Detach tab via drag and drop now implemented

glfw/wl_window.c

@@ -3227,7 +3227,7 @@ static void
 drag_source_dnd_drop_performed(void *data UNUSED, struct wl_data_source *source UNUSED) {
     _GLFWwindow *window = _glfwWindowForId(_glfw.drag.window_id);
     if (window) {
-        GLFWDragEvent ev = {.type=GLFW_DRAG_ACTION_CHANGED};
+        GLFWDragEvent ev = {.type=GLFW_DRAG_DROPPED};
         _glfwInputDragSourceRequest(window, &ev);
     } else drag_source_cancelled(data, source);
 }

kitty/boss.py

@@ -1917,6 +1917,7 @@ class Boss:
             set_tab_being_dragged()
             for tm in self.all_tab_managers:
                 tm.on_tab_drop_move(0, False, 0, 0)
+                tm.layout_tab_bar()  # ensure tab bar is fully updated
             return
         central, tab_bar = viewport_for_window(os_window_id)[:2]
         if central.left <= x < central.right and central.top <= y < central.bottom:
@@ -1932,6 +1933,18 @@ class Boss:
             if (tab_id := tm.tab_bar.tab_id_at(x)) and (tab := self.tab_for_id(tab_id)) and (w := tab.active_window):
                 w.on_drop(drop)
 
+    def on_drag_source_finished(
+        self, was_dropped: bool, was_canceled: bool, accepted_mime_type: str, action: int, data: dict[str, bytes] | None
+    ) -> None:
+        if data and (tidb := data.get(f'application/net.kovidgoyal.kitty-tab-{os.getpid()}')):
+            set_tab_being_dragged()
+            for tm in self.all_tab_managers:
+                tm.on_tab_drop_move(0, False, 0, 0)
+            if not was_dropped:  # detach tab into new OS Window
+                tab_id = int(tidb.decode())
+                if (tab := self.tab_for_id(tab_id)):
+                    self._move_tab_to(tab)
+
     @ac('win', '''
         Focus the nth OS window if positive or the previously active OS windows if negative. When the number is larger
         than the number of OS windows focus the last OS window. A value of zero will refocus the currently focused OS window,

kitty/glfw.c

@@ -746,6 +746,7 @@ on_drop(GLFWwindow *window, GLFWDropEvent *ev) {
             Py_CLEAR(global_state.drop_dest.data);
             if (ev->from_self) {
                 if (global_state.drag_source.drag_data) {
+                    global_state.drag_source.was_dropped = true;
                     WINDOW_CALLBACK(on_drop, "OOii", global_state.drag_source.drag_data, Py_True,
                         global_state.callback_os_window->last_drag_event.x, global_state.callback_os_window->last_drag_event.y);
                 } else log_error("Got a drop from self but drag_source.drag_data is NULL");
@@ -804,12 +805,17 @@ drag_source_callback(GLFWwindow *window UNUSED, GLFWDragEvent *ev) {
             ds.accepted_mime_type = ev->mime_type ? strdup(ev->mime_type) : NULL;
             break;
         case GLFW_DRAG_ACTION_CHANGED: ds.action = ev->action; break;
-        case GLFW_DRAG_DROPPED: ds.was_dropped = true; break;
+        case GLFW_DRAG_DROPPED:
+            ds.was_dropped = true;
+            break;
         case GLFW_DRAG_CANCELLED:
             ds.was_canceled = true;
             /* fallthrough */
         case GLFW_DRAG_FINSHED:
-            ds.is_active = false;
+            call_boss(on_drag_source_finished, "OOsiO",
+                    ds.was_dropped ? Py_True : Py_False, ds.was_canceled ? Py_True: Py_False,
+                    ds.accepted_mime_type ? ds.accepted_mime_type : "",
+                    ds.action, ds.drag_data ? ds.drag_data : Py_None);
             free_drag_source();
             break;
     }