use SCons to build up the mapnik viewer ini file

SConstruct

@@ -1274,3 +1274,6 @@ if not HELP_REQUESTED:
 
     # install pkg-config script and mapnik-config script
     SConscript('utils/mapnik-config/SConscript')
+
+    # write the viewer.ini file
+    SConscript('demo/viewer/SConscript')

demo/viewer/SConscript

@@ -0,0 +1,47 @@
+#
+# This file is part of Mapnik (c++ mapping toolkit)
+#
+# Copyright (C) 2010 Artem Pavlenko, Jean-Francois Doyon
+#
+# Mapnik is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+# $Id$
+
+Import ('env')
+import os
+import platform
+
+lib_dir = os.path.normpath(env['DESTDIR'] + '/' + env['PREFIX'] + '/' + env['LIBDIR_SCHEMA'] + '/mapnik2') 
+
+fonts = 1
+ini_template = '''
+[mapnik]
+plugins_dir=%(lib_dir)s/input
+fonts\1\dir=%(lib_dir)s/fonts
+'''
+
+if platform.uname()[0] == 'Darwin':
+    ini_template += 'fonts\2\dir=/Library/Fonts\n'
+    fonts += 1
+
+ini_template += 'fonts\size=%d\n' % fonts
+
+ini = ini_template % locals()
+
+open('viewer.ini','w').write(ini)
+
+try:
+    os.chmod(viewer.ini,0666)
+except: pass

demo/viewer/viewer.ini

@@ -1,5 +0,0 @@
-[mapnik]
-plugins_dir=/opt/mapnik/lib/mapnik2/input
-fonts\1\dir=/opt/mapnik/lib/mapnik2/fonts
-fonts\2\dir=/Library/Fonts
-fonts\size=2