ConstraintItem.swift 2.0 KB

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  1. //
  2. // SnapKit
  3. //
  4. // Copyright (c) 2011-Present SnapKit Team - https://github.com/SnapKit
  5. //
  6. // Permission is hereby granted, free of charge, to any person obtaining a copy
  7. // of this software and associated documentation files (the "Software"), to deal
  8. // in the Software without restriction, including without limitation the rights
  9. // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10. // copies of the Software, and to permit persons to whom the Software is
  11. // furnished to do so, subject to the following conditions:
  12. //
  13. // The above copyright notice and this permission notice shall be included in
  14. // all copies or substantial portions of the Software.
  15. //
  16. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17. // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19. // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22. // THE SOFTWARE.
  23. #if os(iOS) || os(tvOS)
  24. import UIKit
  25. #else
  26. import AppKit
  27. #endif
  28. public final class ConstraintItem {
  29. internal weak var target: AnyObject?
  30. internal let attributes: ConstraintAttributes
  31. internal init(target: AnyObject?, attributes: ConstraintAttributes) {
  32. self.target = target
  33. self.attributes = attributes
  34. }
  35. internal var layoutConstraintItem: LayoutConstraintItem? {
  36. return self.target as? LayoutConstraintItem
  37. }
  38. }
  39. public func ==(lhs: ConstraintItem, rhs: ConstraintItem) -> Bool {
  40. // pointer equality
  41. guard lhs !== rhs else {
  42. return true
  43. }
  44. // must both have valid targets and identical attributes
  45. guard let target1 = lhs.target,
  46. let target2 = rhs.target,
  47. target1 === target2 && lhs.attributes == rhs.attributes else {
  48. return false
  49. }
  50. return true
  51. }