Refactor extern definition of conn and root_screen

[i3/i3] / libi3 / dpi.c

diff --git a/libi3/dpi.c b/libi3/dpi.c
index 37d5b21502e5882df374933070497d5e73ae0484..897e6e4016a362645f96ee84bd032b577ed0015f 100644 (file)
--- a/libi3/dpi.c
+++ b/libi3/dpi.c
@@ -2,14 +2,12 @@
  * vim:ts=4:sw=4:expandtab
  *
  * i3 - an improved dynamic tiling window manager
- * © 2009-2014 Michael Stapelberg and contributors (see also: LICENSE)
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
  *
  */
 #include "libi3.h"
 #include <math.h>
 
-extern xcb_screen_t *root_screen;
-
 /*
  * Convert a logical amount of pixels (e.g. 2 pixels on a “standard” 96 DPI
  * screen) to a corresponding amount of physical pixels on a standard or retina
@@ -17,6 +15,12 @@ extern xcb_screen_t *root_screen;
  *
  */
 int logical_px(const int logical) {
+    if (root_screen == NULL) {
+        /* Dpi info may not be available when parsing a config without an X
+         * server, such as for config file validation. */
+        return logical;
+    }
+
     const int dpi = (double)root_screen->height_in_pixels * 25.4 /
                     (double)root_screen->height_in_millimeters;
     /* There are many misconfigurations out there, i.e. systems with screens