add apprt action to notify apprt of surface readonly state

include/ghostty.h

@@ -573,6 +573,12 @@ typedef enum {
   GHOSTTY_QUIT_TIMER_STOP,
 } ghostty_action_quit_timer_e;
 
+// apprt.action.Readonly
+typedef enum {
+  GHOSTTY_READONLY_OFF,
+  GHOSTTY_READONLY_ON,
+} ghostty_action_readonly_e;
+
 // apprt.action.DesktopNotification.C
 typedef struct {
   const char* title;
@@ -837,6 +843,7 @@ typedef enum {
   GHOSTTY_ACTION_END_SEARCH,
   GHOSTTY_ACTION_SEARCH_TOTAL,
   GHOSTTY_ACTION_SEARCH_SELECTED,
+  GHOSTTY_ACTION_READONLY,
   } ghostty_action_tag_e;
 
 typedef union {
@@ -874,6 +881,7 @@ typedef union {
   ghostty_action_start_search_s start_search;
   ghostty_action_search_total_s search_total;
   ghostty_action_search_selected_s search_selected;
+  ghostty_action_readonly_e readonly;
 } ghostty_action_u;
 
 typedef struct {

src/Surface.zig

@@ -5424,6 +5424,11 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
 
         .toggle_readonly => {
             self.readonly = !self.readonly;
+            _ = try self.rt_app.performAction(
+                .{ .surface = self },
+                .readonly,
+                if (self.readonly) .on else .off,
+            );
             return true;
         },
 

src/apprt/action.zig

@@ -314,6 +314,9 @@ pub const Action = union(Key) {
     /// The currently selected search match index (1-based).
     search_selected: SearchSelected,
 
+    /// The readonly state of the surface has changed.
+    readonly: Readonly,
+
     /// Sync with: ghostty_action_tag_e
     pub const Key = enum(c_int) {
         quit,
@@ -375,6 +378,7 @@ pub const Action = union(Key) {
         end_search,
         search_total,
         search_selected,
+        readonly,
     };
 
     /// Sync with: ghostty_action_u
@@ -532,6 +536,11 @@ pub const QuitTimer = enum(c_int) {
     stop,
 };
 
+pub const Readonly = enum(c_int) {
+    off,
+    on,
+};
+
 pub const MouseVisibility = enum(c_int) {
     visible,
     hidden,

src/apprt/gtk/class/application.zig

@@ -746,6 +746,7 @@ pub const Application = extern struct {
             .check_for_updates,
             .undo,
             .redo,
+            .readonly,
             => {
                 log.warn("unimplemented action={}", .{action});
                 return false;