Tokamak/Sources/TokamakCore/Shapes/ShapeStyles/BackgroundStyle.swift

88 lines
2.3 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 7/6/21.
//
public struct BackgroundStyle: ShapeStyle {
public init() {}
public func _apply(to shape: inout _ShapeStyle_Shape) {
if let backgroundStyle = shape.environment._backgroundStyle {
backgroundStyle._apply(to: &shape)
} else {
shape.result = .none
}
}
public static func _apply(to shape: inout _ShapeStyle_ShapeType) {}
}
extension EnvironmentValues {
private struct BackgroundStyleKey: EnvironmentKey {
static let defaultValue: AnyShapeStyle? = nil
}
public var _backgroundStyle: AnyShapeStyle? {
get {
self[BackgroundStyleKey.self]
}
set {
self[BackgroundStyleKey.self] = newValue
}
}
}
public extension View {
@inlinable
func background() -> some View {
modifier(_BackgroundStyleModifier(style: BackgroundStyle()))
}
@inlinable
func background<S>(_ style: S) -> some View where S: ShapeStyle {
modifier(_BackgroundStyleModifier(style: style))
}
}
@frozen
public struct _BackgroundStyleModifier<Style>: ViewModifier, _EnvironmentModifier,
EnvironmentReader
where Style: ShapeStyle
{
public var environment: EnvironmentValues!
public var style: Style
@inlinable
public init(style: Style) {
self.style = style
}
public typealias Body = Never
public mutating func setContent(from values: EnvironmentValues) {
environment = values
}
public func modifyEnvironment(_ values: inout EnvironmentValues) {
values._backgroundStyle = .init(
styles: (primary: style, secondary: style, tertiary: style, quaternary: style),
environment: values
)
}
}
public extension ShapeStyle where Self == BackgroundStyle {
static var background: Self { .init() }
}