char editbuf[MAXLEN]; the edit buffer
int editp; cursor: buffer index
int editpmax; length of buffer
int edcflag; buffer change flag
----- */
/* abort any changes made to current line */
edabt()
{
/* get unchanged line and reset cursor */
edgetln();
edredraw();
edbegin();
edcflag = NO;
}
/* put cursor at beginning of current line */
edbegin()
{
editp = 0;
outxy(0,outgety());
}
/* change editbuf[editp] to c
* don't make change if line would become to long
*/
edchng(c) char c;
{
char oldc;
int k;
/* if at right margin then insert char */
if (editp >= editpmax) {
edins(c);
return;
}
/* change char and print length of line */
oldc = editbuf[editp];
editbuf[editp] = c;
fmtadj(editbuf,editp,editpmax);
k = fmtlen(editbuf,editpmax);
if (k > SCRNW1) {
/* line would become too long */
/* undo the change */
editbuf[editp] = oldc;
fmtadj(editbuf,editp,editpmax);
}
else {
/* set change flag, redraw line */
edcflag = YES;
editp++;
edredraw();
}
}
/* delete the char to left of cursor if it exists */
eddel()
{
int k;
/* just move left one column if past end of line */
if (edxpos() < outgetx()) {
outxy(outgetx()-1, outgety());
return;
}
/* do nothing if cursor is at left margin */
if (editp == 0) {
return;
}
edcflag = YES;
/* compress buffer (delete char) */
k = editp;
while (k < editpmax) {
editbuf[k-1] = editbuf[k];
k++;
}
/* update pointers, redraw line */
editp--;
editpmax--;
edredraw();
}
/* edit the next line. do not go to end of buffer */
eddn()
{
int oldx;
/* save visual position of cursor */
oldx = outgetx();
/* replace current edit line */
if (edrepl() != OK) {
return(ERR);
}
/* do not go past last non-null line */
if (bufnrbot()) {
return(OK);
}
/* move down one line in buffer */
if (bufdn() != OK) {
return(ERR);
}
edgetln();
/* put cursor as close as possible on this
* new line to where it was on the old line.
*/
editp = edscan(oldx);
/* update screen */
if (edatbot()) {
edsup(bufln()-SCRNL2);
outxy(oldx, SCRNL1);
}
else {
outxy(oldx, outgety()+1);
}
return(OK);
}
/* comment out ----- put cursor at end of screen
outxy(SCRNW1, outgety());
----- end comment out */
}
/* start editing line n
* redraw the screen with cursor at position p
*/
edgo(n, p) int n, p;
{
/* replace current line */
if (edrepl() == ERR) {
return(ERR);
}
/* go to new line */
if (bufgo(n) == ERR) {
return(ERR);
}
/* prevent going past end of buffer */
if (bufatbot()) {
if (bufup() == ERR) {
return(ERR);
}
}
/* redraw the screen */
bufout(bufln(),1,SCRNL1);
edgetln();
editp = min(p, editpmax);
outxy(edxpos(), 1);
return(OK);
}
/* insert c into the buffer if possible */
edins(c) char c;
{
int k;
/* do nothing if edit buffer is full */
if (editpmax >= MAXLEN) {
return;
}
/* fill out line if we are past its end */
if (editp == editpmax ff edxpos() < outgetx()) {
k = outgetx() - edxpos();
editpmax = editpmax + k;
while (k-- > 0) {
editbuf [editp++] = ' ';
}
editp = editpmax;
}
/* make room for inserted character */
k = editpmax;
while (k > editp) {
editbuf[k] = editbuf[k-1];
k--;
}
/* insert character. update pointers */
editbuf[editp] = c;
editp++;
editpmax++;
/* recalculate print length of line */
fmtadj(editbuf,editp-1,editpmax);
k = fmtlen(editbuf,editpmax);
if (k > SCRNW1) {
/* line would become too long */
/* delete what we just inserted */
eddel();
}
else {
/* set change flag, redraw line */
edcflag = YES;
edredraw();
}
}
/* join (concatenate) the current line with the one above it */
edjoin()
{
int k;
/* do nothing if at top of file */
if (bufattop()) {
return;
}
/* replace lower line temporarily */
if (edrepl() != OK) {
return;
}
/* get upper line into buffer */
if (bufup() != OK) {
return;
}
k = bufgetln(editbuf, MAXLEN);
/* append lower line to buffer */
if (bufdn() != OK) {
return;
}
k = k + bufgetln(editbuf+k, MAXLEN-k);
/* abort if the screen isn't wide enough */
if (k > SCRNW1) {
/* bug fix */
bufgetln(editbuf,MAXLEN);
return;
}
/* replace upper line */
if (bufup() != OK) {
return;
}
editpmax = k;
edcflag = YES;
if (edrepl() != OK) {
return;
}
/* delete the lower line */
if (bufdn() != OK) {
return;
}
if (bufdel() != OK) {
return;
}
if (bufup() != OK) {
return;
}
/* update the screen */
if (edattop()) {
edredraw();
}
else {
k = outgety() - 1;
bufout(bufln(),k,SCRNL-k);
outxy(0,k);
edredraw();
}
}
/* delete chars until end of line or c found */
edkill(c) char c;
{
int k,p;
/* do nothing if at right margin */
if (editp == editpmax) {
return;
}
edcflag = YES;
/* count number of deleted chars */
k = 1;
while ((editp+k) < editpmax) {
if (editbuf[editp+k] == c) {
break;
}
else {
k++;
}
}
/* compress buffer (delete chars) */
p = editp+k;
while (p < editpmax) {
editbuf[p-k] = editbuf[p];
p++;
}
/* update buffer size, redraw line */
editpmax = editpmax-k;
edredraw();
}
/* move cursor left one column.
* never move the cursor off the current line.
*/
edleft()
{
int k;
/* if past right margin, move left one column */
if (edxpos() < outgetx()) {
outxy(max(0, outgetx()-1), outgety());
}
/* inside the line. move left one character */
else if (editp != 0) {
editp--;
outxy(edxpos(),outgety());
}
}
/* insert a new blank line below the current line */
ednewdn()
{
int k;
/* make sure there is a current line and
* put the current line back into the buffer.
*/
if (bufatbot()) {
if (bufins(editbuf,editpmax) != OK) {
return;
}
}
else if (edrepl() != OK) {
return;
}
/* move past current line */
if (bufdn() != OK) {
return;
}
/* insert place holder: zero length line */
if (bufins(editbuf,0) != OK) {
return;
}
/* start editing the zero length line */
edgetln();
/* update the screen */
if (edatbot()) {
/* note: bufln() >= SCRNL */
edsup(bufln()-SCRNL2);
outxy(edxpos(),SCRNL1);
}
else {
k = outgety();
bufout(bufln(),k+1,SCRNL1-k);
outxy(edxpos(),k+1);
}
}
/* insert a new blank line above the current line */
ednewup()
{
int k;
/* put current line back in buffer */
if (edrepl() != OK) {
return;
}
/* insert zero length line at current line */
if (bufins(editbuf,0) != OK) {
return;
}
/* start editing the zero length line */
edgetln();
/* update the screen */
if (edattop()) {
edsdn(bufln());
outxy(edxpos(),1);
}
else {
k = outgety();
bufout(bufln(),k,SCRNL-k);
outxy(edxpos(),k);
}
}
/* move cursor right one character.
* never move the cursor off the current line.
*/
edright()
{
/* if we are outside the line move right one column */
if (edxpos() < outgetx()) {
outxy (min(SCRNW1, outgetx()+1), outgety());
}
/* if we are inside a tab move to the end of it */
else if (edxpos() > outgetx()) {
outxy (edxpos(), outgety());
}
/* move right one character if inside line */
else if (editp < editpmax) {
editp++;
outxy(edxpos(),outgety());
}
/* else move past end of line */
else {
outxy (min(SCRNW1, outgetx()+1), outgety());
}
}
/* split the current line into two parts.
* scroll the first half of the old line up.
*/
edsplit()
{
int p, q;
int k;
/* indicate that edit buffer has been saved */
edcflag = NO;
/* replace current line by the first half of line */
if (bufatbot()) {
if (bufins(editbuf, editp) != OK) {
return;
}
}
else {
if (bufrepl(editbuf, editp) != OK) {
return;
}
}
/* redraw the first half of the line */
p = editpmax;
q = editp;
editpmax = editp;
editp = 0;
edredraw();
/* move the second half of the line down */
editp = 0;
while (q < p) {
editbuf [editp++] = editbuf [q++];
}
editpmax = editp;
editp = 0;
/* insert second half of the line below the first */
if (bufdn() != OK) {
return;
}
if (bufins(editbuf, editpmax) != OK) {
return;
}
/* scroll the screen up and draw the second half */
if (edatbot()) {
edsup(bufln()-SCRNL2);
outxy(1,SCRNL1);
edredraw();
}
else {
k = outgety();
bufout(bufln(), k+1, SCRNL1-k);
outxy(1, k+1);
edredraw();
}
}
/* move cursor right until end of line or
* character c found.
*/
edsrch(c) char c;
{
/* do nothing if at right margin */
if (editp == editpmax) {
return;
}
/* scan for search character */
editp++;
while (editp < editpmax) {
if (editbuf[editp] == c) {
break;
}
else {
editp++;
}
}
/* reset cursor */
outxy(edxpos(),outgety());
}
/* move cursor up one line if possible */
edup()
{
int oldx;
/* save visual position of cursor */
oldx = outgetx();
/* put current line back in buffer */
if (edrepl() != OK) {
return(ERR);
}
/* done if at top of buffer */
if (bufattop()) {
return(OK);
}
/* start editing the previous line */
if (bufup() != OK) {
return(ERR);
}
edgetln();
/* put cursor on this new line as close as
* possible to where it was on the old line.
*/
editp = edscan(oldx);
/* update screen */
if (edattop()) {
edsdn(bufln());
outxy(oldx, 1);
}
else {
outxy(oldx, outgety()-1);
}
return(OK);
}
/* delete the current line */
edzap()
{
int k;
/* delete the line in the buffer */
if (bufdel() != OK) {
return;
}
/* move up one line if now at bottom */
if (bufatbot()) {
if (bufup() != OK) {
return;
}
edgetln();
/* update screen */
if (edattop()) {
edredraw();
}
else {
outdelln();
outxy(0,outgety()-1);
}
return;
}
/* start editing new line */
edgetln();
/* update screen */
if (edattop()) {
edsup(bufln());
outxy(0,1);
}
else {
k = outgety();
bufout(bufln(),k,SCRNL-k);
outxy(0,k);
}
}
/* return true if the current edit line is being
* displayed on the bottom line of the screen.
*/
edatbot()
{
return(outgety() == SCRNL1);
}
/* return true if the current edit line is being
* displayed on the bottom line of the screen.
*/
edattop()
{
return(outgety() == 1);
}
/* redraw edit line from index to end of line */
/* reposition cursor */
/* fill edit buffer from current main buffer line.
* the caller must check to make sure the main
* buffer is available.
*/
edgetln()
{
int k;
/* put cursor on left margin, reset flag */
editp = 0;
edcflag = NO;
/* get edit line from main buffer */
k = bufgetln(editbuf,MAXLEN);
if (k > MAXLEN) {
error("line truncated");
editpmax = MAXLEN;
}
else {
editpmax = k;
}
fmtadj(editbuf,0,editpmax);
}
/* replace current main buffer line by edit buffer.
* the edit buffer is NOT changed or cleared.
* return ERR is something goes wrong.
*/
edrepl()
{
/* do nothing if nothing has changed */
if (edcflag == NO) {
return(OK);
}
/* make sure we don't replace the line twice */
edcflag = NO;
/* insert instead of replace if at bottom of file */
if (bufatbot()) {
return(bufins(editbuf,editpmax));
}
else {
return(bufrepl(editbuf,editpmax));
}
}
/* set editp to the largest index such that
* buf[editp] will be printed <= xpos
*/
edscan(xpos) int xpos;
{
editp = 0;
while (editp < editpmax) {
if (fmtlen(editbuf,editp) < xpos) {
editp++;
}
else {
break;
}
}
return(editp);
}
/* scroll the screen up. topline will be new top line */
