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How to loop a function and wait a second between every loop in google maps project in android studio?

I want to create a program that mark a place on the google map and every second from when I push the "Start" button the marker would jump a km to a random direction until I push the "Stop" button.
I want the marker to jump, wait a second, jump, wait a second and so on... Until I push the "Stop" button.
When I am using the "while" loop the program stuck even before the showing of the "Stop" button.
But if I don't use the loop it's working good. Can you help me please?
This is my code:
import androidx.annotation.DrawableRes;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.view.View;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.Projection;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptor;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.Random;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private double currLat = 32.671677;
private double currLng = 35.195678;
private Marker _marker;
private boolean _stopBWasNotPressed = true;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
// Setting the icon instead of the default marker.
private BitmapDescriptor bitmapDescriptorFromVector(Context context, #DrawableRes int vectorDrawableResourceId) {
Drawable background = ContextCompat.getDrawable(context, R.drawable.car_icon);
background.setBounds(0, 0, background.getIntrinsicWidth(), background.getIntrinsicHeight());
Drawable vectorDrawable = ContextCompat.getDrawable(context, vectorDrawableResourceId);
vectorDrawable.setBounds(40, 20, vectorDrawable.getIntrinsicWidth() + 40, vectorDrawable.getIntrinsicHeight() + 20);
Bitmap bitmap = Bitmap.createBitmap(background.getIntrinsicWidth(), background.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
background.draw(canvas);
vectorDrawable.draw(canvas);
return BitmapDescriptorFactory.fromBitmap(bitmap);
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Hide the Stop button.
Button stopB = (Button) findViewById(R.id.stopB);
stopB.setVisibility(View.GONE);
// Hide the Reset button.
Button resetB = (Button) findViewById(R.id.resetB);
resetB.setVisibility(View.GONE);
// Add a marker in my home and move the camera.
LatLng home = new LatLng(currLat, currLng);
_marker = mMap.addMarker(new MarkerOptions().position(home).icon(bitmapDescriptorFromVector(this, R.drawable.car_icon)));
mMap.moveCamera(CameraUpdateFactory.newLatLng(home));
// Show the Start button.
Button startB = (Button) findViewById(R.id.startB);
startB.setVisibility(View.VISIBLE);
startB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Hide the Start button.
Button startB = (Button) findViewById(R.id.startB);
startB.setVisibility(View.GONE);
// Show the Stop button.
final Button stopB = (Button) findViewById(R.id.stopB);
stopB.setVisibility(View.VISIBLE);
while (_stopBWasNotPressed) {
// Making the program wait a second until it moving the marker again.
new Handler().postDelayed(new Runnable() {
public void run() {
startMoving();
}
}, 1000); // 1 second.
}
}
});
}
// This func generates a random number to use as a direction.
public int generateRandomDirection(){
final int min = 1;
final int max = 4;
final int random = new Random().nextInt((max - min) + 1) + min;
return random;
}
// This func makes the new location and sends it to the animateMarker func.
public void startMoving(){
int directionNumber = generateRandomDirection();
final LatLng toPos;
switch(directionNumber) {
case 1:
toPos = new LatLng((currLat + 0.01), currLng); // North.
_marker.setPosition(toPos);
break;
case 2:
toPos = new LatLng((currLat - 0.01), currLng); // South.
_marker.setPosition(toPos);
break;
case 3:
toPos = new LatLng(currLat, (currLng + 0.01)); // East.
_marker.setPosition(toPos);
break;
default:
toPos = new LatLng(currLat, (currLng - 0.01)); // West.
_marker.setPosition(toPos);
break;
}
}
public void stopButtonClick(View view) {
_stopBWasNotPressed = false; // Stops the while loop.
// Hide the Stop button.
Button stopB = (Button) findViewById(R.id.stopB);
stopB.setVisibility(View.GONE);
// Show the Reset button.
final Button resetB = (Button) findViewById(R.id.resetB);
resetB.setVisibility(View.VISIBLE);
resetB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
_marker.setVisible(false);
currLat = 32.671677;
currLng = 35.195678;
onMapReady(mMap);
}
});
}
}

I searched a bit and I found that I can't use the while loop and the delay function together so I changed it to this:
final Handler handler = new Handler();
Runnable runnable = new Runnable() {
#Override
public void run() {
while (_stopBWasNotPressed) {
try {
Thread.sleep(1000); // Making the program wait a second until it continues.
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
#Override
public void run() {
startMoving();
}
});
}
}
};
Thread myThread = new Thread(runnable); // Creating a thread for the marker movement.
myThread.start();

Handler is abstract ,cannot be instantiated

I am trying to use a Handler in my app. However, when I instantiate it like this:
Handler handler = new Handler();
I get the following error:
Gradle: error: Handler is abstract; cannot be instantiated
And when I check the solutions, it asks me to implement these methods:
Handler handler = new Handler() {
#Override
public void close() {
}
#Override
public void flush() {
}
#Override
public void publish(LogRecord record) {
}
};
I have never used Handlers before and I am using it just to call a method after some delay. To achieve that, I've used:
handler.postDelayed(new Runnable() {
#Override
public void run() {
//Do something after 100ms
}
}, 100);
But it shows the error:
Gradle: error: cannot find symbol method postDelayed(,int)

It seems you have imported a wrong Handler class
import java.util.logging.Handler;
Change it to
import android.os.Handler;

In Place Of
import java.util.logging.Handler;
add
import android.os.Handler;
also if you use
Handler handler = new Handler() {
#Override
public void close() {
}
#Override
public void flush() {
}
#Override
public void publish(LogRecord record) {
}
};
it will give error that boolean found somthing like error so either use boolean handler = new Handler()...
or simply use (new Handler()){....`

Android SDK auto imports the incorrect one. That's why people have problems.

import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class ActionActivity extends ActionBarActivity {
final String LOG_TAG = "myLogs";
TextView tvInfo;
Button btnStart;
Handler h;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.action_activity);
tvInfo = (TextView)findViewById(R.id.tvinfo);
btnStart = (Button)findViewById(R.id.btnstart);
h = new Handler() {
public void handleMessage(android.os.Message msg) {
// update TextView
tvInfo.setText("Закачано файлов: " + msg.what);
if (msg.what == 10) btnStart.setEnabled(true);
};
};
}
public void onclick(View v) {
switch (v.getId()) {
case R.id.btnstart:
btnStart.setEnabled(false);
Thread t = new Thread(new Runnable() {
public void run() {
for (int i = 1; i <= 10; i++) {
// some process
downloadFile();
h.sendEmptyMessage(i);
Log.d(LOG_TAG, "i = " + i);
}
}
});
t.start();
break;
case R.id.btnTets:
Log.d(LOG_TAG, "test");
break;
default:
break;
}
}
public void downloadFile(){
try{
TimeUnit.SECONDS.sleep(1);
}
catch (InterruptedException e){
e.printStackTrace();
};
}
}

It seems like you have implemented the wrong Handler class
import java.util.logging.Handler;
Change it to
import android.os.Handler;

import android.os.Handler;
this the handler needed for your purpous. Before importing the Handler class please try to import the above.

Speak Failed Not Bound to TTS Engine

So I had an original activity with basically the same exact code for speaking, but I had to move that code into another activity. The only difference I can tell is that the text to speech is not called in an asynchronous method. The speaking occurs in the speakFull method.
I get these errors:
speak failed: not bound to TTS engine
isSpeaking failed: not bound to TTS engine
I'm new to android development, I've searched through other solutions to this problem, and I can't really seem to find a solution to make mine work. Any advice, or help is appreciated.
Code:
package com.example.webview;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.speech.tts.TextToSpeech;
import android.text.method.ScrollingMovementMethod;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class ReadOut extends Activity implements TextToSpeech.OnInitListener, OnClickListener {
boolean paused = false;
String leftToRead = null;
String res = null;
#SuppressWarnings("deprecation")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.read_out);
Intent intent = getIntent();
res = intent.getExtras().getString("response");
TextView textv = (TextView) findViewById(R.id.textView1);
textv.setText(res);
textv.setMovementMethod(new ScrollingMovementMethod());
android.view.Display display = ((android.view.WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
textv.setHeight((int)(display.getHeight()*0.76));
leftToRead = speakFull(res);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
return true;
}
public String speakFull(String text){
System.out.println("Speaking: " + text);
TextToSpeech tts = new TextToSpeech(this, this);
System.out.println("Speaking");
String[] sentences = text.split("\n|\\.(?!\\d)|(?<!\\d)\\."); // Regex that splits the body of text into the sentences of that body which are stored in a String array.
for(int i = 0; i < sentences.length; i++){
if(!tts.isSpeaking() && !paused){
System.out.println("Speaking: " + i);
tts.speak(sentences[i], TextToSpeech.QUEUE_FLUSH, null);
}else if(paused){
System.out.println("Paused");
String paused = "";
for(int j = i - 1; j < sentences.length; j++){
paused += sentences[j];
}
return paused;
}else{
i--;
}
if(i == sentences.length - 1){
return "Message 001: Complete";
}
}
return null;
}
#Override
public void onInit(int arg0) {
// TODO Auto-generated method stub
}
public void clickPause(View v){
if(paused){
paused = false;
Button b = (Button) findViewById(R.id.button1);
b.setText("Play");
}else{
paused = true;
Button b = (Button) findViewById(R.id.button1);
b.setText("Pause");
if(leftToRead == null){
leftToRead = speakFull(res);
}else{
leftToRead = speakFull(leftToRead);
}
}
}
#Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub
}
}

You can only call speak() after onInit() was called. So move your tts speak code in onCreate to onInit()
#Override
public void onInit(int status) {
if (status == TextToSpeech.SUCCESS) {
leftToRead = speakFull(res);
}
and initialize pause to true boolean paused = true;

I have this problem but after some minutes. For now I fixed in this way
myTTS.speak(speech, TextToSpeech.QUEUE_FLUSH, null);
if(!myTTS.isSpeaking()) {
myTTS = new TextToSpeech(this, this);
System.out.println("tts restarted");
}
It is not a good solution, I know, but for now it works.
Only 1 problem: at the first fault, the tts doesn't speak.

Need to access method for 1 java class by another

I am trying to access a method from a java class by a another java class. I have created the object of the class and import the class into my java class but i am not able to access it my code.
package com.example.musicplayer;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import android.R.string;
import android.app.ListActivity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.provider.MediaStore.Audio.Playlists;
import android.test.suitebuilder.TestSuiteBuilder.FailedToCreateTests;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends ListActivity {
public static final String MEDIA_PATH = new String("/sdcard/");
private List<String> songs = new ArrayList<String>();
public MediaPlayer mp = new MediaPlayer();
private int currentPosition = 0;
public MediaPlayer getmp(){
return mp;
}
public void setmp(MediaPlayer mp){
this.mp = mp;
}
#Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
updateSongList();
}
private void updateSongList() {
// TODO Auto-generated method stub
File home = new File(MEDIA_PATH);
if(home.listFiles(new Mp3Filter()).length > 0){
for(File file: home.listFiles(new Mp3Filter())){
songs.add(file.getName());
}
}
ArrayAdapter<String> songList = new ArrayAdapter<String>(this, R.layout.song_item, songs);
setListAdapter(songList);
}
#Override
protected void onListItemClick(ListView l, View v, int position, long id){
currentPosition = position;
playSong(MEDIA_PATH + songs.get(position));
//Toast.makeText(getApplicationContext(), songs.get(position).toString(), Toast.LENGTH_SHORT).show();
final String songName = songs.get(position).toString();
//final TextView textchange = (TextView) v.findViewById(R.id.current_song_name);
Intent in = new Intent(this, current_song.class);
in.putExtra("song_name", songName);
startActivity(in);
//Toast.makeText(getApplicationContext(), "End of Song List", Toast.LENGTH_SHORT).show();
//textchange.setText(songName);
}
private void playSong(String songPath) {
// TODO Auto-generated method stub
try{
mp.reset();
mp.setDataSource(songPath);
mp.prepare();
mp.start();
mp.setOnCompletionListener(new OnCompletionListener() {
#Override
public void onCompletion(MediaPlayer mp) {
// TODO Auto-generated method stub
auto_nextSong();
}
});
}
catch (Exception e) {
// TODO: handle exception
}
}
public void pause(){
mp.pause();
}
public void stop(){
mp.stop();
}
public void next(){
Toast.makeText(getApplicationContext(), "In Next()", Toast.LENGTH_SHORT).show();
if(currentPosition < songs.size()){
currentPosition = currentPosition + 1;
playSong(MEDIA_PATH + songs.get(currentPosition));
}
}
public void prv(){
if(currentPosition > songs.size()){
currentPosition = currentPosition - 1;
playSong(MEDIA_PATH + songs.get(currentPosition));
}
}
private void auto_nextSong() {
// TODO Auto-generated method stub
if(++currentPosition >= songs.size()){
currentPosition = 0;
Toast.makeText(getApplicationContext(), "End of Song List", Toast.LENGTH_SHORT).show();
}
else{
playSong(MEDIA_PATH + songs.get(currentPosition));
Toast.makeText(getApplicationContext(), "Next Song", Toast.LENGTH_SHORT).show();
}
}
}
from the above class i am trying to access pause() and stop()
this is my class where i am trying to access
package com.example.musicplayer;
import com.example.musicplayer.MainActivity;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class current_song extends Activity implements OnClickListener{
public MainActivity ma;
protected void onCreate(Bundle icicle, MainActivity ma) {
Bundle extra = getIntent().getExtras();
super.onCreate(icicle);
setContentView(R.layout.songplay_page);
if(extra != null){
String song_name = extra.getString("song_name");
TextView textchange = (TextView)findViewById(R.id.current_song_name);
textchange.setText(song_name);
textchange.setSelected(true);
}
//MainActivity ma = ((MainActivity)getApplicationContext());
//MediaPlayer mp = ma.getmp();
this.ma = ma;
Button btn_pause = (Button)findViewById(R.id.pause_btn);
btn_pause.setOnClickListener(this);
Button btn_next = (Button)findViewById(R.id.next_btn);
btn_next.setOnClickListener(this);
Button btn_prv = (Button)findViewById(R.id.prv_btn);
btn_prv.setOnClickListener(this);
Button btn_stop = (Button)findViewById(R.id.stop_btn);
btn_stop.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
//Toast.makeText(getApplicationContext(), "In Onclick ()", Toast.LENGTH_SHORT).show();
switch(v.getId())
{
case R.id.pause_btn:
((MainActivity)ma).pause();
break;
case R.id.next_btn:
//ma.next();
break;
case R.id.prv_btn:
//ma.prv();
break;
case R.id.stop_btn:
((MainActivity)ma).stop();
break;
}
}
}
The concept is that i want to stop, pause the music which is playing. If my logic i wrong please guide me how to do it else please help me how to control my current music in Current music java class.

Please, move all your music playing code into Service. Activities don't work that way.
Consider the following:
http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
http://developer.android.com/reference/android/app/Service.html

I think You are new to android but no problem: See you can not call the functions of activity from any other class like this (Object.method();)
SO For this type of handling You Should Create a inner Handler class which extends Handler inside your MainActivity. and override onHandle(message msg){} method of it.
And When You start current_song activity pass this handler object in the intent.
And when you want to perform any task from your MainActivity (like stop, pause), pass messages through that handler like object.sendmessage(new msgObject("stop"));
And inside you onHandle() method call your stop or pause methods through diffrentiating command received from the message object.
like if(message's content == stop) MainActivity.this.stop();

How can random string look like slot machine

In my program, I have only 1 button. And first press the program will output a random string. If the user presses it again to stop, my program will slow random (delay) the same slot machine. How can I do it?
my code
package com.Randomsentence;
import java.util.Random;
import android.app.Activity;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class Randomsentence extends Activity {
boolean showRandom = false;
TextView txt;
int time = 30;
int random;
public String[] myString;
Button bt1;
boolean check = false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txt = (TextView) findViewById(R.id.txt);
bt1 = (Button) findViewById(R.id.bt1);
Medaiplayer mp = new Medaiplayer();
Mediaplayer mp2 = new Mediaplayer();
mp = MediaPlayer.create(getApplicationContext(), R.raw.AudioFile1);
mp2 = MediaPlayer.create(getApplicationContext(), R.raw.AudioFile2);
bt1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
showRandom = !showRandom;
t = new Thread() {
public void run() {
try {
while (showRandom) {
mp.start();
mp2.reset();
mp2.prepare();
sleep(1000);
handler.sendMessage(handler.obtainMessage());
}
mp.reset();
mp.prepare();
mp2.start();
} catch (Exception ex) {
ex.printStackTrace();
}
}
};
t.start();
}
});
}
// our handler
Handler handler = new Handler() {
public void handleMessage(Message msg) {//display each item in a single line
{
Random rgenerator = new Random();
Resources res = getResources();
myString = res.getStringArray(R.array.myArray);
String q = myString[rgenerator.nextInt(myString.length)];
txt.setText(q);
}
}
};
}

Ignoring the MediaPlayer part, I think it should be this way:
package com.Randomsentence;
import java.util.Random;
import android.app.Activity;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.Randomsentence.R;
public class Randomsentence extends Activity {
TextView txt;
int random;
public String[] myStrings;
Button bt1;
private static final int MESSAGE_RANDOM = 1;
private static final long MIN_INTERVAL = 500;
private static final long MAX_INTERVAL = 1500;
private static final long STEP = 60;
private long mInterval = 0;
private boolean mStarted = false;
private Random mRandom = new Random();
private Handler mHandler = new Handler() {
#Override
public void handleMessage (Message msg) {
if(msg.what == MESSAGE_RANDOM) {
showRandomString();
if(mStarted) {
this.sendEmptyMessageDelayed(MESSAGE_RANDOM, mInterval);
} else {
if(mInterval <= MAX_INTERVAL) {
this.sendEmptyMessageDelayed(MESSAGE_RANDOM, mInterval);
mInterval += STEP;
} else {
this.removeMessages(MESSAGE_RANDOM);
Toast.makeText(Randomsentence.this, "Stopped!", Toast.LENGTH_SHORT).show();
}
}
}
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txt = (TextView) findViewById(R.id.txt);
bt1 = (Button) findViewById(R.id.bt1);
bt1.setOnClickListener(mBt1OnClick);
myStrings = getResources().getStringArray(R.array.myArray);
}
private void showRandomString() {
final int index = mRandom.nextInt(myStrings.length - 1);
txt.setText(myStrings[index]);
}
private OnClickListener mBt1OnClick = new OnClickListener() {
#Override
public void onClick(View v) {
if(!mStarted) {
// Start
Toast.makeText(Randomsentence.this, "Started!", Toast.LENGTH_SHORT).show();
mStarted = true;
mInterval = MIN_INTERVAL;
mHandler.removeMessages(MESSAGE_RANDOM);
mHandler.sendEmptyMessage(MESSAGE_RANDOM);
} else {
// Stop
mStarted = false;
Toast.makeText(Randomsentence.this, "Stoping...", Toast.LENGTH_SHORT).show();
}
}
};
}