add global `current_focus` pointer

include/sway/container.h

@@ -8,6 +8,7 @@
 typedef struct sway_container swayc_t;
 
 extern swayc_t root_container;
+extern swayc_t *current_focus;
 
 /**
  * Different kinds of containers.

sway/focus.c

@@ -120,6 +120,10 @@ bool set_focused_container(swayc_t *c) {
 		// dispatch a window event
 		ipc_event_window(c, "focus");
 	}
+
+	// update the global pointer
+	current_focus = c;
+
 	// update container focus from here to root, making necessary changes along
 	// the way
 	swayc_t *p = c;

sway/layout.c

@@ -15,6 +15,7 @@
 #include "log.h"
 
 swayc_t root_container;
+swayc_t *current_focus;
 list_t *scratchpad;
 
 int min_sane_h = 60;
@@ -27,6 +28,7 @@ void init_layout(void) {
 	root_container.children = create_list();
 	root_container.handle = -1;
 	root_container.visible = true;
+	current_focus = &root_container;
 	scratchpad = create_list();
 }