Jetpack Compose does not pass the correct constraints to its children

Question

I tested the following code on a physical phone, HUAWEI GR5 KII-L21, running Android Lollipop.

 

@Composable
fun MainScreen() {
    val metrics = LocalContext.current.resources.displayMetrics
    println("the width is ${metrics.widthPixels}")
    println("the height is ${metrics.heightPixels}")

    val configuration = LocalConfiguration.current
    println("height: ${configuration.screenHeightDp.dp}")
    println("width: ${configuration.screenWidthDp.dp}")
    with(LocalDensity.current) {
        println("dp to px: ${210.dp.roundToPx()}")
    }

    BoxWithConstraints(
        modifier = Modifier
            .size(70.dp)
            .background(color = Color.Red)
    ){
        println(constraints)
    }
}

The result in the logcat is:


    I  the width is 1080
    I  the height is 1776

    I  height: 568.0.dp
    I  width: 360.0.dp

    I  dp to px: 630

    I  Constraints(minWidth = 210, maxWidth = 210, minHeight = 210, maxHeight = 210)

First of all, this phone is 5.5'' at 1920x1080. Compose reports 1776x1080. Second, Compose reports a width in dp of 360, but Boxwithconstraints receives a maxWidth of 210 only. I expect it to pass 360 to Boxwithconstraints This, when converted to px, does not match 1080, the physical screen width. Could you shed some light on this?

Jetpack Compose does not pass the correct constraints to its children

0 Answers0