Refactor seat operations to use an interface

This splits each seat operation (drag/move tiling/floating etc) into a
separate file and introduces a struct sway_seatop_impl to abstract the
operation.

The move_tiling_threshold operation has been merged into move_tiling.

The main logic for each operation is untouched aside from variable
renames.

The following previously-static functions have been made public:
* node_at_coords
* container_raise_floating
* render_rect
* premultiply_alpha
* scale_box

1 files changed, 6 insertions, 0 deletions

diff --git a/include/sway/input/cursor.h b/include/sway/input/cursor.h
index 4636bf6b..9f699dcd 100644
--- a/include/sway/input/cursor.h
+++ b/include/sway/input/cursor.h
@@ -50,6 +50,12 @@ struct sway_cursor {
 	size_t pressed_button_count;
 };
 
+struct sway_node;
+
+struct sway_node *node_at_coords(
+		struct sway_seat *seat, double lx, double ly,
+		struct wlr_surface **surface, double *sx, double *sy);
+
 void sway_cursor_destroy(struct sway_cursor *cursor);
 struct sway_cursor *sway_cursor_create(struct sway_seat *seat);