Handle floating centering in one function and test for consistency

src/commands.c

@@ -1761,25 +1761,18 @@ void cmd_move_window_to_center(I3_CMD, char *method) {
     }
 
     if (strcmp(method, "absolute") == 0) {
-        Rect *rect = &focused->parent->rect;
-
         DLOG("moving to absolute center\n");
-        rect->x = croot->rect.width / 2 - rect->width / 2;
-        rect->y = croot->rect.height / 2 - rect->height / 2;
+        floating_center(focused->parent, croot->rect);
 
         floating_maybe_reassign_ws(focused->parent);
         cmd_output->needs_tree_render = true;
     }
 
     if (strcmp(method, "position") == 0) {
-        Rect *wsrect = &con_get_workspace(focused)->rect;
-        Rect newrect = focused->parent->rect;
-
         DLOG("moving to center\n");
-        newrect.x = wsrect->x + wsrect->width / 2 - newrect.width / 2;
-        newrect.y = wsrect->y + wsrect->height / 2 - newrect.height / 2;
+        floating_center(focused->parent, con_get_workspace(focused)->rect);
 
-        floating_reposition(focused->parent, newrect);
+        cmd_output->needs_tree_render = true;
     }
 
     // XXX: default reply for now, make this a better reply

src/floating.c

@@ -246,12 +246,10 @@ void floating_enable(Con *con, bool automatic) {
         if (con->window && con->window->leader != XCB_NONE &&
             (leader = con_by_window_id(con->window->leader)) != NULL) {
             DLOG("Centering above leader\n");
-            nc->rect.x = leader->rect.x + (leader->rect.width / 2) - (nc->rect.width / 2);
-            nc->rect.y = leader->rect.y + (leader->rect.height / 2) - (nc->rect.height / 2);
+            floating_center(nc, leader->rect);
         } else {
             /* center the window on workspace as fallback */
-            nc->rect.x = ws->rect.x + (ws->rect.width / 2) - (nc->rect.width / 2);
-            nc->rect.y = ws->rect.y + (ws->rect.height / 2) - (nc->rect.height / 2);
+            floating_center(nc, ws->rect);
         }
     }
 
@@ -310,8 +308,7 @@ void floating_enable(Con *con, bool automatic) {
     }
 
     ELOG("No output found at destination coordinates, centering floating window on current ws\n");
-    nc->rect.x = ws->rect.x + (ws->rect.width / 2) - (nc->rect.width / 2);
-    nc->rect.y = ws->rect.y + (ws->rect.height / 2) - (nc->rect.height / 2);
+    floating_center(nc, ws->rect);
 
     ipc_send_window_event("floating", con);
 }
@@ -420,6 +417,15 @@ bool floating_maybe_reassign_ws(Con *con) {
     return true;
 }
 
+/*
+ * Centers a floating con above the specified rect.
+ *
+ */
+void floating_center(Con *con, Rect rect) {
+    con->rect.x = rect.x + (rect.width / 2) - (con->rect.width / 2);
+    con->rect.y = rect.y + (rect.height / 2) - (con->rect.height / 2);
+}
+
 DRAGGING_CB(drag_window_callback) {
     const struct xcb_button_press_event_t *event = extra;
 

src/scratchpad.c

@@ -198,10 +198,7 @@ void scratchpad_show(Con *con) {
         con->rect.width = output->rect.width * 0.5;
         con->rect.height = output->rect.height * 0.75;
         floating_check_size(con);
-        con->rect.x = output->rect.x +
-                      ((output->rect.width / 2.0) - (con->rect.width / 2.0));
-        con->rect.y = output->rect.y +
-                      ((output->rect.height / 2.0) - (con->rect.height / 2.0));
+        floating_center(con, con_get_workspace(con)->rect);
     }
 
     /* Activate active workspace if window is from another workspace to ensure