!\-----------------------------------------------------------------------
Opportune.h, a Hugo library contribution for WINDOWS OF OPPORTUNITY
version 1.5 by Jon Blask

This contribution lets you start different 1-turn timers for when you
want a special response only when an action is taken directly after a
specific other action.

It is hoped that using objects (instead of global variables or something)
to keep track of these WINDOWS OF OPPORTUNITY will be a nice way to keep
things organized.

An example:

opp brokelamp
{}

[If somebody pushes the lamp, we'll say it tips over and breaks on the
floor.]

We start our timer with:

NewOpp(broke_lamp)

[Now, let's change the response to >OOPS.]

replace NewParseError(errornumber, obj)
{
    select errornumber
		case 16
		{
			if current_opp = broke_lamp
			{
				"Smooth move, um, Mr. Smooth."
				current_opp = 0
! in this case, we clear the opportunity by hand
! since a ParseError response will not use a turn
         }
			else
				return false
		}
		case else : return false
	 return true
}

-----------------------------------------------------------------------\!

#ifclear _OPPORTUNE_H
#set _OPPORTUNE_H

#ifset VERSIONS
#message "Opportune.h Version 1.5"
#endif

global current_opp ! current opportunity

! A fuse so that each question is only answerable for one turn
! opp_window = short for "opportunity window"
fuse opp_window "(opp_window fuse)"
{}

event opp_window
{
	if not self.tick
		current_opp = 0
}

class Question
{
	type question
}

routine NewQuestion(new_question)
{
	current_opp = new_question
	if new_question.name ~= "(Question)"
		print new_question.name
	else
		run new_question.long_desc  ! Prints the question
	Activate (opp_window, 2) ! Starts the new timer
}

!\
! Optional Yes/No Question Section
! If you want to have some in-game Yes/No questions like those in
! the Infocom games ("Are you sure you're mentally and otherwise prepared to
! meet up with an egress?"), define questions like the following.

! NOTE: >YES and >NO are not supported by verblib.h and verblib.g; they are in
! the verbstub files. If you don't want to define those verbs yourself,
! uncomment #set VERBSTUBS at the beginning of your game file (assuming you
! started out with the Hugo shell).

question egress
{
	long_desc
		"Are you sure you're mentally and otherwise prepared to meet up with
		 an egress?"
}

! When you want to print a question, use NewQuestion, like:
! NewQuestion(egress)

! Then, in your code, where you want to check if the player is currently being
!  asked a question, say:
! if current_opp = egress
!     <code to execute>

! Here is some example code:

room whitewagon "Near White Wagon"
{
	!  Going "south" four times will also leave the circus
	s_to
	{
		local next_topic
		select current_opp
			case mystery : endflag = 3
			case mammal : next_topic = mystery
			case egress : next_topic = mammal
			case 0 : next_topic = egress

		if next_topic
			NewQuestion(next_topic)
	}
}

replace DoYes  ! assuming VERBSTUBS has been included
{
	if not current_opp
	{
		"Yes?"
		return false
	}
	else
	{
		select current_opp
			case egress: NewQuestion(mammal)
			case mammal: "Then you'd be helpless against this dangerous beast."
			case mystery: endflag = 3
	}
	return true
}
\!

routine NewOpp(opportunity)
{
	current_opp = opportunity
	Activate (opp_window, 2)
}

!class opp
!{}

#endif