add direct set_surface_title and set_tab_title actions (#11373)

Fixes #11316

This mirrors the `prompt` actions (hence why there is no window action
here) and enables setting titles via keybind actions which importantly
lets this work via command palettes, App Intents, AppleScript, etc.

include/ghostty.h

@@ -889,6 +889,7 @@ typedef enum {
   GHOSTTY_ACTION_RENDER_INSPECTOR,
   GHOSTTY_ACTION_DESKTOP_NOTIFICATION,
   GHOSTTY_ACTION_SET_TITLE,
+  GHOSTTY_ACTION_SET_TAB_TITLE,
   GHOSTTY_ACTION_PROMPT_TITLE,
   GHOSTTY_ACTION_PWD,
   GHOSTTY_ACTION_MOUSE_SHAPE,
@@ -937,6 +938,7 @@ typedef union {
   ghostty_action_inspector_e inspector;
   ghostty_action_desktop_notification_s desktop_notification;
   ghostty_action_set_title_s set_title;
+  ghostty_action_set_title_s set_tab_title;
   ghostty_action_prompt_title_e prompt_title;
   ghostty_action_pwd_s pwd;
   ghostty_action_mouse_shape_e mouse_shape;

macos/Sources/Ghostty/Ghostty.App.swift

@@ -539,6 +539,9 @@ extension Ghostty {
             case GHOSTTY_ACTION_SET_TITLE:
                 setTitle(app, target: target, v: action.action.set_title)
 
+            case GHOSTTY_ACTION_SET_TAB_TITLE:
+                return setTabTitle(app, target: target, v: action.action.set_tab_title)
+
             case GHOSTTY_ACTION_PROMPT_TITLE:
                 return promptTitle(app, target: target, v: action.action.prompt_title)
 
@@ -1602,6 +1605,33 @@ extension Ghostty {
             }
         }
 
+        private static func setTabTitle(
+            _ app: ghostty_app_t,
+            target: ghostty_target_s,
+            v: ghostty_action_set_title_s
+        ) -> Bool {
+            switch target.tag {
+            case GHOSTTY_TARGET_APP:
+                Ghostty.logger.warning("set tab title does nothing with an app target")
+                return false
+
+            case GHOSTTY_TARGET_SURFACE:
+                guard let title = String(cString: v.title!, encoding: .utf8) else { return false }
+                let titleOverride = title.isEmpty ? nil : title
+                guard let surface = target.target.surface else { return false }
+                guard let surfaceView = self.surfaceView(from: surface) else { return false }
+                guard let window = surfaceView.window,
+                      let controller = window.windowController as? BaseTerminalController
+                else { return false }
+                controller.titleOverride = titleOverride
+                return true
+
+            default:
+                assertionFailure()
+                return false
+            }
+        }
+
         private static func copyTitleToClipboard(
             _ app: ghostty_app_t,
             target: ghostty_target_s) -> Bool {

src/Surface.zig

@@ -5482,6 +5482,26 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
             .tab,
         ),
 
+        .set_surface_title => |v| {
+            const title = try self.alloc.dupeZ(u8, v);
+            defer self.alloc.free(title);
+            return try self.rt_app.performAction(
+                .{ .surface = self },
+                .set_title,
+                .{ .title = title },
+            );
+        },
+
+        .set_tab_title => |v| {
+            const title = try self.alloc.dupeZ(u8, v);
+            defer self.alloc.free(title);
+            return try self.rt_app.performAction(
+                .{ .surface = self },
+                .set_tab_title,
+                .{ .title = title },
+            );
+        },
+
         .clear_screen => {
             // This is a duplicate of some of the logic in termio.clearScreen
             // but we need to do this here so we can know the answer before

src/apprt/action.zig

@@ -201,6 +201,9 @@ pub const Action = union(Key) {
     /// Set the title of the target to the requested value.
     set_title: SetTitle,
 
+    /// Set the tab title override for the target's tab.
+    set_tab_title: SetTitle,
+
     /// Set the title of the target to a prompted value. It is up to
     /// the apprt to prompt. The value specifies whether to prompt for the
     /// surface title or the tab title.
@@ -375,6 +378,7 @@ pub const Action = union(Key) {
         render_inspector,
         desktop_notification,
         set_title,
+        set_tab_title,
         prompt_title,
         pwd,
         mouse_shape,

src/apprt/gtk/class/application.zig

@@ -740,6 +740,7 @@ pub const Application = extern struct {
             .scrollbar => Action.scrollbar(target, value),
 
             .set_title => Action.setTitle(target, value),
+            .set_tab_title => return Action.setTabTitle(target, value),
 
             .show_child_exited => return Action.showChildExited(target, value),
 
@@ -2545,6 +2546,30 @@ const Action = struct {
         }
     }
 
+    pub fn setTabTitle(
+        target: apprt.Target,
+        value: apprt.action.SetTitle,
+    ) bool {
+        switch (target) {
+            .app => {
+                log.warn("set_tab_title to app is unexpected", .{});
+                return false;
+            },
+            .surface => |core| {
+                const surface = core.rt_surface.surface;
+                const tab = ext.getAncestor(
+                    Tab,
+                    surface.as(gtk.Widget),
+                ) orelse {
+                    log.warn("surface is not in a tab, ignoring set_tab_title", .{});
+                    return false;
+                };
+                tab.setTitleOverride(if (value.title.len == 0) null else value.title);
+                return true;
+            },
+        }
+    }
+
     pub fn showChildExited(
         target: apprt.Target,
         value: apprt.surface.Message.ChildExited,

src/input/Binding.zig

@@ -577,6 +577,16 @@ pub const Action = union(enum) {
     /// and persists across focus changes within the tab.
     prompt_tab_title,
 
+    /// Set the title for the current focused surface.
+    ///
+    /// If the title is empty, the surface title is reset to an empty title.
+    set_surface_title: []const u8,
+
+    /// Set the title for the current focused tab.
+    ///
+    /// If the title is empty, the tab title override is cleared.
+    set_tab_title: []const u8,
+
     /// Create a new split in the specified direction.
     ///
     /// Valid arguments:
@@ -1324,6 +1334,8 @@ pub const Action = union(enum) {
             .set_font_size,
             .prompt_surface_title,
             .prompt_tab_title,
+            .set_surface_title,
+            .set_tab_title,
             .clear_screen,
             .select_all,
             .scroll_to_top,
@@ -3292,6 +3304,16 @@ test "parse: action with string" {
         try testing.expect(binding.action == .esc);
         try testing.expectEqualStrings("A", binding.action.esc);
     }
+    {
+        const binding = try parseSingle("a=set_surface_title:surface");
+        try testing.expect(binding.action == .set_surface_title);
+        try testing.expectEqualStrings("surface", binding.action.set_surface_title);
+    }
+    {
+        const binding = try parseSingle("a=set_tab_title:tab");
+        try testing.expect(binding.action == .set_tab_title);
+        try testing.expectEqualStrings("tab", binding.action.set_tab_title);
+    }
 }
 
 test "parse: action with enum" {
@@ -4557,6 +4579,18 @@ test "action: format" {
     try testing.expectEqualStrings("text:\\xf0\\x9f\\x91\\xbb", buf.written());
 }
 
+test "action: format set title" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    const a: Action = .{ .set_tab_title = "foo bar" };
+
+    var buf: std.Io.Writer.Allocating = .init(alloc);
+    defer buf.deinit();
+    try a.format(&buf.writer);
+    try testing.expectEqualStrings("set_tab_title:foo bar", buf.written());
+}
+
 test "set: appendChain with no parent returns error" {
     const testing = std.testing;
     const alloc = testing.allocator;

src/input/command.zig

@@ -689,6 +689,8 @@ fn actionCommands(action: Action.Key) []const Command {
         .esc,
         .cursor_key,
         .set_font_size,
+        .set_surface_title,
+        .set_tab_title,
         .search,
         .scroll_to_row,
         .scroll_page_fractional,