want to skip all line comments except two in antlr4 grammar - parsing

Question

I want to extend the IDL.g4 grammar a bit so that I can distinguish the following two comments //#top-level false and //#top-level true, all other comments I just want to skip like before.
I have tried to add top_level, TOP_LEVEL_TRUEand TOP_LEVEL_FALSElike this, because I thought antr4 gave precedence to lexical rules comming first.
top_level
: TOP_LEVEL_TRUE
| TOP_LEVEL_FALSE
;
TOP_LEVEL_TRUE
: '//#top-level true'
;
TOP_LEVEL_FALSE
: '//#top-level false'
;
LINE_COMMENT
: '//' ~('\n'|'\r')* '\r'? '\' -> channel(HIDDEN)
;
But the listener enterTop_level(...) is never called,
all comments seems to be eaten by LINE_COMMENT. How shall I organize the lexer and parser rules?
And one more question, I also want to be notified when end of input-file is reached. How do I do that? I have tried a finalize() function i the listener class, but never get called.
Updated with a complete example:
I use this grammar file : IDL.g4 as I said above. Then I update it by putting the parser rule top_level just below the event_header rule. The Lexer rules is put just above the ID rule.
Here is my Listener.java file
class Listener extends IDLBaseListener {
#Override
public void enterTop_level(IDLParser.Top_levelContext ctx) {
System.out.println("Found top-level");
}
}
and here is a main program: IDLCheck.java
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.tree.ParseTreeWalker;
import java.io.FileInputStream;
import java.io.InputStream;
public class IDLCheck {
public void process(String[] args) throws Exception {
InputStream is = new FileInputStream("sample.idl");
ANTLRInputStream input = new ANTLRInputStream(is);
IDLLexer lexer = new IDLLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
IDLParser parser = new IDLParser(tokens);
parser.setBuildParseTree(true);
RuleContext tree = parser.specification();
Listener listener = new Listener();
ParseTreeWalker walker = new ParseTreeWalker();
walker.walk(listener, tree);
}
public static void main(String[] args) throws Exception {
new IDLCheck().process(args);
}
}
and a input file: sample.idl
module CommonTypes {
struct WChannel {
int w;
float d;
}; //#top-level false
struct EPlanID {
int kind;
short index;
}; //#top-level TRUE
};
I expect to see the output "Found top-level" twice, but I see nothing

Answer 1

Finally I found a solution. I just added newline characters to the TOP_LEVEL_FALSE and TOP_LEVEL_TRUElexer rules an I also added the top_level parser rule to the definition rule because I only expected top_level to appear after a struct or union. this is a rti.com specific extension to the IDL-format, this modification seems to be good enough for me.
definition
: type_decl SEMICOLON top_level?
| const_decl SEMICOLON
...
TOP_LEVEL_TRUE
: '//#top-level true' '\r'? '\n'
;
TOP_LEVEL_FALSE
: '//#top-level false' '\r'? '\n'
;