Tokamak/Sources/TokamakCore/App/Scenes/SceneStorage.swift

114 lines
3.1 KiB
Swift

// Copyright 2020-2021 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 7/17/20.
//
import OpenCombineShim
/// The renderer must specify a default `_StorageProvider` before any `SceneStorage`
/// values are accessed.
public enum _DefaultSceneStorageProvider {
public static var `default`: _StorageProvider!
}
@propertyWrapper
public struct SceneStorage<Value>: DynamicProperty {
let key: String
let defaultValue: Value
let store: (_StorageProvider, String, Value) -> ()
let read: (_StorageProvider, String) -> Value?
var objectWillChange: AnyPublisher<(), Never> {
_DefaultSceneStorageProvider.default.publisher.eraseToAnyPublisher()
}
public var wrappedValue: Value {
get {
read(_DefaultSceneStorageProvider.default, key) ?? defaultValue
}
nonmutating set {
store(_DefaultSceneStorageProvider.default, key, newValue)
}
}
public var projectedValue: Binding<Value> {
.init {
wrappedValue
} set: {
wrappedValue = $0
}
}
}
extension SceneStorage: ObservedProperty {}
public extension SceneStorage {
init(wrappedValue: Value, _ key: String) where Value == Bool {
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2) }
read = { $0.read(key: $1) }
}
init(wrappedValue: Value, _ key: String) where Value == Int {
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2) }
read = { $0.read(key: $1) }
}
init(wrappedValue: Value, _ key: String) where Value == Double {
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2) }
read = { $0.read(key: $1) }
}
init(wrappedValue: Value, _ key: String) where Value == String {
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2) }
read = { $0.read(key: $1) }
}
init(wrappedValue: Value, _ key: String) where Value: RawRepresentable,
Value.RawValue == Int
{
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2.rawValue) }
read = {
guard let rawValue = $0.read(key: $1) as Int? else {
return nil
}
return Value(rawValue: rawValue)
}
}
init(wrappedValue: Value, _ key: String)
where Value: RawRepresentable, Value.RawValue == String
{
defaultValue = wrappedValue
self.key = key
store = { $0.store(key: $1, value: $2.rawValue) }
read = {
guard let rawValue = $0.read(key: $1) as String? else {
return nil
}
return Value(rawValue: rawValue)
}
}
}