Code review

BlueprintUI/Sources/Layout/Aligned.swift

@@ -119,7 +119,11 @@ public extension Element {
     ///   - vertically: The vertical alignment. Defaults to `.centered`.
     ///   - horizontally: The horizontal alignment. Defaults to `.centered`.
     ///
-    func aligned(vertically: Aligned.VerticalAlignment = .center, horizontally: Aligned.HorizontalAlignment = .center) -> Aligned {
+    func aligned(
+        vertically: Aligned.VerticalAlignment,
+        horizontally: Aligned.HorizontalAlignment
+    ) -> Aligned
+    {
         Aligned(
             vertically: vertically,
             horizontally: horizontally,

BlueprintUI/Sources/Layout/ConstrainedAspectRatio.swift

@@ -79,15 +79,20 @@ public struct ConstrainedAspectRatio: Element {
 }
 
 
-public extension ConstrainedAspectRatio {
-    /// Initializes with the given properties.
+public extension Element {
+    ///
+    /// Constrains the element to the provided aspect ratio.
     ///
     /// - parameters:
     ///   - aspectRatio: The aspect ratio that the content size should match.
     ///   - contentMode: Whether the aspect ratio should be reached by expanding the content
     ///     element's size to fill its parent or shrinking it to fit.
     ///
-    func aspectRatio(with aspectRatio: AspectRatio, contentMode: ContentMode = .fill) -> ConstrainedAspectRatio {
+    func constrainedTo(
+        aspectRatio: AspectRatio,
+        contentMode: ConstrainedAspectRatio.ContentMode = .fill
+    ) -> ConstrainedAspectRatio
+    {
         ConstrainedAspectRatio(aspectRatio: aspectRatio, contentMode: contentMode, wrapping: self)
     }
 }

BlueprintUI/Sources/Layout/ConstrainedSize.swift

@@ -88,7 +88,7 @@ extension ConstrainedSize {
 
 public extension Element {
 
-    /// Constrains the measured size of the content element.
+    /// Constrains the measured size of the element to the provided width and height.
     func constrainedTo(
         width: ConstrainedSize.Constraint = .unconstrained,
         height: ConstrainedSize.Constraint = .unconstrained

BlueprintUI/Sources/Layout/Inset.swift

@@ -79,8 +79,20 @@ public struct Inset: Element {
 public extension Element {
 
     /// Insets the element by the given amount on each side.
-    func inset(top: CGFloat = 0.0, bottom: CGFloat = 0.0, left: CGFloat = 0.0, right: CGFloat = 0.0) -> Inset {
-        Inset(top: top, bottom: bottom, left: left, right: right, wrapping: self)
+    func inset(
+        top: CGFloat = 0.0,
+        bottom: CGFloat = 0.0,
+        left: CGFloat = 0.0,
+        right: CGFloat = 0.0
+    ) -> Inset
+    {
+        Inset(
+            top: top,
+            bottom: bottom,
+            left: left,
+            right: right,
+            wrapping: self
+        )
     }
 
     /// Insets the element by the given amount on each side.
@@ -94,8 +106,18 @@ public extension Element {
     }
 
     /// Insets the element by the given amount on each side.
-    func inset(horizontal : CGFloat = 0.0, vertical : CGFloat = 0.0) -> Inset {
-        Inset(top: vertical, bottom: vertical, left: horizontal, right: horizontal, wrapping: self)
+    func inset(
+        horizontal : CGFloat = 0.0,
+        vertical : CGFloat = 0.0
+    ) -> Inset
+    {
+        Inset(
+            top: vertical,
+            bottom: vertical,
+            left: horizontal,
+            right: horizontal,
+            wrapping: self
+        )
     }
 }
 

BlueprintUICommonControls/Sources/AccessibilityBlocker.swift

@@ -2,13 +2,21 @@ import BlueprintUI
 import UIKit
 
 
+/// Blocks all accessibility on the element, so that it is
+/// is no longer an accessibility element, and its children are
+/// hidden from the accessibility system.
 public struct AccessibilityBlocker: Element {
 
     public var wrapped: Element
 
+    /// Creates a new `AccessibilityBlocker` wrapping the provided element.
     public init(wrapping element: Element) {
         self.wrapped = element
     }
+
+    //
+    // MARK: Element
+    //
 
     public var content: ElementContent {
         return ElementContent(child: wrapped)
@@ -22,7 +30,12 @@ public struct AccessibilityBlocker: Element {
     }
 }
 
+
 public extension Element {
+
+    /// Blocks all accessibility on the element, so that it is
+    /// is no longer an accessibility element, and its children are
+    /// hidden from the accessibility system.
     func blockAccessibility() -> AccessibilityBlocker {
         AccessibilityBlocker(wrapping: self)
     }

BlueprintUICommonControls/Sources/AccessibilityElement.swift

@@ -108,13 +108,16 @@ public struct AccessibilityElement: Element {
 }
 
 
-public extension AccessibilityElement {
+public extension Element {
+
+    /// Wraps the element to provide the passed accessibility
+    /// options to the accessibility system.
     func accessibility(
         label: String? = nil,
         value: String? = nil,
         hint: String? = nil,
         identifier: String? = nil,
-        traits: Set<Trait> = []
+        traits: Set<AccessibilityElement.Trait> = []
         ) -> AccessibilityElement
     {
         AccessibilityElement(

BlueprintUICommonControls/Sources/Box.swift

@@ -118,7 +118,7 @@ extension Box {
 
 public extension Element {
 
-    /// Wraps the given element in a box to provide basic styling.
+    /// Wraps the element in a box to provide basic styling.
     func box(
         background: UIColor = .clear,
         corners: Box.CornerStyle = .square,

BlueprintUICommonControls/Sources/ScrollView.swift

@@ -69,6 +69,9 @@ public struct ScrollView: Element {
 }
 
 public extension Element {
+
+    /// Wraps the element in a `ScrollView` to allow it to be scrolled
+    /// if it takes up more space then is available on screen.
     func scrollable(
         _ contentSize: ScrollView.ContentSize = .fittingHeight,
         configure : (inout ScrollView) -> () = { _ in }

BlueprintUICommonControls/Sources/Tappable.swift

@@ -6,9 +6,9 @@ import UIKit
 public struct Tappable: Element {
 
     public var wrappedElement: Element
-    public var onTap: ()->Void
+    public var onTap: () -> Void
 
-    public init(onTap: @escaping ()->Void, wrapping element: Element) {
+    public init(onTap: @escaping () -> Void, wrapping element: Element) {
         self.wrappedElement = element
         self.onTap = onTap
     }
@@ -26,6 +26,15 @@ public struct Tappable: Element {
 }
 
 
+public extension Element {
+
+    /// Wraps the element and calls the provided closure when tapped.
+    func tappable(onTap: @escaping () -> Void) -> Tappable {
+        Tappable(onTap: onTap, wrapping: self)
+    }
+}
+
+
 fileprivate final class TappableView: UIView {
 
     var onTap: (()->Void)? = nil

CHANGELOG.md

@@ -6,6 +6,39 @@
 
 ### Added
 
+- [Added support](https://github.com/square/Blueprint/pull/88) for `SwiftUI`-style element building within `BlueprintUI` and `BlueprintUICommonControls`.
+
+This allows you to replace this code:
+
+```
+ScrollView(.fittingHeight) (
+   wrapping: Box(
+        backgroundColor .lightGrey,
+       wrapping: Inset(
+          uniformInset: 10.0,
+          wrapping: ConstrainedSize(
+             height: .atLeast(20.0),
+             wrapping: Label(
+                text: "Hello, world!"
+             )
+         )
+      )
+   )
+)
+```
+
+With this code:
+
+```
+Label(text: "Hello, World!")
+   .constrainedTo(height: .atLeast(20.0))
+   .inset(by: 20.0)
+   .box(background: .lightGrey)
+   .scrollable(.fittingHeight)
+```
+
+Improving readability and conciseness of your elements.
+
 ### Removed
 
 ### Changed
@@ -24,7 +57,7 @@
 
 ### Fixed
 
-- Only support `SwiftUI` previews on 32 bit ARM devices.
+- [Don't try to build](https://github.com/square/Blueprint/pull/89) `SwiftUI` previews on 32 bit ARM devices – `SwiftUI` does not exist on these devices.
 
 ## 0.9.1
 

SampleApp/Sources/XcodePreviewDemo.swift

@@ -16,7 +16,7 @@ struct TestElement : ProxyElement {
             $0.verticalUnderflow = .justifyToStart
 
             for index in 1...12 {
-                $0.add(growPriority: 0.0, shrinkPriority: 00, child: Label(text: "Hello, World") {
+                $0.add(child: Label(text: "Hello, World") {
                     $0.font = .boldSystemFont(ofSize: 10.0 + CGFloat(index * 4))
                     $0.color = .init(
                         red: CGFloat.random(in: 0...1),