Fixed SwiftLint warnings with some minor refactors.

.swiftlint.yml

@@ -6,6 +6,7 @@ excluded:
 
 disabled_rules:
   - cyclomatic_complexity
+  - todo
 
 line_length: 100
 

catalog/MDCCatalog/AppDelegate.swift

@@ -23,7 +23,8 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 
   var window: UIWindow?
 
-  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+  func application(_ application: UIApplication, didFinishLaunchingWithOptions
+                   launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
     self.window = MDCCatalogWindow(frame: UIScreen.main.bounds)
 
     let tree = CBCCreateNavigationTree()

catalog/MDCCatalog/MDCCatalogComponentsController.swift

@@ -44,7 +44,10 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
 
     let layout = UICollectionViewFlowLayout()
     let sectionInset: CGFloat = spacing
-    layout.sectionInset = UIEdgeInsets(top: sectionInset, left: sectionInset, bottom: sectionInset, right: sectionInset)
+    layout.sectionInset = UIEdgeInsets(top: sectionInset,
+                                       left: sectionInset,
+                                       bottom: sectionInset,
+                                       right: sectionInset)
     layout.minimumInteritemSpacing = spacing
     layout.minimumLineSpacing = spacing
 
@@ -102,41 +105,10 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
     titleLabel.translatesAutoresizingMaskIntoConstraints = false
 
     containerView.addSubview(titleLabel)
-    _ = NSLayoutConstraint(
-      item: titleLabel,
-      attribute: .leading,
-      relatedBy: .equal,
-      toItem: containerView,
-      attribute: .leading,
-      multiplier: 1.0,
-      constant: titleInsets.left).isActive = true
-
-    _ = NSLayoutConstraint(
-      item: titleLabel,
-      attribute: .trailing,
-      relatedBy: .equal,
-      toItem: containerView,
-      attribute: .trailing,
-      multiplier: 1.0,
-      constant: 0).isActive = true
-
-    _ = NSLayoutConstraint(
-      item: titleLabel,
-      attribute: .bottom,
-      relatedBy: .equal,
-      toItem: containerView,
-      attribute: .bottom,
-      multiplier: 1.0,
-      constant: -titleInsets.bottom).isActive = true
-
-    _ = NSLayoutConstraint(
-      item: titleLabel,
-      attribute: .height,
-      relatedBy: .equal,
-      toItem: nil,
-      attribute: .notAnAttribute,
-      multiplier: 1.0,
-      constant: titleSize.height).isActive = true
+    constrainLabel(label: titleLabel,
+                   containerView: containerView,
+                   insets: titleInsets,
+                   height: titleSize.height)
 
     self.headerViewController.headerView.addSubview(containerView)
 
@@ -183,11 +155,13 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
 
   // MARK: MDCInkTouchControllerDelegate
 
-  func inkTouchController(_ inkTouchController: MDCInkTouchController, shouldProcessInkTouchesAtTouchLocation location: CGPoint) -> Bool {
+  func inkTouchController(_ inkTouchController: MDCInkTouchController,
+                          shouldProcessInkTouchesAtTouchLocation location: CGPoint) -> Bool {
     return self.collectionView!.indexPathForItem(at: location) != nil
   }
 
-  func inkTouchController(_ inkTouchController: MDCInkTouchController, inkViewAtTouchLocation location: CGPoint) -> MDCInkView {
+  func inkTouchController(_ inkTouchController: MDCInkTouchController,
+                          inkViewAtTouchLocation location: CGPoint) -> MDCInkView {
     if let indexPath = self.collectionView!.indexPathForItem(at: location) {
       let cell = self.collectionView!.cellForItem(at: indexPath)
       return self.inkViewForView(cell!)
@@ -197,9 +171,11 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
 
   // MARK: UICollectionViewDelegate
 
-  override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
-    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "MDCCatalogCollectionViewCell",
-      for: indexPath)
+  override func collectionView(_ collectionView: UICollectionView,
+                               cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
+    let cell =
+        collectionView.dequeueReusableCell(withReuseIdentifier: "MDCCatalogCollectionViewCell",
+                                           for: indexPath)
     cell.backgroundColor = UIColor.white
 
     let componentName = self.node.children[indexPath.row].title
@@ -213,7 +189,9 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
     return cell
   }
 
-  func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: IndexPath) -> CGSize {
+  func collectionView(_ collectionView: UICollectionView,
+                      layout collectionViewLayout: UICollectionViewLayout,
+                      sizeForItemAtIndexPath indexPath: IndexPath) -> CGSize {
     let pad = CGFloat(1)
     var cellWidth = (self.view.frame.size.width - 3 * pad) / 2
     if self.view.frame.size.width > self.view.frame.size.height {
@@ -234,6 +212,47 @@ class MDCCatalogComponentsController: UICollectionViewController, MDCInkTouchCon
     self.navigationController?.pushViewController(vc, animated: true)
   }
 
+  // MARK: Private
+  func constrainLabel(label: UILabel,
+                      containerView: UIView,
+                      insets: UIEdgeInsets,
+                      height: CGFloat) {
+    _ = NSLayoutConstraint(
+      item: label,
+      attribute: .leading,
+      relatedBy: .equal,
+      toItem: containerView,
+      attribute: .leading,
+      multiplier: 1.0,
+      constant: insets.left).isActive = true
+
+    _ = NSLayoutConstraint(
+      item: label,
+      attribute: .trailing,
+      relatedBy: .equal,
+      toItem: containerView,
+      attribute: .trailing,
+      multiplier: 1.0,
+      constant: 0).isActive = true
+
+    _ = NSLayoutConstraint(
+      item: label,
+      attribute: .bottom,
+      relatedBy: .equal,
+      toItem: containerView,
+      attribute: .bottom,
+      multiplier: 1.0,
+      constant: -insets.bottom).isActive = true
+
+    _ = NSLayoutConstraint(
+      item: label,
+      attribute: .height,
+      relatedBy: .equal,
+      toItem: nil,
+      attribute: .notAnAttribute,
+      multiplier: 1.0,
+      constant: height).isActive = true
+  }
 }
 
 // UIScrollViewDelegate

catalog/MDCCatalog/MDCCatalogTileView.swift

@@ -52,7 +52,7 @@ class MDCCatalogTileView: UIView {
       let pixelSize = CGSize(width: frame.width * scale, height: frame.height * scale)
       let cachedPixelSize = CGSize(width: cachedImage.size.width * cachedImage.scale,
                                        height: cachedImage.size.height * cachedImage.scale)
-      if (cachedPixelSize != pixelSize) {
+      if cachedPixelSize != pixelSize {
         return createImage()
       }
       return cachedImage
@@ -61,6 +61,9 @@ class MDCCatalogTileView: UIView {
     }
   }
 
+  // This function is long but simple. The name-to-drawing map would be better replaced by a real
+  // dictionary, but Swift's dictionaries can't seem to handle C function pointers.
+  // swiftlint:disable function_body_length
   func createImage() -> UIImage {
     var newImage = UIImage()
 
@@ -122,5 +125,6 @@ class MDCCatalogTileView: UIView {
     imageCache.setObject(newImage, forKey: componentNameString as AnyObject)
     return newImage
   }
+  // swiftlint:enable function_body_length
 
 }