Add ANSI color contrast adjustment for log view

Automatically adjust log text colors when contrast against background is below WCAG AA standard (4.5:1). Light mode darkens colors, dark mode lightens them. Supports iOS, macOS, and tvOS.
2026-01-08 22:12:45 +08:00
parent 1707a3412a
commit b0f1eed827
3 changed files with 193 additions and 12 deletions
@@ -28,6 +28,7 @@ class LogCoordinator {
    var lastLogsCount: Int = 0
    var lastLog: LogEntry?
    var lastSearchText: String = ""
+    var lastBackgroundColorHash: Int?
    var buildVersion: Int = 0
    var currentBuildTask: Task<Void, Never>?

@@ -35,11 +36,20 @@ class LogCoordinator {
        currentBuildTask?.cancel()
    }

-    func shouldUpdate(logs: [LogEntry], searchText: String) -> UpdateStrategy {
+    func shouldUpdate(logs: [LogEntry], searchText: String, backgroundColorHash: Int) -> UpdateStrategy {
        let currentCount = logs.count
        let searchChanged = searchText != lastSearchText
+        let colorSchemeChanged = lastBackgroundColorHash != nil && lastBackgroundColorHash != backgroundColorHash
+
+        lastBackgroundColorHash = backgroundColorHash
+
+        if colorSchemeChanged {
+            lastLogsCount = currentCount
+            lastLog = logs.last
+            lastSearchText = searchText
+            return .fullRebuild
+        }

-        // Check if nothing changed
        if currentCount == lastLogsCount, currentCount > 0, !searchChanged {
            if let lastLog = logs.last, let previousLastLog = self.lastLog {
                if lastLog.id == previousLastLog.id {
@@ -48,16 +58,12 @@ class LogCoordinator {
            }
        }

-        // Determine update strategy
        let strategy: UpdateStrategy
        if currentCount == 0 || searchChanged || lastLogsCount > currentCount {
-            // Full rebuild needed
            strategy = .fullRebuild
        } else if currentCount > lastLogsCount {
-            // Incremental update possible
            strategy = .incremental(from: lastLogsCount)
        } else {
-            // Same count but different last log (shouldn't happen normally)
            strategy = .fullRebuild
        }

@@ -73,6 +79,7 @@ class LogCoordinator {
            searchText: String,
            monoFont: PlatformFont,
            defaultColor: PlatformColor,
+            backgroundColor: PlatformColor,
            startIndex: Int?,
            isViewValid: @escaping @MainActor () -> Bool,
            applyUpdate: @escaping @MainActor (NSAttributedString, Bool) -> Void
@@ -86,6 +93,7 @@ class LogCoordinator {
                    logs: logs,
                    monoFont: monoFont,
                    defaultColor: defaultColor,
+                    backgroundColor: backgroundColor,
                    searchText: searchText,
                    startIndex: startIndex ?? 0
                ) else { return }
@@ -107,7 +115,7 @@ class LogCoordinator {
 }

 #if os(iOS) || os(macOS)
-    private func buildAttributedString(logs: [LogEntry], monoFont: PlatformFont, defaultColor: PlatformColor, searchText: String, startIndex: Int = 0) async throws -> NSAttributedString {
+    private func buildAttributedString(logs: [LogEntry], monoFont: PlatformFont, defaultColor: PlatformColor, backgroundColor: PlatformColor, searchText: String, startIndex: Int = 0) async throws -> NSAttributedString {
        let result = NSMutableAttributedString()
        let highlightColor: PlatformColor = .systemYellow
        let cancellationCheckInterval = 50
@@ -124,7 +132,8 @@ class LogCoordinator {

            for run in attributedString.runs {
                let range = NSRange(run.range, in: attributedString)
-                let color = run.foregroundColor.map { PlatformColor($0) } ?? defaultColor
+                var color = run.foregroundColor.map { PlatformColor($0) } ?? defaultColor
+                color = color.adjustedForContrast(against: backgroundColor)

                nsAttributedString.addAttribute(.foregroundColor, value: color, range: range)
                nsAttributedString.addAttribute(.font, value: monoFont, range: range)
@@ -187,7 +196,10 @@ class LogCoordinator {
        }

        func updateUIView(_ textView: UITextView, context: Context) {
-            let updateStrategy = context.coordinator.shouldUpdate(logs: logs, searchText: searchText)
+            let backgroundColor = UIColor.systemBackground.resolvedColor(with: textView.traitCollection)
+            let backgroundColorHash = backgroundColor.hash
+
+            let updateStrategy = context.coordinator.shouldUpdate(logs: logs, searchText: searchText, backgroundColorHash: backgroundColorHash)

            let startIndex: Int?
            switch updateStrategy {
@@ -205,6 +217,7 @@ class LogCoordinator {
                searchText: searchText,
                monoFont: Self.monoFont,
                defaultColor: Self.defaultColor,
+                backgroundColor: backgroundColor,
                startIndex: startIndex,
                isViewValid: { [weak textView] in textView?.window != nil },
                applyUpdate: { [weak textView] attributedString, isIncremental in
@@ -282,7 +295,10 @@ class LogCoordinator {
            guard let textView = scrollView.documentView as? NSTextView else { return }
            guard let textStorage = textView.textStorage else { return }

-            let updateStrategy = context.coordinator.shouldUpdate(logs: logs, searchText: searchText)
+            let backgroundColor = NSColor.textBackgroundColor
+            let backgroundColorHash = backgroundColor.hash
+
+            let updateStrategy = context.coordinator.shouldUpdate(logs: logs, searchText: searchText, backgroundColorHash: backgroundColorHash)

            let startIndex: Int?
            switch updateStrategy {
@@ -300,6 +316,7 @@ class LogCoordinator {
                searchText: searchText,
                monoFont: Self.monoFont,
                defaultColor: Self.defaultColor,
+                backgroundColor: backgroundColor,
                startIndex: startIndex,
                isViewValid: { [weak textView] in textView?.window != nil },
                applyUpdate: { [weak textView, weak textStorage] attributedString, isIncremental in