Implement tab cycling using mouse wheel

Firstly, a change had to be made to the container_at functions. If you
create layout `T[view H[view view]]` and hover the second tab, the
container_at functions would return the focus_inactive child. They now
return the split container itself. To compensate for this,
dispatch_cursor_button has been adjusted to find the focus_inactive
child before focusing it.

The actual implementation of wheel scrolling is pretty straightforward.
This uses handle_cursor_axis, so I took a similar approach to
handle_cursor_button (ie. creating a dispatch_cursor_axis function).

1 files changed, 2 insertions, 4 deletions

diff --git a/sway/tree/container.c b/sway/tree/container.c
index 47687744..b8af7564 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -215,8 +215,7 @@ static struct sway_container *container_at_tabbed(struct sway_node *parent,
                         child_index = children->length - 1;
                 }
                 struct sway_container *child = children->items[child_index];
-                struct sway_node *node = seat_get_focus_inactive(seat, &child->node);
-                return node->sway_container;
+                return child;
         }
 
         // Surfaces
@@ -243,8 +242,7 @@ static struct sway_container *container_at_stacked(struct sway_node *parent,
         int child_index = (ly - box.y) / title_height;
         if (child_index < children->length) {
                 struct sway_container *child = children->items[child_index];
-                struct sway_node *node = seat_get_focus_inactive(seat, &child->node);
-                return node->sway_container;
+                return child;
         }
 
         // Surfaces