How to refresh an android view? - android

I am writing an app, where one of my views need to blink by the use of a timer constantly, but I have trouble with making it blink.
Here's my handler code
#SuppressWarnings("All")
private Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
try {
circle.setVisibility(View.VISIBLE);
Thread.sleep(100);
circle.setVisibility(View.INVISIBLE);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
So i am sending an empty message to the handler with some INTERVAL constantly, and I want the image to get visible for 100 milliseconds and then hide again. But the problem is, until the method is finished, my UI elements won't get refreshed. How I do this?
Thanks in advance.

Thread t = new Thread() {
#Override
public void run() {
try {
while (!isInterrupted()) {
Thread.sleep(1000);
runOnUiThread(new Runnable() {
#Override
public void run() {
if(circle.isVisible()){circle.setVisibility(View.VISIBLE);}
else{
circle.setVisibility(View.INVISIBLE);
}
}
});
}
} catch (InterruptedException e) {
}
}
};
t.start();

private Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
if(msg.what == 1) circle.setVisibility(View.VISIBLE);
if(msg.what == 2) circle.setVisibility(View.INVISIBLE);
}
};
then send message 1 & 2 somewhere.

Here's an example of runnable that toggles visibility and infinitely reposts itself, delayed every 100 miliseconds. The problem that you are having is you are stopping the main UI thread, so nothing else is going to happen and your program is probably freezing right? Anyways, this is one style of solution. Another might be to do the posting in another thread.
final Handler mHandler = new Handler();
final View circle = ....;
Runnable blink = new Runnable() {
#Override
public void run() {
int vis = circle.getVisibility();
if(vis == View.VISIBLE){
circle.setVisibility(View.INVISIBLE);
}else{
circle.setVisibility(View.VISIBLE);
}
mHandler.postDelayed(this, 100);
}
};
mHandler.post(blink);

An alternative to the above solutions (Handler, Thread ...) is to create an Animator and rely on Androids flexible animation capabilities.
In this code-snippet you animate directly on the visibility-property of your View, whereas you need to define a custom TimeInterpolator (which only return two distinct values 0.0 and 1.0) as shown:
final ObjectAnimator anim = ObjectAnimator.ofInt(circle, "visibility",
View.VISIBLE, View.INVISIBLE);
anim.setRepeatMode(Animation.REVERSE);
anim.setRepeatCount(Animation.INFINITE);
anim.setDuration(1000);
anim.setInterpolator(new TimeInterpolator() {
#Override
public float getInterpolation(float input) {
return Math.round(input);
}
});
anim.start();

Related

How to update a textview frequently with a spesific time delay?

I need to update a TextView frequently with a specific time delay in the android studio. The code is below. Thank you.
Edit: I also need to end the loop with a button click or with an "if" control.
//INFLATION CALCULATION !!!
/**
* This method calculates Inflation value.
*/
public void calculateInflation() {
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
}
}, delay*12);
}
Call the same method inside the runnable in order to keep the loop going
Use a flag in order to be able to stop the loop: shouldCalculate
private boolean shouldCalculate = true; // set to false when you want to end the loop
public void calculateInflation() {
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
if (shouldCalculate) {
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
calculateInflation();
}
}
}, delay*12);
}
private Runnable updateTimerThread = new Runnable() {
public void run() {
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
customHandler.postDelayed(this, 0);
}
};
public void startTimer() {
//timer
startTime = SystemClock.uptimeMillis();
customHandler.postDelayed(updateTimerThread, 0);
}
public void stopTimer() {
//timer stops
customHandler.removeCallbacks(updateTimerThread);
//timer ends
}
make a reference of runnable thread , start it using startTimer() and remove thread using stopTimer() as you said on a button click or up on a specific conditions .Also you can change the postDelayed milliseconds as ur wish
Try below code. This will do the trick. If you find any problem please let me know.
public void calculateInflation() {
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
if(shouldRepeat)
calculateInflation();
}
}, delay*12);
}
And second approach can be CountDownTimer. Make a method as shown in below code
public void timerTask(final int loopTime){
//Loop time is the actual time for repeatation
new CountDownTimer(loopTime, 1000) {
public void onTick(long millisUntilFinished) {
//this tells you one second is passed
}
public void onFinish() {
//here on time finish you need to define your task
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
//call the same method again for looping
timerTask(loopTime);
}
}.start();
}
Simplest way. Here updateRunnable calls itself with delay. Make updateRunnable as global variable to access from anywhere.
Runnable updateRunnable = new Runnable() {
#Override
public void run() {
inflation = (cpi-cpiIni)/cpiIni*100;
displayInflation();
cpiIni = cpi;
handler.postDelayed(this, UPDATE_TIME);
}
};
Start handler. Here we start handler immediately without delay.
handler.postDelayed(updateRunnable, 0)
Stop handler
handler.removeCallbacks(updateRunnable)
By the way don't forget to stop handler on onDestroy()

Running backgound thread every X seconds (Android Studio)

I have a code that plays 5 sounds with 1 second delay between the sounds and I want this part of code to be executed every 5 seconds (so it will run in a row so far as a boolean variable is true, and when it becomes false the tread run stopped - I have a button to both start and stop this executions). Everything works perfectly, but the issue is that I can't get rid of the 5 seconds delay in the first time I click the button, so when I first click, the sounds beggins only after 5 seconds. How can I make it start right away and only after the first time start taking the delays?
Here is the button onClick code:
public void clickHandlerStartTempo(final View view) {
if (!tempoOn) {
Toast toast = Toast.makeText(getApplicationContext(), "Start Tempo!", Toast
.LENGTH_SHORT);
toast.show();
tempoOn = true;
final Handler handler = new Handler();
final int delay = 5000; //milliseconds
handler.postDelayed(new Runnable() {
public void run() {
if (tempoOn) {
runCode(view);
handler.postDelayed(this, delay);
}
}
}, delay);
} else {
Toast toast = Toast.makeText(getApplicationContext(), "Stop Tempo!", Toast
.LENGTH_SHORT);
toast.show();
tempoOn = false;
}
}
And here is the runCode method:
public void runCode(View view) {
Runnable runnable = new Runnable() {
#Override
public void run() {
playSound(0);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
for (int i = 0; i < 4; i++) {
if (tempoOn) {
playSound(1);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
} else {
return;
}
}
}
};
Thread thread = new Thread(runnable);
Log.i(TAG, "runCode: Thread id = " + thread.getId());
thread.start();
}
I'm new to android development and any help would be very much appreciated.
Thanks.
First you need to playsound without thread after that you will execute your reaming 5 second logic stop thread after 4 count.
public void onStartPress(){
playSound();
someMethod();
}
public void someMethod(){
Handler uiHandler = new Handler(Looper.getMainLooper());
uiHandler.postDelayed(new Runnable() {
#Override
public void run() {
playSound();
someMethod();
}
},1000);
}
Don't use actual Threads unless you really want to do something off the Ui thread. Most of the time you do want to keep things on the Ui thread.
For simple repeating tasks, you can easily repurpose the CountDownTimer class. Often with an (almost) infinite run time or Long.MAX_VALUE (292 million years). The fist onTick happens immediately after starting.
private CountDownTimer mTimer;
private void start() {
if (mTimer == null) {
mTimer = new CountDownTimer(Long.MAX_VALUE, 5000) {
#Override
public void onTick(long millisUntilFinished) {
// start a beeping countdown
new CountDownTimer(5000, 1000) {
private int state = 1;
#Override
public void onTick(long millisUntilFinished) {
playSound(state);
state = state + 1 % 2;
}
#Override
public void onFinish() {
playSound(0);
}
}.start();
}
#Override
public void onFinish() { /* ignore, never happens */ }
};
mTimer.start();
}
}
private void stop() {
if (mTimer != null) {
mTimer.cancel();
mTimer = null;
}
}

How to make a picture that would be updated every 30 seconds?

How to make a picture that would be updated every 30 seconds ?
ImageView imageView = (ImageView) findViewById(R.id.imageView);
Picasso.with(this).load("http://i.imgur.com/DvpvklR.png").memoryPolicy(MemoryPolicy.NO_CACHE).networkPolicy(NetworkPolicy.NO_CACHE).into(imageView);
You are going to want to use something like a thread to do this.
For example, below your image view:
Runnable imageUpdater = new Runnable() {
#Override
public void run() {
while (true) {
try {
sleep(30000); // 30 seconds in milliseconds
} catch(InterruptedException e) {
// Someone called thread.interrupt() and tried
// to stop the thread executing
return;
}
// Here load the image in the same way as above:
// But you will need to go onto the UI thread first.
image.post(new Runnable() {
public void run() {
Picasso.with(YourActivity.this).load( "http://i.imgur.com/DvpvklR.png").memoryPolicy(MemoryPolicy.NO_CACHE).networkPolicy(NetworkPolicy.NO_CACHE).into(imageView);
}
});
}
}
};
Then you just start the runnable:
Handler handler = new Handler();
handler.post(imageUpdater);
String[] imageLink = {http://i.imgur.com/DvpvklR.png,
http://i.imgur.com/DvpvklR.png, http://i.imgur.com/DvpvklR.png};
int position = 0;
new Timer().scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(runnable);
}
}, 30 * 1000, 30*1000);
Runnable runnable = new Runnable() {
#Override
public void run() {
Picasso.with(this).load(imageLink[position%imageLink.length]).memoryPolicy(MemoryPolicy.NO_CACHE).networkPolicy(NetworkPolicy.NO_CACHE).into(imageView);
position++;
}
};
Hope the above code will help you :)

Android- Updating UI elements with threading

I have a textview which i want to change with a thread and do it again and again (Like a digital clock). But i'm having problems with setting time between 2 changes. Here, the code:
display1 = (TextView) findViewById(R.id.textView1);
Thread timer2 = new Thread(){
#Override
public void run() {
synchronized (this){
runOnUiThread(new Runnable() {
#Override
public void run() {
int i = 0;
display1.setText("" + i);
try {
sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
display1.setText("" + (i+1));
}
});
}
}
};
timer2.start();
This sleep(2000); function makes textview invisible for the given time but i want it stand still till the next change. How can i do that?
But i'm having problems with setting time between 2 changes
Do NOT do sleep() on your UI thread. If you want to chain some actions with the delay, split your code into two runnables and the first one should set display1 and then post second runnable with the delay using postDelayed()
EDIT
want one of them to increase 3 per sec, and the other 5 per sec until they reach 1000 for instance
You can make your Runnable post itself until some criteria are met (i.e. time, counter value etc). Just at the end your Runnable check your conditions and if not met, call postDelayed(this, delay); and you are good.
You should use a Handler instead and dispatch your changes to the UI thread.
Handler mHandler = new Handler();
mHandler.post(new Runnable() {
#Override
public void run() {
// Code to be run right away
}
});
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
// Code to be run after 2 seconds
}
}, 2000);
Maybe split up what you need to do into separate methods. Here you have a UI method and a sleep method split up. Hope it helps
private void myMethod() {
new Thread() {
#Override
public void run() {
int i = 0;
doWorkOnUI(String.valueOf(i));
pause(2000);
doWorkOnUI(String.valueOf(i++));
}
}.start();
}
private void pause(int pauseTime) {
try {
Thread.sleep(pauseTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void doWorkOnUI(final String string) {
runOnUiThread(new Runnable() {
#Override
public void run() {
display1.setText(string);
}
});
}

Android ProgressBar: loading with Timer

Update:
This post was from when I was learning android with android 2.2, be sure to check if this is compatible with the api level you are working with.
Done alot of looking around for how to load progress bar with a timer, I've tried to use methods posted but always would get a pointer exception and or the testing app would crash at start up.
my question is, lol has anyone ran across any tutorials or examples on how to do this? I'm thinking all i need is a while loop but haven't seen that done on a timer yet. I'm a complete noob but am slowly but surely learning
My Timer
final Timer t = new Timer();
t.schedule(new TimerTask() {
public void run() {
d.dismiss(); //MY DIALOG WINDOW
t.cancel();
}
}, 7000);
this is one i have tried to get to work but think i have done more damage then good with it
isRunning = false;
// handler for the background updating
final Handler handler = new Handler() {
public void handleMessage(Message msg) {
total = total - 1;
String perc = String.valueOf(total).toString();
a.setText(perc + " SECONDS until close");
bar.incrementProgressBy(25);
}
};
super.onStart();
// reset the bar to the default value of 0
bar.setProgress(0);
// create a thread for updating the progress bar
Thread background = new Thread(new Runnable() {
public void run() {
try {
for (int i = 4; i < 20 && isRunning; i++) {
// wait 1000ms between each update
Thread.sleep(1000);
handler.sendMessage(handler.obtainMessage());
}
} catch (Throwable t) {
}
}
});
isRunning = true;
// start the background thread
background.start();
hoping someone might be able to shed some light on this for me,, as always sorry for the short generic question, just looking to find out how to load progress bar with timer
tahnks again for any and all help
Use a android.os.CountDownTimer
countDownTimer = new CountDownTimer(length_in_milliseconds,period_in_milliseconds) {
private boolean warned = false;
#Override
public void onTick(long millisUntilFinished_) {
progressBar.progress = (length_in_milliseconds-millisUntilFinished_)/lenght_in_milliseconds*100.0;
}
#Override
public void onFinish() {
// do whatever when the bar is full
}
}.start();
My answer from here:
You could use an ObjectAnimator to animate the progress of the ProgressBar:
ObjectAnimator animation = ObjectAnimator.ofInt(pb, "progress", 0, 100);
animation.setDuration(5000);
animation.setInterpolator(new DecelerateInterpolator());
animation.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animator) { }
#Override
public void onAnimationEnd(Animator animator) {
//do something when the countdown is complete
}
#Override
public void onAnimationCancel(Animator animator) { }
#Override
public void onAnimationRepeat(Animator animator) { }
});
animation.start();

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