Tokamak/Sources/TokamakCore/Preferences/_PreferenceWritingModifier....

53 lines
1.6 KiB
Swift

// Copyright 2020 Tokamak contributors
//
// 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.
//
// Created by Carson Katri on 11/26/20.
//
public struct _PreferenceWritingModifier<Key>: _PreferenceWritingModifierProtocol
where Key: PreferenceKey
{
public let value: Key.Value
public init(key: Key.Type = Key.self, value: Key.Value) {
self.value = value
}
public func body(_ content: Content, with preferenceStore: inout _PreferenceStore) -> AnyView {
preferenceStore.insert(value, forKey: Key.self)
return content.view
}
public static func _makeView(_ inputs: ViewInputs<Self>) -> ViewOutputs {
.init(
inputs: inputs,
preferenceStore: inputs.preferenceStore ?? .init(),
preferenceAction: { $0.insert(inputs.content.value, forKey: Key.self) }
)
}
}
extension _PreferenceWritingModifier: Equatable where Key.Value: Equatable {
public static func == (a: Self, b: Self) -> Bool {
a.value == b.value
}
}
public extension View {
func preference<K>(key: K.Type = K.self, value: K.Value) -> some View
where K: PreferenceKey
{
modifier(_PreferenceWritingModifier<K>(value: value))
}
}