CurvedParentData.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.
*/
package androidx.wear.compose.foundation
/**
* A [CurvedModifier] that provides data to the parent layout.
* The parent data is commonly used to inform the parent how the child Layout should be measured
* and positioned.
*
* @param modifyParentData provides a parentData, given the parentData provided through the
* modifier's chain.
*/
public fun CurvedModifier.parentDataModifier(
modifyParentData: (Any?) -> Any?
) = this.then { child -> ParentDataWrapper(child, modifyParentData) }
/**
* Size the element's proportional to its [weight] relative to other weighted sibling
* elements in the container (this will be the height in a [curvedColumn] and the width in a
* [curvedRow]). The parent will divide the space remaining after measuring unweighted child
* elements and distribute it according to this weight.
*
* Example usage:
* @sample androidx.wear.compose.foundation.samples.CurvedWeight
*
* @param weight The proportional size to give to this element, as related to the total of
* all weighted siblings. Must be positive.
*/
public fun CurvedModifier.weight(
/* @FloatRange(from = 0f, fromInclusive = false) */
weight: Float
) = parentDataModifier { parentData ->
require(weight > 0f) { "Weights must be positive." }
((parentData as? CurvedScopeParentData) ?: CurvedScopeParentData()).also {
it.weight = weight
}
}
internal class ParentDataWrapper(
child: CurvedChild,
val modifyParentData: (Any?) -> Any?
) : BaseCurvedChildWrapper(child) {
override fun computeParentData(): Any? = modifyParentData(wrapped.computeParentData())
}
internal data class CurvedScopeParentData(var weight: Float = 0f)