lwmanager.java

Zaval Light-Weight Visual Components Library (LwVCL) is a pure Java alternative to humble AWT-based

/**
 *     Caption: Zaval Light-Weight Visual Components Library
 *     $Revision: 2.79 $
 *     $Date: 2003/08/22 11:24:16 $
 *
 *     @author:     Andrei Vishnevsky
 *     @version:    3.50
 *
 * Zaval Light-Weight Visual Components Library (LwVCL) is a pure Java
 * alternative to humble AWT-based and SWING-based GUI interfaces for
 * wide ranges of platforms, including J2SE, PersonalJava and J2ME.
 *
 * Designed as light-weight but, alternatively to Swing, built separately
 * from AWT (not on top of the java.awt library like Swing), the LwVCL is
 * the good alternative to highly performant, memory-efficient, flexible
 * GUI solution for embedded, stand-alone and applet applications.
 *
 * For more info on this product read Zaval Light-Weight Visual Components Library Tutorial
 * (It comes within this package).
 * The latest product version is always available from the product's homepage:
 * http://www.zaval.org/products/lwvcl/
 * and from the SourceForge:
 * http://sourceforge.net/projects/zaval0003/
 *
 * Contacts:
 *   Support : [e-mail]
 *   Change Requests : [e-mail]
 *   Feedback : [e-mail]
 *   Other : [e-mail]
 *
 * Copyright (C) 2001-2003  Zaval Creative Engineering Group (http://www.zaval.org)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * (version 2) as published by the Free Software Foundation.
 *
 * 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 org.zaval.lw;

import java.awt.*;
import java.util.*;
import java.lang.reflect.*;
import org.zaval.lw.event.*;
import org.zaval.util.*;

/**
 * This manager is a core for deploying the library that does following:
 * <ul>
 *   <li>
 *     Initilizes the light wight library. The manager reads light weight properties
 *     file (that is stored in "org/zaval/lw/rs/lw.properties" file) and basing on the
 *     information creates lightweight managers and static objects.
 *   </li>
 *   <li>
 *     Initilizes the extension light wight library. The manager tries to read lwvcl extension
 *     properties file (that is stored in "org/zaval/lw/rs/lwext.properties" file) and
 *     creates extension managers and static objects. The extension can be absent.
 *   </li>
 *   <li>
 *     Provides ability to get static object by a key.
 *   </li>
 * </ul>
 */
public class LwManager
{
 /**
  * The field is used to store all static objects.
  */
  protected static Hashtable staticObjects;
  protected static String    version;

 /**
  * Gets the static object by the specified key.
  * @param <code>key</code> the specified key.
  * @return a static object.
  */
  public static Object getStaticObject(String key) {
    return staticObjects.get(key);
  }

 /**
  * Gets a static object by the specified key as LwView class.
  * @param <code>key</code> the specified key.
  * @return a static object.
  */
  public static LwView getView(String key) {
    return (LwView)staticObjects.get(key);
  }

 /**
  * Gets a static object by the specified key as LwLayout class.
  * @param <code>key</code> the specified key.
  * @return a static object.
  */
  public static LwLayout getLwLayout(String key) {
    return (LwLayout)staticObjects.get(key);
  }

 /**
  * Gets the library version.
  * @return the library version.
  */
  public static String getVersion () {
    return version;
  }

 /**
  * Loads objects by the specified key of the specified properties set into static objects
  * table.
  * @param <code>key</code> the specified key that defines set of objects that should be
  * loaded.
  * @param <code>props</code> the specified properties.
  */
  public static void loadObjects(String key, Properties props)
  throws Exception
  {
    loadObjects(key, props, staticObjects);
  }

  private static void loadObjects(String key, Properties props, Hashtable res)
  throws Exception
  {
      String val = props.getProperty(key);
      if (val != null)
      {
        StringTokenizer st = new StringTokenizer(val, ",");
        for (int i=0; st.hasMoreTokens(); i++)
        {
          Object m         = null;
          String token     = st.nextToken();
          String className = props.getProperty(key + "." + token + ".cl" );
          String keyName   = props.getProperty(key + "." + token + ".key");

          if (className.indexOf ('@') == 0) m = staticObjects == null?res.get(className.substring(1)):getStaticObject(className.substring(1));
          else
          {
            String constructorArg = props.getProperty(key + "." + token + ".arg" );
            Class  classInstance  = Class.forName(className.indexOf('.')>0?className:PACKAGE_NAME + className);

    	    if (constructorArg == null) m = classInstance.newInstance();
            else
            {
              StringTokenizer args       = new StringTokenizer(constructorArg, ",");
              Class[]         argsTypes  = new Class [args.countTokens()];
              Object[]        argsValues = new Object[argsTypes.length];
              for (int j = 0; args.hasMoreTokens(); j++)
              {
                String arg = args.nextToken().trim();
                if (arg.indexOf("\"")==0)
                {
                  argsTypes [j] = String.class;
                  argsValues[j] = arg.substring(1, arg.length() - 1);
                }
                else
                if (arg.equals("true") || arg.equals("false"))
                {
                  argsTypes [j] = Boolean.TYPE;
                  argsValues[j] = new Boolean(arg);
                }
                else
                if (arg.indexOf('@') == 0)
                {
                  argsValues[j] = staticObjects == null?res.get(arg.substring(1)):getStaticObject(arg.substring(1));
                  argsTypes [j] = argsValues[j].getClass();
                }
                else
                {
                  argsTypes [j] = Integer.TYPE;
                  argsValues[j] = new Integer(arg);
                }
              }
              Constructor classMaker = classInstance.getConstructor(argsTypes);
              m = classMaker.newInstance(argsValues);
            }
          }
          res.put(keyName == null?token:keyName, m);
        }
     }
  }

  private static String PACKAGE_NAME;

  static {
    PACKAGE_NAME = (new LwManager()).getClass().getName();
    int index = PACKAGE_NAME.lastIndexOf('.');
    PACKAGE_NAME =(index > 0)?PACKAGE_NAME.substring(0, index+1):"";

    try {
      staticObjects = new Hashtable();
      Properties props = LwToolkit.getProperties("rs/lw.properties");
      if (props == null) throw new RuntimeException("Properties file not found.");
      version = props.getProperty("lwvcl.ver");
      Properties extProps = LwToolkit.getProperties("rs/lwext.properties");

      LwEventManager.manager = ((LwEventManager)Class.forName(PACKAGE_NAME + props.getProperty("man.event.cl")).newInstance());
      staticObjects.put ("event", LwEventManager.manager);
      loadObjects("man", props, staticObjects);
      if (extProps != null) loadObjects("man", extProps, staticObjects);
      for (Enumeration en = staticObjects.elements();en.hasMoreElements();)
      {
        Object manager = en.nextElement();
        Field field = manager.getClass().getField("manager");
        field.set(manager, manager);
        if (manager instanceof EventListener) LwEventManager.manager.addXXXListener((EventListener)manager);
      }

      loadObjects("obj", props, staticObjects);
      if (extProps != null) loadObjects("obj", extProps, staticObjects);
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}