[PolicyKit-gnome] Add a --with-gtk configure option

[Matthias Clasen <matthiasc src gnome org>]

commit 00f1845bed7b7b7412793748976f8eaab7d81053
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Feb 11 23:07:47 2011 -0500

    Add a --with-gtk configure option

 configure.ac |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index bf3bec0..41cbe58 100644
--- a/configure.ac
+++ b/configure.ac
@@ -120,11 +120,29 @@ GNOME_MAINTAINER_MODE_DEFINES
 # Check for required packages
 # ***************************
 
-GTK_REQUIRED=2.17.1
 POLKIT_AGENT_REQUIRED=0.97
 POLKIT_GOBJECT_REQUIRED=0.97
 
-PKG_CHECK_MODULES(GTK, gtk+-2.0 >= $GTK_REQUIRED)
+AC_MSG_CHECKING([which gtk+ version to compile against])
+AC_ARG_WITH([gtk],
+  [AS_HELP_STRING([--with-gtk=2.0|3.0],[which gtk+ version to compile against (default: 2.0)])],
+  [case "$with_gtk" in
+     2.0|3.0) ;;
+     *) AC_MSG_ERROR([invalid gtk version specified]) ;;
+   esac],
+  [with_gtk=2.0])
+AC_MSG_RESULT([$with_gtk])
+case "$with_gtk" in
+  2.0) GTK_API_VERSION=2.0
+       GTK_REQUIRED=2.17.1
+       ;;
+  3.0) GTK_API_VERSION=3.0
+       GTK_REQUIRED=3.0.0
+       ;;
+esac
+
+
+PKG_CHECK_MODULES(GTK, gtk+-$GTK_API_VERSION >= $GTK_REQUIRED)
 AC_SUBST(GTK_CFLAGS)
 AC_SUBST(GTK_LIBS)