#!/usr/bin/ruby

###################################################
# Copyright (C) 2005 by Steve Litt, all rights reserved
# This code licensed under the GNU General Public License,
# version 2. NO WARRANTY, USE AT YOUR OWN RISK
###################################################

require "Node.rb"

#### CALLBACK OBJ HOUSES ENTRY AND EXIT CALLBACK ROUTINES, PLUS ####
#### ANY PERSISTENT VARIABLES THOSE ROUTINES ACCESS             ####
class Callbacks
	def initialize()
		@namecat = ""
		@typecat = ""
	end
	def entry(checker, level)
		for i in 0...level
			print "\t"
		end
		print "Entering " + checker.value
		print " ... " unless checker.firstchild
		print ", Line ", checker.getAttribute("_lineno"), "\n" if checker.firstchild
	end

	def exit(checker, level)
		for i in 0...level;print "\t"; end if checker.firstchild
		print "Leaving " + checker.value
		print ", Line ", checker.getAttribute("_lineno"), "\n"
	end
	attr_reader :namecat, :typecat
end

#### MAIN ROUTINE FROM HERE TO BOTTOM ####
parser = OutlineParser.new()	### Create parser object
parser.skipblanks = true	### Change to false and watch what happens
parser.commentchar = '#'	### Change to b and watch what happens
node=parser.parse(nil)		### Parse from stdin

#### NEXT 4 LINES MANUFACTURE A CONTRIVED NODE TO BE ULTIMATE PARENT ####
#### YOU CAN DELETE THEM AND IT STILL WORKS, BECAUSE THE PARSER      ####
#### ITSELF INSTALLS A PARENT ABOVE ALL THE OUTLINE'S TOP NODES      ####
newnode = Node.new("MadeBySteveLitt", "contrived", "Made by Steve Litt")
# node.setParent(newnode)	### Uncomment and it fails -- protected
newnode.insertFirstChild(node)
node = newnode

cb = Callbacks.new()		### Instantiate callback obj

#### INSTANTIATE WALKER OBJ WITH ENTRY AND EXIT CALLBACKS, THEN RUN IT ####
#### NOTE THE SYNTAX WHEN USING REFERENCES TO THE SUBROUTINES AS ARGS  ####
#### ARGUMENT <NODE> IS THE ULTIMATE PARENT OF THE TREE.               ####
#### NODE TREES CAN HAVE ONLY ONE PARENT.                              ####
#### THAT'S WHY THE PARSER ITSELF INSTALLS A NODE ABOVE THE OUTLINE    ####
walker = Walker.new(node, cb.method(:entry), cb.method(:exit))
walker.walk()