commonMain.androidx.compose.animation.RenderInTransitionOverlayNodeElement.kt Maven / Gradle / Ivy

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/*
 * Copyright 2024 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.
 */

@file:OptIn(ExperimentalSharedTransitionApi::class)

package androidx.compose.animation

import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableFloatStateOf
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Path
import androidx.compose.ui.graphics.drawscope.ContentDrawScope
import androidx.compose.ui.graphics.drawscope.DrawScope
import androidx.compose.ui.graphics.drawscope.clipPath
import androidx.compose.ui.graphics.drawscope.translate
import androidx.compose.ui.graphics.layer.GraphicsLayer
import androidx.compose.ui.graphics.layer.drawLayer
import androidx.compose.ui.modifier.ModifierLocalModifierNode
import androidx.compose.ui.node.DrawModifierNode
import androidx.compose.ui.node.ModifierNodeElement
import androidx.compose.ui.node.requireDensity
import androidx.compose.ui.node.requireGraphicsContext
import androidx.compose.ui.node.requireLayoutCoordinates
import androidx.compose.ui.platform.InspectorInfo
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.LayoutDirection

internal data class RenderInTransitionOverlayNodeElement(
    var sharedTransitionScope: SharedTransitionScopeImpl,
    var renderInOverlay: () -> Boolean,
    val zIndexInOverlay: Float,
    val clipInOverlay: (LayoutDirection, Density) -> Path?
) : ModifierNodeElement() {
    override fun create(): RenderInTransitionOverlayNode {
        return RenderInTransitionOverlayNode(
            sharedTransitionScope, renderInOverlay, zIndexInOverlay, clipInOverlay
        )
    }

    override fun update(node: RenderInTransitionOverlayNode) {
        node.sharedScope = sharedTransitionScope
        node.renderInOverlay = renderInOverlay
        node.zIndexInOverlay = zIndexInOverlay
        node.clipInOverlay = clipInOverlay
    }

    override fun hashCode(): Int =
        ((sharedTransitionScope.hashCode() * 31 + renderInOverlay.hashCode()) * 31 +
            zIndexInOverlay.hashCode()) * 31 + clipInOverlay.hashCode()

    override fun equals(other: Any?): Boolean {
        if (other is RenderInTransitionOverlayNodeElement) {
            return sharedTransitionScope == other.sharedTransitionScope &&
                renderInOverlay === other.renderInOverlay &&
                zIndexInOverlay == other.zIndexInOverlay &&
                clipInOverlay === other.clipInOverlay
        }
        return false
    }

    override fun InspectorInfo.inspectableProperties() {
        name = "renderInSharedTransitionOverlay"
        properties["sharedTransitionScope"] = sharedTransitionScope
        properties["renderInOverlay"] = renderInOverlay
        properties["zIndexInOverlay"] = zIndexInOverlay
        properties["clipInOverlayDuringTransition"] = clipInOverlay
    }
}

internal class RenderInTransitionOverlayNode(
    var sharedScope: SharedTransitionScopeImpl,
    var renderInOverlay: () -> Boolean,
    zIndexInOverlay: Float,
    var clipInOverlay: (LayoutDirection, Density) -> Path?,
) : Modifier.Node(), DrawModifierNode, ModifierLocalModifierNode {
    var zIndexInOverlay by mutableFloatStateOf(zIndexInOverlay)

    val parentState: SharedElementInternalState?
        get() = ModifierLocalSharedElementInternalState.current

    private inner class LayerWithRenderer(val layer: GraphicsLayer) : LayerRenderer {
        override val parentState: SharedElementInternalState?
            get() = [email protected]

        override val zIndex: Float
            get() = [email protected]

        override fun drawInOverlay(drawScope: DrawScope) {
            if (renderInOverlay()) {
                with(drawScope) {
                    val (x, y) = sharedScope.root.localPositionOf(
                        [email protected](), Offset.Zero
                    )
                    val clipPath = clipInOverlay(layoutDirection, requireDensity())
                    if (clipPath != null) {
                        clipPath(clipPath) {
                            translate(x, y) {
                                drawLayer(layer)
                            }
                        }
                    } else {
                        translate(x, y) {
                            drawLayer(layer)
                        }
                    }
                }
            }
        }
    }

    // Render in-place logic. Depending on the result of `renderInOverlay()`, the content will
    // either render in-place or in the overlay, but never in both places.
    override fun ContentDrawScope.draw() {
        val layer = requireNotNull(layer) {
            "Error: layer never initialized"
        }
        layer.record {
            [email protected]()
        }
        if (!renderInOverlay()) {
            drawLayer(layer)
        }
    }

    val layer: GraphicsLayer?
        get() = layerWithRenderer?.layer
    private var layerWithRenderer: LayerWithRenderer? = null
    override fun onAttach() {
        LayerWithRenderer(requireGraphicsContext().createGraphicsLayer()).let {
            sharedScope.onLayerRendererCreated(it)
            layerWithRenderer = it
        }
    }

    override fun onDetach() {
        layerWithRenderer?.let {
            sharedScope.onLayerRendererRemoved(it)
            requireGraphicsContext().releaseGraphicsLayer(it.layer)
        }
    }
}