Wayland: call libdecor_dispatch(), libdecor_unref(), libdecor_get_fd() as expected by libdecor.

Corresponds to these commits to master: 8e9e2b7, f121bc1, e8e5e61, d816da5.

src/drivers/Wayland/Fl_Wayland_Screen_Driver.cxx

@@ -1352,30 +1352,30 @@ static const struct wl_registry_listener registry_listener = {
 };
 
 
-extern int fl_send_system_handlers(void *);
+static void libdecor_fd_callback(int fd, struct libdecor *libdecor_context) {
-
+  if (libdecor_dispatch(libdecor_context, 0) >= 0) return;
-
+  if (wl_display_get_error(Fl_Wayland_Screen_Driver::wl_display) == EPROTO) {
-static void wayland_socket_callback(int fd, struct wl_display *display) {
+    const struct wl_interface *interface;
-  if (fl_send_system_handlers(NULL)) return;
+    int code = wl_display_get_protocol_error(Fl_Wayland_Screen_Driver::wl_display, &interface, NULL);
-  struct pollfd fds = (struct pollfd) { fd, POLLIN, 0 };
+    Fl::fatal("Fatal error no %d in Wayland protocol: %s", code,
-  do {
+              (interface ? interface->name : "unknown") );
-    if (wl_display_dispatch(display) == -1) {
+  } else {
-      int err = wl_display_get_error(display);
+    Fl::fatal("Fatal error while communicating with the Wayland server: %s",
-      if (err == EPROTO) {
+              strerror(errno));
-        const struct wl_interface *interface;
-        int code = wl_display_get_protocol_error(display, &interface, NULL);
-        Fl::fatal("Fatal error no %d in Wayland protocol: %s", code,
-                  (interface ? interface->name : "unknown") );
-      } else {
-        Fl::fatal("Fatal error while communicating with the Wayland server: %s",
-                  strerror(errno));
-      }
-    }
   }
-  while (poll(&fds, 1, 0) > 0);
 }
 
 
+static void handle_error(struct libdecor *libdecor_context, enum libdecor_error error, const char *message)
+{
+  Fl::fatal("Caught error (%d): %s\n", error, message);
+}
+
+static struct libdecor_interface libdecor_iface = {
+  .error = handle_error,
+};
+
+
 Fl_Wayland_Screen_Driver::Fl_Wayland_Screen_Driver() : Fl_Unix_Screen_Driver() {
   libdecor_context = NULL;
   seat = NULL;
@@ -1404,8 +1404,11 @@ static const struct wl_callback_listener sync_listener = {
 
 
 static void do_atexit() {
-  if (Fl_Wayland_Screen_Driver::wl_display) {
+  // Issue #821 no longer seems to require extra operations under gnome version < 44.
-    wl_display_roundtrip(Fl_Wayland_Screen_Driver::wl_display);
+  Fl_Wayland_Screen_Driver *scr_driver = (Fl_Wayland_Screen_Driver*)Fl::screen_driver();
+  if (scr_driver->libdecor_context) { // libdecor recommends a call to libdecor_unref()
+    libdecor_unref(scr_driver->libdecor_context);
+    scr_driver->libdecor_context = NULL;
   }
 }
 
@@ -1431,15 +1434,10 @@ void Fl_Wayland_Screen_Driver::open_display_platform() {
   struct wl_callback *registry_cb = wl_display_sync(wl_display);
   wl_callback_add_listener(registry_cb, &sync_listener, &registry_cb);
   while (registry_cb) wl_display_dispatch(wl_display);
-  Fl::add_fd(wl_display_get_fd(wl_display), FL_READ, (Fl_FD_Handler)wayland_socket_callback,
+  libdecor_context = libdecor_new(wl_display, &libdecor_iface);
-             wl_display);
+  Fl::add_fd(libdecor_get_fd(libdecor_context), FL_READ, (Fl_FD_Handler)libdecor_fd_callback,
+             libdecor_context);
   fl_create_print_window();
-  /* This is useful to avoid crash of the Wayland compositor after
-   FLTK apps terminate in certain situations:
-   - gnome-shell version < 44 (e.g. version 42.9)
-   - focus set to "follow-mouse"
-   See issue #821 for details.
-  */
   atexit(do_atexit);
 }
 
@@ -1519,21 +1517,20 @@ void Fl_Wayland_Screen_Driver::close_display() {
   wl_seat_destroy(seat->wl_seat); seat->wl_seat = NULL;
   if (seat->name) free(seat->name);
   free(seat); seat = NULL;
-  if (libdecor_context) {
-    libdecor_unref(libdecor_context);
-    libdecor_context = NULL;
-  }
   xdg_wm_base_destroy(xdg_wm_base); xdg_wm_base = NULL;
   Fl_Wayland_Plugin *plugin = Fl_Wayland_Window_Driver::gl_plugin();
   if (plugin) plugin->terminate();
 
-  Fl::remove_fd(wl_display_get_fd(Fl_Wayland_Screen_Driver::wl_display));
+  if (libdecor_context) {
+      Fl::remove_fd(libdecor_get_fd(libdecor_context));
+      libdecor_unref(libdecor_context);
+      libdecor_context = NULL;
+  }
   wl_registry_destroy(wl_registry); wl_registry = NULL;
   wl_display_disconnect(Fl_Wayland_Screen_Driver::wl_display);
   Fl_Wayland_Screen_Driver::wl_display = NULL;
   delete Fl_Display_Device::display_device()->driver();
   delete Fl_Display_Device::display_device();
-  delete Fl::system_driver();
   delete this;
 }
 

src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx

@@ -648,17 +648,6 @@ int Fl_Wayland_Window_Driver::scroll(int src_x, int src_y, int src_w, int src_h,
 }
 
 
-static void handle_error(struct libdecor *libdecor_context, enum libdecor_error error, const char *message)
-{
-  Fl::fatal("Caught error (%d): %s\n", error, message);
-}
-
-
-static struct libdecor_interface libdecor_iface = {
-  .error = handle_error,
-};
-
-
 void change_scale(Fl_Wayland_Screen_Driver::output *output, struct wld_window *window,
                   float pre_scale) {
   Fl_Wayland_Window_Driver *win_driver = Fl_Wayland_Window_Driver::driver(window->fl_win);
@@ -1007,11 +996,12 @@ void Fl_Wayland_Window_Driver::wait_for_expose()
   Fl_Window_Driver::wait_for_expose();
   struct wld_window * xid = fl_wl_xid(pWindow);
   if (!xid) return;
+  Fl_Wayland_Screen_Driver *scr_driver = (Fl_Wayland_Screen_Driver*)Fl::screen_driver();
   if (pWindow->fullscreen_active()) {
     if (xid->kind == DECORATED) {
       while (!(xid->state & LIBDECOR_WINDOW_STATE_FULLSCREEN) ||
              !(xid->state & LIBDECOR_WINDOW_STATE_ACTIVE)) {
-        wl_display_dispatch(Fl_Wayland_Screen_Driver::wl_display);
+        libdecor_dispatch(scr_driver->libdecor_context, 0);
       }
     } else if (xid->kind == UNFRAMED) {
       wl_display_roundtrip(Fl_Wayland_Screen_Driver::wl_display);
@@ -1019,7 +1009,7 @@ void Fl_Wayland_Window_Driver::wait_for_expose()
   } else if (xid->kind == DECORATED) {
     // necessary for the windowfocus demo program with recent Wayland versions
     if (!(xid->state & LIBDECOR_WINDOW_STATE_ACTIVE)) {
-      wl_display_dispatch(Fl_Wayland_Screen_Driver::wl_display);
+      libdecor_dispatch(scr_driver->libdecor_context, 0);
     }
   }
 }
@@ -1465,9 +1455,6 @@ void Fl_Wayland_Window_Driver::makeWindow()
 
   } else if (pWindow->border() && !pWindow->parent() ) { // a decorated window
     new_window->kind = DECORATED;
-    if (!scr_driver->libdecor_context)
-      scr_driver->libdecor_context = libdecor_new(Fl_Wayland_Screen_Driver::wl_display,
-                                                  &libdecor_iface);
     new_window->frame = libdecor_decorate(scr_driver->libdecor_context, new_window->wl_surface,
                                           &libdecor_frame_iface, new_window);
     // appears in the Gnome desktop menu bar