eventmanagement.java

一个用 java写的wap浏览器 对于浏览器感兴趣起的可以看看咯

/*
 * j2wap is distributed under the terms of the GNU Public License
 *
 *  j2wap was written by:
 *
 *	        Scott Campbell
 *			Michael Nordling
 *			Karl Maftoum
 * 			Julian Bright
 *
 *			This was a final project for Comp.Engineering at the University of Canberra, Australia
 *
 *			Now released as Open Source software. 28 November 2000
 *
 *			Email: [e-mail] for more info
 *
 *			Use entirely at your own risk.
 */

package wae;
import java.util.Vector;

/**
 * Event Management is used to manage the events from the UI, and layout engine.
 *
 * @author  Julian Bright
 * @version 1.1
 */
public class EventManagement
{

  /** List of registered Event Instances */
  private Vector c_clsEventInstances;
  /** Number of Events Registered.  Used to track the value of the next EventID */
  private int c_intventCount;

  /**
   * Event Management constructor initialises the Event Instances.
   */
  public EventManagement()
  {
    c_clsEventInstances = new Vector(3);
    c_intventCount = 1;
  }

  /**
   * Register a Go Event
   * @param in_strURL The URL for go event. <i>(Pre-condition: URL != null)</i>
   * @param in_bolSendReferer Boolean indicating whether to send the referer. (Not used)
   * @param in_strMethod The method type (GET/POST)
   * @param in_strEncType Determines the Encoding type for data retrived. (Not used)
   * @return Newly Created EventID
   */
  public int registerGo(String  in_strURL,
                        boolean in_bolSendReferer,
                        String  in_strMethod,
                        String  in_strEncType)
  {

    GoEventInstance clsGoEvent = new GoEventInstance (1);
    clsGoEvent.setAttributes( in_strURL, in_bolSendReferer,
                              in_strMethod, in_strEncType);

    return addEventInstance(clsGoEvent);
  }

  /**
   * Register a Prev Event.
   * @return Newly Created EventID
   */
  public int registerPrev()
  {
    EventInstance clsEventInstance = new EventInstance(2);
    return addEventInstance(clsEventInstance);
  }

  /**
   * Register a Refresh Event.
   * @return Newly Created EventID
   */
  public int registerRefresh()
  {
    EventInstance clsEventInstance = new EventInstance(3);
    return addEventInstance(clsEventInstance);
  }

  /**
   * Register a Noop Event.
   * @return int Newly Created EventID
   */
  public int registerNoop()
  {
    EventInstance clsEventInstance = new EventInstance(4);
    return addEventInstance(clsEventInstance);
  }

  /**
   * Set a variable for a go/prev event.
   * @param in_intEventID EventID to assoicate variable to
   * @param in_strName The name of the new variable.
   * @param in_strValue The value associated with the name.
   */
  public void setVariable(int in_intEventID,
                          String in_strName,
                          String in_strValue)
  {
    EventInstance clsEventInstance;
    clsEventInstance = (EventInstance)c_clsEventInstances.elementAt(in_intEventID - 1);
    clsEventInstance.addVariable(in_strName, in_strValue);
  }

  /**
   * Set a postfield for a go event.
   * <i>(Pre-condition: c_clsEventInstances.elementAt(in_intEventID - 1) must be a GoEventInstance object.)</i>
   * @param:  in_intEventID EventID to assoicate postfield with
   * @param in_strName The name of the new postfield.
   * @param in_strValue The value associated with the name.
   */
  public void setPostfield(int    in_intEventID,
                           String in_strName,
                           String in_strVal)
  {
    GoEventInstance clsGoEventInstance =
      (GoEventInstance) c_clsEventInstances.elementAt(in_intEventID - 1);
    clsGoEventInstance.addPostfield(in_strName, in_strVal);
  } // setPostfield

  /**
   * Return a particular event instance.
   * @param in_intEventID EventID to select
   * @param  in_clsBrowserContext Browser Context reference for updating variables
   * @return EventInstance matching EventID
   */
  public EventInstance getEventInstance(int in_intEventID,
                                        BrowserContext in_clsBrowserContext)
  {
    EventInstance clsEventInstance;
    clsEventInstance = (EventInstance)c_clsEventInstances.elementAt(in_intEventID - 1);
    clsEventInstance.setVariablesInStack(in_clsBrowserContext);
    return clsEventInstance;
  }

  /*
   * Private function to add a new instance to the vetor
   * Returns the new int index.
   * @param  in_clsEventInstance EventInstance object to add to list
   * @return EventID of newly created instance.
   */
  private int addEventInstance(EventInstance in_clsEventInstance)
  {
    c_clsEventInstances.addElement(in_clsEventInstance);
    return c_intventCount++;
  }

}