move contrasting color to Theme and cache computed var

Packages/DesignSystem/Sources/DesignSystem/Theme.swift

@@ -167,12 +167,14 @@ import SwiftUI
   public var tintColor: Color {
     didSet {
       themeStorage.tintColor = tintColor
+      computeContrastingTintColor()
     }
   }
 
   public var primaryBackgroundColor: Color {
     didSet {
       themeStorage.primaryBackgroundColor = primaryBackgroundColor
+      computeContrastingTintColor()
     }
   }
 
@@ -185,6 +187,33 @@ import SwiftUI
   public var labelColor: Color {
     didSet {
       themeStorage.labelColor = labelColor
+      computeContrastingTintColor()
+    }
+  }
+
+  public private(set) var contrastingTintColor: Color
+
+  // set contrastingTintColor to either labelColor or primaryBackgroundColor, whichever contrasts
+  // better against the tintColor
+  private func computeContrastingTintColor() {
+    @Environment(\.self) var environment
+
+    func luminance(_ color: Color.Resolved) -> Float {
+      return 0.299 * color.red + 0.587 * color.green + 0.114 * color.blue;
+    }
+
+    let resolvedTintColor = tintColor.resolve(in: environment)
+    let resolvedLabelColor = labelColor.resolve(in: environment)
+    let resolvedPrimaryBackgroundColor = primaryBackgroundColor.resolve(in: environment)
+
+    let tintLuminance = luminance(resolvedTintColor)
+    let labelLuminance = luminance(resolvedLabelColor)
+    let primaryBackgroundLuminance = luminance(resolvedPrimaryBackgroundColor)
+
+    if abs(tintLuminance - labelLuminance) > abs(tintLuminance - primaryBackgroundLuminance) {
+      contrastingTintColor = labelColor
+    } else {
+      contrastingTintColor = primaryBackgroundColor
     }
   }
 
@@ -281,6 +310,7 @@ import SwiftUI
     primaryBackgroundColor = themeStorage.primaryBackgroundColor
     secondaryBackgroundColor = themeStorage.secondaryBackgroundColor
     labelColor = themeStorage.labelColor
+    contrastingTintColor = .red // real work done in computeContrastingTintColor()
     avatarPosition = themeStorage.avatarPosition
     avatarShape = themeStorage.avatarShape
     storedSet = themeStorage.storedSet
@@ -293,6 +323,8 @@ import SwiftUI
     chosenFontData = themeStorage.chosenFontData
     statusActionSecondary = themeStorage.statusActionSecondary
     selectedSet = storedSet
+
+    computeContrastingTintColor()
   }
 
   public static var allColorSet: [ColorSet] {

Packages/StatusKit/Sources/StatusKit/Row/Subviews/StatusRowMediaPreviewView.swift

@@ -177,7 +177,6 @@ struct BlurOverLay: View {
   @Environment(\.isInCaptureMode) private var isInCaptureMode: Bool
   @Environment(UserPreferences.self) private var preferences
   @Environment(\.isMediaCompact) private var isCompact: Bool
-  @Environment(\.self) var environment
 
   @Namespace var buttonSpace
 
@@ -213,7 +212,7 @@ struct BlurOverLay: View {
                   .matchedGeometryEffect(id: "eye", in: buttonSpace)
               }
               .lineLimit(1)
-              .foregroundColor(contrastingColor(against: theme.tintColor))
+              .foregroundColor(theme.contrastingTintColor)
             } else {
               Image(systemName: "eye.slash")
                 .transition(.opacity)
@@ -246,29 +245,6 @@ struct BlurOverLay: View {
     default: false
     }
   }
-  
-  // return either labelColor or primaryBackgroundColor, whichever contrasts better against
-  // the specified background color
-  private func contrastingColor(against backgroundColor: Color) -> Color {
-    
-    func luminance(_ color: Color.Resolved) -> Float {
-      return 0.299 * color.red + 0.587 * color.green + 0.114 * color.blue;
-    }
-    
-    let resolvedBackgroundColor = backgroundColor.resolve(in: environment)
-    let resolvedLabelColor = theme.labelColor.resolve(in: environment)
-    let resolvedPrimaryBackgroundColor = theme.primaryBackgroundColor.resolve(in: environment)
-    
-    let backgroundLuminance = luminance(resolvedBackgroundColor)
-    let labelLuminance = luminance(resolvedLabelColor)
-    let primaryBackgroundLuminance = luminance(resolvedPrimaryBackgroundColor)
-    
-    if backgroundLuminance < 0.5 {
-      return (labelLuminance > primaryBackgroundLuminance) ? theme.labelColor : theme.primaryBackgroundColor
-    } else {
-      return (labelLuminance < primaryBackgroundLuminance) ? theme.labelColor : theme.primaryBackgroundColor
-    }
-  }
 }
 
 struct AltTextButton: View {