Support macOS clear glass background blur

.github/swift-file-length-budget.tsv

@@ -3,36 +3,36 @@
 # Reduce counts as files shrink. CI fails if tracked files exceed this budget.
 20362	CLI/cmux.swift
 17115	Sources/TerminalController.swift
-15872	Sources/ContentView.swift
+15902	Sources/ContentView.swift
 14164	Sources/AppDelegate.swift
 13686	Sources/Workspace.swift
-13354	Sources/GhosttyTerminalView.swift
+13403	Sources/GhosttyTerminalView.swift
 10600	Sources/Panels/BrowserPanel.swift
 8412	Sources/cmuxApp.swift
-7495	Sources/TabManager.swift
+7492	Sources/TabManager.swift
 6811	Sources/Panels/BrowserPanelView.swift
 5218	cmuxTests/AppDelegateShortcutRoutingTests.swift
 4646	cmuxTests/WorkspaceUnitTests.swift
 4639	cmuxTests/TerminalAndGhosttyTests.swift
-4503	cmuxTests/GhosttyConfigTests.swift
-4469	cmuxTests/WorkspaceRemoteConnectionTests.swift
-4324	Sources/BrowserWindowPortal.swift
+4557	cmuxTests/GhosttyConfigTests.swift
+4465	cmuxTests/WorkspaceRemoteConnectionTests.swift
+4226	Sources/BrowserWindowPortal.swift
 3840	Sources/Feed/FeedPanelView.swift
-3660	cmuxTests/BrowserConfigTests.swift
-3229	cmuxTests/BrowserPanelTests.swift
+3588	cmuxTests/BrowserConfigTests.swift
+3121	cmuxTests/BrowserPanelTests.swift
 2826	Sources/CmuxConfig.swift
 2679	Sources/KeyboardShortcutSettings.swift
 2609	Sources/SessionIndexView.swift
 2491	Sources/Panels/CmuxWebView.swift
 2292	cmuxTests/TabManagerUnitTests.swift
-2188	Sources/TerminalWindowPortal.swift
+2171	Sources/TerminalWindowPortal.swift
 2153	cmuxTests/SessionPersistenceTests.swift
 2112	Sources/Update/UpdateTitlebarAccessory.swift
 2026	cmuxTests/CJKIMEInputTests.swift
+2035	cmuxTests/WindowAndDragTests.swift
 1949	Sources/FileExplorerView.swift
 1949	Sources/Panels/BrowserWebAuthnSupport.swift
 1941	Sources/SessionIndexStore.swift
-1951	cmuxTests/WindowAndDragTests.swift
 1784	cmuxTests/ShortcutAndCommandPaletteTests.swift
 1692	cmuxTests/CmuxConfigTests.swift
 1676	Sources/KeyboardShortcutSettingsFileStore.swift
@@ -51,13 +51,13 @@
 987	Sources/CommandPalette/CommandPaletteSearch.swift
 976	cmuxTests/OmnibarAndToolsTests.swift
 908	cmuxTests/CommandPaletteSearchEngineTests.swift
-844	Sources/WorkspaceContentView.swift
+846	Sources/WorkspaceContentView.swift
 834	Sources/RestorableAgentSession.swift
 829	cmuxUITests/TerminalCmdClickUITests.swift
 807	Sources/TerminalSSHSessionDetector.swift
-809	cmuxUITests/BonsplitTabDragUITests.swift
+701	cmuxUITests/BonsplitTabDragUITests.swift
 785	Sources/App/TerminalDirectoryOpenSupport.swift
-761	Sources/GhosttyConfig.swift
+784	Sources/GhosttyConfig.swift
 754	Sources/MainWindowFocusController.swift
 752	cmuxUITests/CloseWorkspaceCmdDUITests.swift
 719	cmuxUITests/BrowserOmnibarSuggestionsUITests.swift
@@ -71,6 +71,7 @@
 586	Sources/Update/UpdateViewModel.swift
 582	cmuxTests/TerminalControllerSocketSecurityTests.swift
 573	Sources/Feed/FeedTextEditorDebugWindowController.swift
+546	Sources/Windowing/WindowGlassEffect.swift
 536	Sources/SessionPersistence.swift
 510	Sources/Update/UpdatePopoverView.swift
 505	cmuxUITests/DisplayResolutionRegressionUITests.swift

Sources/BrowserWindowPortal.swift

@@ -2433,13 +2433,12 @@ final class WindowBrowserPortal: NSObject {
     }
 
     private func installationTarget(for window: NSWindow) -> (container: NSView, reference: NSView)? {
-        guard let contentView = window.contentView else { return nil }
-
-        if contentView.className == "NSGlassEffectView",
-           let foreground = contentView.subviews.first(where: { $0 !== hostView }) {
-            return (contentView, foreground)
+        if let glassTarget = WindowGlassEffect.portalInstallationTarget(for: window) {
+            return glassTarget
         }
 
+        guard let contentView = window.contentView else { return nil }
+
         guard let themeFrame = contentView.superview else { return nil }
         return (themeFrame, contentView)
     }

Sources/ContentView.swift

@@ -1469,6 +1469,21 @@ private func attachFileDropOverlay(_ overlay: FileDropOverlayView, to contentVie
     ])
 }
 
+private func fileDropOverlay(_ overlay: FileDropOverlayView, isAttachedTo contentView: NSView, in themeFrame: NSView) -> Bool {
+    guard overlay.superview === themeFrame else { return false }
+    let requiredAttributes: [NSLayoutConstraint.Attribute] = [.top, .bottom, .leading, .trailing]
+    return requiredAttributes.allSatisfy { attribute in
+        themeFrame.constraints.contains { constraint in
+            let firstView = constraint.firstItem as? NSView
+            let secondView = constraint.secondItem as? NSView
+            return firstView === overlay &&
+                secondView === contentView &&
+                constraint.firstAttribute == attribute &&
+                constraint.secondAttribute == attribute
+        }
+    }
+}
+
 @discardableResult
 func installFileDropOverlay(on window: NSWindow, tabManager: TabManager) -> Bool {
     guard let contentView = window.contentView,
@@ -1481,7 +1496,9 @@ func installFileDropOverlay(on window: NSWindow, tabManager: TabManager) -> Bool
     if let existingOverlay {
         configureFileDropOverlay(existingOverlay, tabManager: tabManager)
         objc_setAssociatedObject(window, &fileDropOverlayKey, existingOverlay, .OBJC_ASSOCIATION_RETAIN)
-        guard existingOverlay.superview !== themeFrame else { return true }
+        guard !fileDropOverlay(existingOverlay, isAttachedTo: contentView, in: themeFrame) else {
+            return true
+        }
         existingOverlay.removeFromSuperview()
         attachFileDropOverlay(existingOverlay, to: contentView, in: themeFrame)
         return true
@@ -3685,7 +3702,7 @@ struct ContentView: View {
             removeSidebarResizerPointerMonitor()
         })
 
-        view = AnyView(view.background(WindowAccessor { [appearance] window in
+        view = AnyView(view.background(WindowAccessor(refreshID: appearance.appKitWindowMutationID) { [appearance] window in
             window.identifier = NSUserInterfaceItemIdentifier(windowIdentifier)
             window.isRestorable = false
             setMinimalModeSidebarTitlebarControlsAvailable(sidebarState.isVisible, in: window)
@@ -3733,7 +3750,7 @@ struct ContentView: View {
                 // terminal focus-driven updates can leave stale opaque window fills.
                 window.backgroundColor = NSColor.white.withAlphaComponent(0.001)
                 // Configure contentView hierarchy for transparency.
-                if let contentView = window.contentView {
+                if let contentView = WindowGlassEffect.originalContentView(for: window) ?? window.contentView {
                     makeViewHierarchyTransparent(contentView)
                 }
             } else {
@@ -3745,17 +3762,29 @@ struct ContentView: View {
 
             if shouldApplyWindowGlass {
                 // Apply liquid glass effect to the window with tint from settings
-                WindowGlassEffect.apply(to: window, tintColor: appearance.windowGlassSettings.tintColor)
+                let didChangeGlassRoot = WindowGlassEffect.apply(
+                    to: window,
+                    tintColor: appearance.windowGlassSettings.tintColor,
+                    style: appearance.windowGlassSettings.style
+                )
+                if didChangeGlassRoot {
+                    TerminalWindowPortalRegistry.scheduleExternalGeometrySynchronize(for: window)
+                    BrowserWindowPortalRegistry.scheduleExternalGeometrySynchronize(for: window)
+                }
             } else {
-                WindowGlassEffect.remove(from: window)
+                if WindowGlassEffect.remove(from: window) {
+                    TerminalWindowPortalRegistry.scheduleExternalGeometrySynchronize(for: window)
+                    BrowserWindowPortalRegistry.scheduleExternalGeometrySynchronize(for: window)
+                }
             }
             AppDelegate.shared?.attachUpdateAccessory(to: window)
             AppDelegate.shared?.applyWindowDecorations(to: window)
             // Let cmux supply the translucent titlebar fills. AppKit's native
             // material otherwise blends a lighter strip over the terminal area.
             syncNativeTitlebarBackdrop(
                 in: window,
-                enabled: true
+                enabled: true,
+                usesGlassStyle: shouldApplyWindowGlass
             )
             AppDelegate.shared?.registerMainWindow(
                 window,
@@ -4038,7 +4067,8 @@ struct ContentView: View {
 
     private func syncNativeTitlebarBackdrop(
         in window: NSWindow,
-        enabled: Bool
+        enabled: Bool,
+        usesGlassStyle: Bool
     ) {
         guard let titlebarContainer = nativeTitlebarContainer(in: window) else { return }
         let titlebarView = firstNativeDescendant(
@@ -4070,10 +4100,10 @@ struct ContentView: View {
         }
 
         titlebarContainer.wantsLayer = true
-        titlebarContainer.layer?.backgroundColor = nil
+        titlebarContainer.layer?.backgroundColor = usesGlassStyle ? NSColor.clear.cgColor : nil
         titlebarContainer.layer?.isOpaque = false
         titlebarView?.wantsLayer = true
-        titlebarView?.layer?.backgroundColor = nil
+        titlebarView?.layer?.backgroundColor = usesGlassStyle ? NSColor.clear.cgColor : nil
         titlebarView?.layer?.isOpaque = false
         for titlebarBackgroundView in titlebarBackgroundViews {
             titlebarBackgroundView.isHidden = true

Sources/GhosttyConfig.swift

@@ -29,6 +29,7 @@ struct GhosttyConfig {
     // Colors (from theme or config)
     var backgroundColor: NSColor = NSColor(hex: "#272822")!
     var backgroundOpacity: Double = 1.0
+    var backgroundBlur: GhosttyBackgroundBlur = .disabled
     var foregroundColor: NSColor = NSColor(hex: "#fdfff1")!
     var cursorColor: NSColor = NSColor(hex: "#c0c1b5")!
     var cursorTextColor: NSColor = NSColor(hex: "#8d8e82")!
@@ -416,6 +417,10 @@ struct GhosttyConfig {
                     if let opacity = Double(value) {
                         backgroundOpacity = opacity
                     }
+                case "background-blur":
+                    if let parsedBlur = Self.parseBackgroundBlur(value) {
+                        backgroundBlur = parsedBlur
+                    }
                 case "foreground":
                     if let color = NSColor(hex: value) {
                         foregroundColor = color
@@ -479,6 +484,24 @@ struct GhosttyConfig {
         return parsed
     }
 
+    private static func parseBackgroundBlur(_ value: String) -> GhosttyBackgroundBlur? {
+        switch value {
+        case "false", "0":
+            return .disabled
+        case "true":
+            return .radius(20)
+        case "macos-glass-regular":
+            return .macosGlassRegular
+        case "macos-glass-clear":
+            return .macosGlassClear
+        default:
+            guard let radius = parseIntegerLiteral(value), radius > 0, radius <= Int(UInt8.max) else {
+                return nil
+            }
+            return .radius(radius)
+        }
+    }
+
     mutating func loadTheme(_ name: String) {
         loadTheme(
             name,