Added better logic for application path:

We could just hard code the path to qgis libs and share dir (as used to be done) 
but that makes qgis non relocatable which is needed for my
generic QGIS linux bundle. So lets start by trying a relative path
and then falling back to the paths set in the make process



git-svn-id: http://svn.osgeo.org/qgis/branches/Release-0_8_0@6605 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: timlinux

src/core/qgsapplication.cpp

@@ -4,7 +4,7 @@
     Date                 : 02-Jan-2006
     Copyright            : (C) 2006 by Tom Elwertowski
     Email                : telwertowski at users dot sourceforge dot net
-/***************************************************************************
+ ***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -15,7 +15,7 @@
 /* $Id$ */
 
 #include "qgsapplication.h"
-
+#include <QFile>
 #include <QDir>
 
 QString QgsApplication::mPrefixPath;
@@ -44,9 +44,22 @@ QgsApplication::QgsApplication(int & argc, char ** argv, bool GUIenabled)
   mPluginPath = mPrefixPath + QString("/lib/qgis");
   mPkgDataPath = mPrefixPath + QString("/share/qgis");
 #else
-  mPrefixPath = PREFIX;
-  mPluginPath = PLUGINPATH;
-  mPkgDataPath = PKGDATAPATH;
+  // We could just hard code teh path to qgis libs and share but
+  // that makes qgis non relocatable which is needed for my
+  // generic QGIS linux bundle. So lets start by trying a relative path
+  // and then falling back to the paths set in the make process
+  if (QFile::exists(applicationDirPath()+"/../share/qgis/images/icons/qgis-icon.png"))
+  {
+    mPrefixPath = applicationDirPath();
+    mPluginPath = mPrefixPath + QString("/../lib/qgis");
+    mPkgDataPath = mPrefixPath + QString("/../share/qgis");
+  }
+  else //fall back to make specified paths
+  {
+    mPrefixPath = PREFIX;
+    mPluginPath = PLUGINPATH;
+    mPkgDataPath = PKGDATAPATH;
+  }
 #endif
   mThemePath = mPkgDataPath + QString("/themes/default/");
 }