Closes #1568: Change truncated method to use Swift 4 (#1602)

* Closes #1568: Changing to truncate using Swift 4 methods, removing unused methods in String Extension and tests

* Correct lint issues

* #1568: Refactoring code into UIConstants

* Resolved lint issues

Blockzilla.xcodeproj/project.pbxproj

@@ -7,7 +7,6 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
-		050E8B1E2064FECE00DF6090 /* StringExtensionTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 050E8B1D2064FECE00DF6090 /* StringExtensionTest.swift */; };
 		0B0D6BC41F3CDDBB00497D08 /* CollapsedURLTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0B0D6BC31F3CDDBB00497D08 /* CollapsedURLTest.swift */; };
 		0B37F9A61E2FCAD4002DF74B /* SearchProviderTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0B37F9A51E2FCAD4002DF74B /* SearchProviderTest.swift */; };
 		0B70C1631DE6128900CEF7E0 /* WebsiteMemoryTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0B70C1621DE6128900CEF7E0 /* WebsiteMemoryTest.swift */; };
@@ -255,7 +254,6 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
-		050E8B1D2064FECE00DF6090 /* StringExtensionTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StringExtensionTest.swift; sourceTree = "<group>"; };
 		0B0D6BC31F3CDDBB00497D08 /* CollapsedURLTest.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CollapsedURLTest.swift; sourceTree = "<group>"; };
 		0B37F9A51E2FCAD4002DF74B /* SearchProviderTest.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SearchProviderTest.swift; sourceTree = "<group>"; };
 		0B4868651F2250A3008C3C09 /* PastenGoTest.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PastenGoTest.swift; sourceTree = "<group>"; };
@@ -1211,7 +1209,6 @@
 				D8E015601FCF409F00CA3B9F /* Info.plist */,
 				D831FEE1205247A400EAE19A /* BrowserViewControllerTests.swift */,
 				D8E0156D1FD9E40F00CA3B9F /* DomainCompletionTests.swift */,
-				050E8B1D2064FECE00DF6090 /* StringExtensionTest.swift */,
 				D803D37320EF1A49001F2819 /* UserAgentTests.swift */,
 			);
 			path = ClientTests;
@@ -1873,7 +1870,6 @@
 				D803D37420EF1A49001F2819 /* UserAgentTests.swift in Sources */,
 				D831FEE2205247A400EAE19A /* BrowserViewControllerTests.swift in Sources */,
 				D8E0155F1FCF409F00CA3B9F /* SearchEngineManagerTests.swift in Sources */,
-				050E8B1E2064FECE00DF6090 /* StringExtensionTest.swift in Sources */,
 				D8E0156E1FD9E40F00CA3B9F /* DomainCompletionTests.swift in Sources */,
 				D025F225218B64D600B262D8 /* SearchEngineTests.swift in Sources */,
 			);

Blockzilla/BrowserViewController.swift

@@ -605,7 +605,13 @@ class BrowserViewController: UIViewController {
     }
 
     fileprivate func presentImageActionSheet(title: String, link: String?, saveAction: @escaping () -> Void, copyAction: @escaping () -> Void) {
-        let alertController = UIAlertController(title: title.truncated(limit: 160, position: .middle), message: nil, preferredStyle: .actionSheet)
+
+        var normalizedTitle = title
+        if title.count > UIConstants.layout.truncateCharactersLimit {
+            normalizedTitle = String("\(title.prefix(UIConstants.layout.truncateHeadCharactersCount))\(UIConstants.strings.truncateLeader)\(title.suffix(UIConstants.layout.truncateTailCharactersCount))")
+        }
+
+        let alertController = UIAlertController(title: normalizedTitle, message: nil, preferredStyle: .actionSheet)
 
         if let link = link {
             alertController.addAction(UIAlertAction(title: UIConstants.strings.copyLink, style: .default) { _ in

Blockzilla/StringExtensions.swift

@@ -5,11 +5,6 @@
 import Foundation
 
 extension String {
-    enum TruncationPosition {
-        case head
-        case middle
-        case tail
-    }
 
     var isUrl: Bool {
         let detector = try! NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
@@ -19,38 +14,4 @@ extension String {
 
         return true
     }
-
-    func truncated(limit: Int, position: TruncationPosition = .tail, leader: String = "...") -> String {
-        guard count > limit else { return self }
-
-        switch position {
-        case .head:
-            let truncated = self[index(endIndex, offsetBy: leader.count - limit)...]
-            return leader + truncated
-        case .middle:
-            let headCharactersCount = (limit - leader.count) / 2
-            let head = self[..<index(startIndex, offsetBy: headCharactersCount)]
-
-            let tailCharactersCount = Int(ceil(Double(limit - leader.count) / 2.0))
-            let tail = self[index(endIndex, offsetBy: -tailCharactersCount)...]
-
-            return head + leader + tail
-        case .tail:
-            let truncated = self[..<index(startIndex, offsetBy: limit - leader.count)]
-            return truncated + leader
-        }
-    }
-
-    public func startsWith(other: String) -> Bool {
-        // rangeOfString returns nil if other is empty, destroying the analogy with (ordered) sets.
-        if other.isEmpty {
-            return true
-        }
-
-        if let range = self.range(of: other, options: .anchored) {
-            return range.lowerBound == self.startIndex
-        }
-
-        return false
-    }
 }

Blockzilla/UIConstants.swift

@@ -218,6 +218,9 @@ struct UIConstants {
         static let shareTrackersHeight: CGFloat = 36
         static let homeViewTextOffset: CGFloat = 5
         static let homeViewLabelMinimumScale: CGFloat = 0.65
+        static let truncateCharactersLimit = 160
+        static let truncateHeadCharactersCount = (truncateCharactersLimit - UIConstants.strings.truncateLeader.count) / 2
+        static let truncateTailCharactersCount = Int(ceil(Double(truncateCharactersLimit - UIConstants.strings.truncateLeader.count) / 2.0))
     }
 
     struct strings {
@@ -451,5 +454,6 @@ struct UIConstants {
         static let sumoTopicUsageData = "usage-data"
         static let encodingNameUTF8 = "utf-8"
         static let googleAmpURLPrefix = "https://www.google.com/amp/s/"
+        static let truncateLeader = "..."
     }
 }