kiosk-shell: Separate (keyboard) input focus from xdg-shell toplevel window activation

This is small follow-up from !568 (closed) in which input focus was tied to window activation.

Note that these series has been split kiosk-shell (current MR) and desktop-shell (which have been migrated to !711 (closed))

This removes the window activation code from the keyboard focus handlers an embeds it straight into the shell's activation parts, such that devices with no keyboard can still use their other input devices (touch) to activate the window.

kiosk-shell/kiosk-shell.c

@@ -57,14 +57,33 @@ get_kiosk_shell_seat(struct weston_seat *seat)
 {
 	struct wl_listener *listener;
 
+	if (!seat)
+		return NULL;
+
 	listener = wl_signal_get(&seat->destroy_signal,
 				 kiosk_shell_seat_handle_destroy);
-	assert(listener != NULL);
+
+	if (!listener)
+		return NULL;
 
 	return container_of(listener,
 			    struct kiosk_shell_seat, seat_destroy_listener);
 }
 
+
+static struct weston_seat *
+get_kiosk_shell_first_seat(struct kiosk_shell *shell)
+{
+	struct wl_list *node;
+	struct weston_compositor *compositor = shell->compositor;
+
+	if (wl_list_empty(&compositor->seat_list))
+		return NULL;
+
+	node = compositor->seat_list.next;
+	return container_of(node, struct weston_seat, link);
+}
+
 static void
 transform_handler(struct wl_listener *listener, void *data)
 {
@@ -343,42 +362,44 @@ kiosk_shell_surface_create(struct kiosk_shell *shell,
 	return shsurf;
 }
 
-/*
- * kiosk_shell_seat
- */
-
 static void
-kiosk_shell_seat_handle_keyboard_focus(struct wl_listener *listener, void *data)
+kiosk_shell_surface_activate(struct kiosk_shell_surface *shsurf,
+			     struct kiosk_shell_seat *kiosk_seat,
+			     uint32_t activate_flags)
 {
-	struct weston_keyboard *keyboard = data;
-	struct kiosk_shell_seat *shseat = get_kiosk_shell_seat(keyboard->seat);
-
-	if (shseat->focused_surface) {
-		struct kiosk_shell_surface *shsurf =
-			get_kiosk_shell_surface(shseat->focused_surface);
-		if (shsurf && --shsurf->focus_count == 0)
-			weston_desktop_surface_set_activated(shsurf->desktop_surface,
-							     false);
-	}
+	struct weston_desktop_surface *dsurface = shsurf->desktop_surface;
+	struct weston_surface *surface =
+		weston_desktop_surface_get_surface(dsurface);
+
+	/* keyboard focus */
+	weston_view_activate_input(shsurf->view, kiosk_seat->seat, activate_flags);
 
-	shseat->focused_surface = weston_surface_get_main_surface(keyboard->focus);
+	/* xdg-shell deactivation if there's a focused one */
+	if (kiosk_seat->focused_surface) {
+		struct kiosk_shell_surface *current_focus =
+			get_kiosk_shell_surface(kiosk_seat->focused_surface);
+		struct weston_desktop_surface *dsurface_focus;
+		assert(current_focus);
 
-	if (shseat->focused_surface) {
-		struct kiosk_shell_surface *shsurf =
-			get_kiosk_shell_surface(shseat->focused_surface);
-		if (shsurf && shsurf->focus_count++ == 0)
-			weston_desktop_surface_set_activated(shsurf->desktop_surface,
-							     true);
+		dsurface_focus = current_focus->desktop_surface;
+		if (--current_focus->focus_count == 0)
+			weston_desktop_surface_set_activated(dsurface_focus, false);
 	}
+
+	/* xdg-shell activation for the new one */
+	kiosk_seat->focused_surface = surface;
+	if (shsurf->focus_count++ == 0)
+		weston_desktop_surface_set_activated(dsurface, true);
 }
 
+/*
+ * kiosk_shell_seat
+ */
+
 static void
 kiosk_shell_seat_destroy(struct kiosk_shell_seat *shseat)
 {
-	wl_list_remove(&shseat->keyboard_focus_listener.link);
-	wl_list_remove(&shseat->caps_changed_listener.link);
 	wl_list_remove(&shseat->seat_destroy_listener.link);
-
 	wl_list_remove(&shseat->link);
 	free(shseat);
 }
@@ -393,31 +414,17 @@ kiosk_shell_seat_handle_destroy(struct wl_listener *listener, void *data)
 	kiosk_shell_seat_destroy(shseat);
 }
 
-static void
-kiosk_shell_seat_handle_caps_changed(struct wl_listener *listener, void *data)
-{
-	struct weston_keyboard *keyboard;
-	struct kiosk_shell_seat *shseat;
-
-	shseat = container_of(listener, struct kiosk_shell_seat,
-			      caps_changed_listener);
-	keyboard = weston_seat_get_keyboard(shseat->seat);
-
-	if (keyboard &&
-	    wl_list_empty(&shseat->keyboard_focus_listener.link)) {
-		wl_signal_add(&keyboard->focus_signal,
-			      &shseat->keyboard_focus_listener);
-	} else if (!keyboard) {
-		wl_list_remove(&shseat->keyboard_focus_listener.link);
-		wl_list_init(&shseat->keyboard_focus_listener.link);
-	}
-}
-
 static struct kiosk_shell_seat *
 kiosk_shell_seat_create(struct kiosk_shell *shell, struct weston_seat *seat)
 {
 	struct kiosk_shell_seat *shseat;
 
+	if (wl_list_length(&shell->seat_list) > 0) {
+		weston_log("WARNING: multiple seats detected. kiosk-shell "
+			   "can not handle multiple seats!\n");
+		return NULL;
+	}
+
 	shseat = zalloc(sizeof *shseat);
 	if (!shseat) {
 		weston_log("no memory to allocate shell seat\n");
@@ -429,14 +436,6 @@ kiosk_shell_seat_create(struct kiosk_shell *shell, struct weston_seat *seat)
 	shseat->seat_destroy_listener.notify = kiosk_shell_seat_handle_destroy;
 	wl_signal_add(&seat->destroy_signal, &shseat->seat_destroy_listener);
 
-	shseat->keyboard_focus_listener.notify = kiosk_shell_seat_handle_keyboard_focus;
-	wl_list_init(&shseat->keyboard_focus_listener.link);
-
-	shseat->caps_changed_listener.notify = kiosk_shell_seat_handle_caps_changed;
-	wl_signal_add(&seat->updated_caps_signal,
-		      &shseat->caps_changed_listener);
-	kiosk_shell_seat_handle_caps_changed(&shseat->caps_changed_listener, NULL);
-
 	wl_list_insert(&shell->seat_list, &shseat->link);
 
 	return shseat;
@@ -619,13 +618,22 @@ desktop_surface_added(struct weston_desktop_surface *desktop_surface,
  * parentage. */
 static struct weston_view *
 find_focus_successor(struct weston_layer *layer,
-		     struct kiosk_shell_surface *shsurf)
+		     struct kiosk_shell_surface *shsurf,
+		     struct weston_surface *focused_surface)
 {
 	struct kiosk_shell_surface *parent_root =
 		kiosk_shell_surface_get_parent_root(shsurf);
 	struct weston_view *top_view = NULL;
 	struct weston_view *view;
 
+	/* we need to take into account that the surface being destroyed it not
+	 * always the same as the focus_surface, which could result in picking
+	 * and *activating* the wrong window, so avoid returning a view for
+	 * that case. A particular case is when a top-level child window, would
+	 * pick a parent window below the focused_surface. */
+	if (focused_surface != shsurf->view->surface)
+		return top_view;
+
 	wl_list_for_each(view, &layer->view_list.link, layer_link.link) {
 		struct kiosk_shell_surface *view_shsurf;
 		struct kiosk_shell_surface *root;
@@ -659,17 +667,27 @@ desktop_surface_removed(struct weston_desktop_surface *desktop_surface,
 		weston_desktop_surface_get_surface(desktop_surface);
 	struct weston_view *focus_view;
 	struct weston_seat *seat;
+	struct kiosk_shell_seat* kiosk_seat;
 
 	if (!shsurf)
 		return;
 
-	focus_view = find_focus_successor(&shell->normal_layer, shsurf);
+	seat = get_kiosk_shell_first_seat(shell);
+	kiosk_seat = get_kiosk_shell_seat(seat);
+
+	if (seat && kiosk_seat) {
+		focus_view = find_focus_successor(&shell->normal_layer, shsurf,
+						  kiosk_seat->focused_surface);
+
+		if (focus_view) {
+			struct kiosk_shell_surface *focus_shsurf =
+				get_kiosk_shell_surface(focus_view->surface);
 
-	if (focus_view) {
-		wl_list_for_each(seat, &shell->compositor->seat_list, link) {
-			struct weston_keyboard *keyboard = seat->keyboard_state;
-			if (keyboard && keyboard->focus == surface)
-				weston_view_activate_input(focus_view, seat, 0);
+			kiosk_shell_surface_activate(focus_shsurf, kiosk_seat,
+						     WESTON_ACTIVATE_FLAG_NONE);
+		} else {
+			if (kiosk_seat->focused_surface == surface)
+				kiosk_seat->focused_surface = NULL;
 		}
 	}
 
@@ -687,6 +705,8 @@ desktop_surface_committed(struct weston_desktop_surface *desktop_surface,
 	bool is_resized;
 	bool is_fullscreen;
 
+	assert(shsurf);
+
 	if (surface->width == 0)
 		return;
 
@@ -716,15 +736,19 @@ desktop_surface_committed(struct weston_desktop_surface *desktop_surface,
 	}
 
 	if (!weston_surface_is_mapped(surface)) {
-		struct weston_seat *seat;
+		struct weston_seat *seat =
+			get_kiosk_shell_first_seat(shsurf->shell);
+		struct kiosk_shell_seat *kiosk_seat;
 
 		weston_layer_entry_insert(&shsurf->shell->normal_layer.view_list,
 					  &shsurf->view->layer_link);
 		shsurf->view->is_mapped = true;
 		surface->is_mapped = true;
 
-		wl_list_for_each(seat, &shsurf->shell->compositor->seat_list, link)
-			weston_view_activate_input(shsurf->view, seat, 0);
+		kiosk_seat = get_kiosk_shell_seat(seat);
+		if (seat && kiosk_seat)
+			kiosk_shell_surface_activate(shsurf, kiosk_seat,
+						     WESTON_ACTIVATE_FLAG_NONE);
 	}
 
 	if (!is_fullscreen && (sx != 0 || sy != 0)) {
@@ -916,6 +940,8 @@ kiosk_shell_activate_view(struct kiosk_shell *shell,
 		weston_surface_get_main_surface(view->surface);
 	struct kiosk_shell_surface *shsurf =
 		get_kiosk_shell_surface(main_surface);
+	struct kiosk_shell_seat *kiosk_seat =
+		get_kiosk_shell_seat(seat);
 
 	if (!shsurf)
 		return;
@@ -932,7 +958,8 @@ kiosk_shell_activate_view(struct kiosk_shell *shell,
 		weston_surface_damage(view->surface);
 	}
 
-	weston_view_activate_input(view, seat, flags);
+	if (kiosk_seat)
+		kiosk_shell_surface_activate(shsurf, kiosk_seat, flags);
 }
 
 static void