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May 23, 2017 13:38
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MulticastDelegate
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import Foundation | |
/** | |
* `MulticastDelegate` lets you easily create a "multicast delegate" for a given protocol or class. | |
*/ | |
open class MulticastDelegate<T> { | |
/// The delegates hash table. | |
private let delegates: NSHashTable<AnyObject> | |
/** | |
* Use this method to initialize a new `MulticastDelegate` specifying whether delegate references should be weak or | |
* strong. | |
* | |
* - parameter strongReferences: Whether delegates should be strongly referenced, false by default. | |
* | |
* - returns: A new `MulticastDelegate` instance | |
*/ | |
public init(strongReferences: Bool = false) { | |
delegates = strongReferences ? NSHashTable<AnyObject>() : NSHashTable<AnyObject>.weakObjects() | |
} | |
/** | |
* Use this method to initialize a new `MulticastDelegate` specifying the storage options yourself. | |
* | |
* - parameter options: The underlying storage options to use | |
* | |
* - returns: A new `MulticastDelegate` instance | |
*/ | |
public init(options: NSPointerFunctions.Options) { | |
delegates = NSHashTable(options: options, capacity: 0) | |
} | |
/** | |
* Use this method to add a delelgate. | |
* | |
* Alternatively, you can use the `+=` operator to add a delegate. | |
* | |
* - parameter delegate: The delegate to be added. | |
*/ | |
public func addDelegate(_ delegate: T) { | |
delegates.add(delegate as AnyObject) | |
} | |
/** | |
* Use this method to remove a previously-added delegate. | |
* | |
* Alternatively, you can use the `-=` operator to add a delegate. | |
* | |
* - parameter delegate: The delegate to be removed. | |
*/ | |
public func removeDelegate(_ delegate: T) { | |
delegates.remove(delegate as AnyObject) | |
} | |
/** | |
* Use this method to invoke a closure on each delegate. | |
* | |
* Alternatively, you can use the `|>` operator to invoke a given closure on each delegate. | |
* | |
* - parameter invocation: The closure to be invoked on each delegate. | |
*/ | |
public func invokeDelegates(_ invocation: (T) -> ()) { | |
for delegate in delegates.allObjects { | |
invocation(delegate as! T) | |
} | |
} | |
/** | |
* Use this method to determine if the multicast delegate contains a given delegate. | |
* | |
* - parameter delegate: The given delegate to check if it's contained | |
* | |
* - returns: `true` if the delegate is found or `false` otherwise | |
*/ | |
public func containsDelegate(_ delegate: T) -> Bool { | |
return delegates.contains(delegate as AnyObject) | |
} | |
} | |
/** | |
* Use this operator to add a delegate. | |
* | |
* This is a convenience operator for calling `addDelegate`. | |
* | |
* - parameter left: The multicast delegate | |
* - parameter right: The delegate to be added | |
*/ | |
public func +=<T>(left: MulticastDelegate<T>, right: T) { | |
left.addDelegate(right) | |
} | |
/** | |
* Use this operator to remove a delegate. | |
* | |
* This is a convenience operator for calling `removeDelegate`. | |
* | |
* - parameter left: The multicast delegate | |
* - parameter right: The delegate to be removed | |
*/ | |
public func -=<T>(left: MulticastDelegate<T>, right: T) { | |
left.removeDelegate(right) | |
} | |
/** | |
* Use this operator invoke a closure on each delegate. | |
* | |
* This is a convenience operator for calling `invokeDelegates`. | |
* | |
* - parameter left: The multicast delegate | |
* - parameter right: The closure to be invoked on each delegate | |
* | |
* - returns: The `MulticastDelegate` after all its delegates have been invoked | |
*/ | |
precedencegroup MulticastPrecedence { | |
associativity: left | |
higherThan: TernaryPrecedence | |
} | |
infix operator |> : MulticastPrecedence | |
public func |><T>(left: MulticastDelegate<T>, right: (T) -> ()) { | |
left.invokeDelegates(right) | |
} |
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