%
% A HyperNeWS Menu
%
% NOTE: altough ClassMenuCanvas is a  subclass of ClassTrackingCanvas it 
% does NOT use any of the tracking functionality. It could also be a subclass
% of ClassCanvas.
%

/ClassMenuCanvas ClassTrackingCanvas []
classbegin
/menuprocess 	null def
/Menuable?	true def
/onmenu		nullproc def

/MenuStart {	% posname event -- posname event menu? boolean
	{
		currentprocess /ProcessName (HyperNeWS menu handler) put
		currentprocess /track_evt 3 -1 roll put
		currentprocess /menuok true put
		clear {onmenu} stopped pop
		currentprocess /track_evt undef
		currentprocess /menuok undef
	} fork {
		pause dup /State get
		dup /breakpoint eq {
			pop /menuprocess 1 index promote
			/OperandStack get dup length 
			2 copy 1 sub get 3 1 roll 2 sub get
			4 -1 roll pop 3 1 roll true exit
		} if
		/runnable ne {pop false exit} if
	} loop
} def

/MenuStop {	% menu --
	pop menuprocess null ne {
		menuprocess /State get /breakpoint eq {
			menuprocess continueprocess
		} if
		/menuprocess unpromote
	} if
} def
classend def

%
% HyperNeWS menu class
%

/ClassHNMenu ClassMenu []
classbegin
/ExecuteNotifier {	% value notifier --
	dup null ne {
		% make sure this gets executed in the hypernews context
		dup type /nametype eq {
			exch [exch] exch
			[3 1 roll /self cvx /Send cvx] cvx /target self send send
		} {
			[3 1 roll]
			[exch /doit /self cvx /Send cvx] cvx /target self send send
		} ifelse
	} {pop pop} ifelse
} def
classend def

%
% Utillities
%

/menuable {	% -- boolean
	currentprocess /track_evt known
	currentprocess /menuok known and
} def

/doshowmenu {	% posname menu --
	self soften /settarget 2 index send
	soften breakpoint
	null /settarget 2 index send
	null /setinvoker 2 index send
	currentprocess /track_evt undef
	currentprocess /menuok undef
	pop pop
} def

/showmenu {	% menu --
	dup null ne menuable and {
		/Default exch //doshowmenu exec
	} {pop} ifelse
} def

/showxymenu {	% menu x y --
	2 index null ne menuable and {
		mouseevent begin /YLocation exch def /XLocation exch def end
		/NorthWest exch //doshowmenu exec
	} {pop pop pop} ifelse
} def

currentdict /doshowmenu undef