapter);
}
And one more thing, you don't require runOnUiThread in onPostExecute method. You can directly change your listview.
You are sending your AsyncTask context to your Adapter , you should put your Activity context which hosts your Listview to your AsyncTask class then use that Context to construct your Adapter.
Edit : look at this as an example and onPostExecute by default runs on Ui thread and it doesn't need to define a runOnUiThread
public class SyncHandler extends AsyncTask<String, Void, ResponseType>{
private Activity activity;
public SyncHandler (Activity activity)
{
this.activity = activity;
}
then in your calling Activity pass the Activity context to your Async class :
new SyncHandler(this).execute();
I'm using SherlockListFragment(whichis the same as ListFragment) for displaying sms conversation list
Here is the code
public static class TitlesFragment extends SherlockListFragment
{
static ConversationAdapter adapter;
static List<String> msgList;
static Activity activity;
static ListView listView;
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
DataGetters dataGetters = new DataGetters();
activity = getActivity();
msgList = dataGetters.getCONVERSATIONS(activity.getApplicationContext());
adapter = new ConversationAdapter(activity, msgList);
setListAdapter(adapter);
}
Code above prints all current sms conversations
like this:
I'm refreshing adapter from code below by calling adapter.notifyDataSetChanged(); witch is called when new sms is received
public class ReceiverClass extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
Thread.sleep(2000);
return null;
}
#Override
protected void onPostExecute(String result) {
TitlesFragment.adapter.notifyDataSetChanged();
}
But fallowing code overides existing list view items insted of adding new list item position like this:
When i activity is recreated i get what i want but only then: example:
You are most likely incorrectly modifying the List that the ListAdapter is attached to.
So the problem was not me not modifiy adpater list with new position
Here is the code that neded to be added
msgList= dataGetters.getCONVERSATIONS(activity.getApplicationContext());
ConversationAdapter.msgList = msgList;
TitlesFragment.adapter.notifyDataSetChanged();
Solved thanks to Mark Nguyen