Develop Reference

Android view doesn't update when trying to set values over time

I got a fragment which got a control called RingProgress which is simply a ring that fills itself according to a percentage value given. For example, if I do:
ringProgress.setProgress(20);
It means that 20% of the ring will now be filled.
What I'm trying to do is to animate the ring being filled over a few seconds. So what I've tried to do is this:
#Override
public void onResume()
{
super.onResume();
HandlerThread handlerThread = new HandlerThread("countdown");
handlerThread.start();
Handler handler = new Handler(handlerThread.getLooper());
handler.post(new Runnable()
{
#Override
public void run()
{
final Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask()
{
int totalSeconds = secondsToStart + minutesToStart * 60;
int secondsPassed = 0;
#Override
public void run()
{
if(secondsPassed == totalSeconds)
{
timer.cancel();
}
final int currentProgress = (secondsPassed / totalSeconds) * 100;
secondsPassed++;
getActivity().runOnUiThread(new Runnable()
{
#Override
public void run()
{
mRingProgressBar.setProgress(currentProgress);
}
});
}
}, 0, 1000);
}
});
}
The problem is that the update of the ring is not shown until the time is up. For example, if I set it for 5 seconds then when the fragment loads the ring is set to 0, then nothing happens for 5 seconds and then the ring is full with 100% all at once..
How can I start this animation properly?

I guess the problem is with
final int currentProgress = (secondsPassed / totalSeconds) * 100;
secondsPassed / totalSeconds return int value so it will be 0 or 1 only. And you multiply it to 100.
You have to use float or double instead
something like
final int currentProgress = Math.round(((float) secondsPassed)/((float) totalSeconds)*100f);

On this line:
Handler handler = new Handler(handlerThread.getLooper());
You are trying to get the looper from a handlerThread. But how sure you are the looper has already been initialized?
From the documentation of getLooper()
This method returns the Looper associated with this thread. If this thread not been started or for any reason is isAlive() returns false, this method will return null. If this thread has been started, this method will block until the looper has been initialized.
onLooperPrepared() is the callback, where you can be sure, that the Looper has been initialized, and therefore you can construct logics on that.
Thus, what you have to do, is to subclass HandlerThread and create appropriate logics from onLooperPrepared() callback.
Here's a nice post which will help you out. See implementation of MyWorkerThread class there.

Instead of using a handler, you could use a property animator as follows:
ObjectAnimator.ofInt(mRingProgressBar, "progress", 0, 100)
.setDuration(totalSeconds * 1000) //time is in miliseconds
.start();
This will find a method setProgress() in your mRingProgressBarand set the value according to the limits given. In the example above, 0 to 100.
You can read more about it here

Since you want to run on a different thread, you can use this handler in the top of the class:
private int progress = 0;
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
#Override
public void run() {
ringProgress.setProgress(progress);
progress += 20;
if (progress == 100) { //clear??
}
timerHandler.postDelayed(this, 1000);
}
};
In inCreate set the max:
ringProgress.setMax(100);
This will complete the animation within 5 seconds, then you can clear the animation. If you want smaller increments, change the line below (update every tenth of a second), and change the steps
timerHandler.postDelayed(this, 100);

Android Creating a variable that increments once per second

In Java for Android, I want to create a variable that increases by 1 every second, in other words, it counts, that way I can check to see if a function has been called in the past 3 seconds, and if not, I want it to do something different than if it had been.
Is there any built-in way to do this? I'm familiar with the Timer class, but it doesn't seem to work the way I would want it to.. is there anything else?
tl;dr: I want to create a variable that increases by 1 every second, so I can use it to treat a function differently based on how long it has been since its last call. Is there an easy way to do this? If not, what is the hard way to do this?

Why not store the last time the method was called instead, then check it against the current time?
private long timeLastCalled;
public void someMethod() {
timeLastCalled = SystemClock.elapsedRealTime();
}
public boolean someMethodCalledRecently() {
return (SystemClock.elapsedRealTime() - timeLastCalled) > 3000;
}

final int[] yourVariable = new int[1];
yourVariable[0] = 0;
updateVariableTimer = new CountDownTimer(howLongYouWantTimerToLast, 1000) {
#Override
public void onTick(long l) {
yourVariable[0] += 1;
}
}.start();
Or Alternatively to do it with a flag instead of keeping track of variable counting:
final boolean functionCalledRecently = false;
hasFunctionBeenCalledRecentlyTimer = new CountDownTimer(3000, 1000) {
#Override
public void onTick(long l) {
functionCalledRecently = true;
}
#Override
public void onFinish() {
functionCalledRecently = false;
}
}.start();

If you just need to see if the method has been called within the last 3 seconds you can use a Handler and a Boolean flag to acomplish this.
private Handler mHandler = new Handler();
private boolean wasRun = false;
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
if(wasRun){
//whatever you want to do if run
}
mHandler.postDelayed(this, 3000);
}
},3000); //3 sec
In this example the Handler will run on a 3 second delay. Each time it runs it will check to see if the other method was perviously called by evaluating if(wasRun). This way you can change what happens if the method was/was not called. The handler will then start iself again on another 3 second delay. All you have to do then is update the wasRun flag to be true if your method was called, or false if it was not. .

Call a method in variable period on everytime? [duplicate]

This question already exists:
Timer time does not change as variable?
Closed 9 years ago.
I have to call some webservice method in variable times, every time method runs it returns me next period time as long. I tried it with timer but after first calling, it can not understand new variable time.
This is the link asked yesterday something about it: Timer time does not change as variable?
Here is the sample code:
private int V_Time = 1;
.
.
.
try {
final Timer V_Timer;
final Handler V_Handler;
V_Timer = new Timer();
V_Handler = new Handler(Looper.getMainLooper());
V_Timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
V_Handler.post(new Runnable() {
public void run() {
webservice_method();
V_Time = 2; // it returns from method, not manually right as shown
//and it can be change every time method calls..
}
});
}
}, 0, V_Time * 1000 * 60);
} catch (Exception hata) {
}
It works first time after 1 minute, but others does not change (eg 2 min), it works every 1 minute.
I want just it works properly, with timer or without timer with anything else...
I think I may cancel timer but I guess I cannot resume or restart it again.
It must be something to do what I want, but I do not to know how?
I want to change period time, every timer task run what return from method.

What you are trying to achieve is impossible. You have to cancel the current task and reschedule a new one with the new interval.
private TimerTask mTask = new TimerTask() {
#Override
public void run() {
V_Handler.post(new Runnable() {
public void run() {
webservice_method();
V_Time = 2; // it returns from method, not manually right as shown
//and it can be change every time method calls..
V_Timer.cancel();
V_Timer.scheduleAtFixedRate(mTask, 0, V_Time * 1000 * 60);
}
});
}
}
try {
final Timer V_Timer;
final Handler V_Handler;
V_Timer = new Timer();
V_Handler = new Handler(Looper.getMainLooper());
V_Timer.scheduleAtFixedRate(mTask, 0, V_Time * 1000 * 60);
} catch (Exception hata) {
}

Updating UI on button click after a certain time

I have a TextView. I want to update its text (append a "1") after 1 second of a button click.
public class HaikuDisplay extends Activity {
Method m;
Timer t;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
t = new Timer();
m = HaikuDisplay.class.getMethod("change");
}
//Event handler of the button
public void onRefresh(View view)
{
//To have the reference of this inside the TimerTask
final HaikuDisplay hd = this;
TimerTask task1 = new TimerTask(){
public void run(){
/*
* I tried to update the text here but since this is not the UI thread, it does not allow to do so.
*/
//Calls change() method
m.invoke(hd, (Object[])null);
}
};
t.schedule(task1, 1000);
}
public void change()
{
//Appends a "1" to the TextView
TextView t = (TextView)findViewById(R.id.textView1);
t.setText(t.getText() + "1");
}
//Event handler of another button which updates the text directly by appending "2".
//This works fine unless I click the first button.
public void onRefresh1(View view)
{
TextView t = (TextView)findViewById(R.id.textView1);
t.setText(t.getText() + "2");
}
}
Consider all Exceptions be handled.
On first click, m.invoke gives InvocationTargetException. But it calls the method change() on successive invokes without any Exceptions(verified by logging). But it does not update the text. Where am I wrong?
Also, I see in the debugger that it creates a new Thread every time I click the button. That is fine. But why isn't it removing the previous Threads though their execution has been completed?

Do something like this
public void onRefresh1(View v) {
// You can have this in a field not to find it every time
final EditText t = (EditText) findViewById(R.id.textView1);
t.postDelayed(new Runnable() {
#Override
public void run() {
t.append("1");
}
}, 1000);
}

new Handler().postDelayed(new Runnable() {
#Override
public void run() {
// Update UI
}
}, 1000);
implement this on button click
UPDATE:
There are some other answers. dtmilano suggested another solution which is almost same to mine except he is calling the postDelayed method of View class and In my answer I used postDelayed method of handler class.
from the api reference of android the postDelayed method of Handler says
The runnable will be run on the thread to which this handler is
attached.
and the postDelayed method of View says
The runnable will be run on the user interface thread.
This is the only difference between these two solution. in my answer instead of creating new Handler every time you can use any other handler instance. Then the runnable will be run on that thread where that specific handler is declared. And if the postDelayed of EditText is used the the runnable method will be run on the user Interface Thread.
Now the performance issue, both has the same performance (If anybody can prove me wrong with reference I will be happy)

That's looking awful convoluted - have you considered using CountDownTimer instead?
new CountDownTimer(1000, 1000) {
public void onTick(long millisUntilFinished) {
// no-op
}
public void onFinish() {
change();
}
}.start();
This should call change (and hence change the text) on the UI thread, avoiding reflection and threading errors.

Hi Use the following code for that. Hope this will help you .
new java.util.Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
// your code here
}
},
1000
);
Have a look of this question also.
display data after every 10 seconds in Android
You can try with this also.
private Handler handler = new Handler();
private Runnable runnable = new Runnable() {
public void run() {
doStuff();
/*
* Now register it for running next time
*/
handler.postDelayed(this, 1000);
}
};
**EDIT 3**
Try with this once you are need to enable once (i mean if you put your code in yourmethod()== this will get automatically call 1 seconds once.
private Timer timer;
TimerTask refresher;
// Initialization code in onCreate or similar:
timer = new Timer();
refresher = new TimerTask() {
public void run() {
yourmethod();
};
};
// first event immediately, following after 1 seconds each
timer.scheduleAtFixedRate(refresher, 0,100);

Send a number of "Toast"s spaced by 2 seconds

I need to display 4 "Toast"s spaced by 2 seconds between them.
How do I do this in such a way that they wait for each other and that the program itself waits until the last of them has displayed?

simply use handlers.
handler has a method called sendMessageDelayed(Message msg, long delayMillis).
just schedule your messages at the interval of 2 seconds.
here is a sample code.
int i=1;
while(i<5){
Message msg=Message.obtain();
msg.what=0;
hm.sendMessageDealayed(msg, i*2);
i++;
}
now this code will call handler's method handleMessage after every 2 seconds.
here is your Handler
Handler hm = new Handler(){
public void handleMessage(Message msg)
{
//Toast code.
}
};
and you are done.
Thanks.

Handlers are definitely the way to go but I would just postDelayed instead of handling an empty message.
Also extending Toast and creating a method for showing it longer is nice.
Sample Code:
// make sure to declare a handler in the class
private final Handler mHandler = new Handler();
// The method to show longer
/**
* Show the Toast Longer by repeating it.
* Depending upon LENGTH_LONG (3.5 seconds) or LENGTH_SHORT (2 seconds)
* - The number of times to repeat will extend the length by a factor
*
* #param number of times to repeat
*/
public void showLonger(int repeat) {
// initial show
super.show();
// to keep the toast from fading in/out between each show we need to check for what Toast duration is set
int duration = this.getDuration();
if (duration == Toast.LENGTH_SHORT) {
duration = 1000;
} else if (duration == Toast.LENGTH_LONG) {
duration = 2000;
}
for (int i = 1; i <= repeat; i++) {
// show again
handler.postDelayed(new Runnable() {
#Override
public void run() {
show();
}
}, i * duration);
}
}