Android textview wont update outside oncreate

Android textview wont update outside oncreate - java

I have an text view (Text1) that updates fine when i set the text in the oncreate but when i try to update it in the onEvent method it doesn't update I have searched similar posts but cant narrow down whats causing my specific problem
public class MainActivity extends Activity implements ProximityManager.ProximityListener {
private static final String TAG = MainActivity.class.getSimpleName();
private ProximityManagerContract proximityManager;
private ScanContext scanContext;
private TextView Text1;
private TextView Text2;
private TextView Text3;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
KontaktSDK.initialize("").setDebugLoggingEnabled(BuildConfig.DEBUG)
.setLogLevelEnabled(LogLevel.DEBUG, true);
;
proximityManager = new KontaktProximityManager(this);
Text1 = (TextView) findViewById(R.id.textView);
Text2 = (TextView) findViewById(R.id.textView2);
}
#Override
protected void onStart() {
super.onStart();
proximityManager.initializeScan(getScanContext(), new OnServiceReadyListener() {
#Override
public void onServiceReady() {
proximityManager.attachListener(MainActivity.this);
EddystoneScanContext eddystoneScanContext = new EddystoneScanContext.Builder()
.setEventTypes(Arrays.asList(
EventType.SPACE_ENTERED,
EventType.DEVICES_UPDATE,
EventType.SPACE_ABANDONED))
.build();
ScanContext scanContext = new ScanContext.Builder()
.setEddystoneScanContext(eddystoneScanContext)
.build();
}
#Override
public void onConnectionFailure() {
}
});
}
#Override
protected void onStop() {
super.onStop();
proximityManager.detachListener(this);
proximityManager.disconnect();
}
#Override
public void onEvent(BluetoothDeviceEvent bluetoothDeviceEvent) {
final List<? extends RemoteBluetoothDevice> deviceList = bluetoothDeviceEvent.getDeviceList();
long timestamp = bluetoothDeviceEvent.getTimestamp();
DeviceProfile deviceProfile = bluetoothDeviceEvent.getDeviceProfile();
switch (bluetoothDeviceEvent.getEventType()) {
case SPACE_ENTERED:
Log.d(TAG, "namespace or region entered");
break;
case DEVICE_DISCOVERED:
Log.d(TAG, "found new beacon");
break;
case DEVICES_UPDATE:
Log.d(TAG, "updated beacons");
Log.d("Scan", String.valueOf(deviceProfile.toString()));
Log.d("List", deviceList.toString());
//Log.d("List", deviceProfile.name(deviceList.get(1)));
Log.d("distance", String.valueOf(deviceList.get(1).getDistance()));
Text1.setText("Is Updated");
break;
case DEVICE_LOST:
Log.d(TAG, "lost device");
break;
case SPACE_ABANDONED:
Log.d(TAG, "namespace or region abandoned");
break;
}
}
#Override
public void onScanStart() {
Log.d(TAG, "scan started");
}
#Override
public void onScanStop() {
Log.d(TAG, "scan stopped");
}
private ScanContext getScanContext() {
if (scanContext == null) {
scanContext = new ScanContext.Builder()
.setScanPeriod(ScanPeriod.RANGING) // or for monitoring for 15 seconds scan and 10 seconds waiting:
//.setScanPeriod(new ScanPeriod(TimeUnit.SECONDS.toMillis(15), TimeUnit.SECONDS.toMillis(10)))
.setScanMode(ProximityManager.SCAN_MODE_LOW_LATENCY)
.setActivityCheckConfiguration(ActivityCheckConfiguration.MINIMAL)
.setForceScanConfiguration(ForceScanConfiguration.MINIMAL)
.setIBeaconScanContext(new IBeaconScanContext.Builder().build())
.setEddystoneScanContext(new EddystoneScanContext.Builder().build())
.setForceScanConfiguration(ForceScanConfiguration.MINIMAL)
.build();
}
return scanContext;
}
}

You cannot update view outside the main thread (UI thread). Try to wrap your method with runOnUiThread.
runOnUiThread(new Runnable() {
public void run() {
Text1.setText("Is Updated");
}
});

new Handler(new Runnable() {
public void run() {
Text1.setText("Is Updated");
}
});
you have to use Handler or runOnUIThread because you cant edit on a component in main thread from outside

Related

How to reconnect MQTT with this program?

I'm have some project, realtime sending RSSI and MAC of Bluetooth Low Energy.
I've seen questions regarding MQTT reconnecting. But I'm confused when it is applied to my origin code.
MainActivity.Java
public class MainActivity extends AppCompatActivity {
private Button turnon, changeLayout;
MqttAndroidClient client;
private boolean state=false;
private BluetoothAdapter bluetoothAdapter;
public static final int REQUEST_ACCESS_COARSE_LOCATION = 1;
public static final int REQUEST_ENABLE_BLUETOOTH = 11;
public static String mqtt_server,mqtt_port,mqtt_id,mqtt_topic;
private TextView textView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
setContentView(R.layout.activity_main);
Log.d("Logger", "On Create Android");
turnon = findViewById(R.id.turnon);
changeLayout = findViewById(R.id.mqttSet);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
textView = findViewById(R.id.textView4);
textView.setText("id "+mqtt_id+" port "+mqtt_port+" server "+mqtt_server);
client = new MqttAndroidClient(this.getApplicationContext(), "tcp://"+mqtt_server+":"+mqtt_port,mqtt_id);
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
stateCheck();
Log.d("Logger", "State Check");
handler.postDelayed(this, 1000);
}
}, 1000);
turnon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!state){
turnon.setText("Turn Off");
Log.d("Logger", "Turn On State");
if(mqtt_server!=null||mqtt_id!=null||mqtt_port!=null||mqtt_topic!=null){
try {
Log.d("Logger", "Try ");
IMqttToken token = client.connect();
token.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.d("Logger", "Connect MQTT");
Toast.makeText(MainActivity.this,"connected!!",Toast.LENGTH_LONG).show();
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.d("Logger", "Connect Failed");
Toast.makeText(MainActivity.this,"connection failed!!",Toast.LENGTH_LONG).show();
}
});
} catch (MqttException e) {
e.printStackTrace();
Log.d("Logger", "error"+e);
}}
state = true;
}else{
turnon.setText("Turn On");
state = false;
}
}
});
changeLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(MainActivity.this,MqttActivity.class));
}
});
}
public void stateCheck(){
if (state){
Log.d("Logger", "Discover");
}
}
}
The code I made has not been able to reconnect when my server restarts.
Can anyone help me? But I'm asking for help with indicating which code I should change. Thanks

App crash when calling a method after a delay

I am trying to execute the doit() method in OnCreate, waiting for 5 seconds to allow for the method's functionality to fully load and then call the tester() method within the wait function.
The app functions properly without the delay and displays 'TextView' which is the output of the textbox before the function has finished, I would like to wait for 5 seconds until doit() has finished loading and then display the contents of texx from the tester() after the wait. Any help would be appreciated.
Images linked below is a crash output and the app working.
Crash output
App working without delay, but doesn't output textbox content because it hasn't loaded
public class AppHome extends AppCompatActivity implements PopupMenu.OnMenuItemClickListener {
TextView texx;
private ArrayList<String> al;
private ArrayAdapter<String> arrayAdapter;
private int i;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_app_home);
new doit().execute();
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
tester();
}
}, 5000);
}
public void tester() {
texx = findViewById(R.id.text1);
String text = texx.getText().toString();
//String num = text;
String[] str = text.split(",");
final ArrayList al = new ArrayList<String>(Arrays.asList(str));
arrayAdapter = new ArrayAdapter<>(this, R.layout.item, R.id.helloText, al);
SwipeFlingAdapterView flingContainer = findViewById(R.id.frame);
registerForContextMenu(flingContainer);
flingContainer.setAdapter(arrayAdapter);
flingContainer.setFlingListener(new SwipeFlingAdapterView.onFlingListener() {
#Override
public void removeFirstObjectInAdapter() {
// this is the simplest way to delete an object from the Adapter (/AdapterView)
Log.d("LIST", "removed object!");
al.remove(0);
arrayAdapter.notifyDataSetChanged();
}
#Override
public void onLeftCardExit(Object dataObject) {
//Do something on the left!
//You also have access to the original object.
//If you want to use it just cast it (String) dataObject
Toast.makeText(AppHome.this, "left", Toast.LENGTH_SHORT).show();
}
#Override
public void onRightCardExit(Object dataObject) {
Toast.makeText(AppHome.this, "right", Toast.LENGTH_SHORT).show();
}
#Override
public void onAdapterAboutToEmpty(int itemsInAdapter) {
// Ask for more data here
al.add("XML ".concat(String.valueOf(i)));
arrayAdapter.notifyDataSetChanged();
Log.d("LIST", "notified");
i++;
}
#Override
public void onScroll(float scrollProgressPercent) {
}
});
// Optionally add an OnItemClickListener
/*
flingContainer.setOnItemClickListener(new SwipeFlingAdapterView.OnItemClickListener() {
#Override
public void onItemClicked(int itemPosition, Object dataObject) {
}
});
*/
}
public class doit extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... voids) {
String words = "";
try {
Document doc = Jsoup.connect("https://screenscrape4top40.000webhostapp.com/").get();
words = doc.text();
} catch (Exception e) {
e.printStackTrace();
}
return words;
}
#Override
public void onPostExecute(String words) {
super.onPostExecute(words);
texx.setText(words);
}
}
public void showPopup (View v){
PopupMenu popup = new PopupMenu(this, v);
popup.setOnMenuItemClickListener(this);
popup.inflate(R.menu.dropdown_menu1);
popup.show();
}
#Override
public boolean onMenuItemClick (MenuItem item){
switch (item.getItemId()) {
case R.id.item1:
Toast.makeText(this, "Item 1 clicked", Toast.LENGTH_SHORT).show();
return true;
case R.id.item2:
Toast.makeText(this, "Item 2 clicked", Toast.LENGTH_SHORT).show();
return true;
case R.id.item3:
Toast.makeText(this, "Item 3 clicked", Toast.LENGTH_SHORT).show();
return true;
case R.id.item4:
Toast.makeText(this, "Item 4 clicked", Toast.LENGTH_SHORT).show();
return true;
default:
return false;
}
}
}

move following line in onCreate(), after setContentView() :
texx = findViewById(R.id.text1);

Convert Activity to Fragment which use Database and Adapter class

I'm loading json file from online and saving it on Sqlite such that when app is offline...Then still user will be able to see the data.
It works fine in MainActivity.
But when I try to covert it into fragment, I'm getting errors of Fragment cannot be cast in to FlowerAdapter$FlowerClickListener
Here is the error file
My Fragment name is nepali.
Here is the Mainactivity
public class MainActivity extends AppCompatActivity implements FlowerAdapter.FlowerClickListener, FlowerFetchListener {
private static final String TAG = MainActivity.class.getSimpleName();
private RecyclerView mRecyclerView;
private RestManager mManager;
private FlowerAdapter mFlowerAdapter;
private FlowerDatabase mDatabase;
private Button mReload;
private ProgressDialog mDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
configViews();
mManager = new RestManager();
mDatabase = new FlowerDatabase(this);
loadFlowerFeed();
mReload.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loadFlowerFeed();
}
});
}
private void loadFlowerFeed() {
mDialog = new ProgressDialog(MainActivity.this);
mDialog.setMessage("Loading Flower Data...");
mDialog.setCancelable(true);
mDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mDialog.setIndeterminate(true);
mFlowerAdapter.reset();
mDialog.show();
if (getNetworkAvailability()) {
getFeed();
} else {
getFeedFromDatabase();
}
}
private void getFeedFromDatabase() {
mDatabase.fetchFlowers(this);
}
private void configViews() {
mReload = (Button) findViewById(R.id.reload);
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setRecycledViewPool(new RecyclerView.RecycledViewPool());
mRecyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext(), LinearLayoutManager.VERTICAL, false));
mFlowerAdapter = new FlowerAdapter(this);
mRecyclerView.setAdapter(mFlowerAdapter);
}
#Override
public void onClick(int position) {
}
public void getFeed() {
Call<List<Flower>> listCall = mManager.getFlowerService().getAllFlowers();
listCall.enqueue(new Callback<List<Flower>>() {
#Override
public void onResponse(Call<List<Flower>> call, Response<List<Flower>> response) {
if (response.isSuccessful()) {
List<Flower> flowerList = response.body();
for (int i = 0; i < flowerList.size(); i++) {
Flower flower = flowerList.get(i);
SaveIntoDatabase task = new SaveIntoDatabase();
task.execute(flower);
mFlowerAdapter.addFlower(flower);
}
} else {
int sc = response.code();
switch (sc) {
case 400:
Log.e("Error 400", "Bad Request");
break;
case 404:
Log.e("Error 404", "Not Found");
break;
default:
Log.e("Error", "Generic Error");
}
}
mDialog.dismiss();
}
#Override
public void onFailure(Call<List<Flower>> call, Throwable t) {
mDialog.dismiss();
Toast.makeText(getApplicationContext(), t.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
public boolean getNetworkAvailability() {
return Utils.isNetworkAvailable(getApplicationContext());
}
#Override
public void onDeliverAllFlowers(List<Flower> flowers) {
}
#Override
public void onDeliverFlower(Flower flower) {
mFlowerAdapter.addFlower(flower);
}
#Override
public void onHideDialog() {
mDialog.dismiss();
}
public class SaveIntoDatabase extends AsyncTask<Flower, Void, Void> {
private final String TAG = SaveIntoDatabase.class.getSimpleName();
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Flower... params) {
Flower flower = params[0];
try {
} catch (Exception e) {
Log.d(TAG, e.getMessage());
}
return null;
}
}
}
and FlowerDatabase class is
public class FlowerDatabase extends SQLiteOpenHelper {
private static final String TAG = FlowerDatabase.class.getSimpleName();
public FlowerDatabase(Context context) {
super(context, Constants.DATABASE.DB_NAME, null, Constants.DATABASE.DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(Constants.DATABASE.CREATE_TABLE_QUERY);
} catch (SQLException ex) {
Log.d(TAG, ex.getMessage());
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL(Constants.DATABASE.DROP_QUERY);
this.onCreate(db);
}
public void addFlower(Flower flower) {
Log.d(TAG, "Values Got " + flower.getName());
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(Constants.DATABASE.PRODUCT_ID, flower.getProductId());
values.put(Constants.DATABASE.CATEGORY, flower.getCategory());
values.put(Constants.DATABASE.PRICE, Double.toString(flower.getPrice()));
values.put(Constants.DATABASE.INSTRUCTIONS, flower.getInstructions());
values.put(Constants.DATABASE.NAME, flower.getName());
try {
db.insert(Constants.DATABASE.TABLE_NAME, null, values);
} catch (Exception e) {
}
db.close();
}
public void fetchFlowers(FlowerFetchListener listener) {
FlowerFetcher fetcher = new FlowerFetcher(listener, this.getWritableDatabase());
fetcher.start();
}
public class FlowerFetcher extends Thread {
private final FlowerFetchListener mListener;
private final SQLiteDatabase mDb;
public FlowerFetcher(FlowerFetchListener listener, SQLiteDatabase db) {
mListener = listener;
mDb = db;
}
#Override
public void run() {
Cursor cursor = mDb.rawQuery(Constants.DATABASE.GET_FLOWERS_QUERY, null);
final List<Flower> flowerList = new ArrayList<>();
if (cursor.getCount() > 0) {
if (cursor.moveToFirst()) {
do {
Flower flower = new Flower();
flower.setFromDatabase(true);
flower.setName(cursor.getString(cursor.getColumnIndex(Constants.DATABASE.NAME)));
flower.setPrice(Double.parseDouble(cursor.getString(cursor.getColumnIndex(Constants.DATABASE.PRICE))));
flower.setInstructions(cursor.getString(cursor.getColumnIndex(Constants.DATABASE.INSTRUCTIONS)));
flower.setCategory(cursor.getString(cursor.getColumnIndex(Constants.DATABASE.CATEGORY)));
flower.setProductId(Integer.parseInt(cursor.getString(cursor.getColumnIndex(Constants.DATABASE.PRODUCT_ID))));
flowerList.add(flower);
publishFlower(flower);
} while (cursor.moveToNext());
}
}
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
#Override
public void run() {
mListener.onDeliverAllFlowers(flowerList);
mListener.onHideDialog();
}
});
}
public void publishFlower(final Flower flower) {
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
#Override
public void run() {
mListener.onDeliverFlower(flower);
}
});
}
}
}
and FlowerAdapter Class is
public class FlowerAdapter extends RecyclerView.Adapter<FlowerAdapter.Holder> {
private static final String TAG = FlowerAdapter.class.getSimpleName();
private final FlowerClickListener mListener;
private List<Flower> mFlowers;
public FlowerAdapter(FlowerClickListener listener) {
mFlowers = new ArrayList<>();
mListener = listener;
}
#Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
View row = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_item, null, false);
return new Holder(row);
}
#Override
public void onBindViewHolder(Holder holder, int position) {
Flower currFlower = mFlowers.get(position);
holder.mName.setText(currFlower.getName());
holder.minstruction.setText(currFlower.getInstructions());
}
#Override
public int getItemCount() {
return mFlowers.size();
}
public void addFlower(Flower flower) {
mFlowers.add(flower);
notifyDataSetChanged();
}
/**
* #param position
* #return
*/
public Flower getSelectedFlower(int position) {
return mFlowers.get(position);
}
public void reset() {
mFlowers.clear();
notifyDataSetChanged();
}
public class Holder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView mName, minstruction;
public Holder(View itemView) {
super(itemView);
mName = (TextView) itemView.findViewById(R.id.flowerName);
minstruction = (TextView) itemView.findViewById(R.id.flowerPrice);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
mListener.onClick(getLayoutPosition());
}
}
public interface FlowerClickListener {
void onClick(int position);
}
}
My fragment class is that I try to convert above Mainactivity code into Frament class is
public class nepali extends Fragment {
private static final String TAG = nepali.class.getSimpleName();
private RecyclerView mRecyclerView;
private RestManager mManager;
private FlowerAdapter mFlowerAdapter;
private FlowerDatabase mDatabase;
private Button mReload;
private ProgressDialog mDialog;
View view;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.activity_data, container, false);
configViews();
mManager = new RestManager();
mDatabase = new FlowerDatabase(getActivity());
loadFlowerFeed();
mReload.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loadFlowerFeed();
}
});
return view;
}
private void loadFlowerFeed() {
mDialog = new ProgressDialog(getActivity());
mDialog.setMessage("Loading Flower Data...");
mDialog.setCancelable(true);
mDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mDialog.setIndeterminate(true);
mFlowerAdapter.reset();
mDialog.show();
if (getNetworkAvailability()) {
getFeed();
} else {
getFeedFromDatabase();
}
}
private void getFeedFromDatabase() {
mDatabase.fetchFlowers(this);
}
private void configViews() {
mReload = (Button) view.findViewById(R.id.reload);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setRecycledViewPool(new RecyclerView.RecycledViewPool());
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));
mFlowerAdapter = new FlowerAdapter((FlowerAdapter.FlowerClickListener) this);;
mRecyclerView.setAdapter(mFlowerAdapter);
}
public void getFeed() {
Call<List<Flower>> listCall = mManager.getFlowerService().getAllFlowers();
listCall.enqueue(new Callback<List<Flower>>() {
#Override
public void onResponse(Call<List<Flower>> call, Response<List<Flower>> response) {
if (response.isSuccessful()) {
List<Flower> flowerList = response.body();
for (int i = 0; i < flowerList.size(); i++) {
Flower flower = flowerList.get(i);
SaveIntoDatabase task = new SaveIntoDatabase();
task.execute(flower);
mFlowerAdapter.addFlower(flower);
}
} else {
int sc = response.code();
switch (sc) {
case 400:
Log.e("Error 400", "Bad Request");
break;
case 404:
Log.e("Error 404", "Not Found");
break;
default:
Log.e("Error", "Generic Error");
}
}
mDialog.dismiss();
}
#Override
public void onFailure(Call<List<Flower>> call, Throwable t) {
mDialog.dismiss();
Toast.makeText(getActivity(), t.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
public boolean getNetworkAvailability() {
return Utils.isNetworkAvailable(getActivity());
}
public void onDeliverFlower(Flower flower) {
mFlowerAdapter.addFlower(flower);
}
public void onHideDialog() {
mDialog.dismiss();
}
public class SaveIntoDatabase extends AsyncTask<Flower, Void, Void> {
private final String TAG = SaveIntoDatabase.class.getSimpleName();
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Flower... params) {
Flower flower = params[0];
try {
} catch (Exception e) {
Log.d(TAG, e.getMessage());
}
return null;
}
}
}
Lastly the FlowerService class is
public interface FlowerService {
#GET("/routine/first.json")
Call<List<Flower>> getAllFlowers();
}
and FlowerFetchListener Class is
public interface FlowerFetchListener {
void onDeliverAllFlowers(List<Flower> flowers);
void onDeliverFlower(Flower flower);
void onHideDialog();
}
Please Help....and Thanks in advance.

You should not call db and network from activity or fragment. Try to learn MVVM architecture and use ViewModel to store the data from db or network. You may put a lot of effort making your app work but it will still lead to crashes (especially after you introduce fragment and call db and API from there). You will need to handle your data state during configuration changes. Listen to this talk and start writing clean code https://m.youtube.com/watch?v=5qlIPTDE274
The error you get is because you pass wrong parameter into adapter constructor ‘new FlowerAdapter((FlowerAdapter.FlowerClickListener) this)’. If you want to pass a listener to the adapter you need to pass the class which implements the listener: either activity - then pass getActivity(), or fragment ‘this’ - then make fragment implement implements FlowerAdapter.FlowerClickListener.Be aware that it can be null when fragment is not attached to activity, eg configuration change.

Updating main thread from new Runnable class [duplicate]

This question already has answers here:
Running code in main thread from another thread
(17 answers)
Closed 5 years ago.
I'm trying to dynamically update an android LinearLayout in the main thread.
Unfortunately I'm having a lot of trouble ascertaining anything from the tutorials online. None of them seem to provide a complete picture of how to communicate between threads.
My idea is something like this:
public class MainActivity extends AppCompatActivity {
private LinearLayout layout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
layout = new LinearLayout(this);
setContentView(layout);
Updater updater = new Updater();
Thread workerThread = new Thread(updater);
//somehow update layout
The updater class would look something like this:
public class Updater implements Runnable {
private int count = 0;
public Updater() {}
#Override
public void run()
{
for (int i = 0; i < 10; i ++){
try {
count++;
TimeUnit.SECONDS.sleep(3);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
I know I need a Handler in order to communicate messages between the threads, but I don't know how to set that up.
I would like to avoid anonymous classes, and dynamically create new TextViews whenever Updater has a new message.

create WorkerThreadListener interface:
public interface WorkerThreadListener {
void onUpdate(int counter);
}
Change your Updater class:
public class Updater implements Runnable {
private final WorkerThreadListener mWorkerThreadListener;
private final Handler mHandler;
private int count = 0;
public Updater(final WorkerThreadListener workerThreadListener) {
this.mWorkerThreadListener = workerThreadListener;
this.mHandler = new Handler();
}
#Override
public void run() {
for (int i = 0; i < 10; i++) {
try {
count++;
mHandler.post(new Runnable() {
#Override
public void run() {
mWorkerThreadListener.onUpdate(count);
}
});
TimeUnit.SECONDS.sleep(3);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
Change MainActivity class:
public class MainActivity extends AppCompatActivity {
private LinearLayout layout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
layout = new LinearLayout(this);
setContentView(layout);
Updater updater = new Updater(new WorkerThreadListener() {
#Override
public void onUpdate(int counter) {
//update layout here
}
});
Thread workerThread = new Thread(updater);
workerThread.start();
}
}

Hi please check my below answer hope it helps you.
public class ProgressTestActivity extends Activity {
private ProgressBar progress;
private TextView text;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
progress = (ProgressBar) findViewById(R.id.progressBar1);
text = (TextView) findViewById(R.id.textView1);
}
public void startProgress(View view) {
// do something long
Runnable runnable = new Runnable() {
#Override
public void run() {
for (int i = 0; i <= 10; i++) {
final int value = i;
doFakeWork();
progress.post(new Runnable() {
#Override
public void run() {
// here you can add any view or anyof your logic which is related to UI put it into here.
text.setText("Updating");
progress.setProgress(value);
}
});
}
}
};
new Thread(runnable).start();
}
// Simulating something timeconsuming
private void doFakeWork() {
SystemClock.sleep(5000);e.printStackTrace();
}
}
Other ways are also possible.if you have any doubt please comment below post i will explain you in details.

If you just want to use a tick timer and set progress to ui thread . You can use CountDownTimer.
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private TextView textView;
private CountDownTimer countDownTimer;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new);
textView = (TextView) findViewById(R.id.textView);
findViewById(R.id.b2).setOnClickListener(this);
}
public void processData() {
countDownTimer = new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
textView.setText("seconds remaining: " + millisUntilFinished / 1000);
}
public void onFinish() {
textView.setText("done!");
}
}.start();
}
#Override
protected void onStop() {
super.onStop();
if (countDownTimer != null) {
countDownTimer.cancel();
}
}
#Override
public void onClick(View v) {
processData();
}
}
Apart from that to post a callback on UI thread you can use Handler .
Handler mainThreadHandler = new Handler(Looper.getMainLooper());
mainThreadHandler.post(new Runnable() {
#Override
public void run() {
}
});

Error with Twitter4J from Android with browser user authentication: No authentication challenges found

I am trying to develop my own Android application using Android Studio 0.4.2 and the Twitter4J library. My idea is to use a WebView to load there the Twitter authentication page and get the AccessToken from there. I can get the oauth_token and oauth_verifier, but after that all the Twitter methods to get followers, post twits, whatever are not working.
This is my code:
public class TwitterLoginFragment extends Fragment {
private static String TWITTER_CONSUMER_KEY = "***";
private static String TWITTER_CONSUMER_SECRET = "***";
private static final String TWITTER_CALLBACK_URL = "http://www.hita.pro";
private static SharedPreferences sharedPreferences;
private Button btnTwitterLogin;
private Button btnTwitterLogOut;
private WebView wvTwitterLogin;
private IDs iDs;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
sharedPreferences = getActivity().getSharedPreferences("CONNECTION_INFO", Context.MODE_PRIVATE);
TwitterFactory.getSingleton().setOAuthConsumer(TWITTER_CONSUMER_KEY, TWITTER_CONSUMER_SECRET);
return inflater.inflate(R.layout.fragment_twitter_login, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstance) {
super.onActivityCreated(savedInstance);
wvTwitterLogin = (WebView) getView().findViewById(R.id.wvTwitterLogin);
wvTwitterLogin.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("KEY_TWITTER_LOGIN", true);
editor.putString("OAUTH_TOKEN", url.substring(url.indexOf("oauth_token=") + 12, url.indexOf("&")));
editor.putString("OAUTH_VERIFIER", url.substring(url.indexOf("oauth_verifier=") + 15));
editor.commit();
TwitterFactory.getSingleton().setOAuthAccessToken(new AccessToken(sharedPreferences.getString("OAUTH_TOKEN", ""), sharedPreferences.getString("OAUTH_VERIFIER", "")));
new GetTwitterFollowers().execute();
return true;
}
});
btnTwitterLogin = (Button) getView().findViewById(R.id.btnTwitterLogin);
btnTwitterLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
loginToTwitter();
}
});
btnTwitterLogOut = (Button) getView().findViewById(R.id.btnTwitterLogOut);
btnTwitterLogOut.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
twitterLogOut();
}
});
}
public void loginToTwitter() {
if (!isTwitterLoggedInAlready()) {
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
wvTwitterLogin.loadUrl(TwitterFactory.getSingleton().getOAuthRequestToken(TWITTER_CALLBACK_URL).getAuthenticationURL());
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
goToTwitterLogin();
}
});
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getActivity(), getString(R.string.error_already_logged_twitter), Toast.LENGTH_LONG).show();
}
}
});
thread.start();
} else
Toast.makeText(getActivity(), getString(R.string.error_already_logged_twitter), Toast.LENGTH_LONG).show();
}
private void goToTwitterLogin() {
btnTwitterLogin.setVisibility(View.GONE);
btnTwitterLogOut.setVisibility(View.GONE);
wvTwitterLogin.setVisibility(View.VISIBLE);
}
private boolean isTwitterLoggedInAlready() {
return sharedPreferences.getBoolean("KEY_TWITTER_LOGIN", false);
}
private void twitterLogOut() {
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("KEY_TWITTER_LOGIN", false);
editor.commit();
}
private class GetTwitterFollowers extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... v) {
try {
iDs = TwitterFactory.getSingleton().getFollowersIDs(-1);
} catch (TwitterException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
iDs.getIDs();
}
}
}
When I call to TwitterFactory.getSingleton().getFollowersIDs(-1) after the user has singed in, I'm getting this exception:
java.io.IOException: No authentication challenges found
I'm desperated, I have spent one week trying to solve this problem but all the threads I have found in StackOverflow and other sites are not working. The system clock is OK, I have tried with ConfigurationBuilder and other solutions, but no luck. Can somebody help me?
Thanks a lot!

Have you tried to work with instance not singleton from TwitterFactory?
Uri uri = Uri.parse(url);
String token = uri.getQueryParameter("OAUTH_TOKEN");
String verifier = uri.getQueryParameter("OAUTH_VERIFIER");
Twitter twitter = TwitterFactory.getInstance(
new AccessToken(token,verifier);
twitter.getFollowers(-1);

Develop Reference

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Android textview wont update outside oncreate - java

You cannot update view outside the main thread (UI thread). Try to wrap your method with runOnUiThread. runOnUiThread(new Runnable() { public void run() { Text1.setText("Is Updated"); } });

new Handler(new Runnable() { public void run() { Text1.setText("Is Updated"); } }); you have to use Handler or runOnUIThread because you cant edit on a component in main thread from outside

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