Hey guys, i would like to know how to manage delays in an android application, for example, I have an overridden method onTextChanged(). In relation to that I want to set a delay like .5 seconds in order to finalized what the user is typing in my autocomplete textbox. If the user hangs/stop typing in .5 sec, i wanted a certain method or implementation to execute in my code(i.e. my own filtering scheme/logic in my autocomplete textbox, just to lessen resource usage within my app, thanks).
Here's my sample code:
protected AutoCompleteTextView autoCompleteView;
protected AutoCompleteAdapter suggsAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
countries = getResources().getStringArray(R.array.countries_array);
autoCompleteView = (AutoCompleteTextView) findViewById(R.id.autocomplete_country);
TextWatcher textChecker = new TextWatcher() {
#Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
//here inside this overridden method, I wanted to create a delay in order to lessen the
//use of resources.
String enteredText = autoCompleteView.getText().toString();
refreshList(enteredText);
}
};
autoCompleteView.addTextChangedListener(textChecker);
}
and for example, the user typed "Lond"(for String like "London") with each letter typed less than .5 sec, I want all the previous onTextChanged() method called(method call in typing "L", "o" and "n") to be disregarded and only the onTextChanged() when the last letter was typed would be granted for execution.
How would I do that, please help me:(.
You can create a Handler subclass and call Handler.sendEmptyMessageDelayed() or Handler.sendMessageDelayed() method when onTextChanged() is triggered. And you can remove messages from the message queue using Handler.removeMessages(). You should process messages in Handler.handleMessage() method. So your onTextChanged() method will be something like:
mHandler.removeMessages(MESSAGE_TEXT_CHANGED);
mHandler.sendEmptyMessage(MESSAGE_TEXT_CHANGED, 500);
EDIT: Here's an example of code. I haven't tested it yet, so I'm not sure it works.
private static final int AUTOCOMPLETE_DELAY = 500;
private static final int MESSAGE_TEXT_CHANGED = 0;
private Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
if (msg.what == MESSAGE_TEXT_CHANGED) {
String enteredText = (String)msg.obj;
refreshList(enteredText);
}
}
};
// ... your code here
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
String enteredText = autoCompleteView.getText().toString();
mHandler.removeMessages(MESSAGE_TEXT_CHANGED);
final Message msg = Message.obtain(mHandler, MESSAGE_TEXT_CHANGED, enteredText);
mHandler.sendMessageDelayed(msg, AUTOCOMPLETE_DELAY);
}
I am writing Running code for autocomplete.
First onTextChanged will be called.
public void onTextChanged(CharSequence s, int start, int before, int count) {
String newText = s.toString();
if(!newText.trim().equals(""))
Autocompletes_Timer(newText);
}
now we need a Handler.
Hander handler = new Handler();
private void Autocompletes_Timer(final String newText) {
// new text will be here. so if you type fast within 1 sec.
// handler will be remover each time so that handler post delay also be remove.
if(handler!= null)
handler.removeCallbacksAndMessages(null);
// new text will be in runnable with 1 sec delay.
handler.postDelayed(runnable(newText), 1000);
}
// it will be start work after 1 sec.
// if you stop the typing then it will complete work like as sending data at server.
// if you continue typing , it will not complete work and each type will be removeCallbackAndMessage.
private Runnable runnable(final String newText) {
Runnable runnable = new Runnable() {
#Override
public void run() {
Log.d("Autocompleted", newText);
// call AysncTask here
}
};
return runnable;
}
just copy and paste my code. It should be fix your problem . Enjoy.
use a CountDownTimer
protected AutoCompleteTextView autoCompleteView;
protected AutoCompleteAdapter suggsAdapter;
String TAG = "Timer";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
countries = getResources().getStringArray(R.array.countries_array);
autoCompleteView = (AutoCompleteTextView) findViewById(R.id.autocomplete_country);
TextWatcher textChecker = new TextWatcher() {
CountDownTimer countDownTimer = new CountDownTimer(500,100) {
#Override
public void onTick(long millisUntilFinished) {
Log.d(TAG, "addressTextWatcher.countDownTimer.onTick() -> Tick: " + millisUntilFinished);
}
#Override
public void onFinish() {
Log.d(TAG, "addressTextWatcher.countDownTimer.onTick() -> Finish");
String enteredText = autoCompleteView.getText().toString();
refreshList(enteredText);
}
};
#Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
countDownTimer.cancel();
countDownTimer.start();
}
};
autoCompleteView.addTextChangedListener(textChecker);
}
Related
I have an AutoCompleteTextView in my layout. After the user entered the first character, I'd like to do an API call, which I'm doing in an AsyncTask. I've used addTextChangedListener and I'm doing the API call on TextChanged. But the problem is that the API call is getting done each time the user makes any change to the AutoCompleteTextView.
But I'd want the API call to happen only once, that is after the first character is inputted. How do I achieve this ?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_places_search);
search_airport = (AutoCompleteTextView) findViewById(R.id.place_search);
autocompleteadapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, airports);
search_airport.setAdapter(autocompleteadapter);
search_airport.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
mAirport = new AsyncTaskAirport(search_airport.getEditableText().toString().substring(0, 1));
mAirport.execute((Void) null);
}
#Override
public void afterTextChanged(Editable s) {
}
});
}
try this,
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().trim().length()==1){
mAirport = new AsyncTaskAirport(search_airport.getEditableText().toString().substring(0, 1));
mAirport.execute((Void) null);
}
}
You can solve your problem with a timer.Here is how
#Override
public void onTextChanged(CharSequence s, int start, int before, int count)
{
int COMPLETION_DELAY = 2000;
if (timer != null)
{
timer.cancel();
timer.purge();
timer = null;
}
timer = new Timer();
timer.schedule(new TimerTask()
{
#Override
public void run()
{
new Handler(Looper.getMainLooper()).post(new Runnable()
{
#Override
public void run()
{
if (s.toString().length() >= appCompatAutoCompleteTextView.getThreshold())
{
//CALL WebService Here
}
}
});
}
}, COMPLETION_DELAY);
}
now your service will not be called when user making changes while typing in auto complete. service will only be called once user stops + 2 Second.
I'm confronted to an optimisation problem: I want to do a dynamic AutoCompleteTextView, so I implemented "TextWatcher" to my class. I want that each time user type and make a pause or finished typing, I launch my DB request to get him a list for Autocompletion, so my question is:
How can i know when user finished/paused typing in an AutoCompleteTextView ?
Actually, my code do a request each time user type a character. So for "Hello" it will send 4 request to my DB, but i need it to send an unique request with the complete world "Hello" when the user finished typing.
Is that possible ?
Here's a part of my actual code:
public class MainActivity extends AppCompatActivity implements TextWatcher {
public final static String CLUB_NAME = "com.mycompany.myfirstapp.FAV_CLUB";
List<devaddict.footbarcom.modelPOJO.Object> list;
Button searching;
AutoCompleteTextView searchbar_club;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
searching = (Button)findViewById(R.id.buttonseek);
searchbar_club = (AutoCompleteTextView) findViewById(R.id.searchbar_club);
searchbar_club.addTextChangedListener(this);
searchbar_club.setThreshold(3);
}
And then, in the same "MainActivity" class, below i got theses:
#Override
public void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
System.out.println("TEXT CHANGED BY onTextChanged");
}
#Override
public void beforeTextChanged(final CharSequence s, final int start, final int count, final int after) {
}
#Override
public void afterTextChanged(final Editable s) {
//System.out.println("TEXT CHANGED BY afterTextChanged");
}
I thought that "afterTextChanged" method would be what i actually wanted, but i don't see any difference between it and onTextChanged.
System.out are here only for tests.
onTextChanged() is the main method where you could write down your logic..
if you are willing to wait for user to type 2 or more words you could write your onTextChanged() method like below:
#Override
public void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
if(count > 4){
new Handler().postDelayed(new Runnable(){
public void run(){
//write db insertion logic here...
}},700);
}
}
basically you wait for 700 msecs and then do some action to make sure that user might have stopped typing..
See if this helps!!
P.S: Ali's answer below using timer is also the correct approach to problem asked by OP
Timer timer;
#Override
public void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
timer = new Timer();
timer.schedule(new TimerTask()
{
#Override
public void run()
{
MainActivity.activity.runOnUiThread(new Runnable() {
#Override
public void run() {
timer.cancel();
//do something
}
});
}
}, 1000);//after 1 second do whatever you want
}
#Override
public void beforeTextChanged(final CharSequence s, final int start, final int count, final int after) {
}
#Override
public void afterTextChanged(final Editable s) {
//System.out.println("TEXT CHANGED BY afterTextChanged");
}
Here's how to do it using Kotlin and Coroutines:
First define a job for doing that in your Activity or Fragment, like this:
private var textChangeCountDownJob: Job = Job()
then add a text watcher like this:
editText.doAfterTextChanged {
textChangeCountDownJob.cancel()
textChangeCountDownJob = lifecycleScope.launch {
delay(500) // for half a second delay, as an example
search(it.toString()) // doing your logic here
}
}
I use this code for AutoCompleteTextView - so when you delete the last character to show the list. But mAutoCompleteTextView.showDropDown(); dont work.
mAutoCompleteTextView.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
if (s.toString().equals("")) {
mAutoCompleteTextView.showDropDown();
}
}
});
When initializing the widget, I remembered the adapter in a class field.
use this to set adapter
mAdapter = (ArrayAdapter<String>)actv.getAdapter(); // mAdapter is a class field
actv.setText("Tim Hortons");
actv.setSelection(0, actv.getText().length());
actv.setAdapter((ArrayAdapter<String>)null); // turn off the adapter
actv.requestFocus();
Handler handler = new Handler() {
public void handleMessage(Message msg) {
((AutoCompleteTextView)msg.obj).setAdapter(mAdapter);
};
Message msg = mHandler.obtainMessage();
msg.obj = actv;
handler.sendMessageDelayed(msg, 200);
hope this will help you
I have an editText which represent an input for a search criteria. I want to know if there is a way to detect when user stops editing this editText so I can query the db for data for my list. For example, if the user types "test" I want to be notified only after user has typed the word, not after user types each letter, like text watcher does. Do you have any ideas? I would avoid to use some timer to measure milliseconds elapsed between key pres events.
Not incredibly elegant, but this should work.
Initializations:
long idle_min = 4000; // 4 seconds after user stops typing
long last_text_edit = 0;
Handler h = new Handler();
boolean already_queried = false;
Set up your runnable that will be called from the text watcher:
private Runnable input_finish_checker = new Runnable() {
public void run() {
if (System.currentTimeMillis() > (last_text_edit + idle_min - 500)) {
// user hasn't changed the EditText for longer than
// the min delay (with half second buffer window)
if (!already_queried) { // don't do this stuff twice.
already_queried = true;
do_stuff(); // your queries
}
}
}
};
Put this in your text watcher:
last_text_edit = System.currentTimeMillis();
h.postDelayed(input_finish_checker, idle_min);
First create the following field :
private Date _lastTypeTime = null;
Then make sure your your editText implements 'TextWatcher':
_editText.addTextChangedListener(this);
then, override the interface`s methods as follows:
#Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)
{
_lastTypeTime = new Date();
}
#Override
public void afterTextChanged(Editable arg0)
{
}
#Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)
{
// dispatch after done typing (1 sec after)
Timer t = new Timer();
TimerTask tt = new TimerTask()
{
#Override
public void run()
{
Date myRunTime = new Date();
if ((_lastTypeTime.getTime() + 1000) <= myRunTime.getTime())
{
post(new Runnable()
{
#Override
public void run()
{
Log.d("<tag>", "typing finished!!!");
}
});
}
else
{
Log.d("<tag>", "Canceled");
}
}
};
t.schedule(tt, 1000);
}
Here's how you can detect event you are looking for.
Declarations and initialization:
private Timer timer = new Timer();
private final long DELAY = 1000; // in ms
Listener in e.g. onCreate()
EditText editText = (EditText) findViewById(R.id.editTextStopId);
editText.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
#Override
public void onTextChanged(final CharSequence s, int start, int before,
int count) {
if(timer != null)
timer.cancel();
}
#Override
public void afterTextChanged(final Editable s) {
//avoid triggering event when text is too short
if (s.length() >= 3) {
timer = new Timer();
timer.schedule(new TimerTask() {
#Override
public void run() {
// TODO: do what you need here (refresh list)
// you will probably need to use
// runOnUiThread(Runnable action) for some specific
// actions
queryDB();
}
}, DELAY);
}
}
});
So, when text is changed the timer is starting to wait for any next changes to happen. When they occure timer is cancelled and then started once again.
This is how I did and works for me!
long delay = 1000; // 1 seconds after user stops typing
long last_text_edit = 0;
Handler handler = new Handler();
private Runnable input_finish_checker = new Runnable() {
public void run() {
if (System.currentTimeMillis() > (last_text_edit + delay - 500)) {
// TODO: do what you need here
DoStaff();
}
}
};
EditText editText = (EditText) findViewById(R.id.editTextStopId);
editText.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
#Override
public void onTextChanged(final CharSequence s, int start, int before,
int count) {
//You need to remove this to run only once
handler.removeCallbacks(input_finish_checker);
}
#Override
public void afterTextChanged(final Editable s) {
//avoid triggering event when text is empty
if (s.length() > 0) {
last_text_edit = System.currentTimeMillis();
handler.postDelayed(input_finish_checker, delay);
} else {
}
}
});
the easiest way to check if editText is has text or NOT (only once) , do this :
private boolean newState;
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.somLayout);
edt.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void afterTextChanged(Editable editable) {
if (!editable.trim().isEmpty()) {
checkIsTyping(true);
} else {
checkIsTyping(false);
}
}
});
}
private void checkIsTyping(boolean typeState) {
if (newState != typeState) {
Toast.makeText(appCompatActivity, "typingState " + newState,
Toast.LENGTH_SHORT).show();
}
newState = typeState;
}
i am using an editText listener in my application.Now suppose i am typing something
in the editBox its reacting to each and every keyhits as expected ,but i want it to wait it until i complete my text that i am typing
ex : i typed www.goog preety fast then i halted for about .5 sec . i want this .5 sec delay to trigger the an editText Listener for the text "www.goog" only one time instead each and every letter . Is it possible.Hope i am clear enough ..plss help
editText.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
String searchText =editText.getText().toString();
Toast.makeText(getApplicationContext(), searchText,
Toast.LENGTH_SHORT).show();
//XXX do something
}
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
//XXX do something
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
});
I couldn't find anything to do the job, so created this:
import android.os.AsyncTask;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
public abstract class DelayedTextWatcher implements TextWatcher {
private long delayTime;
private WaitTask lastWaitTask;
public DelayedTextWatcher(long delayTime) {
super();
this.delayTime = delayTime;
}
#Override
public void afterTextChanged(Editable s) {
synchronized (this) {
if (lastWaitTask != null){
lastWaitTask.cancel(true);
}
lastWaitTask = new WaitTask();
lastWaitTask.execute(s);
}
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// TODO Auto-generated method stub
}
public abstract void afterTextChangedDelayed(Editable s);
private class WaitTask extends AsyncTask<Editable, Void, Editable> {
#Override
protected Editable doInBackground(Editable... params) {
try {
Thread.sleep(delayTime);
} catch (InterruptedException e) {
}
return params[0];
}
#Override
protected void onPostExecute(Editable result) {
super.onPostExecute(result);
afterTextChangedDelayed(result);
}
}
}
When you want to use it do this:
editText.addTextChangedListener(new DelayedTextWatcher(2000) {
#Override
public void afterTextChangedDelayed(Editable s) {
log.debug("afterTextChangedDelayed >>>>>>>>>>>>> "+s.toString());
}
});
You could add an instance variable holding the timestamp of the last time afterTextChange was fired. You can then test in afterTextChange if currentTime - lastTimeTextChanged is above said threshold. If it is, execute code, if not, then not ;)
Something like this:
public void afterTextChanged(Editable s) {
long currentTime = System.currentTimeMillis();
if ((currentTime - lastTimeTextChanged) > 500 ) {
String searchText =editText.getText().toString();
Toast.makeText(getApplicationContext(), searchText, Toast.LENGTH_SHORT).show();
//XXX do something
}
lastTimeTextChanged = currentTime;
}