Line highlight improvements when not using theme background (#181)

### Description Not using theme highlight color when not using theme background. Instead, we are using system colors to highlight the current line. ### Checklist <!--- Add things that are not yet implemented above --> - [x] I read and understood the [contributing guide](https://github.com/CodeEditApp/CodeEdit/blob/main/CONTRIBUTING.md) as well as the [code of conduct](https://github.com/CodeEditApp/CodeEdit/blob/main/CODE_OF_CONDUCT.md) - [x] The issues this PR addresses are related to each other - [x] My changes generate no new warnings - [x] My code builds and runs on my machine - [x] My changes are all related to the related issue above - [x] I documented my code ### Screenshots When using the theme background... <img width="628" alt="image" src="https://user-images.githubusercontent.com/806104/234382400-afa7ce2f-4e81-47e1-a022-5a4cf24d8db1.png"> When not using the theme background... Before <img width="626" alt="image" src="https://user-images.githubusercontent.com/806104/234380570-5b3aac7e-4baa-4aa3-8d09-b2d4e4113b7c.png"> After <img width="634" alt="image" src="https://user-images.githubusercontent.com/806104/234380524-eb4167f4-750c-4f3b-b4d4-5467738d3cdc.png">

Author: austincondiff

Sources/CodeEditTextView/Controller/STTextViewController+Highlighter.swift

@@ -39,4 +39,17 @@ extension STTextViewController {
  highlighter?.setHighlightProvider(provider)
  }
  }
+
+ /// Gets all attributes for the given capture including the line height, background color, and text color.
+ /// - Parameter capture: The capture to use for syntax highlighting.
+ /// - Returns: All attributes to be applied.
+ public func attributesFor(_ capture: CaptureName?) -> [NSAttributedString.Key: Any] {
+ return [
+ .font: font,
+ .foregroundColor: theme.colorFor(capture),
+ .baselineOffset: baselineOffset,
+ .paragraphStyle: paragraphStyle,
+ .kern: kern
+ ]
+ }
 }

Sources/CodeEditTextView/Controller/STTextViewController.swift

@@ -36,6 +36,10 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  /// Whether the code editor should use the theme background color or be transparent
  public var useThemeBackground: Bool
 
+ public var systemAppearance: NSAppearance.Name?
+
+ var cancellables = Set<AnyCancellable>()
+
  /// The visual width of tab characters in the text view measured in number of spaces.
  public var tabWidth: Int {
  didSet {
@@ -85,7 +89,7 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  }
 
  /// The kern to use for characters. Defaults to `0.0` and is updated when `letterSpacing` is set.
- private var kern: CGFloat = 0.0
+ internal var kern: CGFloat = 0.0
 
  private var fontCharWidth: CGFloat {
  (" " as NSString).size(withAttributes: [.font: font]).width
@@ -160,7 +164,9 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  rulerView.drawSeparator = false
  rulerView.baselineOffset = baselineOffset
  rulerView.font = rulerFont
- rulerView.selectedLineHighlightColor = theme.lineHighlight
+ rulerView.selectedLineHighlightColor = useThemeBackground ? theme.lineHighlight : systemAppearance == .darkAqua
+ ? NSColor.quaternaryLabelColor
+ : NSColor.selectedTextBackgroundColor.withSystemEffect(.disabled)
  rulerView.rulerInsets = STRulerInsets(leading: rulerFont.pointSize * 1.6, trailing: 8)
  rulerView.allowsMarkers = false
 
@@ -180,7 +186,9 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  textView.insertionPointColor = theme.insertionPoint
  textView.insertionPointWidth = 1.0
  textView.selectionBackgroundColor = theme.selection
- textView.selectedLineHighlightColor = theme.lineHighlight
+ textView.selectedLineHighlightColor = useThemeBackground ? theme.lineHighlight : systemAppearance == .darkAqua
+ ? NSColor.quaternaryLabelColor
+ : NSColor.selectedTextBackgroundColor.withSystemEffect(.disabled)
  textView.string = self.text.wrappedValue
  textView.isEditable = self.isEditable
  textView.highlightSelectedLine = true
@@ -240,6 +248,19 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  ) { [weak self] _ in
  self?.updateTextContainerWidthIfNeeded()
  }
+
+ systemAppearance = NSApp.effectiveAppearance.name
+
+ NSApp.publisher(for: \.effectiveAppearance)
+ .receive(on: RunLoop.main)
+ .sink { [weak self] newValue in
+ guard let self = self else { return }
+
+ if self.systemAppearance != newValue.name {
+ self.systemAppearance = newValue.name
+ }
+ }
+ .store(in: &cancellables)
  }
 
  public override func viewWillAppear() {
@@ -254,7 +275,7 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  // MARK: UI
 
  /// A default `NSParagraphStyle` with a set `lineHeight`
- private lazy var paragraphStyle: NSMutableParagraphStyle = generateParagraphStyle()
+ internal lazy var paragraphStyle: NSMutableParagraphStyle = generateParagraphStyle()
 
  private func generateParagraphStyle() -> NSMutableParagraphStyle {
  // swiftlint:disable:next force_cast
@@ -284,7 +305,9 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  textView.backgroundColor = useThemeBackground ? theme.background : .clear
  textView?.insertionPointColor = theme.insertionPoint
  textView?.selectionBackgroundColor = theme.selection
- textView?.selectedLineHighlightColor = theme.lineHighlight
+ textView?.selectedLineHighlightColor = useThemeBackground ? theme.lineHighlight : systemAppearance == .darkAqua
+ ? NSColor.quaternaryLabelColor
+ : NSColor.selectedTextBackgroundColor.withSystemEffect(.disabled)
  textView?.isEditable = isEditable
  textView.highlightSelectedLine = isEditable
  textView?.typingAttributes = attributesFor(nil)
@@ -293,7 +316,9 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
 
  rulerView?.backgroundColor = useThemeBackground ? theme.background : .clear
  rulerView?.separatorColor = theme.invisibles
- rulerView?.selectedLineHighlightColor = theme.lineHighlight
+ rulerView?.selectedLineHighlightColor = useThemeBackground ? theme.lineHighlight : systemAppearance == .darkAqua
+ ? NSColor.quaternaryLabelColor
+ : NSColor.selectedTextBackgroundColor.withSystemEffect(.disabled)
  rulerView?.baselineOffset = baselineOffset
  rulerView.highlightSelectedLine = isEditable
  rulerView?.rulerInsets = STRulerInsets(leading: rulerFont.pointSize * 1.6, trailing: 8)
@@ -312,19 +337,6 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  updateTextContainerWidthIfNeeded()
  }
 
- /// Gets all attributes for the given capture including the line height, background color, and text color.
- /// - Parameter capture: The capture to use for syntax highlighting.
- /// - Returns: All attributes to be applied.
- public func attributesFor(_ capture: CaptureName?) -> [NSAttributedString.Key: Any] {
- return [
- .font: font,
- .foregroundColor: theme.colorFor(capture),
- .baselineOffset: baselineOffset,
- .paragraphStyle: paragraphStyle,
- .kern: kern
- ]
- }
-
  /// Calculated line height depending on ``STTextViewController/lineHeightMultiple``
  internal var lineHeight: Double {
  font.lineHeight * lineHeightMultiple
@@ -348,5 +360,6 @@ public class STTextViewController: NSViewController, STTextViewDelegate, ThemeAt
  deinit {
  textView = nil
  highlighter = nil
+ cancellables.forEach { $0.cancel() }
  }
 }