DesignKit: Update ElementFonts with new Fonts protocol.

DesignKit/Extensions/UIFont.swift

@@ -0,0 +1,55 @@
+// 
+// Copyright 2021 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import UIKit
+
+public extension UIFont {
+    
+    // MARK: - Convenient methods
+    
+    /// Update current font with a SymbolicTraits
+    func vc_withTraits(_ traits: UIFontDescriptor.SymbolicTraits) -> UIFont {
+        guard let descriptor = fontDescriptor.withSymbolicTraits(traits) else {
+            return self
+        }
+        return UIFont(descriptor: descriptor, size: 0) // Size 0 means keep the size as it is
+    }
+    
+    /// Update current font with a given Weight
+    func vc_withWeight(weight: Weight) -> UIFont {
+        // Add the font weight to the descriptor
+        let weightedFontDescriptor = fontDescriptor.addingAttributes([
+            UIFontDescriptor.AttributeName.traits: [
+                UIFontDescriptor.TraitKey.weight: weight
+            ]
+        ])
+        return UIFont(descriptor: weightedFontDescriptor, size: 0)
+    }
+    
+    // MARK: - Shortcuts
+    
+    var vc_bold: UIFont {
+        return self.vc_withTraits(.traitBold)
+    }
+    
+    var vc_semiBold: UIFont {
+        return self.vc_withWeight(weight: .semibold)
+    }
+
+    var vc_italic: UIFont {
+        return self.vc_withTraits(.traitItalic)
+    }
+}

DesignKit/Variants/Fonts/ElementFonts.swift

@@ -18,38 +18,57 @@ import UIKit
 
 /// Fonts at  https://www.figma.com/file/X4XTH9iS2KGJ2wFKDqkyed/Compound?node-id=1362%3A0
 @objcMembers
-public class ElementFonts: Fonts {
+public class ElementFonts {
     
     // MARK: - Setup
     
     public init() {
     }
     
-    // MARK: - Public
+    // MARK: - Private
     
     /// Returns an instance of the font associated with the text style and scaled appropriately for the content size category defined in the trait collection.
-    public func font(forTextStyle textStyle: UIFont.TextStyle, compatibleWith traitCollection: UITraitCollection?) -> UIFont {
+    /// Keep this method private method at the moment and create a DesignKit.Fonts.TextStyle if needed.
+    fileprivate func font(forTextStyle textStyle: UIFont.TextStyle, compatibleWith traitCollection: UITraitCollection? = nil) -> UIFont {
         return UIFont.preferredFont(forTextStyle: textStyle, compatibleWith: traitCollection)
     }
-    
-    // MARK: TextStyle shortcuts
+}
+
+// MARK: - Fonts protocol
+extension ElementFonts: Fonts {    
     
     public var largeTitle: UIFont {
         return self.font(forTextStyle: .largeTitle)
     }
+    
+    public var largeTitleB: UIFont {
+        return self.largeTitle.vc_bold
+    }
             
     public var title1: UIFont {
         return self.font(forTextStyle: .title1)
     }
     
+    public var title1B: UIFont {
+        return self.title1.vc_bold
+    }
+    
     public var title2: UIFont {
         return self.font(forTextStyle: .title2)
     }
     
+    public var title2B: UIFont {
+        return self.title2.vc_bold
+    }
+    
     public var title3: UIFont {
         return self.font(forTextStyle: .title3)
     }
     
+    public var title3SB: UIFont {
+        return self.title3.vc_semiBold
+    }
+    
     public var headline: UIFont {
         return self.font(forTextStyle: .headline)
     }
@@ -62,15 +81,39 @@ public class ElementFonts: Fonts {
         return self.font(forTextStyle: .body)
     }
     
+    public var bodySB: UIFont {
+        return self.body.vc_semiBold
+    }
+    
     public var callout: UIFont {
         return self.font(forTextStyle: .callout)
     }
     
+    public var calloutSB: UIFont {
+        return self.callout.vc_semiBold
+    }
+    
+    public var footnote: UIFont {
+        return self.font(forTextStyle: .footnote)
+    }
+    
+    public var footnoteSB: UIFont {
+        return self.footnote.vc_semiBold
+    }
+    
     public var caption1: UIFont {
         return self.font(forTextStyle: .caption1)
     }
     
+    public var caption1SB: UIFont {
+        return self.caption1.vc_semiBold
+    }
+    
     public var caption2: UIFont {
         return self.font(forTextStyle: .caption2)
     }
+    
+    public var caption2SB: UIFont {
+        return self.caption2.vc_semiBold
+    }
 }