macos: set background opacity/blur on window controller not surface

include/ghostty.h

@@ -513,7 +513,6 @@ ghostty_surface_config_s ghostty_surface_config_new();
 ghostty_surface_t ghostty_surface_new(ghostty_app_t, ghostty_surface_config_s*);
 void ghostty_surface_free(ghostty_surface_t);
 ghostty_app_t ghostty_surface_app(ghostty_surface_t);
-bool ghostty_surface_transparent(ghostty_surface_t);
 bool ghostty_surface_needs_confirm_quit(ghostty_surface_t);
 void ghostty_surface_refresh(ghostty_surface_t);
 void ghostty_surface_draw(ghostty_surface_t);
@@ -586,7 +585,7 @@ bool ghostty_inspector_metal_shutdown(ghostty_inspector_t);
 
 // APIs I'd like to get rid of eventually but are still needed for now.
 // Don't use these unless you know what you're doing.
-void ghostty_set_window_background_blur(ghostty_surface_t, void*);
+void ghostty_set_window_background_blur(ghostty_app_t, void*);
 
 #ifdef __cplusplus
 }

macos/Sources/Features/Terminal/TerminalController.swift

@@ -166,6 +166,16 @@ class TerminalController: NSWindowController, NSWindowDelegate,
     private func syncAppearance() {
         guard let window = self.window as? TerminalWindow else { return }
         
+        // If our window is not visible, then delay this. This is possible specifically
+        // during state restoration but probably in other scenarios as well. To delay,
+        // we just loop directly on the dispatch queue. We have to delay because some
+        // APIs such as window blur have no effect unless the window is visible.
+        guard window.isVisible else {
+            // Weak window so that if the window changes or is destroyed we aren't holding a ref
+            DispatchQueue.main.async { [weak self] in self?.syncAppearance() }
+            return
+        }
+        
         // Set the font for the window and tab titles.
         if let titleFontName = ghostty.config.windowTitleFontFamily {
             window.titlebarFont = NSFont(name: titleFontName, size: NSFont.systemFontSize)
@@ -173,6 +183,18 @@ class TerminalController: NSWindowController, NSWindowDelegate,
             window.titlebarFont = nil
         }
         
+        // If we have window transparency then set it transparent. Otherwise set it opaque.
+        if (ghostty.config.backgroundOpacity < 1) {
+            window.isOpaque = false
+            window.hasShadow = false
+            window.backgroundColor = .clear
+            ghostty_set_window_background_blur(ghostty.app, Unmanaged.passUnretained(window).toOpaque())
+        } else {
+            window.isOpaque = true
+            window.hasShadow = true
+            window.backgroundColor = .windowBackgroundColor
+        }
+        
         guard window.hasStyledTabs else { return }
 
         // The titlebar is always updated. We don't need to worry about opacity

macos/Sources/Ghostty/SurfaceView_AppKit.swift

@@ -342,40 +342,6 @@ extension Ghostty {
         
         // MARK: - NSView
         
-        override func viewDidMoveToWindow() {
-            // Set our background blur if requested
-            setWindowBackgroundBlur(window)
-        }
-        
-        /// This function sets the window background to blur if it is configured on the surface.
-        private func setWindowBackgroundBlur(_ targetWindow: NSWindow?) {
-            // Surface must desire transparency
-            guard let surface = self.surface,
-                  ghostty_surface_transparent(surface) else { return }
-            
-            // Our target should always be our own view window
-            guard let target = targetWindow,
-                  let window = self.window,
-                  target == window else { return }
-            
-            // If our window is not visible, then delay this. This is possible specifically
-            // during state restoration but probably in other scenarios as well. To delay,
-            // we just loop directly on the dispatch queue.
-            guard window.isVisible else {
-                // Weak window so that if the window changes or is destroyed we aren't holding a ref
-                DispatchQueue.main.async { [weak self, weak window] in self?.setWindowBackgroundBlur(window) }
-                return
-            }
-            
-            // Set the window transparency settings
-            window.isOpaque = false
-            window.hasShadow = false
-            window.backgroundColor = .clear
-
-            // If we have a blur, set the blur
-            ghostty_set_window_background_blur(surface, Unmanaged.passUnretained(window).toOpaque())
-        }
-        
         override func becomeFirstResponder() -> Bool {
             let result = super.becomeFirstResponder()
             if (result) { focusDidChange(true) }

src/apprt/embedded.zig

@@ -1474,11 +1474,6 @@ pub const CAPI = struct {
         return surface.app;
     }
 
-    /// Returns true if the surface has transparency set.
-    export fn ghostty_surface_transparent(surface: *Surface) bool {
-        return surface.app.config.@"background-opacity" < 1.0;
-    }
-
     /// Returns true if the surface needs to confirm quitting.
     export fn ghostty_surface_needs_confirm_quit(surface: *Surface) bool {
         return surface.core_surface.needsConfirmQuit();
@@ -1850,13 +1845,13 @@ pub const CAPI = struct {
     /// This uses an undocumented, non-public API because this is what
     /// every terminal appears to use, including Terminal.app.
     export fn ghostty_set_window_background_blur(
-        ptr: *Surface,
+        app: *App,
         window: *anyopaque,
     ) void {
         // This is only supported on macOS
         if (comptime builtin.target.os.tag != .macos) return;
 
-        const config = ptr.app.config;
+        const config = app.config;
 
         // Do nothing if we don't have background transparency enabled
         if (config.@"background-opacity" >= 1.0) return;

src/config/Config.zig

@@ -368,9 +368,6 @@ palette: Palette = .{},
 /// The opacity level (opposite of transparency) of the background. A value of
 /// 1 is fully opaque and a value of 0 is fully transparent. A value less than 0
 /// or greater than 1 will be clamped to the nearest valid value.
-///
-/// Changing this value at runtime (and reloading config) will only affect new
-/// windows, tabs, and splits.
 @"background-opacity": f64 = 1.0,
 
 /// A positive value enables blurring of the background when background-opacity