focus stack and next/prev toplevel keybinds

src/focus.c

@@ -1,4 +1,5 @@
 #include <wayland-server-core.h>
+#include <wlr/util/log.h>
 
 #include "types.h"
 #include "absinthe-toplevel.h"
@@ -26,11 +27,45 @@ void focus_toplevel(struct absinthe_toplevel *toplevel)
 
     struct wlr_keyboard *keyboard = wlr_seat_get_keyboard(seat);
     wlr_scene_node_raise_to_top(&toplevel->scene_tree->node);
-    wl_list_remove(&toplevel->link);
-    wl_list_insert(&server->toplevels, &toplevel->link);
+    wl_list_remove(&toplevel->flink);
+    wl_list_insert(&server->focus_stack, &toplevel->flink);
     wlr_xdg_toplevel_set_activated(toplevel->xdg_toplevel, true);
     absinthe_toplevel_set_border_color(toplevel, focused_border_color);
 
     if (keyboard)
         wlr_seat_keyboard_notify_enter(seat, surface, keyboard->keycodes, keyboard->num_keycodes, &keyboard->modifiers);
 }
+
+static struct absinthe_toplevel *focus_get_topmost(struct absinthe_server *server)
+{
+    struct absinthe_toplevel *toplevel;
+    wl_list_for_each(toplevel, &server->focus_stack, flink) {
+        if (toplevel)
+            return toplevel;
+    }
+    return NULL;
+}
+
+void focus_next(struct absinthe_server *server)
+{
+    struct absinthe_toplevel *toplevel = focus_get_topmost(server);
+    struct absinthe_toplevel *next;
+    wl_list_for_each(next, &toplevel->link, link) {
+        if (&next->link == &toplevel->server->toplevels)
+            continue;
+        break;
+    }
+    focus_toplevel(next);
+}
+
+void focus_prev(struct absinthe_server *server)
+{
+    struct absinthe_toplevel *toplevel = focus_get_topmost(server);
+    struct absinthe_toplevel *prev;
+    wl_list_for_each_reverse(prev, &toplevel->link, link) {
+        if (&prev->link == &toplevel->server->toplevels)
+            continue;
+        break;
+    }
+    focus_toplevel(prev);
+}