activate

SnapLayout/Classes/SnapLayout.swift

@@ -23,57 +23,66 @@ public extension UIView {
     ///   - height: Constant to apply from heightAnchor  (if nil, not applied)
     ///   - centerX: Constant offset to apply from centerXAnchor  (if nil, not applied)
     ///   - centerY: Constant offset to apply from centerXAnchor  (if nil, not applied)
+    ///   - isActive: Boolean determining if constraint should be activated (default true)
     /// - Note: width and height are not in respect to superview, but always to self
     /// - Returns: SnapManager holding all the values associated with constraints
     @discardableResult
     func snap(to view: UIView? = nil, top: CGFloat? = nil, leading: CGFloat? = nil, bottom: CGFloat? = nil,
               trailing: CGFloat? = nil, width: CGFloat? = nil, height: CGFloat? = nil, centerX: CGFloat? = nil,
-              centerY: CGFloat? = nil) -> SnapManager {
+              centerY: CGFloat? = nil, isActive: Bool = true) -> SnapManager {
         translatesAutoresizingMaskIntoConstraints = false
         var snapManager = SnapManager(view: self)
+        var constraintList = [NSLayoutConstraint]()
+        defer {
+            if isActive {
+                NSLayoutConstraint.activate(constraintList)
+                if constraintList.count == 0 {
+                    print("SnapLayout Error - No constraint was applied for view: \(String(describing: view))")
+                }
+            }
+        }
         if let width = width {
-            snapManager.width = widthAnchor.constraint(equalToConstant: width)
-            snapManager.width?.isActive = true
+            let constraint = widthAnchor.constraint(equalToConstant: width)
+            snapManager.width = constraint
+            constraintList.append(constraint)
         }
         if let height = height {
-            snapManager.height = heightAnchor.constraint(equalToConstant: height)
-            snapManager.height?.isActive = true
+            let constraint = heightAnchor.constraint(equalToConstant: height)
+            snapManager.height = constraint
+            constraintList.append(constraint)
         }
         guard let view = view ?? superview else {
-            if snapManager.width == nil && snapManager.height == nil {
-                print("SnapLayout Error - No constraint was applied for view: \(String(describing: self))")
-            }
             return snapManager
         }
         if let top = top {
-            snapManager.top = topAnchor.constraint(equalTo: view.topAnchor, constant: top)
-            snapManager.top?.isActive = true
+            let constraint = topAnchor.constraint(equalTo: view.topAnchor, constant: top)
+            snapManager.top = constraint
+            constraintList.append(constraint)
         }
         if let leading = leading {
-            snapManager.leading = leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: leading)
-            snapManager.leading?.isActive = true
+            let constraint = leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: leading)
+            snapManager.leading = constraint
+            constraintList.append(constraint)
         }
         if let bottom = bottom {
-            snapManager.bottom = view.bottomAnchor.constraint(equalTo: bottomAnchor, constant: bottom)
-            snapManager.bottom?.isActive = true
+            let constraint = view.bottomAnchor.constraint(equalTo: bottomAnchor, constant: bottom)
+            snapManager.bottom = constraint
+            constraintList.append(constraint)
         }
         if let trailing = trailing {
-            snapManager.trailing = view.trailingAnchor.constraint(equalTo: trailingAnchor, constant: trailing)
-            snapManager.trailing?.isActive = true
+            let constraint = view.trailingAnchor.constraint(equalTo: trailingAnchor, constant: trailing)
+            snapManager.trailing = constraint
+            constraintList.append(constraint)
         }
         if let centerX = centerX {
-            snapManager.centerX = centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: centerX)
-            snapManager.centerX?.isActive = true
+            let constraint = centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: centerX)
+            snapManager.centerX = constraint
+            constraintList.append(constraint)
         }
         if let centerY = centerY {
-            snapManager.centerY = centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: centerY)
-            snapManager.centerY?.isActive = true
-        }
-        let inActiveCount = [snapManager.width, snapManager.height, snapManager.top, snapManager.leading,
-                           snapManager.bottom, snapManager.trailing, snapManager.centerX,
-                           snapManager.centerY].filter ({ $0?.isActive == true }).count
-        if inActiveCount == 0 {
-            print("SnapLayout Error - No constraint was applied for view: \(String(describing: view))")
+            let constraint = centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: centerY)
+            snapManager.centerY = constraint
+            constraintList.append(constraint)
         }
         return snapManager
     }