macos: put next/prev split focus into menu

include/ghostty.h

@@ -258,6 +258,8 @@ void ghostty_surface_mouse_scroll(ghostty_surface_t, double, double);
 void ghostty_surface_ime_point(ghostty_surface_t, double *, double *);
 void ghostty_surface_request_close(ghostty_surface_t);
 void ghostty_surface_split(ghostty_surface_t, ghostty_split_direction_e);
+void ghostty_surface_split_focus_previous(ghostty_surface_t);
+void ghostty_surface_split_focus_next(ghostty_surface_t);
 
 #ifdef __cplusplus
 }

macos/Sources/Ghostty/AppState.swift

@@ -94,6 +94,16 @@ extension Ghostty {
             ghostty_surface_split(surface, direction)
         }
         
+        func splitMoveFocus(surface: ghostty_surface_t, direction: SplitFocusDirection) {
+            switch (direction) {
+            case .previous:
+                ghostty_surface_split_focus_previous(surface)
+                
+            case .next:
+                ghostty_surface_split_focus_next(surface)
+            }
+        }
+        
         // MARK: Ghostty Callbacks
         
         static func newSplit(_ userdata: UnsafeMutableRawPointer?, direction: ghostty_split_direction_e) {

macos/Sources/GhosttyApp.swift

@@ -37,6 +37,13 @@ struct GhosttyApp: App {
                 Button("Close", action: close).keyboardShortcut("w", modifiers: [.command])
                 Button("Close Window", action: Self.closeWindow).keyboardShortcut("w", modifiers: [.command, .shift])
              }
+            
+            CommandGroup(before: .windowArrangement) {
+                Divider()
+                Button("Select Previous Split", action: splitMoveFocusPrevious).keyboardShortcut("[", modifiers: .command)
+                Button("Select Next Split", action: splitMoveFocusNext).keyboardShortcut("]", modifiers: .command)
+                Divider()
+            }
         }
         
         Settings {
@@ -76,6 +83,18 @@ struct GhosttyApp: App {
         guard let surface = surfaceView.surface else { return }
         ghostty.split(surface: surface, direction: GHOSTTY_SPLIT_DOWN)
     }
+    
+    func splitMoveFocusPrevious() {
+        guard let surfaceView = focusedSurface else { return }
+        guard let surface = surfaceView.surface else { return }
+        ghostty.splitMoveFocus(surface: surface, direction: .previous)
+    }
+    
+    func splitMoveFocusNext() {
+        guard let surfaceView = focusedSurface else { return }
+        guard let surface = surfaceView.surface else { return }
+        ghostty.splitMoveFocus(surface: surface, direction: .next)
+    }
 }
 
 class AppDelegate: NSObject, NSApplicationDelegate {

src/apprt/embedded.zig

@@ -503,4 +503,14 @@ pub const CAPI = struct {
     export fn ghostty_surface_split(ptr: *Surface, direction: input.SplitDirection) void {
         ptr.newSplit(direction) catch {};
     }
+
+    /// Focus on the next split (if any).
+    export fn ghostty_surface_split_focus_next(ptr: *Surface) void {
+        ptr.gotoNextSplit();
+    }
+
+    /// Focus on the previous split (if any).
+    export fn ghostty_surface_split_focus_previous(ptr: *Surface) void {
+        ptr.gotoPreviousSplit();
+    }
 };