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, 65 insertions, 0 deletions

diff --git a/sway/input/seatop_move_floating.c b/sway/input/seatop_move_floating.c
new file mode 100644
index 00000000..08e3a5a4
--- /dev/null
+++ b/sway/input/seatop_move_floating.c
@@ -0,0 +1,65 @@
+#define _POSIX_C_SOURCE 200809L
+#include <wlr/types/wlr_cursor.h>
+#include "sway/desktop.h"
+#include "sway/input/cursor.h"
+#include "sway/input/seat.h"
+
+struct seatop_move_floating_event {
+        struct sway_container *con;
+};
+
+static void handle_motion(struct sway_seat *seat, uint32_t time_msec) {
+        struct seatop_move_floating_event *e = seat->seatop_data;
+        desktop_damage_whole_container(e->con);
+        container_floating_translate(e->con,
+                        seat->cursor->cursor->x - seat->cursor->previous.x,
+                        seat->cursor->cursor->y - seat->cursor->previous.y);
+        desktop_damage_whole_container(e->con);
+}
+
+static void handle_finish(struct sway_seat *seat) {
+        struct seatop_move_floating_event *e = seat->seatop_data;
+
+        // We "move" the container to its own location
+        // so it discovers its output again.
+        container_floating_move_to(e->con, e->con->x, e->con->y);
+        cursor_set_image(seat->cursor, "left_ptr", NULL);
+}
+
+static void handle_abort(struct sway_seat *seat) {
+        cursor_set_image(seat->cursor, "left_ptr", NULL);
+}
+
+static void handle_unref(struct sway_seat *seat, struct sway_container *con) {
+        struct seatop_move_floating_event *e = seat->seatop_data;
+        if (e->con == con) {
+                seatop_abort(seat);
+        }
+}
+
+static const struct sway_seatop_impl seatop_impl = {
+        .motion = handle_motion,
+        .finish = handle_finish,
+        .abort = handle_abort,
+        .unref = handle_unref,
+};
+
+void seatop_begin_move_floating(struct sway_seat *seat,
+                struct sway_container *con, uint32_t button) {
+        seatop_abort(seat);
+
+        struct seatop_move_floating_event *e =
+                calloc(1, sizeof(struct seatop_move_floating_event));
+        if (!e) {
+                return;
+        }
+        e->con = con;
+
+        seat->seatop_impl = &seatop_impl;
+        seat->seatop_data = e;
+        seat->seatop_button = button;
+
+        container_raise_floating(con);
+
+        cursor_set_image(seat->cursor, "grab", NULL);
+}