/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package javax.faces.component;
  
  import javax.faces.context.FacesContext;
  import javax.faces.el.EvaluationException;
  import javax.faces.el.MethodBinding;
  import javax.faces.el.ValueBinding;
  import javax.faces.event.*;
  
  /**
   * UICommand is a base abstraction for components that implement ActionSource.
   * <p>
   * See the javadoc for this class in the
   * <a href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/api/index.html">JSF Specification</a>
   * for further details.
   *
   * @JSFComponent
   *   type = "javax.faces.Command"
   *   family = "javax.faces.Command"
   *   desc = "UICommand executes an action"
   *
   * @author Manfred Geiler (latest modification by $Author: skitching $)
   * @version $Revision: 685669 $ $Date: 2008-08-13 15:25:49 -0500 (Wed, 13 Aug 2008) $
   */
  public class UICommand extends UIComponentBase implements ActionSource
  {
      public static final String COMPONENT_TYPE = "javax.faces.Command";
      public static final String COMPONENT_FAMILY = "javax.faces.Command";
      private static final String DEFAULT_RENDERER_TYPE = "javax.faces.Button";
      private static final boolean DEFAULT_IMMEDIATE = false;
  
      private Boolean _immediate = null;
      private Object _value = null;
  
      private MethodBinding _action = null;
      private MethodBinding _actionListener = null;
  
      public void setAction(MethodBinding action)
      {
          _action = action;
      }
  
      /**
       * Specifies the action to take when this command is invoked.
       *
       * If the value is an expression, it is expected to be a method 
       * binding EL expression that identifies an action method. An action method
       * accepts no parameters and has a String return value, called the action
       * outcome, that identifies the next view displayed. The phase that this
       * event is fired in can be controlled via the immediate attribute.
       *
       * If the value is a string literal, it is treated as a navigation outcome
       * for the current view.  This is functionally equivalent to a reference to
       * an action method that returns the string literal.
       * 
       * @JSFProperty
       *   returnSignature="java.lang.String"
       */
      public MethodBinding getAction()
      {
          return _action;
      }
  
      public void setActionListener(MethodBinding actionListener)
      {
          _actionListener = actionListener;
      }
  
      /**
       * A method binding EL expression that identifies an action listener method
       * to be invoked if this component is activated by the user. An action
       * listener method accepts a parameter of type javax.faces.event.ActionEvent
       * and returns void. The phase that this event is fired in can be controlled
       * via the immediate attribute.
       *  
       * @JSFProperty
       *   returnSignature="void"
       *   methodSignature="javax.faces.event.ActionEvent"
       */
      public MethodBinding getActionListener()
      {
          return _actionListener;
     }
 
     public void addActionListener(ActionListener listener)
     {
         addFacesListener(listener);
     }
 
     public ActionListener[] getActionListeners()
     {
         return (ActionListener[])getFacesListeners(ActionListener.class);
     }
 
     public void removeActionListener(ActionListener listener)
     {
         removeFacesListener(listener);
     }
 
     public void broadcast(FacesEvent event)
             throws AbortProcessingException
     {
         super.broadcast(event);
 
         if (event instanceof ActionEvent)
         {
             FacesContext context = getFacesContext();
 
             MethodBinding actionListenerBinding = getActionListener();
             if (actionListenerBinding != null)
             {
                 try
                 {
                     actionListenerBinding.invoke(context, new Object[] {event});
                 }
                 catch (EvaluationException e)
                 {
                     Throwable cause = e.getCause();
                     if (cause != null && cause instanceof AbortProcessingException)
                     {
                         throw (AbortProcessingException)cause;
                     }
                     else
                     {
                         throw e;
                     }
                 }
             }
 
             ActionListener defaultActionListener
                     = context.getApplication().getActionListener();
             if (defaultActionListener != null)
             {
                 defaultActionListener.processAction((ActionEvent)event);
             }
         }
     }
 
     public void queueEvent(FacesEvent event)
     {
         if (event != null && this == event.getSource() && event instanceof ActionEvent)
         {
             if (isImmediate())
             {
                 event.setPhaseId(PhaseId.APPLY_REQUEST_VALUES);
             }
             else
             {
                 event.setPhaseId(PhaseId.INVOKE_APPLICATION);
             }
         }
         super.queueEvent(event);
     }
 
 
     public UICommand()
     {
         setRendererType(DEFAULT_RENDERER_TYPE);
     }
 
     public String getFamily()
     {
         return COMPONENT_FAMILY;
     }
 
     public void setImmediate(boolean immediate)
     {
         _immediate = Boolean.valueOf(immediate);
     }
 
     
 
     /**
      * A boolean value that identifies the phase during which action events
      * should fire. During normal event processing, action methods and
      * action listener methods are fired during the "invoke application"
      * phase of request processing. If this attribute is set to "true",
      * these methods are fired instead at the end of the "apply request
      * values" phase.
      * 
      * @JSFProperty
      *   defaultValue="false"
      */
     public boolean isImmediate()
     {
         if (_immediate != null) return _immediate.booleanValue();
         ValueBinding vb = getValueBinding("immediate");
         Boolean v = vb != null ? (Boolean)vb.getValue(getFacesContext()) : null;
         return v != null ? v.booleanValue() : DEFAULT_IMMEDIATE;
     }
 
     public void setValue(Object value)
     {
         _value = value;
     }
 
     /**
      * The initial value of this component.
      * 
      * @JSFProperty
      */
     public Object getValue()
     {
         if (_value != null) return _value;
         ValueBinding vb = getValueBinding("value");
         return vb != null ? vb.getValue(getFacesContext()) : null;
     }
 
 
 
     public Object saveState(FacesContext context)
     {
         Object values[] = new Object[5];
         values[0] = super.saveState(context);
         values[1] = saveAttachedState(context, _action);
         values[2] = saveAttachedState(context, _actionListener);
         values[3] = _immediate;
         values[4] = _value;
         return values;
     }
 
     public void restoreState(FacesContext context, Object state)
     {
         Object values[] = (Object[])state;
         super.restoreState(context, values[0]);
         _action = (MethodBinding)restoreAttachedState(context, values[1]);
         _actionListener = (MethodBinding)restoreAttachedState(context, values[2]);
         _immediate = (Boolean)values[3];
         _value = values[4];
     }
 }