[gnome-control-center] info: Get renderer from gnome-session under Wayland

[Bastien Nocera <hadess src gnome org>]

commit 83c8c57761f849d535da554bc2362608eb4c1bf9
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Oct 11 13:41:16 2016 +0200

    info: Get renderer from gnome-session under Wayland
    
    Now that gnome-session's acceleration helper can print the renderer
    under Wayland, launch it locally. We need to launch it locally as
    Wayland is not available at the time gnome-session would launch the
    helper, as there's no Wayland compositor yet.
    
    Note that this code expects the gnome-session helper scripts to live
    in $libexecdir, but distributions can use
    --with-gnome-session-libexecdir=DIR to pass another one.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=756914

 configure.ac                |   12 ++++++++++++
 m4/as-ac-expand.m4          |   43 +++++++++++++++++++++++++++++++++++++++++++
 panels/info/Makefile.am     |   13 +++++++------
 panels/info/cc-info-panel.c |   39 +++++++++++++++++++++++++++++++--------
 4 files changed, 93 insertions(+), 14 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 079777b..709f271 100644
--- a/configure.ac
+++ b/configure.ac
@@ -340,6 +340,17 @@ AC_SUBST(KRB5_LIBS)
 USER_ACCOUNTS_PANEL_CFLAGS="$USER_ACCOUNTS_PANEL_CFLAGS $KRB5_CFLAGS"
 USER_ACCOUNTS_PANEL_LIBS="$USER_ACCOUNTS_PANEL_LIBS $KRB5_LIBS"
 
+dnl Check for info panel
+AC_ARG_WITH([gnome-session-libexecdir],
+           AS_HELP_STRING([--with-gnome-session-libexecdir=DIR], [Directory for gnome-session s libexecdir]),
+           [],
+           [with_gnome_session_libexecdir=${libexecdir}])
+if test x$with_gnome_session_libexecdir == xno; then
+       with_gnome_session_libexecdir=${libexecdir}
+fi
+AS_AC_EXPAND(GNOMESESSIONDIR, $with_gnome_session_libexecdir)
+AC_SUBST([gnome_session_libexecdir], [$GNOMESESSIONDIR])
+
 dnl =======================================
 dnl Panels
 dnl =======================================
@@ -589,4 +600,5 @@ if test "x$enable_ibus" = "xyes"; then
 else
        AC_MSG_NOTICE([   Region panel IBus support disabled])
 fi
+AC_MSG_NOTICE([** gnome-session libexecdir: $GNOMESESSIONDIR])
 AC_MSG_NOTICE([End options])
diff --git a/m4/as-ac-expand.m4 b/m4/as-ac-expand.m4
new file mode 100644
index 0000000..d6c9e33
--- /dev/null
+++ b/m4/as-ac-expand.m4
@@ -0,0 +1,43 @@
+dnl as-ac-expand.m4 0.2.0
+dnl autostars m4 macro for expanding directories using configure's prefix
+dnl thomas apestaart org
+
+dnl AS_AC_EXPAND(VAR, CONFIGURE_VAR)
+dnl example
+dnl AS_AC_EXPAND(SYSCONFDIR, $sysconfdir)
+dnl will set SYSCONFDIR to /usr/local/etc if prefix=/usr/local
+
+AC_DEFUN([AS_AC_EXPAND],
+[
+  EXP_VAR=[$1]
+  FROM_VAR=[$2]
+
+  dnl first expand prefix and exec_prefix if necessary
+  prefix_save=$prefix
+  exec_prefix_save=$exec_prefix
+
+  dnl if no prefix given, then use /usr/local, the default prefix
+  if test "x$prefix" = "xNONE"; then
+    prefix="$ac_default_prefix"
+  fi
+  dnl if no exec_prefix given, then use prefix
+  if test "x$exec_prefix" = "xNONE"; then
+    exec_prefix=$prefix
+  fi
+
+  full_var="$FROM_VAR"
+  dnl loop until it doesn't change anymore
+  while true; do
+    new_full_var="`eval echo $full_var`"
+    if test "x$new_full_var" = "x$full_var"; then break; fi
+    full_var=$new_full_var
+  done
+
+  dnl clean up
+  full_var=$new_full_var
+  AC_SUBST([$1], "$full_var")
+
+  dnl restore prefix and exec_prefix
+  prefix=$prefix_save
+  exec_prefix=$exec_prefix_save
+])
diff --git a/panels/info/Makefile.am b/panels/info/Makefile.am
index 4569fa2..6e6f460 100644
--- a/panels/info/Makefile.am
+++ b/panels/info/Makefile.am
@@ -1,11 +1,12 @@
 cappletname = info
 
-AM_CPPFLAGS =                                          \
-       $(PANEL_CFLAGS)                                 \
-       $(INFO_PANEL_CFLAGS)                            \
-       -DGNOMELOCALEDIR="\"$(datadir)/locale\""        \
-       -DDATADIR="\"$(datadir)\""                      \
-       -DBINDIR="\"$(bindir)\""                        \
+AM_CPPFLAGS =                                                  \
+       $(PANEL_CFLAGS)                                         \
+       $(INFO_PANEL_CFLAGS)                                    \
+       -DGNOMELOCALEDIR="\"$(datadir)/locale\""                \
+       -DDATADIR="\"$(datadir)\""                              \
+       -DGNOME_SESSION_DIR="\"$(gnome_session_libexecdir)\""   \
+       -DBINDIR="\"$(bindir)\""                                \
        $(NULL)
 
 noinst_LTLIBRARIES = libinfo.la
diff --git a/panels/info/cc-info-panel.c b/panels/info/cc-info-panel.c
index 79729dd..943b4a3 100644
--- a/panels/info/cc-info-panel.c
+++ b/panels/info/cc-info-panel.c
@@ -235,6 +235,9 @@ prettify_info (const char *info)
     { "Graphics Controller", "Graphics"},
   };
 
+  if (*info == '\0')
+    return NULL;
+
   pretty = g_markup_escape_text (info, -1);
 
   for (i = 0; i < G_N_ELEMENTS (rs); i++)
@@ -322,6 +325,27 @@ get_renderer_from_session (void)
   return renderer;
 }
 
+static char *
+get_renderer_from_helper (void)
+{
+  int status;
+  char *argv[] = { GNOME_SESSION_DIR "/gnome-session-check-accelerated", NULL };
+  char *renderer, *ret;
+
+  if (!g_spawn_sync (NULL, (char **) argv, NULL, 0, NULL, NULL, &renderer, NULL, &status, NULL))
+    return NULL;
+
+  if (!g_spawn_check_exit_status (status, NULL))
+    return NULL;
+
+  if (renderer == NULL || *renderer == '\0')
+    return NULL;
+
+  ret = prettify_info (renderer);
+  g_free (renderer);
+  return ret;
+}
+
 static GraphicsData *
 get_graphics_data (void)
 {
@@ -332,19 +356,18 @@ get_graphics_data (void)
 
   display = gdk_display_get_default ();
 
-#ifdef GDK_WINDOWING_X11
-  if (GDK_IS_X11_DISPLAY (display))
+#if defined(GDK_WINDOWING_X11) || defined(GDK_WINDOWING_WAYLAND)
+  if (GDK_IS_X11_DISPLAY (display) ||
+      GDK_IS_WAYLAND_DISPLAY (display))
     {
       result->renderer = get_renderer_from_session ();
+      if (!result->renderer)
+        result->renderer = get_renderer_from_helper ();
       result->hardware_string = result->renderer;
     }
-  else
-#endif
-#ifdef GDK_WINDOWING_WAYLAND
-  if (GDK_IS_WAYLAND_DISPLAY (display))
-    result->hardware_string = _("Wayland");
-  else
 #endif
+
+  if (!result->renderer)
     result->hardware_string = _("Unknown");
 
   return result;