How do I get the size of a composable AFTER it's been laid out and measured? i.e. I want to know tha...

# compose

[Colton Idle]

How do I get the size of a composable AFTER it's been laid out and measured? i.e. I want to know that my image is laid out on the screen at a final resolution of 200px x 400px.

[Colton Idle]

In standard android-view land, if I wanted to get the size of an imageView being laid out I would do something like this

imageView.viewTreeObserver.addOnPreDrawListener(
       object : ViewTreeObserver.OnPreDrawListener {
           override fun onPreDraw(): Boolean {
               viewTreeObserver.removeOnPreDrawListener(this)
               //get size of view and do something with it.
               return true
    }
})

android ktx made this simpler by adding this

view.doOnPreDraw { 
//get size of view and do something with it.
}

how do I grab this in compose though, without potentially grabbing a size of 0 because it hasn't been laid out?

[Albert Chang]

Modifier.onSizeChanged()

[romainguy]

@Colton Idle from Android-KTX, doOnLayout() is more appropriate

[Colton Idle]

Whoops. @romainguy that's what I meant.

@Albert Chang thanks. I will try that.