compose/foundation/foundation-layout/src/commonMain/kotlin/androidx/compose/foundation/layout/WindowInsetsSize.kt

/*
 * Copyright 2022 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(ExperimentalLayoutApi::class)

package androidx.compose.foundation.layout

import androidx.compose.runtime.Stable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.layout.Measurable
import androidx.compose.ui.layout.MeasureResult
import androidx.compose.ui.layout.MeasureScope
import androidx.compose.ui.node.LayoutModifierNode
import androidx.compose.ui.node.ModifierNodeElement
import androidx.compose.ui.node.invalidateMeasurement
import androidx.compose.ui.platform.InspectorInfo
import androidx.compose.ui.platform.debugInspectorInfo
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.LayoutDirection

/**
 * Sets the width to that of [insets] at the [start][androidx.compose.ui.Alignment.Start] of the
 * screen, using either [left][WindowInsets.getLeft] or [right][WindowInsets.getRight], depending on
 * the [LayoutDirection].
 *
 * When used, the [WindowInsets] will respect the consumed insets from [windowInsetsPadding] and
 * [consumeWindowInsets], but won't consume any insets.
 *
 * @sample androidx.compose.foundation.layout.samples.insetsStartWidthSample
 */
@Stable
fun Modifier.windowInsetsStartWidth(insets: WindowInsets) =
    this then
        DerivedWidthModifierElement(
            insets,
            debugInspectorInfo {
                name = "insetsStartWidth"
                properties["insets"] = insets
            },
            startCalc,
        )

internal fun interface WindowInsetsWidthCalculator {
    fun calculate(insets: WindowInsets, layoutDirection: LayoutDirection, density: Density): Int
}

private val startCalc = WindowInsetsWidthCalculator { insets, layoutDirection, density ->
    if (layoutDirection == LayoutDirection.Ltr) {
        insets.getLeft(density, layoutDirection)
    } else {
        insets.getRight(density, layoutDirection)
    }
}

/**
 * Sets the width to that of [insets] at the [end][androidx.compose.ui.Alignment.End] of the screen,
 * using either [left][WindowInsets.getLeft] or [right][WindowInsets.getRight], depending on the
 * [LayoutDirection].
 *
 * When used, the [WindowInsets] will respect the consumed insets from [windowInsetsPadding] and
 * [consumeWindowInsets], but won't consume any insets.
 *
 * @sample androidx.compose.foundation.layout.samples.insetsEndWidthSample
 */
@Stable
fun Modifier.windowInsetsEndWidth(insets: WindowInsets) =
    this then
        DerivedWidthModifierElement(
            insets,
            debugInspectorInfo {
                name = "insetsEndWidth"
                properties["insets"] = insets
            },
            endCalc,
        )

private val endCalc = WindowInsetsWidthCalculator { insets, layoutDirection, density ->
    if (layoutDirection == LayoutDirection.Rtl) {
        insets.getLeft(density, layoutDirection)
    } else {
        insets.getRight(density, layoutDirection)
    }
}

/**
 * Sets the height to that of [insets] at the [top][WindowInsets.getTop] of the screen.
 *
 * When used, the [WindowInsets] will respect the consumed insets from [windowInsetsPadding] and
 * [consumeWindowInsets], but won't consume any insets.
 *
 * @sample androidx.compose.foundation.layout.samples.insetsTopHeightSample
 */
@Stable
fun Modifier.windowInsetsTopHeight(insets: WindowInsets) =
    this then
        DerivedHeightModifierElement(
            insets,
            debugInspectorInfo {
                name = "insetsTopHeight"
                properties["insets"] = insets
            },
            topCalc,
        )

internal fun interface WindowInsetsHeightCalculator {
    fun calculate(insets: WindowInsets, density: Density): Int
}

private val topCalc = WindowInsetsHeightCalculator { insets, density -> insets.getTop(density) }

/**
 * Sets the height to that of [insets] at the [bottom][WindowInsets.getBottom] of the screen.
 *
 * When used, the [WindowInsets] will respect the consumed insets from [windowInsetsPadding] and
 * [consumeWindowInsets], but won't consume any insets.
 *
 * @sample androidx.compose.foundation.layout.samples.insetsBottomHeightSample
 */
@Stable
fun Modifier.windowInsetsBottomHeight(insets: WindowInsets) =
    this then
        DerivedHeightModifierElement(
            insets,
            debugInspectorInfo {
                name = "insetsBottomHeight"
                properties["insets"] = insets
            },
            bottomCalc,
        )

private val bottomCalc = WindowInsetsHeightCalculator { insets, density ->
    insets.getBottom(density)
}

private class DerivedWidthModifierElement(
    private val insets: WindowInsets,
    private val inspectorInfo: InspectorInfo.() -> Unit,
    private val widthCalc: WindowInsetsWidthCalculator,
) : ModifierNodeElement<DerivedWidthModifierNode>() {
    override fun create(): DerivedWidthModifierNode = DerivedWidthModifierNode(insets, widthCalc)

    override fun update(node: DerivedWidthModifierNode) {
        node.update(insets, widthCalc)
    }

    override fun InspectorInfo.inspectableProperties() {
        inspectorInfo()
    }

    override fun hashCode(): Int = 31 * insets.hashCode() + widthCalc.hashCode()

    override fun equals(other: Any?): Boolean {
        if (this === other) {
            return true
        }
        if (other !is DerivedWidthModifierElement) {
            return false
        }
        return insets == other.insets && widthCalc === other.widthCalc
    }
}

/**
 * Sets the width based on [widthCalc]. If the width is 0, the height will also always be 0 and the
 * content will not be placed.
 */
private class DerivedWidthModifierNode(
    private var insets: WindowInsets,
    private var widthCalc: WindowInsetsWidthCalculator,
) : InsetsConsumingModifierNode(), LayoutModifierNode {
    private var widthInsets = WindowInsets()

    override fun calculateInsets(ancestorConsumedInsets: WindowInsets): WindowInsets =
        ancestorConsumedInsets

    override fun insetsInvalidated() {
        widthInsets = insets.exclude(ancestorConsumedInsets)
        super.insetsInvalidated()
        invalidateMeasurement()
    }

    fun update(insets: WindowInsets, widthCalc: WindowInsetsWidthCalculator) {
        if (this.insets != insets || widthCalc !== this.widthCalc) {
            this.insets = insets
            this.widthCalc = widthCalc
            widthInsets = insets.exclude(ancestorConsumedInsets)
            invalidateMeasurement()
        }
    }

    override fun MeasureScope.measure(
        measurable: Measurable,
        constraints: Constraints,
    ): MeasureResult {
        val width = widthCalc.calculate(widthInsets, layoutDirection, this)
        if (width == 0) {
            return layout(0, 0) {}
        }
        // check for height first
        val childConstraints = constraints.copy(minWidth = width, maxWidth = width)
        val placeable = measurable.measure(childConstraints)
        return layout(width, placeable.height) { placeable.placeRelative(0, 0) }
    }
}

private class DerivedHeightModifierElement(
    private val insets: WindowInsets,
    private val inspectorInfo: InspectorInfo.() -> Unit,
    private val heightCalc: WindowInsetsHeightCalculator,
) : ModifierNodeElement<DerivedHeightModifierNode>() {
    override fun create(): DerivedHeightModifierNode = DerivedHeightModifierNode(insets, heightCalc)

    override fun update(node: DerivedHeightModifierNode) {
        node.update(insets, heightCalc)
    }

    override fun InspectorInfo.inspectableProperties() {
        inspectorInfo()
    }

    override fun hashCode(): Int = 31 * insets.hashCode() + heightCalc.hashCode()

    override fun equals(other: Any?): Boolean {
        if (this === other) {
            return true
        }
        if (other !is DerivedHeightModifierElement) {
            return false
        }
        return insets == other.insets && heightCalc === other.heightCalc
    }
}

/**
 * Sets the height based on [heightCalc]. If the height is 0, the height will also always be 0 and
 * the content will not be placed.
 */
private class DerivedHeightModifierNode(
    private var insets: WindowInsets,
    private var heightCalc: WindowInsetsHeightCalculator,
) : InsetsConsumingModifierNode(), LayoutModifierNode {
    private var heightInsets = WindowInsets()

    override fun calculateInsets(ancestorConsumedInsets: WindowInsets): WindowInsets =
        ancestorConsumedInsets

    override fun insetsInvalidated() {
        heightInsets = insets.exclude(ancestorConsumedInsets)
        super.insetsInvalidated()
        invalidateMeasurement()
    }

    fun update(insets: WindowInsets, heightCalc: WindowInsetsHeightCalculator) {
        if (this.insets != insets || heightCalc !== this.heightCalc) {
            this.insets = insets
            this.heightCalc = heightCalc
            heightInsets = insets.exclude(ancestorConsumedInsets)
            invalidateMeasurement()
        }
    }

    override fun MeasureScope.measure(
        measurable: Measurable,
        constraints: Constraints,
    ): MeasureResult {
        val height = heightCalc.calculate(heightInsets, this)
        if (height == 0) {
            return layout(0, 0) {}
        }
        // check for height first
        val childConstraints = constraints.copy(minHeight = height, maxHeight = height)
        val placeable = measurable.measure(childConstraints)
        return layout(placeable.width, height) { placeable.placeRelative(0, 0) }
    }
}