1 /*
2  * Copyright 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.compose.ui.draganddrop
18 
19 import android.graphics.Canvas as AndroidCanvas
20 import android.graphics.Point
21 import android.view.View
22 import androidx.compose.ui.geometry.Size
23 import androidx.compose.ui.graphics.Canvas
24 import androidx.compose.ui.graphics.drawscope.CanvasDrawScope
25 import androidx.compose.ui.graphics.drawscope.DrawScope
26 import androidx.compose.ui.unit.Density
27 import androidx.compose.ui.unit.LayoutDirection
28 
29 /**
30  * Draws a drag shadow for a [View.DragShadowBuilder] with the DrawScope lambda provided by
31  * [drawDragDecoration].
32  */
33 internal class ComposeDragShadowBuilder(
34     private val density: Density,
35     private val decorationSize: Size,
36     private val drawDragDecoration: DrawScope.() -> Unit,
37 ) : View.DragShadowBuilder() {
38 
onProvideShadowMetricsnull39     override fun onProvideShadowMetrics(outShadowSize: Point, outShadowTouchPoint: Point) =
40         with(density) {
41             outShadowSize.set(
42                 decorationSize.width.toDp().roundToPx(),
43                 decorationSize.height.toDp().roundToPx()
44             )
45             outShadowTouchPoint.set(outShadowSize.x / 2, outShadowSize.y / 2)
46         }
47 
onDrawShadownull48     override fun onDrawShadow(canvas: AndroidCanvas) {
49         CanvasDrawScope()
50             .draw(
51                 density = density,
52                 size = decorationSize,
53                 layoutDirection = LayoutDirection.Ltr,
54                 canvas = Canvas(canvas),
55                 block = drawDragDecoration,
56             )
57     }
58 }
59