meta/Sources/View/StateWrapper.swift
2024-06-30 09:48:56 +02:00

98 lines
3.3 KiB
Swift

//
// StateWrapper.swift
// Meta
//
// Created by david-swift on 09.06.24.
//
import Observation
/// A storage for `@State` properties.
public struct StateWrapper: ConvenienceWidget {
/// The content.
var content: () -> Body
/// The state information (from properties with the `State` wrapper).
var state: [String: StateProtocol] = [:]
/// The identifier of the field storing whether to update the wrapper's content.
private var updateID: String { "update" }
/// Initialize a `StateWrapper`.
/// - Parameter content: The view content.
public init(@ViewBuilder content: @escaping () -> Body) {
self.content = content
}
/// Initialize a `StateWrapper`.
/// - Parameters:
/// - content: The view content.
/// - state: The state information.
init(content: @escaping () -> Body, state: [String: StateProtocol]) {
self.content = content
self.state = state
}
/// Update a view storage.
/// - Parameters:
/// - storage: The view storage.
/// - modifiers: Modify views before being updated.
/// - updateProperties: Whether to update properties.
/// - type: The type of the widgets.
public func update<WidgetType>(
_ storage: ViewStorage,
modifiers: [(AnyView) -> AnyView],
updateProperties: Bool,
type: WidgetType.Type
) {
var updateProperties = updateProperties ? true : (storage.fields[updateID] as? Bool ?? false)
storage.fields[updateID] = false
for property in state {
if let oldID = storage.state[property.key]?.id {
StateManager.changeID(old: oldID, new: property.value.id)
storage.state[property.key]?.id = property.value.id
}
if StateManager.getUpdateState(id: property.value.id) {
updateProperties = true
StateManager.updatedState(id: property.value.id)
}
}
guard let storages = storage.content[.mainContent] else {
return
}
content().update(storages, modifiers: modifiers, updateProperties: updateProperties, type: type)
}
/// Get a view storage.
/// - Parameters:
/// - modifiers: Modify views before being updated.
/// - type: The type of the widgets.
/// - Returns: The view storage.
public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
let content = content().storages(modifiers: modifiers, type: type)
let storage = ViewStorage(nil, content: [.mainContent: content])
storage.state = state
if #available(macOS 14, *), #available(iOS 17, *), state.contains(where: { $0.value.isObservable }) {
observe(storage: storage)
}
return storage
}
/// Observe the observable properties accessed in the view.
/// - Parameter storage: The view storage
@available(macOS, introduced: 14)
@available(iOS, introduced: 17)
func observe(storage: ViewStorage) {
withObservationTracking {
_ = content()
} onChange: {
Task {
StateManager.updateState(id: storage.state.first?.value.id ?? .init())
StateManager.updateViews()
observe(storage: storage)
}
}
}
}