Draw a colored shadow in Android Jetpack Compose

ColoredShadow.kt

/*
Copyright 2020 Cedric Kring.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
    
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import androidx.compose.ui.Modifier
import androidx.compose.ui.drawBehind
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Paint
import androidx.compose.ui.graphics.drawscope.drawIntoCanvas
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp

fun Modifier.drawColoredShadow(
    color: Color,
    alpha: Float = 0.2f,
    borderRadius: Dp = 0.dp,
    shadowRadius: Dp = 20.dp,
    offsetY: Dp = 0.dp,
    offsetX: Dp = 0.dp
) = this.drawBehind {
    val transparentColor = android.graphics.Color.toArgb(color.copy(alpha = 0.0f).value.toLong())
    val shadowColor = android.graphics.Color.toArgb(color.copy(alpha = alpha).value.toLong())
    this.drawIntoCanvas {
        val paint = Paint()
        val frameworkPaint = paint.asFrameworkPaint()
        frameworkPaint.color = transparentColor
        frameworkPaint.setShadowLayer(
            shadowRadius.toPx(),
            offsetX.toPx(),
            offsetY.toPx(),
            shadowColor
        )
        it.drawRoundRect(
            0f,
            0f,
            this.size.width,
            this.size.height,
            borderRadius.toPx(),
            borderRadius.toPx(),
            paint
        )
    }
}

@fatemeh-afshari I can't say which API versions exactly are supported or what's necessary to make it work on your devices. I tested it on my Samsung Galaxy S8 on which it worked perfectly fine. I'd be happy to update the snippet if you find a solution for your problem.

@awBSH Hey Andy, I added a basic license on top of the file. Feel free to use and distribute this snippet :)

@cedrickring Hi Cedric, thank you very much 👍

android.graphics.Color.toArgb( requires API 26+

you can use this version
https://gist.github.com/tasjapr/ed66e6ba1d70cc1c6ff65ae38500a7b4

color.copy(alpha = 0.0f).toArgb()