change Constraint to protocol

.gitignore

@@ -0,0 +1,2 @@
+project.xcworkspace
+xcuserdata

Snappy/CompositeConstraint.swift

@@ -10,17 +10,23 @@ import UIKit
 
 class CompositeConstraint: Constraint, ConstraintDelegate {
     var children = [Constraint]()
+    weak var delegate: ConstraintDelegate?
     
     init(children: [Constraint]) {
         self.children = children
-        super.init()
         for constraint in children {
             constraint.delegate = self
         }
     }
     
     func constraint(constraint: Constraint, shouldBeReplacedWithConstraint replacementConstraint: Constraint) {
-        var index = find(self.children, constraint)
+        var index: Int?
+        for (i, c) in enumerate(self.children) {
+            if (c === constraint) {
+                index = i
+            }
+        }
+        
         if (index) {
             self.children[index!] = replacementConstraint
         }
@@ -33,4 +39,69 @@ class CompositeConstraint: Constraint, ConstraintDelegate {
         return newConstraint
     }
 
+    var left: Constraint { return addConstraint(.Left) }
+    var top: Constraint { return addConstraint(.Top) }
+    var right: Constraint { return addConstraint(.Right) }
+    var bottom: Constraint { return addConstraint(.Bottom) }
+    var leading: Constraint { return addConstraint(.Leading) }
+    var trailing: Constraint { return addConstraint(.Trailing) }
+    var width: Constraint { return addConstraint(.Width) }
+    var height: Constraint { return addConstraint(.Height) }
+    var centerX: Constraint { return addConstraint(.CenterX) }
+    var centerY: Constraint { return addConstraint(.CenterY) }
+    var baseline: Constraint { return addConstraint(.Baseline) }
+    
+    var and: Constraint { return self }
+    var with: Constraint { return self }
+    
+    func addConstraint(NSLayoutAttribute) -> Constraint {
+        return self;
+    }
+    
+    func equalTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func greaterThanOrEqualTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func lessThanOrEqualTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func insets(insets: Any) -> Constraint {
+        return self
+    }
+    
+    func offset(offset: Any) -> Constraint {
+        return self
+    }
+    
+    func multipliedBy(multiplier: Float) -> Constraint {
+        return self
+    }
+    
+    func dividedBy(divider: Float) -> Constraint {
+        return self
+    }
+    
+    func priority(priority: UILayoutPriority) -> Constraint {
+        return self
+    }
+    
+    func priorityLow() -> Constraint {
+        return self
+    }
+    
+    func priorityMedium() -> Constraint {
+        return self
+    }
+    
+    func priorityHigh() -> Constraint {
+        return self
+    }
+    
+    func install() {
+    }
 }

Snappy/Constraint.swift

@@ -13,78 +13,49 @@ import UIKit
     func constraint(constraint: Constraint?, addConstraintWithLayoutAttribute layoutAttribute: NSLayoutAttribute) -> Constraint
 }
 
-class Constraint: Equatable {
-    weak var delegate: ConstraintDelegate?
-    
-    init() {
-        
-    }
+typealias Delegate = ConstraintDelegate?
+
+@class_protocol protocol Constraint {
+    weak var delegate: Delegate { get set }
+
+    var left: Constraint { get }
+    var top: Constraint { get }
+    var right: Constraint { get }
+    var bottom: Constraint { get }
+    var leading: Constraint { get }
+    var trailing: Constraint { get }
+    var width: Constraint { get }
+    var height: Constraint { get }
+    var centerX: Constraint { get }
+    var centerY: Constraint { get }
+    var baseline: Constraint { get }
     
-    var left: Constraint { return Constraint() }
-    var top: Constraint { return Constraint() }
-    var right: Constraint { return Constraint() }
-    var bottom: Constraint { return Constraint() }
-    var leading: Constraint { return Constraint() }
-    var trailing: Constraint { return Constraint() }
-    var width: Constraint { return Constraint() }
-    var height: Constraint { return Constraint() }
-    var centerX: Constraint { return Constraint() }
-    var centerY: Constraint { return Constraint() }
-    var baseline: Constraint { return Constraint() }
+    var and: Constraint { get }
+    var with: Constraint { get }
     
-    var and: Constraint { return self }
-    var with: Constraint { return self }
+    func addConstraint(NSLayoutAttribute) -> Constraint
     
-    func equalTo(attr: Any) -> Constraint {
-        return self
-    }
+    func equalTo(attr: Any) -> Constraint
     
-    func greaterThanOrEqualTo(attr: Any) -> Constraint {
-        return self
-    }
+    func greaterThanOrEqualTo(attr: Any) -> Constraint
     
-    func lessThanOrEqualTo(attr: Any) -> Constraint {
-        return self
-    }
+    func lessThanOrEqualTo(attr: Any) -> Constraint
     
-    func insets(insets: Any) -> Constraint {
-        return self
-    }
+    func insets(insets: Any) -> Constraint
     
-    func offset(offset: Any) -> Constraint {
-        return self
-    }
+    func offset(offset: Any) -> Constraint
     
-    func multipliedBy(multiplier: Float) -> Constraint {
-        return self
-    }
+    func multipliedBy(multiplier: Float) -> Constraint
     
-    func dividedBy(divider: Float) -> Constraint {
-        return self
-    }
+    func dividedBy(divider: Float) -> Constraint
     
-    func priority(priority: UILayoutPriority) -> Constraint {
-        return self
-    }
+    func priority(priority: UILayoutPriority) -> Constraint
     
-    func priorityLow() -> Constraint {
-        return self
-    }
+    func priorityLow() -> Constraint
     
-    func priorityMedium() -> Constraint {
-        return self
-    }
+    func priorityMedium() -> Constraint
     
-    func priorityHigh() -> Constraint {
-        return self
-    }
+    func priorityHigh() -> Constraint
     
-    func install() {
-        
-    }
+    func install()
 }
-
-
-@infix func ==(lhs: Constraint, rhs: Constraint) -> Bool {
-    return lhs === rhs;
-}

Snappy/ConstraintMaker.swift

@@ -59,7 +59,13 @@ class ConstraintMaker: ConstraintDelegate {
     }
     
     func constraint(constraint: Constraint, shouldBeReplacedWithConstraint replacementConstraint: Constraint) {
-        var index = find(self.constraints, constraint)
+        var index: Int?
+        for (i, c) in enumerate(self.constraints) {
+            if (c === constraint) {
+                index = i
+            }
+        }
+        
         if (index) {
             self.constraints[index!] = replacementConstraint
         }

Snappy/ViewConstraint.swift

@@ -10,14 +10,87 @@ import UIKit
 
 class ViewConstraint: Constraint {
     weak var view: View?
+    
     var firstViewAttribute: ViewAttribute
-    var layoutPriority: UILayoutPriority
+    var secondViewAttribute: ViewAttribute?
+    
+    var layoutPriority = 1000.0// UILayoutPriorityRequired gives error?!
     var layoutMultiplier = 1.0
+    var layoutConstraint: NSLayoutConstraint?
+    var layoutRelation = NSLayoutRelation.Equal
+    var layoutConstant = 0.0
+    var hasLayoutRelation = false;
+    
+    weak var delegate: ConstraintDelegate?
     
     init(view: View, firstViewAttribute: ViewAttribute)  {
         self.view = view;
         self.firstViewAttribute = firstViewAttribute;
-        self.layoutPriority = 750 //UILayoutPriorityRequired gives build error!?
-        super.init()
+    }
+    
+    var left: Constraint { return addConstraint(.Left) }
+    var top: Constraint { return addConstraint(.Top) }
+    var right: Constraint { return addConstraint(.Right) }
+    var bottom: Constraint { return addConstraint(.Bottom) }
+    var leading: Constraint { return addConstraint(.Leading) }
+    var trailing: Constraint { return addConstraint(.Trailing) }
+    var width: Constraint { return addConstraint(.Width) }
+    var height: Constraint { return addConstraint(.Height) }
+    var centerX: Constraint { return addConstraint(.CenterX) }
+    var centerY: Constraint { return addConstraint(.CenterY) }
+    var baseline: Constraint { return addConstraint(.Baseline) }
+    
+    var and: Constraint { return self }
+    var with: Constraint { return self }
+    
+    func addConstraint(NSLayoutAttribute) -> Constraint {
+        return self;
+    }
+    
+    func equalTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func greaterThanOrEqualTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func lessThanOrEqualTo(attr: Any) -> Constraint {
+        return self
+    }
+    
+    func insets(insets: Any) -> Constraint {
+        return self
+    }
+    
+    func offset(offset: Any) -> Constraint {
+        return self
+    }
+    
+    func multipliedBy(multiplier: Float) -> Constraint {
+        return self
+    }
+    
+    func dividedBy(divider: Float) -> Constraint {
+        return self
+    }
+    
+    func priority(priority: UILayoutPriority) -> Constraint {
+        return self
+    }
+    
+    func priorityLow() -> Constraint {
+        return self
+    }
+    
+    func priorityMedium() -> Constraint {
+        return self
+    }
+    
+    func priorityHigh() -> Constraint {
+        return self
+    }
+    
+    func install() {
     }
 }