Anchor extensions.

 * Anchor extensions for multiplicative versions of Axis

Author: Alan Westbrook

Onboarding.xcodeproj/project.pbxproj

@@ -99,7 +99,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0730;
-				LastUpgradeCheck = 0730;
+				LastUpgradeCheck = 0800;
 				ORGANIZATIONNAME = rockwood;
 				TargetAttributes = {
 					E755CDA91CAF236900980DE8 = {
@@ -279,6 +279,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.rockwood.Onboarding;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 				SWIFT_VERSION = 3.0;
 			};
 			name = Release;

Onboarding.xcodeproj/xcshareddata/xcschemes/Onboarding.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0730"
+   LastUpgradeVersion = "0800"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.1</string>
+	<string>1.2</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>

Sources/NSLayoutConstraint+Convenience.swift

@@ -10,41 +10,46 @@ import Foundation
 import UIKit
 
 extension NSLayoutConstraint {
-    // Apple hasn't bothered to make multiplicitave constraints for anchors that aren't dimensions...
-    public class func constraintFor(view:UIView, attribute:NSLayoutAttribute, equalToView:UIView, multiplier:CGFloat) -> NSLayoutConstraint {
-        return NSLayoutConstraint(item: view, 
-                                  attribute: attribute, 
-                                  relatedBy: .equal, 
-                                  toItem: equalToView, 
-                                  attribute: attribute, 
-                                  multiplier: multiplier, 
-                                  constant: 0)
+
+    public class func constraints(for view:UIView, filling:UIView) -> [NSLayoutConstraint] {
+        return [view.leadingAnchor.constraint(equalTo: filling.leadingAnchor),
+                view.trailingAnchor.constraint(equalTo: filling.trailingAnchor),
+                view.topAnchor.constraint(equalTo: filling.topAnchor),
+                view.bottomAnchor.constraint(equalTo: filling.bottomAnchor)]
     }
+}
+
+// Apple hasn't bothered to make multiplicitave constraints for anchors that aren't dimensions...
+// This weird function signature is working around a compiler bug.
+private func con(straint constraint:NSLayoutConstraint, multiplier:CGFloat) -> NSLayoutConstraint {
+    return NSLayoutConstraint(item: constraint.firstItem, attribute: constraint.firstAttribute, relatedBy: constraint.relation, toItem: constraint.secondItem, attribute: constraint.secondAttribute, multiplier: multiplier, constant: constraint.constant)
+}
 
-    public class func constraintFor(view:UIView, attribute:NSLayoutAttribute, lessThanOrEqualToView:UIView, multiplier:CGFloat) -> NSLayoutConstraint {
-        return NSLayoutConstraint(item: view, 
-                                  attribute: attribute, 
-                                  relatedBy: .lessThanOrEqual, 
-                                  toItem: lessThanOrEqualToView, 
-                                  attribute: attribute, 
-                                  multiplier: multiplier, 
-                                  constant: 0)
+extension NSLayoutYAxisAnchor {
+    func constraint(equalTo anchor: NSLayoutAnchor<NSLayoutYAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(equalTo: anchor), multiplier: multiplier)
     }
 
-    public class func constraintFor(view:UIView, attribute:NSLayoutAttribute, greaterThanOrEqualToView:UIView, multiplier:CGFloat) -> NSLayoutConstraint {
-        return NSLayoutConstraint(item: view, 
-                                  attribute: attribute, 
-                                  relatedBy: .greaterThanOrEqual, 
-                                  toItem: greaterThanOrEqualToView, 
-                                  attribute: attribute, 
-                                  multiplier: multiplier, 
-                                  constant: 0)
+    func constraint(lessThanOrEqualTo anchor: NSLayoutAnchor<NSLayoutYAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(lessThanOrEqualTo: anchor), multiplier: multiplier)
+    }
+    
+    func constraint(greaterThanOrEqualTo anchor: NSLayoutAnchor<NSLayoutYAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(greaterThanOrEqualTo: anchor), multiplier: multiplier)
     }
+}
 
-    public class func constraintsFor(view:UIView, fillingParentView:UIView) -> [NSLayoutConstraint] {
-        return [view.leadingAnchor.constraint(equalTo: fillingParentView.leadingAnchor),
-                view.trailingAnchor.constraint(equalTo: fillingParentView.trailingAnchor),
-                view.topAnchor.constraint(equalTo: fillingParentView.topAnchor),
-                view.bottomAnchor.constraint(equalTo: fillingParentView.bottomAnchor)]
+extension NSLayoutXAxisAnchor {
+    func constraint(equalTo anchor: NSLayoutAnchor<NSLayoutXAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(equalTo: anchor), multiplier: multiplier)
+    }
+
+    func constraint(lessThanOrEqualTo anchor: NSLayoutAnchor<NSLayoutXAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(lessThanOrEqualTo: anchor), multiplier: multiplier)
+    }
+
+    func constraint(greaterThanOrEqualTo anchor: NSLayoutAnchor<NSLayoutXAxisAnchor>, multiplier:CGFloat) -> NSLayoutConstraint {
+        return con(straint: super.constraint(greaterThanOrEqualTo: anchor), multiplier: multiplier)
     }
 }
+

Sources/OnboardingPage.swift

@@ -9,7 +9,7 @@
 import UIKit
 
 public 
-protocol OnboardingDoneDelegate {
+protocol OnboardingDoneDelegate: AnyObject {
     func donePressed(_ page:OnboardingPage)
 }
 
@@ -120,7 +120,7 @@ class OnboardingContentPage : OnboardingPage {
         backgroundImageView.contentMode = .scaleAspectFill
 
         insertSubview(backgroundImageView, at: 0)
-        NSLayoutConstraint.activate((NSLayoutConstraint.constraintsFor(view: backgroundImageView, fillingParentView: self)))
+        NSLayoutConstraint.activate((NSLayoutConstraint.constraints(for: backgroundImageView, filling: self)))
     }
 
     private func setupTitleTopStyle() {
@@ -148,20 +148,14 @@ class OnboardingContentPage : OnboardingPage {
     }
 
     private func setupTitleSubordinateStyle() {
-        
-        NSLayoutConstraint(
-            item: foregroundImageView, 
-            attribute: .centerY, 
-            relatedBy: .equal, 
-            toItem: self, 
-            attribute: .centerY, 
-            multiplier: 0.66, 
-            constant: 0).isActive = true
 
         titleLabel.font = UIFont.systemFont(ofSize: 24)
         titleLabel.numberOfLines = 0
-        NSLayoutConstraint.constraintFor(view: titleLabel, attribute: .centerY, equalToView: self, multiplier: 1.25).isActive = true
 
+        NSLayoutConstraint.activate([
+            titleLabel.centerYAnchor.constraint(equalTo: centerYAnchor, multiplier: 1.25),
+            foregroundImageView.centerYAnchor.constraint(equalTo: centerYAnchor, multiplier: 0.66)
+        ])
 
         setupCommonTitleConstraints()
         setupCommonForegroundImageConstraints()
@@ -231,7 +225,7 @@ class OnboardingFinalPage : OnboardingContentPage {
     override public func setupConstraints() {
         super.setupConstraints()
 
-        let buttonYConstraint = NSLayoutConstraint.constraintFor(view: doneButton, attribute: .centerY, equalToView: self, multiplier: 1.7)
+        let buttonYConstraint = doneButton.centerYAnchor.constraint(equalTo: centerYAnchor, multiplier: 1.7)
         buttonYConstraint.priority = UILayoutPriorityDefaultLow
 
         NSLayoutConstraint.activate([

Sources/OnboardingViewController.swift

@@ -215,7 +215,7 @@ class OnboardingViewController: UIViewController, UIScrollViewDelegate, Onboardi
         pager.pageIndicatorTintColor = UIColor.lightGray()
         overlayView.addSubview(pager)
 
-        NSLayoutConstraint.activate(NSLayoutConstraint.constraintsFor(view: overlayView, fillingParentView: view))
+        NSLayoutConstraint.activate(NSLayoutConstraint.constraints(for: overlayView, filling: view))
 
         NSLayoutConstraint.activate([
             pager.leadingAnchor.constraint(equalTo: overlayView.leadingAnchor),
@@ -231,7 +231,7 @@ class OnboardingViewController: UIViewController, UIScrollViewDelegate, Onboardi
         scroller.showsHorizontalScrollIndicator = false
         view.addSubview(scroller)
 
-        NSLayoutConstraint.activate(NSLayoutConstraint.constraintsFor(view: scroller, fillingParentView: view))
+        NSLayoutConstraint.activate(NSLayoutConstraint.constraints(for: scroller, filling: view))
     }
 
     public func scrollViewDidScroll(_ scrollView: UIScrollView) {