Develop Reference

Reset value to default when using OnclickListener in Android

I'm trying to do some example about countdown timer using Button and set OnclickListener for that Button. My Default value is 10 and it will be decrease each second, how can i reset my value back to 10?

CountDownTimer cannot be restarted, it can only be used once. You either have to create your own count down class that can handle being restarted, or just create a new instance of your CountDownTimer and cancel the old instance.
See the example code below where we have a CountDownTimer that counts down for 10 seconds in 1 second intervals, a Button that resets the timer when clicked (by cancelling the current timer and starting a new one), and a TextView that displays the time left in the current timer.
public class YourActivity extends Activity {
private CountDownTimer countDownTimer;
private TextView timerDisplayTextView;
private static final long TEN_SECONDS = TimeUnit.SECONDS.toMillis(10);
private static final long COUNTDOWN_INTERVAL = TimeUnit.SECONDS.toMillis(1);
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
Button myButton; // initialized here
// timerDisplayTextView initialized here
myButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
countDownTimer.cancel();
countDownTimer = getNewCountDownTimer(TEN_SECONDS);
countDownTimer.start();
showTimeInTextView(TEN_SECONDS);
}
});
countDownTimer = getNewCountDownTimer(TEN_SECONDS);
countDownTimer.start();
}
#Override
protected void onDestroy() {
super.onDestroy();
countDownTimer.cancel();
}
private void showTimeInTextView(long millisecondsLeft) {
timerDisplayTextView.setText(TimeUnit.MILLISECONDS.toSeconds(millisecondsLeft) + " seconds left");
}
private CountDownTimer getNewCountDownTimer(long length) {
return new CountDownTimer(length, COUNTDOWN_INTERVAL) {
#Override
public void onTick(long millisUntilFinished) {
showTimeInTextView(millisUntilFinished);
}
#Override
public void onFinish() {
}
};
}
}

How to change page in ViewPager Android?

I am using View Pager in my App. I need to trigger page change every 1 min. I know that if user swipes, page change happens. But if we have to trigger it, is there any API for it.

How to change page in ViewPager Android?
Use ViewPager.setCurrentItem(int item) for changing ViewPager pages programmatically.
Where item is index of Page which want to set as current item in ViewPager.

private int mInterval = 5000; // 5 seconds by default, can be changed later
private Handler mHandler;
#Override
protected void onCreate(Bundle bundle) {
...
mHandler = new Handler();
startRepeatingTask();
}
Runnable mStatusChecker = new Runnable() {
#Override
public void run() {
updatePage(); //this function can change value of mInterval.
mHandler.postDelayed(mStatusChecker, mInterval);
}
};
void startRepeatingTask() {
mStatusChecker.run();
}
void stopRepeatingTask() {
mHandler.removeCallbacks(mStatusChecker);
}
private void updatePage(){
viewPager.setCurrentItem(pageno)
}

Handler handler = new Handler();
handler.post(new Updater());
class Updater implements Runnable {
public void run() {
mViewPager.setCurrentItem(mViewPager.getCurrentItem() + 1);
if (mViewPager.getAdapter().getCount() - 1 > mViewPager.getCurrentItem()){
handler.postDelayed(new Updater, 60000);
}
}
}

You can use CountDownTimer do this easily.Change the page after every 60sec using below example
class MyTimer extends CountDownTimer{
public MyTimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onTick(long l) {
}
#Override
public void onFinish() {
viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
myTimer.start();
}
MyTimer myTimer = new MyTimer(1000*60, 1000);
myTimer.start();

How to stop images animation?

The following program displays full screen images that animate automatically by using the loadAnimation() method. Here is is the code.
public class MainActivity extends ActionBarActivity {
/** Called when the activity is first created. */
public int currentimageindex=0;
Timer timer;
TimerTask task;
ImageView slidingimage;
private int[] IMAGE_IDS = {
R.drawable.picture1, R.drawable.picture2, R.drawable.picture3,
R.drawable.picture4
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Handler mHandler = new Handler();
// Create runnable for posting
final Runnable mUpdateResults = new Runnable() {
public void run() {
AnimateandSlideShow();
}
};
int delay = 1000; // delay for 1 sec.
int period = 3000; // repeat every 4 sec.
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
mHandler.post(mUpdateResults);
}
}, delay, period);
}
/**
* Helper method to start the animation on the splash screen
*/
private void AnimateandSlideShow() {
slidingimage = (ImageView)findViewById(R.id.ImageView3_Left);
slidingimage.setImageResource(IMAGE_IDS[currentimageindex%IMAGE_IDS.length]);
currentimageindex++;
Animation leftToRight = AnimationUtils.loadAnimation(this, R.anim.left_to_right);
slidingimage.startAnimation(leftToRight);
}
}
As you can see the full sized picture change every 4 seconds. Now what i want to do is to stop the animation after the appearance of the last image(picture 4 in this case). After fixing this,I will try fetch images from a server using JSON.
Thank you,
Theo.

1)You have to load animation until only you have image in IMAGE_IDS array
2)Then stop your timer also
Add following lines in AnimateandSlideShow() below currentimageindex++
if(currentimageindex <= IMAGE_IDS.length)
{
Animation leftToRight = AnimationUtils.loadAnimation(this, R.anim.letf_anim);
slidingimage.startAnimation(leftToRight);
}
else
{
timer.cancel();
}
Also replace following line
Timer timer = new Timer();
To
timer = new Timer();

How to display a timer in activity in Android

I want to show timer, with every second. After 20 seconds I want that activity to call itself.
But when I don't display the timer it waits for 20 seconds as I wish to do but as soon as I implement code to display timer it just starts and suddenly stops suddenly.
Here is my code. Please help me out.
public class MainActivity extends Activity {
public int time=20;
Button end;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Thread timerdisp = new Thread(){
TextView tv = (TextView) findViewById(R.id.timer);
public void run(){
try{
sleep(1000); // sleep for 1 seconds
tv.setText(String.valueOf(time));
time-=1;
if(time==0){
startActivity(new Intent(MainActivity.this,MainActivity.class));
}
run();
}
catch (InterruptedException e){
e.printStackTrace();
}
}
};
timerdisp.start();
);
}

Android provides a better facility of CountDownTimer, may be you should use that. As it provides many inbuilt methods and runs on background thread by default.
You can use onFinish() method to execute your call to the activity.
Here is an example of the same.

Try Below Code:
private long ms=0;
private long splashTime=2000;
private boolean splashActive = true;
private boolean paused=false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Hides the titlebar
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.splash);
Thread mythread = new Thread() {
public void run() {
try {
while (splashActive && ms < splashTime) {
if(!paused)
ms=ms+100;
sleep(100);
}
} catch(Exception e) {}
finally {
Intent intent = new Intent(Splash.this, Home.class);
startActivity(intent);
}
}
};
mythread.start();
}
and you can try this also
public class MainActivity extends Activity {
private CountDownTimer countDownTimer;
public TextView text;
private final long startTime = 20 * 1000;
private final long interval = 1 * 1000;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (TextView) findViewById(R.id.textView1);
countDownTimer = new MyCountDownTimer(startTime, interval);
text.setText(String.valueOf(startTime / 1000));
countDownTimer.start();
}
public class MyCountDownTimer extends CountDownTimer {
public MyCountDownTimer(long startTime, long interval) {
super(startTime, interval);
}
#Override
public void onFinish() {
Intent intent = new Intent();
intent.setClass(getApplicationContext(),xxxx.class);
startActivity(intent);
}
#Override
public void onTick(long millisUntilFinished) {
text.setText("" + millisUntilFinished / 1000);
}
}
}

Use runOnUiThread
This acts as a normal Thread and will not allow your UI to sleep.
and the system will not hang.
or you can also use AsyncTask. I will prefer you using AsyncTask.

Use below code to call the function for every 20 seconds.
private Timer timer;
TimerTask refresher;
timer = new Timer();
refresher = new TimerTask() {
public void run() {
// your code to call every 20 seconds.
};
};
// first event immediately, following after 20 seconds each
timer.scheduleAtFixedRate(refresher, 0,1000*20);
Use below lines to show the time :
package com.example.test;
public class MainActivity extends Activity {
private Long startTime;
public native String getLastShotName();
public native String colorNormal();
public native String flipImage();
public native String forceInvertColor();
public native String getLastTitle();
public native String myMethod();
boolean mbFlip = false;
private Timer timer;
private Handler handler = new Handler();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TimerTask refresher;
startTime = System.currentTimeMillis();
handler.removeCallbacks(updateTimer);
handler.postDelayed(updateTimer, 1000);
}
#Override
protected void onResume() {
super.onResume();
handler.postDelayed(updateTimer, 1000);
}
private Runnable updateTimer = new Runnable() {
public void run() {
final TextView time = (TextView) findViewById(R.id.textView1);
Long spentTime = System.currentTimeMillis() - startTime;
Long minius = (spentTime/1000)/60;
Long seconds = (spentTime/1000) % 60;
time.setText(minius+":"+seconds);
handler.postDelayed(this, 1000);
}
};
}

Android: how display images at varying intervals?

I want to display several images with varying intervals, for the time, i can show the pictures but at equal intervals, as may make it show at varying intervals? for example, the first image displayed 5 seconds, the second image 7 seconds, the third image 4 seconds, etc... any ideas and/or examples?
this is my activity that I'm showing the pictures, but in equal intervals:
public class WCourse extends Activity implements OnClickListener, OnTouchListener, OnCompletionListener, OnBufferingUpdateListener{
//mp3 player
private ImageButton buttonPlayPause;
private SeekBar seekBarProgress;
public EditText editTextSongURL;
public static TextView TextViewTopTitle;
//Slider
public int currentimageindex=0;
Timer timer;
TimerTask task;
ImageView slidingimage;
//images ids
private int[] IMAGE_IDS = {
R.drawable.c5_d1, R.drawable.c5_d2, R.drawable.c5_d3, R.drawable.c5_d4, R.drawable.c5_d5,
R.drawable.c5_d6, R.drawable.c5_d7, R.drawable.c5_d8, R.drawable.c5_d9, R.drawable.c5_d10,
R.drawable.c5_d11, R.drawable.c5_d12, R.drawable.c5_d13, R.drawable.c5_d14, R.drawable.c5_d15,
R.drawable.c5_d16, R.drawable.c5_d17, R.drawable.c5_d18, R.drawable.c5_d19, R.drawable.c5_d20,
R.drawable.c5_d21, R.drawable.c5_d22, R.drawable.c5_d23, R.drawable.c5_d24, R.drawable.c5_d25,
R.drawable.c5_d26, R.drawable.c5_d27, R.drawable.c5_d28, R.drawable.c5_d29, R.drawable.c5_d30,
R.drawable.c5_d31, R.drawable.c5_d32, R.drawable.c5_d33, R.drawable.c5_d34, R.drawable.c5_d35,
R.drawable.c5_d36, R.drawable.c5_d37, R.drawable.c5_d38, R.drawable.c5_d39, R.drawable.c5_d40,
R.drawable.c5_d41, R.drawable.c5_d42, R.drawable.c5_d43, R.drawable.c5_d44, R.drawable.c5_d45,
R.drawable.c5_d46
};
//player
private MediaPlayer mediaPlayer;
private int mediaFileLengthInMilliseconds; // this value contains the song duration in milliseconds. Look at getDuration() method in MediaPlayer class
//slider handler
private final Handler handler = new Handler();
/** Called when the activity is first created.
* #param <MyCount>*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.watch_course);
//intent
TextViewTopTitle = (TextView) findViewById(R.id.TextViewTopTitle);
Bundle bundle = getIntent().getExtras();
TextViewTopTitle.setText(bundle.getString("RESULT2")+" ");
getText(bundle.getString("RESULT2"));
final Handler mHandler = new Handler();
initView();
final Runnable mUpdateResults = new Runnable() {
public void run() {
AnimateandSlideShow();
}
};
final int delay = 5000; // delay for xx sec.
final long period = 11000;//repet every xx seconds
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
mHandler.post(mUpdateResults);
}
}, delay, period);}
// Helper method to start the animation on the splash screen
private void AnimateandSlideShow() {
slidingimage = (ImageView)findViewById(R.id.ImageView3_Left);
slidingimage.setImageResource(IMAGE_IDS[currentimageindex%IMAGE_IDS.length]);
currentimageindex++;
slidingimage.getAnimation();}
really would appreciate your help.

public void run(){
try{
Thread.sleep(4000);
}
catch(Exception ex){
Log.e("Welcome Exception :",ex.toString());
}
mHandler.sendEmptyMessage(0);
}

why not use a random generated number instead of the currently specific values?
i mean :
final int delay = 5000; // delay for xx sec.
final long period = 11000;//repet every xx seconds
? seems like an oversite or maybe im reading this wrong