; QT-GENIE.Z keyboard map function and user function to enable
; line splitting

.var	linesz	30		; default number of chars before we start
				; looking for a space

.var	free	0x0400		; where in the patch we can place things

.org	0x0276			; patch into the user function
	jp	user		; go do ours

.org	0x0279
	jp	kbmap		; hook into keyboard map routine

.var	ilprmt	0x027c		; in line prompt call

.org	free
user:
	call	ilprmt		; prompt for and get an answer
	db	'Auto line splitting enable (Y/n)? \0'
	ld	hl,0x7f		; point just before it
byp:	inc	hl
	ld	a,(hl)		; get the next character
	cp	' '		; space?
	jr	z,byp		; yes, skip over it
	sub	'0'
	cp	10
	jr	c,number	; numeric input - go handle it
	add	a,'0'		; convert back
	or	0x20		; force lower case
	xor	0x20		; this really tests for a null .....
	jr	z,gotans	; yes, save zero byte
	xor	0x20 ^ 'y'	; and check for a 'y' (including 'Y')
gotans:	ld	(split),a	; save the flag - zero enables, non-zero
				; disables
	ld	a,linesz	; set line length to default of 30
setll:	ld	(linlen),a	; set the line length from a
	xor	a
	ld	(count),a	; and set the count to zero
	ret

number:	ld	e,a		; save current value in e
	inc	hl		; point to next character
	ld	a,(hl)
	sub	'0'		; convert .....
	cp	10		; and test if it's a digit
	jr	nc,gotnum	; nope - we're all done
	ld	d,a
	ld	a,e
	add	a,a		; a = e * 2
	add	a,a		;       * 4
	add	a,e		;       * 5
	add	a,a		;       * 10
	add	a,d		;       + d
	jr	number
gotnum:	ld	a,e		; get value back from e
	or	a		; if it's zero .....
	ld	a,1		; set a != 0 to disable
	jr	z,gotans	; and go do it
	xor	a
	ld	(split),a	; else set split flag to enable
	ld	a,e		; and get the line length back from e
	jr	setll		; go do the set with whatever we have

kbmap:
	and	0x7f		; ditch bit 7, just because I'm paranoid
	cp	0x7f		; is the key a delete?
	jr	nz,nodel	; nope, leave it alone
	ld	a,'\b'		; else change it into a backspace
nodel:	ld	hl,split	; point at the flag
	inc	(hl)
	dec	(hl)
	ret	nz		; not splitting - get outa here
	ld	c,a		; save char in c
	ld	hl,(state)
	ld	a,h
	or	l		; are we in the middle of a line break?
	jr	nz,linbrk	; yes, so handle it elsewhere
	ld	a,c		; get the character back from c
	ld	hl,0x01cf	; point at the escape character
	cp	(hl)
	ret	z		; we have to let these through!
	ld	hl,count	; point hl at the count for everyone
	cp	'\b'
	jr	z,backsp	; handle backspaces
	cp	'\r'
	jr	z,return	; and returns
	cp	'\n'
	jr	z,newlin	; and linefeeds
	inc	b		; set b to 1 for a potential swallow
	cp	0x7f		; throw away deletes
	ret	z
	cp	' '		; is it a space?
	jr	z,space		; handle specially if so
	ret	c		; and throw away other control characters
	dec	b		; reset b to pass the single character
	inc	(hl)		; bump count
	ret			; and return - char is still in a

backsp:
	dec	(hl)		; anything in the current count
	ret	p		; yes, return, char in a, b is OK
	inc	(hl)		; nothing on line, restore count
	inc	b		; set b to 1 for a swallow
	ret			; all done

return:
	ld	hl,retstr	; point at the return string
	jr	linbrk

newlin:
	ld	hl,nlstr	; point at the new line string
	jr	linbrk

space:
	inc	(hl)		; we passed another character, count it
	ld	a,(linlen)	; get the line length
	cp	(hl)		; too long yet?
	ld	a,c
	dec	b
	ret	nc		; no, return character in a
	ld	hl,string	; else point at the string to send

linbrk:
	ld	a,(hl)		; get the next character from the string
	inc	hl		; move the pointer
	inc	(hl)
	dec	(hl)		; end of string?
	ld	b,2		; set b to 2 to say there's more coming
	jr	nz,savehl	; not end of string, save hl and return
	ld	b,(hl)		; set b to zero again
	ld	hl,count
	ld	(hl),b		; zero out the count from b
	ld	h,b
	ld	l,b		; set hl to zero to reset the state machine
savehl:	ld	(state),hl	; save the pointer / NULL
	ret

count:	db	0		; count of chars since the last new line
linlen:	db	linesz		; line size we're currently using
split:	db	1		; flag if we're splitting: zero => we are
state:	dw	0		; what state are we in?

string:	db	' .....\r\0'	; space string to break lines
retstr:	db	' /end\r\0'	; return string to end a paragraph
nlstr:	db	'\r\0'		; newline to end