macos: hook up all the bindings so we're ready to handle focus event

include/ghostty.h

@@ -32,6 +32,8 @@ typedef const char* (*ghostty_runtime_read_clipboard_cb)(void *);
 typedef void (*ghostty_runtime_write_clipboard_cb)(void *, const char *);
 typedef void (*ghostty_runtime_new_split_cb)(void *, ghostty_split_direction_e);
 typedef void (*ghostty_runtime_close_surface_cb)(void *);
+typedef void (*ghostty_runtime_focus_next_split_cb)(void *);
+typedef void (*ghostty_runtime_focus_previous_split_cb)(void *);
 
 typedef struct {
     void *userdata;
@@ -41,6 +43,8 @@ typedef struct {
     ghostty_runtime_write_clipboard_cb write_clipboard_cb;
     ghostty_runtime_new_split_cb new_split_cb;
     ghostty_runtime_close_surface_cb close_surface_cb;
+    ghostty_runtime_focus_next_split_cb focus_next_split_cb;
+    ghostty_runtime_focus_previous_split_cb focus_previous_split_cb;
 } ghostty_runtime_config_s;
 
 typedef struct {

macos/Sources/Ghostty/AppState.swift

@@ -58,7 +58,9 @@ extension Ghostty {
                 read_clipboard_cb: { userdata in AppState.readClipboard(userdata) },
                 write_clipboard_cb: { userdata, str in AppState.writeClipboard(userdata, string: str) },
                 new_split_cb: { userdata, direction in AppState.newSplit(userdata, direction: ghostty_split_direction_e(UInt32(direction))) },
-                close_surface_cb: { userdata in AppState.closeSurface(userdata) }
+                close_surface_cb: { userdata in AppState.closeSurface(userdata) },
+                focus_next_split_cb: { userdata in AppState.focusSplit(userdata, direction: .next) },
+                focus_previous_split_cb: { userdata in AppState.focusSplit(userdata, direction: .previous) }
             )
 
             // Create the ghostty app.
@@ -106,6 +108,17 @@ extension Ghostty {
             NotificationCenter.default.post(name: Notification.ghosttyCloseSurface, object: surface)
         }
         
+        static func focusSplit(_ userdata: UnsafeMutableRawPointer?, direction: SplitFocusDirection) {
+            guard let surface = self.surfaceUserdata(from: userdata) else { return }
+            NotificationCenter.default.post(
+                name: Notification.ghosttyFocusSplit,
+                object: surface,
+                userInfo: [
+                    Notification.SplitDirectionKey: direction,
+                ]
+            )
+        }
+        
         static func readClipboard(_ userdata: UnsafeMutableRawPointer?) -> UnsafePointer<CChar>? {
             guard let appState = self.appState(fromSurface: userdata) else { return nil }
             guard let str = NSPasteboard.general.string(forType: .string) else { return nil }

macos/Sources/Ghostty/Ghostty.SplitView.swift

@@ -123,11 +123,14 @@ extension Ghostty {
         @Binding var requestClose: Bool
         
         var body: some View {
-            let pub = NotificationCenter.default.publisher(for: Notification.ghosttyNewSplit, object: leaf.surface)
-            let pubClose = NotificationCenter.default.publisher(for: Notification.ghosttyCloseSurface, object: leaf.surface)
+            let center = NotificationCenter.default
+            let pub = center.publisher(for: Notification.ghosttyNewSplit, object: leaf.surface)
+            let pubClose = center.publisher(for: Notification.ghosttyCloseSurface, object: leaf.surface)
+            let pubFocus = center.publisher(for: Notification.ghosttyFocusSplit, object: leaf.surface)
             SurfaceWrapper(surfaceView: leaf.surface)
                 .onReceive(pub) { onNewSplit(notification: $0) }
                 .onReceive(pubClose) { _ in requestClose = true }
+                .onReceive(pubFocus) { onMoveFocus(notification: $0) }
         }
         
         private func onNewSplit(notification: SwiftUI.Notification) {
@@ -162,6 +165,13 @@ extension Ghostty {
             Self.fixFocus(container.bottomRight, previous: node)
         }
         
+        private func onMoveFocus(notification: SwiftUI.Notification) {
+            // Determine our desired direction
+            guard let directionAny = notification.userInfo?[Notification.SplitDirectionKey] else { return }
+            guard let direction = directionAny as? SplitFocusDirection else { return }
+            print("MOVE FOCUS: \(direction)")
+        }
+        
         /// There is a bug I can't figure out where when changing the split state, the terminal view
         /// will lose focus. There has to be some nice SwiftUI-native way to fix this but I can't
         /// figure it out so we're going to do this hacky thing to bring focus back to the terminal

macos/Sources/Ghostty/Package.swift

@@ -1,4 +1,28 @@
+import SwiftUI
+
 struct Ghostty {
     // All the notifications that will be emitted will be put here.
     struct Notification {}
 }
+
+// MARK: Surface Notifications
+
+extension Ghostty {
+    /// An enum that is used for the directions that a split focus event can change.
+    enum SplitFocusDirection {
+        case previous, next
+    }
+}
+
+extension Ghostty.Notification {
+    /// Posted when a new split is requested. The sending object will be the surface that had focus. The
+    /// userdata has one key "direction" with the direction to split to.
+    static let ghosttyNewSplit = Notification.Name("com.mitchellh.ghostty.newSplit")
+    
+    /// Close the calling surface.
+    static let ghosttyCloseSurface = Notification.Name("com.mitchellh.ghostty.closeSurface")
+    
+    /// Focus previous/next split. Has a SplitFocusDirection in the userinfo.
+    static let ghosttyFocusSplit = Notification.Name("com.mitchellh.ghostty.focusSplit")
+    static let SplitDirectionKey = ghosttyFocusSplit.rawValue
+}

macos/Sources/Ghostty/SurfaceView.swift

@@ -509,18 +509,6 @@ extension Ghostty {
             0x4E: GHOSTTY_KEY_KP_SUBTRACT,
         ];
     }
-
-}
-
-// MARK: Surface Notifications
-
-extension Ghostty.Notification {
-    /// Posted when a new split is requested. The sending object will be the surface that had focus. The
-    /// userdata has one key "direction" with the direction to split to.
-    static let ghosttyNewSplit = Notification.Name("com.mitchellh.ghostty.newSplit")
-    
-    /// Close the calling surface.
-    static let ghosttyCloseSurface = Notification.Name("com.mitchellh.ghostty.closeSurface")
 }
 
 // MARK: Surface Environment Keys

src/Surface.zig

@@ -947,6 +947,18 @@ pub fn keyCallback(
                     } else log.warn("runtime doesn't implement newSplit", .{});
                 },
 
+                .next_split => {
+                    if (@hasDecl(apprt.Surface, "gotoNextSplit")) {
+                        self.rt_surface.gotoNextSplit();
+                    } else log.warn("runtime doesn't implement gotoNextSplit", .{});
+                },
+
+                .previous_split => {
+                    if (@hasDecl(apprt.Surface, "gotoPreviousSplit")) {
+                        self.rt_surface.gotoPreviousSplit();
+                    } else log.warn("runtime doesn't implement gotoPreviousSplit", .{});
+                },
+
                 .close_surface => {
                     if (@hasDecl(apprt.Surface, "closeSurface")) {
                         try self.rt_surface.closeSurface();

src/apprt/embedded.zig

@@ -51,6 +51,10 @@ pub const App = struct {
 
         /// Close the current surface given by this function.
         close_surface: ?*const fn (SurfaceUD) callconv(.C) void = null,
+
+        /// Focus the previous/next split (if any).
+        focus_next_split: ?*const fn (SurfaceUD) callconv(.C) void = null,
+        focus_previous_split: ?*const fn (SurfaceUD) callconv(.C) void = null,
     };
 
     core_app: *CoreApp,
@@ -166,7 +170,25 @@ pub const Surface = struct {
 
     pub fn closeSurface(self: *const Surface) !void {
         const func = self.app.opts.close_surface orelse {
-            log.info("runtime embedder does not closing a surface", .{});
+            log.info("runtime embedder does not support closing a surface", .{});
+            return;
+        };
+
+        func(self.opts.userdata);
+    }
+
+    pub fn gotoNextSplit(self: *const Surface) void {
+        const func = self.app.opts.focus_next_split orelse {
+            log.info("runtime embedder does not support focus next split", .{});
+            return;
+        };
+
+        func(self.opts.userdata);
+    }
+
+    pub fn gotoPreviousSplit(self: *const Surface) void {
+        const func = self.app.opts.focus_previous_split orelse {
+            log.info("runtime embedder does not support focus previous split", .{});
             return;
         };
 

src/config.zig

@@ -311,6 +311,16 @@ pub const Config = struct {
             .{ .key = .d, .mods = .{ .super = true, .shift = true } },
             .{ .new_split = .down },
         );
+        try result.keybind.set.put(
+            alloc,
+            .{ .key = .left_bracket, .mods = .{ .super = true } },
+            .{ .previous_split = {} },
+        );
+        try result.keybind.set.put(
+            alloc,
+            .{ .key = .right_bracket, .mods = .{ .super = true } },
+            .{ .next_split = {} },
+        );
         {
             // Cmd+N for goto tab N
             const start = @enumToInt(inputpkg.Key.one);

src/input/Binding.zig

@@ -184,6 +184,12 @@ pub const Action = union(enum) {
     /// in the direction given.
     new_split: SplitDirection,
 
+    /// Go to the previous split.
+    previous_split: void,
+
+    /// Go to the next split.
+    next_split: void,
+
     /// Close the current "surface", whether that is a window, tab, split,
     /// etc. This only closes ONE surface.
     close_surface: void,