/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    itkbase.java.in
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

  Portions of this code are covered under the VTK copyright.
  See VTKCopyright.txt or http://www.kitware.com/VTKCopyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
package InsightToolkit;

import java.util.StringTokenizer;

/**
 * A class used to load shared libs. It must be used to be able to pass
 * options to dlopen() on some systems.
 * I will first search in the build tree, then in the install treee, and finally
 * in the the standard paths of the system (PATH on windows, LD_LIBRARY_PATH on
 * linux, DYDL_LYBRARY_PATH on mac os x, ...)
 */
public class itkbase
{
  private static String buildDir = "@ITK_JAVA_BUILD_DIR@";
  private static String installDir = "@ITK_JAVA_INSTALL_DIR@";
  private static String libDir = "/InsightToolkit.jar must be in CLASSPATH";

  static
    {
    // Detect whether we are in the build or install tree.
    String sep = System.getProperty("path.separator");
    String classpath = System.getProperty("java.class.path");
    StringTokenizer tokenizer = new StringTokenizer(classpath, sep);
    while(tokenizer.hasMoreTokens())
      {
      String dir = tokenizer.nextToken();
      if(dir.endsWith("InsightToolkit.jar") &&
         (new java.io.File(dir)).exists())
        {
        int index = dir.lastIndexOf("InsightToolkit.jar");
        String self = dir.substring(0, index);
        if((new java.io.File(self+"itk_build_tree.mark")).exists())
          {
          libDir = buildDir;
          break;
          }
        else
          {
          libDir = dir.substring(0, index-1)+installDir;
          break;
          }
        }
      }

    // Load JavaCWD helper code.
    sep = System.getProperty("file.separator");
    String lib = System.mapLibraryName("SwigRuntimeJava");
    String libPath = libDir + sep + lib;
    if( (new java.io.File(libPath)).exists() )
      {
      System.load(libPath);
      }
    else
      {
      // must use the name for System.loadLibrary()
      System.loadLibrary("SwigRuntimeJava");
      }
    }

  // Method called by wrapper code to load native libraries.
  public static void LoadLibrary(String name)
    {
    // Change to directory containing libraries so dependents are found.
    String old = JavaCWD.GetCWD();
    JavaCWD.SetCWD(libDir);
    String sep = System.getProperty("file.separator");
    String lib = System.mapLibraryName(name);
    String libPath = libDir + sep + lib;
    if( (new java.io.File(libPath)).exists() )
      {
      JavaCWD.Load(libPath);
      System.load(libPath);
      }
    else
      {
      // System.loadLibrary() create the lib name by itself, but not JavaCWD.Load()
      // so one must get lib and the other name
      JavaCWD.Load(lib);
      System.loadLibrary(name);
      }
    JavaCWD.SetCWD(old);
    }
}