Convert indefinitely running Runnable from java to kotlin

Question

I have some code like this in java that monitors a certain file:

private Handler mHandler = new Handler();
private final Runnable monitor = new Runnable() {

    public void run() {
        // Do my stuff
        mHandler.postDelayed(monitor, 1000); // 1 second
    }
};

This is my kotlin code:

private val mHandler = Handler()
val monitor: Runnable = Runnable {
    // do my stuff
    mHandler.postDelayed(whatToDoHere, 1000) // 1 second
}

I dont understand what Runnable I should pass into mHandler.postDelayed. What is the right solution? Another interesting thing is that the kotlin to java convertor freezes when I feed this code.

There was an interesting discussion about this same issue recently: https://stackoverflow.com/questions/35100389/writing-a-kotlin-util-function-which-provides-self-reference-in-initializer — Sam, Jun 27 '17 at 21:00

Miha_x64 · Accepted Answer · 2018-07-04T13:17:59.050

48

Lambda-expressions do not have this, but object expressions (anonymous classes) do.

object : Runnable {
    override fun run() {
        handler.postDelayed(this, 1000)
    }
}

edited Jul 04 '18 at 13:17

answered Jun 27 '17 at 21:00

Miha_x64

5,973
1
41
63

score 9 · Answer 2 · answered Jun 27 '17 at 21:06

A slightly different approach which may be more readable

val timer = Timer()
val monitor = object : TimerTask() {
    override fun run() {
        // whatever you need to do every second
    }
}

timer.schedule(monitor, 1000, 1000)

From: Repeat an action every 2 seconds in java

score 2 · Answer 3 · answered Dec 23 '20 at 04:26

runnable display Toast Message "Hello World every 4 seconds

//Inside a class main activity

    val handler: Handler = Handler()
    val run = object : Runnable {
       override fun run() {
           val message: String = "Hello World" // your message
           handler.postDelayed(this, 4000)// 4 seconds
           Toast.makeText(this@MainActivity,message,Toast.LENGTH_SHORT).show() // toast method
       }

   }
    handler.post(run)
}

score 1 · Answer 4 · answered Jun 01 '20 at 05:18

Lambda-expressions do not have this, but object expressions (anonymous classes) do. Then the corrected code would be:

private val mHandler = Handler()
val monitor: Runnable = object : Runnable{
 override fun run() {
                   //any action
                }
                //runnable

            }

 mHandler.postDelayed(monitor, 1000)

score 0 · Answer 5 · edited Apr 30 '22 at 15:45

0

var handler=Handler() 
handler.postDelayed(Runnable { kotlin.run { 

// enter code here

} },2000)

edited Apr 30 '22 at 15:45

Robert Columbia

6,313
15
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answered Apr 30 '22 at 15:40

saeed ghafari

1

Convert indefinitely running Runnable from java to kotlin

5 Answers5