/*
	e screen editor

	(C) G. Nigel Gilbert, MICROLOGY, 1981

	August-December 1981

	FILE: e7

	FUNCTIONS: getkey,testkey,getlow,testlow,getscankey,inkey,putret,
			dispch,putch,inword,uspr,makedim,makebright,
			putclr,dohelp
		   
	PURPOSE: low level terminal i/o functions

*/

#include "e.h"

getkey()	/*wait for a key to be pressed & return it, translating
			to internal codes */
{
	char c;

	while (!(c=testkey()));
	return c;
}

testkey()	/*if a key has been pressed, return it, else 0, translating*/
{
	char c, *tranp;
	int i;

	if (!(c=inkey())) return 0;
	if (c == *(tranp=tran)) {
		while (!(c=inkey()));
		c|=PARBIT;
		}
	for (i=1,tranp++; i < NKEYS; i++, tranp++)
		if (c == *tranp) return i;
	return c;
}

getlow()	/*get a key, converting control and u/c keys to l/c,
			translation of ESCKEY only */
{
	char c;
	
	while (!(c=testlow()));
	return c;
}

testlow()	/*test for a key, convert upper and control chars to lower case*/
{
	char c;

	if (!(c=inkey())) return 0;
	if (tran[ESCKEY] == c) return ESCKEY;
	if (c < ' ') c=c+96;
	return (c >= 'A' && c <= 'Z' ? c+32 : c);
}

getscankey()	/*get a key, translation of ESCKEY, CR, LEFTKEY, DELLEFT,
			RETRIEVE only */
{
	char c;
	
	while (!(c=inkey()));
	if (tran[ESCKEY] == c) return ESCKEY;
	if (tran[CR] == c) return CR;
	if (tran[LEFTKEY] == c) return LEFTKEY;
	if (tran[DELLEFT] == c) return DELLEFT;
	if (tran[RETRIEVE] == c) return RETRIEVE;
	
	return c;
}

inkey()		/*return last key press,or 0 if none*/
{
	char c;
	sint i;

	if (inbufp) {
		c=inbuf[0];
		inbufp--;
		for (i=0; i < inbufp; i++) inbuf[i]=inbuf[i+1];
		}
	else c=bdos(DIRIO,0xff) & ~PARBIT;
	return c;
}

putret()	/*type a CR/LF*/
{
	putch('\r');
	putch('\n');
}

dispch(c)	/*type a character (in different intensity if non-printable*/
char c;
{
	if (c < ' ') {
		makeother();
		putch(c+64);
		makeother();
		}
	else putch(c);
}

putch(c)	/*type a character; test for keyboard input*/
char c;
{
	bdos(DIRIO,c);
	if ( (c=bdos(DIRIO,0xff))) inbuf[inbufp++]=c & ~PARBIT;
}

inword(c)	/*return true if c is letter or digit*/
char c;
{
	return  isalpha(c) || isdigit(c);
}

uspr(n)		/*print 'n' as a number; return number of chars typed*/
unsigned n;
{
	int temp;

	if (n < 10) {
		putch(n+'0');
		return 1;
		}
	temp=uspr(n/10);
	uspr(n%10);
	return temp+1;
}

makedim()
{
	if (!isdim) {
		begdim();
		isdim=YES;
		}
}

makebright()
{
	if (isdim) {
		enddim();
		isdim=NO;
		}
}

makeother()
{
	if (isdim) makebright();
	else makedim();
}

putclr()	/*clear the screen */
{
	delpage(0);
}

dohelp()	/*display help menu */
{
	int y;

	pfirst=loc(pfirst,(HELPLINES-1));
	topline=HELPLINES;
	for (y=1; y < HELPLINES; y++) deleteline(y);
	if (cline < pfirst || pfirst == lastl) {
		puttext(); 
		putpage(); 
		}
	gotoxy(0,1);
	displayhelp();
}
	return c;
}

testlow()	/*test for a key, convert upper and control chars to lower case*/
{
	char c;

	if (!(c=ink