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@cedrickring
Last active September 5, 2024 21:56
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Draw a colored shadow in Android Jetpack Compose
/*
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
)
}
}
@tasjapr
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tasjapr commented Sep 12, 2022

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

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

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

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