| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| package androidx.ui.core |
| |
| import androidx.compose.Stable |
| import androidx.compose.ui.graphics.RectangleShape |
| import androidx.compose.ui.graphics.Shape |
| import androidx.compose.ui.unit.Dp |
| import androidx.compose.ui.unit.dp |
| import androidx.compose.ui.util.annotation.FloatRange |
| |
| /** |
| * Creates a [DrawLayerModifier] that draws the shadow. The [elevation] defines the visual |
| * depth of the physical object. The physical object has a shape specified by [shape]. |
| * |
| * Note that [elevation] is only affecting the shadow size and doesn't change the drawing order. |
| * Use [zIndex] modifier if you want to draw the elements with larger [elevation] after all the |
| * elements with a smaller one. |
| * |
| * Example usage: |
| * |
| * @sample androidx.ui.core.samples.DrawShadowSample |
| * |
| * @param elevation The elevation for the shadow in pixels |
| * @param shape Defines a shape of the physical object |
| * @param clip When active, the content drawing clips to the shape. |
| * @param opacity The opacity of the layer, including the shadow. |
| */ |
| @Stable |
| fun Modifier.drawShadow( |
| elevation: Dp, |
| shape: Shape = RectangleShape, |
| clip: Boolean = elevation > 0.dp, |
| @FloatRange(from = 0.0, to = 1.0) opacity: Float = 1f |
| ) = if (elevation > 0.dp || clip || opacity != 1f) { |
| composed { |
| drawLayer( |
| alpha = opacity, |
| shadowElevation = with(DensityAmbient.current) { elevation.toPx() }, |
| shape = shape, |
| clip = clip |
| ) |
| } |
| } else { |
| this |
| } |