; flags.z - code to handle trivial flag toggles

.incl	"c:termcap"

.var	ipbuf	0x80

.extern	msbtog
msbtog:	call	force		; go see what we're doing to the flag
	ld	hl,bmask	; address where mask lives
	jr	z,domsbt	; zero => straight toggle
	sub	'0'		; was it a '0'?
	res	7,(hl)
	jr	z,domsbt	; bit 7 off (so it gets turned on) if so
	set	7,(hl)		; else bit 7 on, so it gets turned off
domsbt:	ld	a,(hl)
	xor	0x80		; toggle the bit
	ld	(hl),a
	inc	a		; now 0xff => no mask becomes zero
	ld	de,bit7ms	; point de at the "label"
.dseg
bit7ms:	db	'Bit 7 masking\0'
.cseg
	jr	pdisen		; and print whether we turned it on or off

.extern	echo
echo:	ld	hl,eflg		; point at echo flag
	ld	de,ecomsg	; and message
.dseg
ecomsg:	db	'Remote echo\0'
.cseg
	jr	toggle		; go do the toggle

.extern	hdxtog
hdxtog:	ld	hl,hflg		; same as echo
	ld	de,hdxmsg
.dseg
hdxmsg:	db	'Half duplex\0'
.cseg
	jr	toggle

.extern	jctog
jctog:	ld	hl,jflg		; same as echo
	ld	de,jcmsg
.dseg
jcmsg:	db	'Control character discard\0'
.cseg
	jr	toggle

.extern	lftog
lftog:	ld	hl,lflg		; same as echo
	ld	de,lfmsg
.dseg
lfmsg:	db	'Line feed in print\0'
.cseg
	jr	toggle

.extern	optog
optog:	ld	hl,oflg		; same as echo
	ld	de,opmsg
.dseg
opmsg:	db	'Output to printer\0'
.cseg
	jr	toggle

.extern	vttog
vttog:	call	initv
	ld	hl,vflg
	ld	de,vtmsg
.dseg
vtmsg:	db	'VT-100 emulation\0'
.cseg
toggle:	call	togflg		; flip the flag as needed
pdisen:	push	af		; save flag state
	push	de		; and message
	call	crlf		; throw a new line
	call	dim		; go into dim mode
	pop	hl
	call	prtslp		; print the message
	pop	af		; restore the flag state
	jr	z,pdis		; zero - it got disabled
	call	ilprt
	db	' enabled\0'	; print the enabled message
	jr	finis
pdis:	call	ilprt
	db	' disabled\0'	; or disabled
finis:	jp	crlf

.extern	togflg
togflg:	push	hl
	push	de		; save some registers
	call	force		; get input state depending on if we're in
	pop	de		; a chat script
	pop	hl
	jr	z,doftog	; zero => straight toggle
	sub	'0'		; '0' => turn it off
	set	0,(hl)		; turn the bit on so the xor turns it off
	jr	z,doftog
	res	0,(hl)		; else clear bit - xor will set it
doftog:	ld	a,(hl)
	xor	1		; flip the bit
	ld	(hl),a
	ret

force:	ld	a,(prmpfl)
	or	a
	ret	z		; return zero if we're not in a chat script
	call	areabp		; get the character
	or	a		; see if one was given
	ret

.dseg
.extern	bmask
bmask:	db	0xff
.extern	jflg
jflg:	db	0
.extern	lflg
lflg:	db	0
.extern	oflg
oflg:	db	0

; These next to _MUST_ remain adjacent, and in this order

.extern	vflg
vflg:	db	0
.extern	wflg
wflg:	db	0

.extern	hflg
hflg:	db	0

.extern	eflg
eflg:	db	0