class VisitorPatternRefactoringListener(JavaParserLabeledListener):
"""
implement the visitor pattern refactoring
"""
def __init__(self, common_token_stream: CommonTokenStream = None,
SuperClass_identifier: str = None,
SubClass_identifier: list = None):
"""
:param common_token_stream:
"""
self.enter_class = False
self.token_stream = common_token_stream
self.SuperClass_identifier = SuperClass_identifier
self.SubClass_identifier = SubClass_identifier
self.InSuperClass = False
self.InSubClass = False
self.InMainClass = False
self.CurrentCC = None
self.Visitors = {}
# Move all the tokens in the source code in a buffer, token_stream_rewriter.
if common_token_stream is not None:
self.token_stream_rewriter = TokenStreamRewriter(common_token_stream)
else:
raise TypeError('common_token_stream is None')
def enterClassDeclaration(self, ctx: JavaParserLabeled.ClassDeclarationContext):
if ctx.IDENTIFIER().getText() == self.SuperClass_identifier:
self.InSuperClass = True
elif ctx.IDENTIFIER().getText() in self.SubClass_identifier:
self.InSubClass = True
elif ctx.IDENTIFIER().getText() == "Main":
self.InMainClass = True
if ctx.EXTENDS().__str__() == "extends":
# SubClass Headers Rename
self.token_stream_rewriter.insertAfter(ctx.start.tokenIndex + 4, "implements")
self.token_stream_rewriter.deleteIndex(ctx.start.tokenIndex + 4)
def exitClassDeclaration(self, ctx: JavaParserLabeled.ClassDeclarationContext):
if self.InSuperClass:
# SuperClass Interface Make
interface_text = (
"interface "
+ self.SuperClass_identifier
+ "\n{\n\tpublic void accept (Visitor"
+ self.SuperClass_identifier
+ " visitor);\n}"
)
self.token_stream_rewriter.insertAfter(ctx.start.tokenIndex - 1, "\n" + interface_text + "\n")
# SuperClass Visitor interface Make
interface_text_vistor = "interface Visitor" + self.SuperClass_identifier + "\n{"
index = 0
for item in self.Visitors:
interface_text_vistor += "\n\t" + "public void " + "visit(" + self.SubClass_identifier[
index] + " " + item + ");"
index += 1
interface_text_vistor += "\n}"
self.token_stream_rewriter.insertAfter(ctx.start.tokenIndex - 1, "\n" + interface_text_vistor + "\n")
# SuperClass DoVisitor Make
newSC = (
"\nclass DoVisitor"
+ self.SuperClass_identifier
+ " implements Visitor"
+ self.SuperClass_identifier + "\n{"
)
method_body = ""
index = 0
# SuperClassDoVisitor Mathods Make
for item in self.Visitors:
method_body = str_list(self.Visitors[item])
method_body = "{\n\t" + method_body[2:-2] + "\n\t}"
newSC += "\n\t" + "@Override\n\tpublic void visit(" + self.SubClass_identifier[
index] + " " + item + ")\n\t" + method_body
index += 1
newSC += "\n}"
self.token_stream_rewriter.replaceRange(ctx.start.tokenIndex, ctx.stop.tokenIndex, newSC)
self.InSuperClass = False
self.InSubClass = False
self.InMainClass = False
def enterMethodDeclaration(self, ctx: JavaParserLabeled.MethodDeclarationContext):
# Extract Methods Name & Methods body of SuperClass
if self.InSuperClass:
new_class_name = ctx.IDENTIFIER().getText()
new_method_body = ctx.methodBody().getText()
self.Visitors[new_class_name] = [new_method_body]
def exitClassBody(self, ctx: JavaParserLabeled.ClassBodyContext):
if self.InSubClass:
# Implement Mathod of SuperClass InterFace
override_text = (
"@Override\n\tpublic void accept(Visitor"
+ self.SuperClass_identifier
+ " visitor)\n\t{\n\t\tvisitor.visit(this);\n\t}"
)
self.token_stream_rewriter.insertAfter(ctx.start.tokenIndex, "\n\t" + override_text)
def enterMethodCall0(self, ctx: JavaParserLabeled.MethodCall0Context):
if self.InMainClass:
# Modify Main Method
if ctx.IDENTIFIER().getText() in self.Visitors:
self.token_stream_rewriter.replaceRange(
from_idx=ctx.start.tokenIndex,
to_idx=ctx.stop.tokenIndex,
text="accept(new DoVisitor" + self.SuperClass_identifier + "())")
