LazyGridItemScopeImpl.kt

/*
 * Copyright 2021 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.compose.foundation.lazy.grid

import androidx.compose.animation.core.FiniteAnimationSpec
import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.ui.Modifier
import androidx.compose.ui.node.ModifierNodeElement
import androidx.compose.ui.node.ParentDataModifierNode
import androidx.compose.ui.platform.InspectorInfo
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.IntOffset

@OptIn(ExperimentalFoundationApi::class)
internal object LazyGridItemScopeImpl : LazyGridItemScope {
    @ExperimentalFoundationApi
    override fun Modifier.animateItemPlacement(animationSpec: FiniteAnimationSpec<IntOffset>) =
        this then AnimateItemPlacementElement(animationSpec)
}

private class AnimateItemPlacementElement(
    val animationSpec: FiniteAnimationSpec<IntOffset>
) : ModifierNodeElement<AnimateItemPlacementNode>() {
    override fun create(): AnimateItemPlacementNode = AnimateItemPlacementNode(animationSpec)

    override fun update(node: AnimateItemPlacementNode): AnimateItemPlacementNode = node.also {
        it.animationSpec = animationSpec
    }

    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (other !is AnimateItemPlacementElement) return false
        return animationSpec != other.animationSpec
    }

    override fun hashCode(): Int {
        return animationSpec.hashCode()
    }

    override fun InspectorInfo.inspectableProperties() {
        name = "animateItemPlacement"
        value = animationSpec
    }
}

private class AnimateItemPlacementNode(
    var animationSpec: FiniteAnimationSpec<IntOffset>
) : Modifier.Node(), ParentDataModifierNode {
    override fun Density.modifyParentData(parentData: Any?): Any = animationSpec
}