Implement floating_modifier and mouse operations for floating views

This implements the following:

* `floating_modifier` configuration directive
* Drag a floating window by its title bar
* Hold mod + drag a floating window from anywhere
* Resize a floating view by dragging the border
* Resize a floating view by holding mod and right clicking anywhere on
the view
* Resize a floating view and keep aspect ratio by holding shift while
resizing using either method
* Mouse cursor turns into resize when hovering floating border or corner

1 files changed, 16 insertions, 0 deletions

diff --git a/include/sway/input/seat.h b/include/sway/input/seat.h
index eac1626b..be1f3610 100644
--- a/include/sway/input/seat.h
+++ b/include/sway/input/seat.h
@@ -34,6 +34,8 @@ struct sway_drag_icon {
         struct wl_listener destroy;
 };
 
+enum resize_edge;
+
 struct sway_seat {
         struct wlr_seat *wlr_seat;
         struct sway_cursor *cursor;
@@ -52,6 +54,20 @@ struct sway_seat {
         int32_t touch_id;
         double touch_x, touch_y;
 
+        // Operations (drag and resize)
+        enum {
+                OP_NONE,
+                OP_DRAG,
+                OP_RESIZE,
+        } operation;
+        struct sway_container *op_container;
+        enum resize_edge op_resize_edge;
+        uint32_t op_button;
+        bool op_resize_preserve_ratio;
+        double op_ref_lx, op_ref_ly;         // cursor's x/y at start of op
+        double op_ref_width, op_ref_height;  // container's size at start of op
+        double op_ref_con_lx, op_ref_con_ly; // container's x/y at start of op
+
         struct wl_listener focus_destroy;
         struct wl_listener new_container;
         struct wl_listener new_drag_icon;