Develop Reference

Android app to play mp3 file in specific time with countdown timer

I was trying to create an android app that should get time in minutes from a seek bar then it should begin to play a sound file until the countdown timer ends.
Things are mostly fine with the countdown timer BUT my question is how should I call some methods of the countdown timer instance when a button is pressed.
In the code below, I want to call onFinish() whenever the stop button pressed.
Here is my code:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SeekBar sb = (SeekBar) findViewById(R.id.seekBar);
Button bt_stop = (Button) findViewById(R.id.btn1);
final TextView tv = (TextView)findViewById(R.id.textView);
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
int millisec_time = (i*60)/1000;
new CountDownTimer(millisec_time, 1000) {
public void onTick(long millisUntilFinished) {
tv.setText("seconds remaining: " + millisUntilFinished / 1000);
}
public void onFinish() {
tv.setText("done!");
}
}.start();
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
// Toast.makeText(getApplicationContext(),"GOT",Toast.LENGTH_LONG).show();
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
// Toast.makeText(getApplicationContext(),"OFF",Toast.LENGTH_LONG).show();
}
});
bt_stop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
}
}

First, I'd recommend you only start your CountdownTimer in onStopTrackingTouch - reason being that currently you're creating a brand new timer every time the progress changes on your seekbar (which could be happening a lot).
Secondly, you'll need to retain a reference to your timer in order to cancel it. So:
public class MainActivity extends AppCompatActivity {
private CountdownTimer timer = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final SeekBar sb = (SeekBar) findViewById(R.id.seekBar);
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
restartTimer(seekBar);
}
}
final Button bt_stop = (Button) findViewById(R.id.btn1);
bt_stop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(timer != null) {
timer.cancel();
}
}
});
}
private void restartTimer(SeekBar sb) {
if(timer!=null) {
timer.cancel();
}
final long millis = TimeUnit.SECONDS.toMillis(sb.getProgress());
final long interval = TimeUnit.SECONDS.toMillis(1);
timer = new CountdownTimer(millis, interval) {
#Override
public void onTick(long millisUntilFinished) {
tv.setText(String.format("Seconds Remaining: %d", TimeUnit.MILLIS.toSeconds(millisUntilFinished));
}
#Override
public void onFinish() {
tv.setText("done!");
}
}
timer.start();
}
}

Multiple seekbars - set listeneners more efficiently?

I have 12 seekbars in an activity. Each seekbar needs a listener. At the moment I am manually setting a listener for each seekbar, this doesnt seem particularly efficient.
Can anyone recommend a more efficient practice to set the seekbars???

Try something like this:
public class MainActivity extends AppCompatActivity {
SeekBar seekBar1;
SeekBar seekBar2;
SeekBar.OnSeekBarChangeListener mlistener;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
seekBar1 = findViewById(R.id.seekBar_1);
seekBar2 = findViewById(R.id.seekBar_2);
mlistener = new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
switch (seekBar.getId()) {
case R.id.seekBar_1:
//do something
break;
case R.id.seekBar_2:
//do something else
break;
}
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
};
seekBar1.setOnSeekBarChangeListener(mlistener);
seekBar2.setOnSeekBarChangeListener(mlistener);
}

If your SeekBars all require different interaction logic then obviously you will need to provide unique code to each of the objects. However, you can re-use listeners if each SeekBar is doing the same thing. For example:
public class SeekBarTest extends Activity{
private Context myContext;
public SeekBarTest(Context c){
myContext = c;
}
private void initialize(){
SeekBar seekbar1 = new SeekBar(myContext);
SeekBar seekbar2 = new SeekBar(myContext);
SeekBar seekbar3 = new SeekBar(myContext);
SeekBar.OnSeekBarChangeListener myListener = new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
//logic
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
//logic
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
//logic
}
};
seekbar1.setOnSeekBarChangeListener(myListener);
seekbar2.setOnSeekBarChangeListener(myListener);
seekbar3.setOnSeekBarChangeListener(myListener);
}
}

Instead of creating switch in onProgressChanged method you can send variables to SeekBar initiating method.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_options);
SeekBar volBar = initiateSeekBar(R.id.volume,R.id.volumeValue,0,1,"%");
SeekBar playSpeedBar = initiateSeekBar(R.id.autoPlay,R.id.autoPlayValue,100, 100,"ms");
}
private SeekBar initiateSeekBar(int barId, int textId, final int min, final int step, final String unit) {
SeekBar bar = findViewById(barId);
final TextView text = findViewById(textId);
bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
int value = min + progress * step;
text.setText(value + " " + unit);
autoPlayDelayTime = value;
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
return bar;
}

You can just make a reference equality, like this:
override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
seekBar?. let {
if (this.seekBar1 === it) {
...
}
if (this.seekBar2 === it) {
...
}}
...
}
and call outside:
seekBar1.setOnSeekBarChangeListener(this)
seekBar2.setOnSeekBarChangeListener(this)

I cannot get OnSeekBarChangeListener to work in Android code

I'm trying to use OOP in my Java/Android code, but I don't understand why OnSeekBarChangeListener is not working in my new class.
Is it prohibited to use a OnSeekBarChangeListener outside main activity?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mp = new MediaPlayer();
timescroller = (SeekBar) findViewById(R.id.seekBar);
TimeScroller Tm = new TimeScroller();
Tm.mp = mp;
Tm.ts = timescroller;
Tm.mTimeScroller();
timescroller.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
if(b){
mp.seekTo(i);
}
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
mp.setVolume(0,0);
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
mp.setVolume(1,1);
}
});
}
And here is my class
package com.phillipvm.gridlayout;
import android.media.MediaPlayer;
import android.widget.SeekBar;
public class TimeScroller {
MediaPlayer mp;
SeekBar ts;
public void mTimeScroller(MediaPlayer _mp,SeekBar _ts){
mp =_mp;
ts = _ts;
ts.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
if(b){
mp.seekTo(i);
}
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
mp.setVolume(0,0);
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
mp.setVolume(1,1);
}
});
}
}

i can't see the code where you are using the class!
you are calling Tm.mTimeScroller(); but in your class the method takes 2 parameters !

how to stop a Runnable running on an UIThread

I have a Runnable on a UIThread updating a SeekBar while a MediaPlayer is playing. Yet, when I switch to another activity my application crashes with an exception cause the Runnable keeps on forever even after the MediaPlayer has been destroyed.
This is my code:
public class Guide extends AppCompatActivity implements MediaPlayer.OnPreparedListener {
Button back;
private MediaPlayer m_audio_player;
private Handler m_handler_seek_bar = new Handler();
private SeekBar m_seek_bar;
private Runnable m_seek_bar_runnable;
private void set_up_audio(){
m_audio_player = MediaPlayer.create(this, g_audio[NativeLib.get_active_landmark()] );
m_audio_player.setOnPreparedListener(this);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_guide);
implement_back_button();
set_up_audio();
}
#Override
protected void onStart() {
super.onStart();
set_up_seek_bar();
}
private void set_up_seek_bar() {
m_seek_bar = (SeekBar) findViewById(R.id.seek_bar);
m_seek_bar.setMax(m_audio_player.getDuration());
m_seek_bar_runnable = new Runnable() {
#Override
public void run() {
if(m_audio_player != null ){
m_seek_bar.setProgress(m_audio_player.getCurrentPosition());
}
m_handler_seek_bar.postDelayed(this, 1000);
}
};
// update Seekbar on UI thread
Guide.this.runOnUiThread(m_seek_bar_runnable);
m_seek_bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onStopTrackingTouch(SeekBar seekBar) { }
#Override
public void onStartTrackingTouch(SeekBar seekBar) {}
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if(m_audio_player != null && fromUser){
m_audio_player.seekTo(progress);
}
}
});
}
#Override
protected void onStop() {
if (debug_mode) Log.d(TAG, "onStop");
if (m_audio_player.isPlaying()) {
m_audio_player.stop();
}
m_audio_player.release();
super.onStop();
findViewById(R.id.activity_guide).removeCallbacks(m_seek_bar_runnable);
}
// return button
private void implement_back_button() {
final Intent intent = new Intent(/* pointing at some other activity */);
back = (Button) findViewById(R.id.back_button);
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(intent);
}
});
}
}

You need to use:
m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable);
to remove the runnable from handler
#Override
protected void onStop() {
if (debug_mode) Log.d(TAG, "onStop");
if (m_audio_player.isPlaying()) {
m_audio_player.stop();
}
m_audio_player.release();
m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable);
super.onStop();
}
Alternatively you can override the onPause() method of the activity:
#Override
protected void onPause() {
m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable);
super.onPause();
}

Remove all the callbacks from the Handler in onStop using handler.removeCallbacks

Android: cancel() on Animation does not work

I have been working on a little game and I need a progress bar animation, which begins when I touch a button for the first time and if I touch the button again before the animation ended the progressbar needs to reset.
In my code animation.start(); works well but the animation.cancel() does not seem to work.
French Version of this Question
My Activity Code containing the line that does not work:
public class MainActivity extends Activity {
Button b_bleu;
PrgressBar bar1;
#Override
public void onWindowFocusChanged(boolean hasFocus) {
b_bleu.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ObjectAnimator animation = ObjectAnimator.ofInt(bar1, "progress", 100, 0);
animation.setDuration(5000);
animation.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationEnd(Animator animator) {
//application se termine
}
#Override
public void onAnimationCancel(Animator animator) {
}
#Override
public void onAnimationRepeat(Animator animator) {
}
});
animation.cancel();
animation.start();
}
});
}

I think the problem is that animation.cancel() has no effect since you call animation.start(); right after it.
Try something like this:
Declare a field:
private boolean mStarted = false;
Then set it in animation callbacks and check its value:
animation.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animation) {
mHasStarted = true;
}
#Override
public void onAnimationEnd(Animator animation) {
mHasStarted = false; // reset the field value so that it can be started again onClick once it has ened
}
#Override
public void onAnimationCancel(Animator animation) {
mHasStarted = false;
}
});
if (mStarted) {
animation.cancel();
} else {
animation.start();
}
Hope this helps!