38 lines
1.3 KiB
Swift
38 lines
1.3 KiB
Swift
//
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// Copyright 2021 New Vector Ltd
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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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//
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import Foundation
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/**
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Used to avoid retain cycles by creating a proxy that holds a weak reference to the original object.
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One example of that would be using CADisplayLink, which strongly retains its target, when manually invalidating it is unfeasable.
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*/
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class WeakTarget: NSObject {
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private(set) weak var target: AnyObject?
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let selector: Selector
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static let triggerSelector = #selector(WeakTarget.handleTick(parameter:))
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init(_ target: AnyObject, selector: Selector) {
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self.target = target
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self.selector = selector
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}
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@objc private func handleTick(parameter: Any) {
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_ = self.target?.perform(self.selector, with: parameter)
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}
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}
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