| gvSIG desktop 1

/*

 *  $Id: OsConstraint.java,v 1.1 2006/06/14 07:29:07 cesar Exp $

 *  IzPack

 *  Copyright (C) 2002 Olexij Tkatchenko

 *

 *  File :               OsConstraint.java

 *  Description :        A constraint on the OS to perform some action on.

 *  Author's email :     ot@parcs.de

 *  Website :            http://www.izforge.com

 *

 *  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 the Free Software Foundation; either version 2

 *  of the License, or any later version.

 *

 *  This program 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 General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 */

package com.izforge.izpack.util;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import net.n3.nanoxml.XMLElement;

/**

 * Encapsulates OS constraints specified on creation time and allows

 * to check them against the current OS.

 *

 * For example, this is used for <executable>s to check whether

 * the executable is suitable for the current OS.

 *

 * @author     Olexij Tkatchenko <ot@parcs.de>

 */

public class OsConstraint implements java.io.Serializable

{

  /**  The OS family */

  private String family;

  /**  OS name from java system properties */

  private String name;

  /**  OS version from java system properties */

  private String version;

  /**  OS architecture from java system properties */

  private String arch;

  /**

   * Constructs a new instance. Please remember, MacOSX belongs to Unix family.

   *

   * @param  family   The OS family (unix, windows or mac).

   * @param  name     The exact OS name.

   * @param  version  The exact OS version (check property <code>os.version</code> for values).

   * @param  arch     The machine architecture (check property <code>os.arch</code> for values).

   */

  public OsConstraint(String family, String name, String version, String arch)

  {

    this.family = family != null ? family.toLowerCase() : null;

    this.name = name != null ? name.toLowerCase() : null;

    this.version = version != null ? version.toLowerCase() : null;

    this.arch = arch != null ? arch.toLowerCase() : null;

  }

  /**

   *  Matches OS specification in this class against current system properties.

   *

   * @return    Description of the Return Value

   */

  public boolean matchCurrentSystem()

  {

    boolean match = true;

    String osName = System.getProperty("os.name").toLowerCase();

    if (arch != null && arch.length() != 0)

    {

      match = System.getProperty("os.arch").toLowerCase().equals(arch);

    }

    if (match && version != null && version.length() != 0)

    {

      match = System.getProperty("os.version").toLowerCase().equals(version);

    }

    if (match && name != null && name.length() != 0)

    {

      match = osName.equals(name);

    }

    if (match && family != null)

    {

      if (family.equals("windows"))

      {

        match = OsVersion.IS_WINDOWS;

      }

      else if (family.equals("mac") || family.equals("osx"))

      {

        match = OsVersion.IS_OSX;

      }

      else if (family.equals("unix"))

      {

        match = OsVersion.IS_UNIX;

      }

    }

    return match && (family != null || name != null || version != null || arch != null);

  }

  /**

   * Extract a list of OS constraints from given element.

   * 

   * @param element parent XMLElement

   * @return List of OsConstraint (or empty List if no constraints found)

   */

  static public List getOsList(XMLElement element)

  {

    // get os info on this executable

    ArrayList osList = new ArrayList();

    Iterator osIterator = element.getChildrenNamed("os").iterator();

    while (osIterator.hasNext())

    {

      XMLElement os = (XMLElement) osIterator.next();

      osList.add (new OsConstraint (

          os.getAttribute("family", null),

          os.getAttribute("name", null),

          os.getAttribute("version", null),

          os.getAttribute("arch", null)

          )

        );

    }

    // backward compatibility: still support os attribute

    String osattr = element.getAttribute ("os");

    if (osattr != null && osattr.length() > 0)

    {

      // add the "os" attribute as a family constraint

      osList.add (new OsConstraint (osattr, null, null, null));

    }

    return osList;

  }

  /**

   * Helper function: Scan a list of OsConstraints for a match.

   *

   * @param constraint_list List of OsConstraint to check

   *

   * @return true if one of the OsConstraints matched the current system or 

   *       constraint_list is null (no constraints), false if none of the OsConstraints matched

   */

  public static boolean oneMatchesCurrentSystem (List constraint_list)

  {

    if (constraint_list == null)

      return true;

    Iterator constraint_it = constraint_list.iterator ();

    // no constraints at all - matches!

    if (! constraint_it.hasNext ())

      return true;

    while (constraint_it.hasNext ())

    {

      OsConstraint osc = (OsConstraint)constraint_it.next();

      Debug.trace ("checking if os constraints "+osc+" match current OS");

      // check for match

      if (osc.matchCurrentSystem ())

      {

        Debug.trace ("matched current OS.");

        return true; // bail out on first match

      }

    }

    Debug.trace ("no match with current OS!");

    // no match found

    return false;

  }

  /**

   * Helper function: Check whether the given XMLElement is "suitable" for the

   * current OS.

   *

   * @param el The XMLElement to check for OS constraints.

   *

   * @return true if there were no OS constraints or the constraints matched the current OS.  

   *       

   */

  public static boolean oneMatchesCurrentSystem (XMLElement el)

  {

    return oneMatchesCurrentSystem(getOsList(el));

  }

  public void setFamily(String f)

  {

    family = f.toLowerCase();

  }

  public String getFamily()

  {

    return family;

  }

  public void setName(String n)

  {

    name = n.toLowerCase();

  }

  public String getName()

  {

    return name;

  }

  public void setVersion(String v)

  {

    version = v.toLowerCase();

  }

  public String getVersion()

  {

    return version;

  }

  public void setArch(String a)

  {

    arch = a.toLowerCase();

  }

  public String getArch()

  {

    return arch;

  }

  public String toString()

  {

          StringBuffer retval = new StringBuffer();

          retval.append("[Os ");

          retval.append(" family "+family);

          retval.append(" name "+name);

          retval.append(" version "+version);

          retval.append(" arch "+arch);

          retval.append(" ]");

          return retval.toString();

  }

}