apprt: support a pwd change action

include/ghostty.h

@@ -430,6 +430,11 @@ typedef struct {
   const char* title;
 } ghostty_action_set_title_s;
 
+// apprt.action.Pwd.C
+typedef struct {
+  const char* pwd;
+} ghostty_action_pwd_s;
+
 // terminal.MouseShape
 typedef enum {
   GHOSTTY_MOUSE_SHAPE_DEFAULT,
@@ -552,6 +557,7 @@ typedef enum {
   GHOSTTY_ACTION_RENDER_INSPECTOR,
   GHOSTTY_ACTION_DESKTOP_NOTIFICATION,
   GHOSTTY_ACTION_SET_TITLE,
+  GHOSTTY_ACTION_PWD,
   GHOSTTY_ACTION_MOUSE_SHAPE,
   GHOSTTY_ACTION_MOUSE_VISIBILITY,
   GHOSTTY_ACTION_MOUSE_OVER_LINK,
@@ -576,6 +582,7 @@ typedef union {
   ghostty_action_inspector_e inspector;
   ghostty_action_desktop_notification_s desktop_notification;
   ghostty_action_set_title_s set_title;
+  ghostty_action_pwd_s pwd;
   ghostty_action_mouse_shape_e mouse_shape;
   ghostty_action_mouse_visibility_e mouse_visibility;
   ghostty_action_mouse_over_link_s mouse_over_link;

src/Surface.zig

@@ -856,6 +856,20 @@ pub fn handleMessage(self: *Surface, msg: Message) !void {
             },
         },
 
+        .pwd_change => |w| {
+            defer w.deinit();
+
+            // We always allocate for this because we need to null-terminate.
+            const str = try self.alloc.dupeZ(u8, w.slice());
+            defer self.alloc.free(str);
+
+            try self.rt_app.performAction(
+                .{ .surface = self },
+                .pwd,
+                .{ .pwd = str },
+            );
+        },
+
         .close => self.close(),
 
         // Close without confirmation.

src/apprt/action.zig

@@ -151,6 +151,9 @@ pub const Action = union(Key) {
     /// Set the title of the target.
     set_title: SetTitle,
 
+    /// The current working directory has changed for the target terminal.
+    pwd: Pwd,
+
     /// Set the mouse cursor shape.
     mouse_shape: terminal.MouseShape,
 
@@ -215,6 +218,7 @@ pub const Action = union(Key) {
         render_inspector,
         desktop_notification,
         set_title,
+        pwd,
         mouse_shape,
         mouse_visibility,
         mouse_over_link,
@@ -417,6 +421,21 @@ pub const SetTitle = struct {
     }
 };
 
+pub const Pwd = struct {
+    pwd: [:0]const u8,
+
+    // Sync with: ghostty_action_set_pwd_s
+    pub const C = extern struct {
+        pwd: [*:0]const u8,
+    };
+
+    pub fn cval(self: Pwd) C {
+        return .{
+            .pwd = self.pwd.ptr,
+        };
+    }
+};
+
 /// The desktop notification to show.
 pub const DesktopNotification = struct {
     title: [:0]const u8,

src/apprt/glfw.zig

@@ -224,6 +224,7 @@ pub const App = struct {
             .cell_size,
             .renderer_health,
             .color_change,
+            .pwd,
             => log.info("unimplemented action={}", .{action}),
         }
     }

src/apprt/gtk/App.zig

@@ -486,6 +486,7 @@ pub fn performAction(
         .render_inspector,
         .renderer_health,
         .color_change,
+        .pwd,
         => log.warn("unimplemented action={}", .{action}),
     }
 }

src/apprt/surface.zig

@@ -76,6 +76,9 @@ pub const Message = union(enum) {
         color: terminal.color.RGB,
     },
 
+    /// The terminal has reported a change in the working directory.
+    pwd_change: WriteReq,
+
     pub const ReportTitleStyle = enum {
         csi_21_t,
 

src/termio/stream_handler.zig

@@ -1123,6 +1123,14 @@ pub const StreamHandler = struct {
         log.debug("terminal pwd: {s}", .{path});
         try self.terminal.setPwd(path);
 
+        // Report it to the surface. If creating our write request fails
+        // then we just ignore it.
+        if (apprt.surface.Message.WriteReq.init(self.alloc, path)) |req| {
+            self.surfaceMessageWriter(.{ .pwd_change = req });
+        } else |err| {
+            log.warn("error notifying surface of pwd change err={}", .{err});
+        }
+
         // If we haven't seen a title, use our pwd as the title.
         if (!self.seen_title) {
             try self.changeWindowTitle(path);