SnapKit/Source/LayoutConstraint.swift

81 lines
2.6 KiB
Swift

//
// SnapKit
//
// Copyright (c) 2011-Present SnapKit Team - https://github.com/SnapKit
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#if os(iOS) || os(tvOS)
import UIKit
#else
import AppKit
#endif
public class LayoutConstraint : NSLayoutConstraint {
public var label: String? {
get {
return self.identifier
}
set {
self.identifier = newValue
}
}
internal weak var constraint: Constraint? = nil
}
internal func ==(lhs: LayoutConstraint, rhs: LayoutConstraint) -> Bool {
#if os(OSX)
// ensure first anchor items match
guard let item1 = lhs.firstAnchor.item,
let item2 = rhs.firstAnchor.item,
item1 === item2 else {
return false
}
// ensure second anchor items match
guard ((lhs.secondAnchor?.item == nil && rhs.secondAnchor?.item == nil) ||
(lhs.secondAnchor?.item === rhs.secondAnchor?.item)) else {
return false
}
#else
guard lhs.firstAnchor == rhs.firstAnchor else {
return false
}
guard ((lhs.secondAnchor == nil && rhs.secondAnchor == nil) ||
(lhs.secondAnchor! == rhs.secondAnchor!)) else {
return false
}
#endif
// ensure attributes, relation, priorty and multiplier match
guard lhs.firstAttribute == rhs.firstAttribute &&
lhs.secondAttribute == rhs.secondAttribute &&
lhs.relation == rhs.relation &&
lhs.priority == rhs.priority &&
lhs.multiplier == rhs.multiplier else {
return false
}
return true
}