CODEWITHSUNDEEP
androidandroid-runonuithread
Kamalakannan J
Kamalakannan J

Reputation: 2998

Android : runOnUiThread not working, working if user touches screen

When I do some processing in the background thread and wants to update the UI using runOnUiThread(), the code inside the function is running successfully without any error, but the UI gets rendered only if the user touches the screen. Otherwise, it's rendering consistently.

Why it's rendering only after touching the screen ?

Upvotes: 0

Views: 421

Answers (3)

savepopulation
savepopulation

Reputation: 11921

It's possible that an operation is blocking (for example notifying an adapter too often) your ui thread and gets unblocked with an interrupt occurs. Touching the screen is an interrupt in your scenario.

If you paste your code maybe we can find an exact solution.

Edit: Debounce example code with RxJava

          yourSearchObservable
            .throttleLast(100, TimeUnit.MILLISECONDS)
            .debounce(200, TimeUnit.MILLISECONDS)
            .onBackpressureLatest()
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(
                    searchResults -> {
                        // Your success

                   } ,
                    () -> {
                        // Error
                    }
            ));

Upvotes: 2

Volodymyr Shalashenko
Volodymyr Shalashenko

Reputation: 159

Try using callbacks or android.os.Handler.post() to interact with the Main Thread

Upvotes: 1

Alex Shutov
Alex Shutov

Reputation: 3282

It is possible if your screen gets overlapped by another screen. This causing Activity to move to paused state (.onPause()) method. when you touch it again, it become foreground again so can receive UI update events

Upvotes: 2

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