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 com.android.compose.animation.scene.transformation 18 19 import androidx.compose.ui.unit.IntSize 20 import com.android.compose.animation.scene.Element 21 import com.android.compose.animation.scene.ElementKey 22 import com.android.compose.animation.scene.ElementMatcher 23 import com.android.compose.animation.scene.Scene 24 import com.android.compose.animation.scene.SceneKey 25 import com.android.compose.animation.scene.SceneTransitionLayoutImpl 26 import com.android.compose.animation.scene.TransitionState 27 28 /** Anchor the size of an element to the size of another element. */ 29 internal class AnchoredSize( 30 override val matcher: ElementMatcher, 31 private val anchor: ElementKey, 32 ) : PropertyTransformation<IntSize> { transformnull33 override fun transform( 34 layoutImpl: SceneTransitionLayoutImpl, 35 scene: Scene, 36 element: Element, 37 sceneValues: Element.SceneValues, 38 transition: TransitionState.Transition, 39 value: IntSize, 40 ): IntSize { 41 fun anchorSizeIn(scene: SceneKey): IntSize { 42 val size = layoutImpl.elements[anchor]?.sceneValues?.get(scene)?.size 43 return if (size != null && size != Element.SizeUnspecified) { 44 size 45 } else { 46 value 47 } 48 } 49 50 // This simple implementation assumes that the size of [element] is the same as the size of 51 // the [anchor] in [scene], so simply transform to the size of the anchor in the other 52 // scene. 53 return if (scene.key == transition.fromScene) { 54 anchorSizeIn(transition.toScene) 55 } else { 56 anchorSizeIn(transition.fromScene) 57 } 58 } 59 } 60