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@edwardIshaq
Last active December 15, 2015 22:27
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Generic protocols to map out the properties of DataSource
public protocol Generative {
typealias GeneratedType
var elements: [GeneratedType] { get }
}
public extension Generative {
func count() -> Int {
return elements.count
}
subscript(index:Int) -> GeneratedType? {
if index >= count() {
return nil
}
return elements[index]
}
}
public protocol Selectable {
typealias SelectableType: Hashable
var selectedElements: Set<SelectableType> { get set }
}
extension Selectable {
public func isSelected(elem: SelectableType) -> Bool {
return selectedElements.contains(elem)
}
public mutating func addSelection(elem: SelectableType) {
selectedElements.insert(elem)
}
public mutating func removeSelection(elem: SelectableType) {
selectedElements.remove(elem)
}
public mutating func clearSelections() {
selectedElements.removeAll()
}
}
func selectedIndices<S: Selectable where S: Generative, S.GeneratedType == S.SelectableType>(ds: S) -> [NSIndexPath] {
return ds.selectedElements
.flatMap { (p: S.GeneratedType) -> NSIndexPath? in
if let idx = ds.elements.indexOf(p) { idx
return NSIndexPath(forRow: idx, inSection: 0)
}
return nil
}
}
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