I've gone through stackoverflow and all the similar answers - but have found them not of use.
Can anyone please point out why this is not working? It should be simple: update the image every 6 seconds (will be every 3 mins but for testing I've put it as 6 seconds).
What the code does is - goes through each of the 4 images step by step but does not change the image. HOWEVER when it gets to the last image - it does change it(??).
Questions:
What's wrong with this?
Why would it only update the last image?
If I start the code with just a "post" to the handler instead of a "postDelayed" - the tablet just stays with a black screen. Why do I have to start the code with a delay to make it work?
int currentIndex = 0;
boolean start = false;
ImageView descriptionImage;
private Runnable timerRunnable;
long startTime = 0;
private Handler handler;
int[] pictureIds = new int[]{R.drawable.hang, R.drawable.dog, R.drawable.coffee, R.drawable.about};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pictureDescription = new ArrayList<String>();
handler = new Handler(Looper.getMainLooper());
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_picture_test, container, false);
descriptionImage = (ImageView) v.findViewById(R.id.iv_picture);
return v;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
start();
}
private void start() {
start = true;
startTime = System.currentTimeMillis();
loadImage();
timerRunnable = new Runnable() {
#Override
public void run() {
while (start) {
long time = System.currentTimeMillis() - startTime;
float mins = (float) time / (60 * 1000);
if (mins >= 0.1f) {
startTime = System.currentTimeMillis();
if (currentIndex < pictureIds.length) {
currentIndex++;
loadImage();
}
}
}
}
};
handler.postDelayed(timerRunnable, 1000);
}
private void loadImage() {
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
if (currentIndex < pictureIds.length) {
descriptionImage.setImageResource(pictureIds[currentIndex]);
} else {
start = false; // finish
}
}
});
}
Thanks!
EDIT: Doesn't work if I post it to the imageview thread either, instead of the handler.
descriptionImage.postDelayed(timerRunnable, 1000);
What's wrong with this?
while the UI Thread is busy ( while (start) ) , waiting to your condition to became true ( if (mins >= 0.1f) { ), it can't take care of the rest (like drawing).
Why would it only update the last image?
because it can draw only when if (currentIndex < pictureIds.length) { is not true, start becomes false, and the UI thread can finally draw
If I start the code with just a "post" to the handler instead of a
"postDelayed" - the tablet just stays with a black screen. Why do I
have to start the code with a delay to make it work?
see point 1.
if you want to change your image every 3 seconds, you could keep using Handler#postDelayed. E.g.
start = true;
startTime = System.currentTimeMillis();
loadImage();
timerRunnable = new Runnable() {
#Override
public void run() {
currentIndex = currentIndex++ % pictureIds.length;
loadImage();
handler.postDelayed(this, 3000);
}
};
handler.postDelayed(timerRunnable, 3000);
The problem you're facing is that your while loop is running on the main thread. This means the UI never has a chance to update until after the while loop ends (thus why you're only seeing the final image). Try this as your start function:
private void start() {
timerRunnable = new Runnable() {
#Override
public void run() {
if (currentIndex < pictureIds.length) {
loadImage();
currentIndex++;
handler.postDelayed(timerRunnable, 6 * 1000);
}
}
};
handler.post(timerRunnable);
}
Related
I'm currently working on a weather project in Android Studio where I want to schedule image changes in my design background every 5 seconds, I have all the image resources in my #drawable directory. I watched a basic tutorial where they explained some things in the demo but it only helped a little and didn't quite suit me, I'm still confused because I'm getting a lot of errors but I've currently tried these few codes:
HomeActivity.java:
public class HomeActivity extends AppCompatActivity {
public static int count=0;
int[] drawablearray=new int[]{R.drawable.burj_khalifa,R.drawable.central_bank_of_nigeria,R.drawable.eiffel_tower,R.drawable.hong_kong,R.drawable.statue_of_liberty};
Timer _t;
ImageView imageView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
imageView = findViewById(R.id.imageView);
ImageView = (ConstraintLayout) findViewById(R.id.lnMain);
_t = new Timer();
_t.scheduleAtFixedRate(new TimerTask); {
public void run(); {
runOnUiThread(new Runnable() { // run on ui thread
#Override
public void run() {
if (count < drawablearray.length) {
lnMain.setBackgroundDrawable(drawablearray[count]);
count = (count + 1) % drawablearray.length;
}
}
});
}
}, 5000, 5000);
}
}
Any Idea on how to Organize it to suit the design?
final Handler h = new Handler();
Runnable r = new Runnable() {
public void run() {
Home.this.getWindow.setBackgroundDrawableResource(drawableArray[count]);
cout += (count + 1) % drawableArray.length;
h.postDelayed(this, 5000);
}
};
final Runnable r = new Runnable() {
public void run() {
imageView.setBackgroundDrawableResource(drawablearray[count]);
count += (count+1)%(drawablearray.length);
handler.postDelayed(this, 5000);
}
};
And the call is like this:
handler.postDelayed(r,0);
This will call the runnable to execute and handle.postDelayed will run the method every 5000 millsec.
I already fixed the error by using constraintlayout in place of imageview and inmain. I also got id for the layout:
constraintLayout = findViewById(R.id.layout);
constraintLayout.setBackgroundResource(R.drawable.burj_khalifa);
_t = new Timer();
_t.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() { // run on ui thread
#Override
public void run() {
if (count < drawable.length) {
constraintLayout.setBackgroundResource(drawable[count]);
count = (count + 1) % drawable.length;
}
}
});
}
}, 5000, 5000);
}
}
I have created two TextViews and updating their contents through two different handlers, one for each TextView. I am incremented two counters in both handlers, one in each, and posting their values to respective TextView.
My first handler is ticking according to the value of long speed variable, and second handler is ticking 10 times later.
public class Main extends Activity{
private View root;
private final Context context = this;
private int count1 = 0, count2 = 0;
private TextView view1, view2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
init();
}
private void init() {
setContentView(R.layout.s_main);
root = findViewById(R.id.root);
view1 = findViewById(R.id.txv1);
view2 = findViewById(R.id.txv2);
//
ViewTreeObserver vto = root.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
root.getViewTreeObserver().removeOnPreDrawListener(this);
startRuns();
return true;
}
});
}
private void startRuns() {
try {
final long sleep = 10;
final Handler handler1 = new Handler();
handler1.postDelayed(new Runnable() {
#Override
public void run() {
view1.setText(String.valueOf(count1++));
handler1.postDelayed(this, sleep);
}
}, 1);
final Handler handler2 = new Handler();
handler1.postDelayed(new Runnable() {
#Override
public void run() {
view2.setText(String.valueOf(count2++));
handler2.postDelayed(this, sleep * 10);
}
}, 1);
Threads.run = true;
} catch (Exception ex) {
Alerts.alert(context, ex.getMessage());
}
}
}
This is good till the value of speed is 10 or above, but as soon i set the value of speed to 1, both handlers work with same duration or speed. First handler should work with speed of 1, and second handler should work with speed of 10, but both works with speed of 10 ms.
EDIT
In short, minimum delay on which postDelayed is working is 10 ms, not less than that, not 1, not 5, at least 10. I need to run a runnable with 5 ms delay in a project.
Can you please suggest where I am wrong?
In one activity of my app, there are an imagview and a textview that are changing every 3 seconds.
I first set this up with a handler and thread runnable. It works fine, but when I use removeCallbacks with the pause button, it will not pause in the middle of the Thread. It completes the Thread runnable before pausing. I need it to pause when the button is clicked no matter where it is in the runnable.
I thought about using an asynctask but I'm not sure how this would work.
I know there has to be a way to do this, as you can pause almost any game you download. Does anyone have any suggestions on the best/easiest way to do this?
Thanks so much!! :)
public class Workout extends AppCompatActivity {
private String[] messages = {"1", "2", "3", "4", "5"};
final Handler handler = new Handler();
private int nextIndex;
String mDrawableName[] = {"bodypart70", "equipment70", "settings70", "time70", "bodypart70"};
private int nextImage;
ImageView image;
private ProgressBar progressBar;
private int progressStatus = 0;
Runnable r = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.workout);
image = (ImageView) findViewById(R.id.exerciseImage);
final TextView text = (TextView)findViewById(R.id.textView4);
progressBar = (ProgressBar) findViewById(R.id.progressBar1);
//changing
r = new Runnable(){
#Override
public void run(){
if (messages.length > nextIndex) {
//change textview
text.setText(messages[nextIndex++]);
//change image
int resID = getResources().getIdentifier(mDrawableName[nextImage++] , "drawable", getPackageName());
image.setImageResource(resID);
//restart progress bar
progressStatus = 0;
progress();
//do it after 3 seconds
handler.postDelayed(this, 3000);
}
}
};
handler.postDelayed(r, 0);
}
public void progress(){
new Thread(new Runnable() {
public void run() {
long timerEnd = System.currentTimeMillis() + 3 * 1000;
while (timerEnd > System.currentTimeMillis()) {
progressStatus = 3 - (int) (timerEnd - System.currentTimeMillis()) / 1000;
// Update the progress bar
handler.post(new Runnable() {
public void run() {
progressBar.setProgress(progressStatus);
}
});
try {
Thread.sleep(10);
} catch (InterruptedException e) {
Log.w("App", "Progress thread cannot sleep");
}
}
}
}).start();
}
public void pauseWorkout(View view){
handler.removeCallbacks(r);
}
public void resumeWorkout(View view){
handler.postDelayed(r, 0);
}
}
It looks like the while-loop in your progress() function is still working after you press your pause button.
Try the following: Create a global boolean that indicates you're in a paused or resuming state. Put it at the top of your code:
boolean resume = true;
Update your while condition in progress()
while (resume && timerEnd > System.currentTimeMillis()) {
Update your workout functions:
public void pauseWorkout(View view){
handler.removeCallbacks(r);
resume = false;
}
public void resumeWorkout(View view){
handler.postDelayed(r, 0);
resume = true;
}
First, I used animation to hide and show TextView. I saw that using animation costing memory. So I used another way:
SetVisibility(VISIBLE) and SetVisibility(INVISIBLE) with TaskTimer
it works well and it performs better considering the memory.
The main issue is that after a restarting the timer for many times, the TextView disappear.
I need to restart the app to get it back again!
this is the code snippet:
myTimerForAnimation = new Timer();
myTimerForAnimation.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() // run on ui thread
{
public void run() {
counter++;
if (counter < 7) {
if (counter % 2 == 1) {
list_textView[x].setVisibility(View.INVISIBLE);
} else {
list_textView[x].setVisibility(View.VISIBLE);
}
} else {
myTimerForAnimation.cancel();
myTimerForAnimation.purge();
list_textView[x].setVisibility(View.VISIBLE);
}
}
});
}
}, 1000, 600);
Dont use Timer use handler,something like this:
// init the runnables
// the runnable should be members
Handler hanlder = new Handler();//If you arent on the UI thread pass a correct looper
for (int i=1; i<7 ; i++){
long delay = i * 1000;
if (i%2==0)
{
handler.postDelayed(mVisibleRunnable,delay);
}else{
handler.postDelayed(mInVisibleRunnable,delay);
}
}
Whereas the get runnablebs should be memebers because if u choose to cancel the callbacks then call
handler.removeCallbacks(runnable);
Play with it. It should fix your issue.
thanks to #EE66 for the loop idea, I used this code to solve my problem:
private void animateView(final View view){
for (int counter = 0; counter < 7; counter++) {
long delay = counter * 1000;
if (counter % 2 == 0) {
view.postDelayed(new Runnable() {
public void run() {
view.setVisibility(View.VISIBLE);
}
;
}, delay);
} else {
view.postDelayed(new Runnable() {
public void run() {
view.setVisibility(View.INVISIBLE);
}
;
}, delay);
}
}
}
I have a timer in android to countdown to a future date, but it is not refreshing. Any help appreciated. my code is posted below:
public class Activity1 extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView t = (TextView)findViewById(R.id.countdown);
t.setText(timeDif());
I believe that t.setText just needs to be constantly updated, but am unsure of how to do that.
}
public String timeDif()
{
GregorianCalendar then = new GregorianCalendar(2012, 07, 21, 6, 0, 0);
Calendar now = Calendar.getInstance();
long arriveMilli = then.getTimeInMillis();
long nowMilli = now.getTimeInMillis();
long diff = arriveMilli - nowMilli;
int seconds = (int) (diff / 1000);
int minutes = seconds / 60;
seconds %= 60;
int hours = minutes / 60;
minutes %= 60;
int days = hours / 24;
hours %= 24;
String time = days + ":" +zero(hours)+":"+zero(minutes)+":"+zero(seconds);
return time;
}
private int zero(int hours) {
// TODO Auto-generated method stub
return 0;
}
}
The textbox wont update unless you do it in its own thread. The Timer runs on a different thread than the UI. Here is how I did it.
myTimer = new Timer();
myTimerTask = new TimerTask() {
#Override
public void run() {
TimerMethod();
}
};
myTimer.schedule(myTimerTask, 0, 100);
private void TimerMethod()
{
//This method is called directly by the timer
//and runs in the same thread as the timer.
//We call the method that will work with the UI
//through the runOnUiThread method.
if (isPaused != true) {
this.tmrMilliSeconds--;
this.runOnUiThread(Timer_Tick);
}
}
private Runnable Timer_Tick = new Runnable() {
public void run() {
//This method runs in the same thread as the UI.
if (tmrSeconds > 0) {
if (tmrMilliSeconds <= 0) {
tmrSeconds--;
tmrMilliSeconds = 9;
}
} else {
Vibrator v = (Vibrator)getSystemService(Context.VIBRATOR_SERVICE);
v.vibrate(1000);
myTimer.cancel();
tmrSeconds = setTime;
tmrMilliSeconds = 0;
isPaused = true;
}
//Do something to the UI thread here
timerText.setText(String.format("%03d.%d", tmrSeconds, tmrMilliSeconds));
}
};
That is part of the code for a count down clock I made for an ap. It demonstrates how to have one thread run (The public void run()) part, and then another part that runs on the UI thread. Hope that helps.
You shouldn't be doing this with a timer. A timer uses a thread and you don't need one (and it complicates things unnecessarily). You need to use a Runable and Handler's postDelayed method to do it. It is easier and lighter weight.
Handler mHandler = new Handler();
private Runnable mUpdateTimeTask = new Runnable() {
public void run() {
//update here
mHandler.postDelayed(mUpdateTimeTask, 100);
}
};
private void startTimer()
{
mHandler.removeCallbacks(mUpdateTimeTask);
mHandler.postDelayed(mUpdateTimeTask, 100);
}