Lab3 part2 (CreateDecorator.java)

created by: Adrian Pop (adrpo@ida.liu.se)
date      : 2004-10-04

Ideea: 
- create an empty member list and add to it:
  + the PRIVATE delegate field
  + the public constructor
  + the public list of methods with calls to the delegate field
- create the class declaration using the created member list
   use attach the class to the first position in the cu like this: 
   this.astTransformation.attach(decorator, createdCu, 0);
   NOTE: this is the ONLY attach in the program

The same thing broken in steps:
NOTES: 
 + use ProgramFactory pf almost everywhere when creating stuff!!! 
 + exceptions:
   - new ModifierArrayList(...);             // needed to set public/private for members
   - new StatementArrayList(...);            // needed when creating a StatementBlock
   - new ParameterDeclarationArrayList(...); // needed when creating parameters for constructor
   - new ExpressionArrayList(...);           // needed to add variables for method calls
 + DO NOT use deepClone() for methods! create new ones
 + use deepClone() only for:
   - method.getParameters().deepClone();    // used for new method declaration
   - method.getTypeReference().deepClone(); // used for new method declaration
 

Step1: Create the empty member list
 MemberDeclarationMutableList members = new MemberDeclarationArrayList();

Step2: Create the delegate field and append it to the members
 FieldDeclaration delegateField = pf.createFieldDeclaration(...);
 members.add(delegateField);
 
Step3: Create and add the constructor to the members list
 - create copy assignment and add it to the constructor body
 - create the parameter declaration
 - create the constructor constructorDecl = pf.createConstructorDeclaration(...);
 - members.add(constructorDecl);

Step4: Create the new methods of the decorator and add them to the member list
 - for each method in the component create a new method and add it to the method list
   for (int i = 0; i < component.getMethods().size(); i++) 
   {
      MethodDeclaration method = (MethodDeclaration)component.getMethods().getMethod(i);
      // create new method here using the information from the method
      // before you can actually create the new method you need to build:
      // 1. method reference arguments (take them from method.getParameters()) methodArguments
      //     NOTE!!!: one parameter can have several variables, use param.getVariables()
      // 2. create the method reference
      //     MethodReference methodRef = pf.createMethodReference(..., methodArguments);
      // 3. now look at the return type of the method (it tells you if you have to create a return statement or not)
      //     if (method.getTypeReference().getName().equals(....))
      //        make call to the delegate 
      //     else
      //        create return statement with call to delegate
      // 4. create the new method declaration
      //     MethodDeclaration newMethod = pf.createMethodDeclaration(...);
      // 5. add the method to the members
      //     members.add(newMethod);
   }


Step5: Create the decorator class and attach it to the createdCu
  TypeReference componentReference = pf.createTypeReference(...);
  ClassDeclaration decorator = pf.createClassDeclaration(..., pf.createImplements(componentReference), members);
  // attach the class to the first position in the cu.
  this.astTransformation.attach(decorator, createdCu, 0); // the only attach in this transformation


Well that's all folks!
Regular mistakes are to use new XXX instead of pf.createXXX()

Have fun!

Regards,
Adrian Pop/