40 lines
1.2 KiB
Swift
40 lines
1.2 KiB
Swift
// Copyright 2020 Tokamak contributors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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protocol TargetRefType {
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var target: Target? { get set }
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}
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public struct _TargetRef<V: View, T>: View, TargetRefType {
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let binding: Binding<T?>
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let view: V
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var target: Target? {
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get { binding.wrappedValue as? Target }
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set { binding.wrappedValue = newValue as? T }
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}
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public var body: V { view }
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}
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extension View {
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/** Allows capturing target instance of aclosest descendant host view. The resulting instance
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is written to a given `binding`. */
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public func _targetRef<T: Target>(_ binding: Binding<T?>) -> _TargetRef<Self, T> {
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.init(binding: binding, view: self)
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}
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}
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