Merge pull request #231 from kyleve/kve/dark-mode-bg

Change the default BG color for dark mode.

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 - [Ensure we respect both `frame` and `bounds` changes](https://github.com/kyleve/Listable/pull/227) to update the inner `CollectionView`'s frame. We previously used to only respect `frame` changes, but we should also respect `bounds` changes, as these are used by auto layout.
 
+- [`Appearance.backgroundColor` now respects the current `UITraitCollection.userInterfaceStyle`](https://github.com/kyleve/Listable/pull/231). This means that the background color will default to `white` in light mode, and `black` in dark mode.
+
 ### Added
 
 - [Introduce `onSelectionChanged` on `ListStateObserver`](https://github.com/kyleve/Listable/pull/223) to allow observing when the selected rows change.

ListableUI/Sources/Appearance.swift

@@ -22,7 +22,7 @@ public struct Appearance : Equatable
 
     /// Creates a new appearance object with the provided options.
     public init(
-        backgroundColor : UIColor = .white,
+        backgroundColor : UIColor = Self.defaultBackgroundColor,
         showsScrollIndicators : Bool = true,
         configure : (inout Self) -> () = { _ in }
     ) {
@@ -32,4 +32,22 @@ public struct Appearance : Equatable
 
         configure(&self)
     }
+
+    /// The default background color for the `Appearance`.
+    public static var defaultBackgroundColor : UIColor {
+        if #available(iOS 13.0, *) {
+            return UIColor { traits in
+                switch traits.userInterfaceStyle {
+                case .unspecified, .light:
+                    return .white
+                case .dark:
+                    return .black
+                @unknown default:
+                    return .white
+                }
+            }
+        } else {
+            return .white
+        }
+    }
 }

ListableUI/Tests/AppearanceTests.swift

@@ -16,7 +16,13 @@ class AppearanceTests: XCTestCase
     {
         let appearance = Appearance()
 
-        XCTAssertEqual(appearance.backgroundColor, .white)
+        if #available(iOS 13.0, *) {
+            XCTAssertEqual(appearance.backgroundColor.resolvedColor(with: .init(userInterfaceStyle: .dark)), .black)
+            XCTAssertEqual(appearance.backgroundColor.resolvedColor(with: .init(userInterfaceStyle: .light)), .white)
+        } else {
+            XCTAssertEqual(appearance.backgroundColor, .white)
+        }
+
         XCTAssertEqual(appearance.showsScrollIndicators, true)
     }
 }