Kotlin update textview every 1 second - kotlin

Question

i want to update text of progressbar and i have this error
i tried but not work anything
some advice?
why i cant update text ?
Thanks!
2021-10-26 22:31:00.555 6192-6227/? E/AndroidRuntime: FATAL EXCEPTION: Timer-0
Process: com.example.myapplication, PID: 6192
android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:8798)
at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:1606)
at android.view.View.requestLayout(View.java:25390)
at android.view.View.requestLayout(View.java:25390)
at android.view.View.requestLayout(View.java:25390)
at android.view.View.requestLayout(View.java:25390)
at android.view.View.requestLayout(View.java:25390)
at android.view.View.requestLayout(View.java:25390)
at androidx.constraintlayout.widget.ConstraintLayout.requestLayout(ConstraintLayout.java:3593)
at android.view.View.requestLayout(View.java:25390)
at androidx.constraintlayout.widget.ConstraintLayout.requestLayout(ConstraintLayout.java:3593)
at android.view.View.requestLayout(View.java:25390)
at android.widget.TextView.checkForRelayout(TextView.java:9719)
at android.widget.TextView.setText(TextView.java:6311)
at android.widget.TextView.setText(TextView.java:6139)
at android.widget.TextView.setText(TextView.java:6091)
at com.example.myapplication.MainActivity$onCreate$1$1$onResponse$2$1.run(MainActivity.kt:84)
at java.util.TimerThread.mainLoop(Timer.java:562)
at java.util.TimerThread.run(Timer.java:512)
class MainActivity() : AppCompatActivity() {
private lateinit var textViewTur: TextView
companion object myCompanion {
var test8: Int = 0
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
textViewTur = findViewById(R.id.textTur)
val url = "http://blynk-cloud.com/b3Uq-vB64Hz1D_X3AJ506Q9OwmQLwha7/get/V5"
val request = Request.Builder().url(url).build()
val client = OkHttpClient()
with(client) {
newCall(request).enqueue(object : Callback {
override fun onFailure(call: Call, e: IOException) {
println("faillllllllllllllllllllllll")
}
override fun onResponse(call: Call, response: Response) {
val body = response.body?.string()
var test = body?.replace("[", "")?.replace("]", "")?.replace("\"", "")
val tboiler = findViewById<CircularProgressBar>(R.id.PB_Tb)
tboiler.apply {
val timer = Timer()
timer.schedule(
object : TimerTask() {
override fun run() {
progress = test?.toFloat()!!
myCompanion.test8 = progress.toInt()
textViewTur.text = progress.toString()
}
},
0,
2000
)
}
}
})
}
}

Answer 1

The Timer class runs its code on a new thread, but you can only update UI elements like TextView from the main thread.
You can use postDelayed on a view to tell it to run code on the main thread after some delay, for example:
tBoiler.apply {
postDelayed(2000L, {
progress = test?.toFloat()!!
myCompanion.test8 = progress.toInt()
textViewTur.text = progress.toString()
})
}
This will not run the code repeatedly. If you want to do that, you could move the delayed action into a separate function that can recursively call itself, and call the function to start the loop. You need to store the runnable in a property if you want to be able to stop the loop.
private val progressRunnable = Runnable {
tBoiler.apply {
progress = test?.toFloat()!!
myCompanion.test8 = progress.toInt()
textViewTur.text = progress.toString()
loopProgress()
}
}
private fun loopProgress() {
tBoiler.postDelayed(2000L, progressRunnable)
}
private fun stopLoopProgress {
tBoiler.removeCallbacks(progressRunnable)
}
Alternatively, your code could be simplified with a coroutine:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
textViewTur = findViewById(R.id.textTur)
lifecycleScope.launch {
val url = "http://blynk-cloud.com/b3Uq-vB64Hz1D_X3AJ506Q9OwmQLwha7/get/V5"
val request = Request.Builder().url(url).build()
val client = OkHttpClient()
val response = try {
client.newCall(request)
} catch (e: IOException) {
println("faillllllllllllllllllllllll")
return#launch
}
val test = response.body?.string()?.filter { it.isDigit() || it == '.' }
.toFloatOrNull()
if (test == null) {
println("body cannot be parsed as Float: ${response.body}")
return#launch
}
val tboiler = findViewById<CircularProgressBar>(R.id.PB_Tb)
while (true) {
delay(2000L)
tboiler.apply {
progress = test
myCompanion.test8 = progress.toInt()
textViewTur.text = progress.toString()
}
}
}
}
// You can put this in a file for http utility functions
public suspend fun Call.await(): Response = suspendCancellableCoroutine { cont ->
enqueue(object : Callback {
override fun onResponse(call: Call, response: Response) {
cont.resume(response)
}
override fun onFailure(call: Call, e: IOException) {
cont.resumeWithException(e)
}
})
cont.invokeOnCancellation {
runCatching { cancel() }
}
}