97 lines
3.3 KiB
Swift

//
// Property.swift
// Meta
//
// Created by david-swift on 16.09.24.
//
/// Assign an observing and updating closure to a widget's binding property.
///
/// This will be used if you do not provide a custom ``Widget/update(_:data:updateProperties:type:)`` method
/// or call the ``Widget/updateProperties(_:updateProperties:)`` method in your custom update method.
@propertyWrapper
public struct BindingProperty<Value, Pointer>: BindingPropertyProtocol where Value: Sendable {
/// The wrapped binding.
public var wrappedValue: Binding<Value>
/// Observe the UI element.
var observe: @Sendable (Pointer, Binding<Value>, ViewStorage) async -> Void
/// Set the UI element's property.
var setValue: @Sendable (Pointer, Value, ViewStorage) async -> Void
/// Initialize a property.
/// - Parameters:
/// - wrappedValue: The wrapped value.
/// - getProperty: Get the property from the UI.
/// - setProperty: The function applying the property to the UI.
/// - pointer: The type of the pointer.
public init(
wrappedValue: Binding<Value>,
observe: @Sendable @escaping (Pointer, Binding<Value>, ViewStorage) async -> Void,
set setValue: @Sendable @escaping (Pointer, Value, ViewStorage) async -> Void,
pointer: Pointer.Type
) {
self.wrappedValue = wrappedValue
self.observe = observe
self.setValue = setValue
}
/// Initialize a property.
/// - Parameters:
/// - wrappedValue: The wrapped value.
/// - getProperty: Get the property from the UI.
/// - setProperty: The function applying the property to the UI.
/// - pointer: The type of the pointer.
public init(
wrappedValue: Binding<Value>,
observe: @Sendable @escaping (Pointer, Binding<Value>) async -> Void,
set setValue: @Sendable @escaping (Pointer, Value) async -> Void,
pointer: Pointer.Type
) {
self.init(
wrappedValue: wrappedValue,
observe: { pointer, value, _ in await observe(pointer, value) },
set: { pointer, value, _ in await setValue(pointer, value) },
pointer: pointer
)
}
}
/// The binding property protocol.
protocol BindingPropertyProtocol: Sendable {
/// The binding's wrapped value.
associatedtype Value: Sendable
/// The storage's pointer.
associatedtype Pointer
/// The wrapped value.
var wrappedValue: Binding<Value> { get }
/// Observe the property.
var observe: @Sendable (Pointer, Binding<Value>, ViewStorage) async -> Void { get }
/// Set the property.
var setValue: @Sendable (Pointer, Value, ViewStorage) async -> Void { get }
}
extension Widget {
/// Apply a binding property to the framework.
/// - Parameters:
/// - property: The property.
/// - storage: The view storage.
func setBindingProperty<Property>(
property: Property,
storage: ViewStorage
) async where Property: BindingPropertyProtocol {
if let optional = property.wrappedValue.wrappedValue as? any OptionalProtocol, optional.optionalValue == nil {
return
}
if let pointer = await storage.pointer as? Property.Pointer {
await property.setValue(pointer, property.wrappedValue.wrappedValue, storage)
}
}
}