api/src/main/java/javax/faces/component/_MethodBindingToListener.java

/*
 * 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.FacesException;
import javax.faces.component.StateHolder;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.MethodBinding;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.FacesEvent;

/**
 * Common base class for converting a MethodBinding to a FacesListener
 *
 * @author Stan Silvert
 */
abstract class _MethodBindingToListener implements StateHolder {
    
    protected MethodBinding methodBinding;
    
    public _MethodBindingToListener() {
    }
    
    /**
     * Creates a new instance of MethodBindingToListener
     */
    public _MethodBindingToListener(MethodBinding methodBinding) {
        if (methodBinding == null) throw new NullPointerException("methodBinding can not be null");
        if (!(methodBinding instanceof StateHolder)) throw new IllegalArgumentException("methodBinding must implement the StateHolder interface");
        
        this.methodBinding = methodBinding;
    }

    private FacesContext getFacesContext() {
        return FacesContext.getCurrentInstance();
    }

    protected void invokeMethodBinding(FacesEvent event) throws AbortProcessingException {
        try {
            methodBinding.invoke(getFacesContext(), new Object[] {event});
        }
        catch (EvaluationException e) {
            Throwable cause = e.getCause();
            if (cause != null && cause instanceof AbortProcessingException) {
                throw (AbortProcessingException)cause;
            }
            
            throw e;
        }
    }
    
    public MethodBinding getMethodBinding() {
        return methodBinding;
    }
    
    public void restoreState(FacesContext context, Object state) {
        Object[] stateArray = (Object[])state;
        try {
            methodBinding = (MethodBinding)Thread.currentThread()
                                                 .getContextClassLoader()
                                                 .loadClass((String)stateArray[0])
                                                 .newInstance();
        } catch (Exception e) {
            throw new FacesException(e);
        }
       
        ((StateHolder)methodBinding).restoreState(context, stateArray[1]);
    }

    public Object saveState(FacesContext context) {
        Object[] stateArray = new Object[2];
        stateArray[0] = methodBinding.getClass().getName();
        stateArray[1] = ((StateHolder)methodBinding).saveState(context);
        return stateArray;
    }

    public void setTransient(boolean newTransientValue) {
        ((StateHolder)methodBinding).setTransient(newTransientValue);
    }

    public boolean isTransient() {
        return ((StateHolder)methodBinding).isTransient();
    }
    
}