package org.apache.myfaces.tobago.component;
   
   /*
    * 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.
   */
  
  import javax.el.MethodExpression;
  import javax.el.MethodInfo;
  import javax.el.ELContext;
  import javax.el.MethodNotFoundException;
  import javax.el.ELException;
  import javax.faces.component.StateHolder;
  import javax.faces.el.MethodBinding;
  import javax.faces.el.EvaluationException;
  import javax.faces.context.FacesContext;
  import javax.faces.FacesException;
  
  @SuppressWarnings("deprecation")
  public class MethodBindingToMethodExpression extends MethodExpression implements StateHolder {
    private MethodBinding methodBinding;
  
    private boolean transientFlag;
  
    private transient MethodInfo methodInfo;
  
    /**
     * No-arg constructor used during restoreState
     */
    protected MethodBindingToMethodExpression() {
    }
  
    /**
     * Creates a new instance of MethodBindingToMethodExpression
     */
    public MethodBindingToMethodExpression(MethodBinding methodBinding) {
      checkNullArgument(methodBinding, "methodBinding");
      this.methodBinding = methodBinding;
    }
  
    /**
     * Return the wrapped MethodBinding.
     */
    public MethodBinding getMethodBinding() {
      return methodBinding;
    }
  
    void setMethodBinding(MethodBinding methodBinding) {
      this.methodBinding = methodBinding;
    }
  
    /**
     * Note: MethodInfo.getParamTypes() may incorrectly return an empty class array if invoke() has not been called.
     *
     * @throws IllegalStateException if expected params types have not been determined.
     */
    public MethodInfo getMethodInfo(ELContext context) throws ELException {
      checkNullArgument(context, "elcontext");
      checkNullState(methodBinding, "methodBinding");
  
      if (methodInfo == null) {
        final FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
        if (facesContext != null) {
          methodInfo = invoke(new Invoker<MethodInfo>() {
            public MethodInfo invoke() {
              return new MethodInfo(null, methodBinding.getType(facesContext), null);
            }
          });
        }
      }
      return methodInfo;
    }
  
    public Object invoke(ELContext context, final Object[] params) throws ELException {
      checkNullArgument(context, "elcontext");
      checkNullState(methodBinding, "methodBinding");
      final FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
      if (facesContext != null) {
        return invoke(new Invoker<Object>() {
          public Object invoke() {
            return methodBinding.invoke(facesContext, params);
          }
        });
      }
      return null;
    }
  
   public boolean isLiteralText() {
     if (methodBinding == null) {
       throw new IllegalStateException("methodBinding is null");
     }
     String expr = methodBinding.getExpressionString();
     return !(expr.startsWith("#{") && expr.endsWith("}"));
   }
 
   public String getExpressionString() {
     return methodBinding.getExpressionString();
   }
 
   public Object saveState(FacesContext context) {
     if (!isTransient()) {
       if (methodBinding instanceof StateHolder) {
         Object[] state = new Object[2];
         state[0] = methodBinding.getClass().getName();
         state[1] = ((StateHolder) methodBinding).saveState(context);
         return state;
       } else {
         return methodBinding;
       }
     }
     return null;
   }
 
   public void restoreState(FacesContext context, Object state) {
     if (state instanceof MethodBinding) {
       methodBinding = (MethodBinding) state;
       methodInfo = null;
     } else if (state != null) {
       Object[] values = (Object[]) state;
       methodBinding = (MethodBinding) newInstance(values[0].toString());
       ((StateHolder) methodBinding).restoreState(context, values[1]);
       methodInfo = null;
     }
   }
 
   public void setTransient(boolean transientFlag) {
     this.transientFlag = transientFlag;
   }
 
   public boolean isTransient() {
     return transientFlag;
   }
 
   @Override
   public int hashCode() {
     final int prime = 31;
     int result = 1;
     result = prime * result + ((methodBinding == null) ? 0 : methodBinding.hashCode());
     return result;
   }
 
   @Override
   public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
     if (obj == null) {
       return false;
     }
     if (getClass() != obj.getClass()) {
       return false;
     }
     final MethodBindingToMethodExpression other = (MethodBindingToMethodExpression) obj;
     if (methodBinding == null) {
       if (other.methodBinding != null) {
         return false;
       }
     } else if (!methodBinding.equals(other.methodBinding)) {
       return false;
     }
     return true;
   }
 
   private void checkNullState(Object notNullInstance, String instanceName) {
     if (notNullInstance == null) {
       throw new IllegalStateException(instanceName + " is null");
     }
   }
 
   private void checkNullArgument(Object notNullInstance, String instanceName) {
     if (notNullInstance == null) {
       throw new IllegalArgumentException(instanceName + " is null");
     }
   }
 
   private <T> T invoke(Invoker<T> invoker) {
     try {
       return invoker.invoke();
     } catch (javax.faces.el.MethodNotFoundException e) {
       throw new MethodNotFoundException(e.getMessage(), e);
     } catch (EvaluationException e) {
       throw new ELException(e.getMessage(), e);
     }
   }
 
   private interface Invoker<T> {
     T invoke();
   }
 
   private static Object newInstance(String type) {
     if (type == null) {
       throw new NullPointerException("type");
     }
     try {
       try {
         return Class.forName(type, false, Thread.currentThread().getContextClassLoader()).newInstance();
       } catch (ClassNotFoundException e) {
         // ignore
         return Class.forName(type, false, MethodBindingToMethodExpression.class.getClassLoader()).newInstance();
       }
     } catch (ClassNotFoundException e) {
       throw new FacesException(e);
     } catch (NoClassDefFoundError e) {
       throw new FacesException(e);
     } catch (InstantiationException e) {
       throw new FacesException(e);
     } catch (IllegalAccessException e) {
       throw new FacesException(e);
     }
   }
 
 }