emailler/apps/edit.c

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/////////////////////////////////////////////////////////////////////////////
// Prototype of text editor
// Bobbi July 2020
/////////////////////////////////////////////////////////////////////////////
// TODO: We need to erase rest of screen to deal with updates where we are
// close to end of buffer. Junk was being left behind at end of screen.
// TODO: Sometimes backspacing doesn't delete chars on screen.
// TODO: update_after_delete() does do CLREOL when it should sometimes (?)
// TODO: The code doesn't check for error cases when calling gap buffer
// functions.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <conio.h>
#include <ctype.h>
#include <peekpoke.h>
#define NCOLS 80 // Width of editing screen
#define NROWS 22 // Height of editing screen
#define CURSORROW 10 // Row cursor is initially shown on (if enough text)
#define PROMPT_ROW NROWS + 2 // Row where input prompt is shown
#define EOL '\r' // For ProDOS
#define BELL 0x07
#define BACKSPACE 0x08
#define CURDOWN 0x0a
#define RETURN 0x0d
#define NORMAL 0x0e
#define INVERSE 0x0f
#define HOME 0x19
#define CLRLINE 0x1a
#define CLREOL 0x1d
#define DELETE 0x7f
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
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#define BUFSZ 20000 // 65535
char gapbuf[BUFSZ];
uint16_t gapbegin = 0;
uint16_t gapend = BUFSZ - 1;
uint8_t rowlen[NROWS]; // Number of chars on each row of screen
char filename[80];
char userentry[80];
// Interface to read_char_update_pos()
uint8_t do_print;
uint16_t pos;
uint8_t row, col;
uint8_t cursrow, curscol; // Cursor position is kept here by draw_screen()
uint8_t quit_to_email;
/*
* Return number of bytes of freespace in gapbuf
*/
#define FREESPACE() (gapend - gapbegin + 1)
/*
* Return number of bytes of data in gapbuf
*/
#define DATASIZE() (gapbegin + (BUFSZ - 1 - gapend))
/*
* Obtain current position in gapbuf
* This is the positon where the next character will be inserted
*/
#define GETPOS() (gapbegin)
/*
* Put cursor at beginning of PROMPT_ROW
*/
void goto_prompt_row(void) {
uint8_t i;
putchar(HOME);
for (i = 0; i < PROMPT_ROW - 1; ++i)
putchar(CURDOWN);
}
/*
* Prompt for a name in the bottom line of the screen
* Returns number of chars read.
* prompt - Message to display before > prompt
* is_file - if 1, restrict chars to those allowed in ProDOS filename
* Returns number of chars read
*/
uint8_t prompt_for_name(char *prompt, uint8_t is_file) {
uint16_t i;
char c;
cursor(0);
goto_prompt_row();
printf("%c%s>", INVERSE, prompt);
i = 0;
while (1) {
c = cgetc();
if (is_file && !isalnum(c) && (c != RETURN) && (c != BACKSPACE) &&
(c != DELETE) && (c != '.') && (c != '/')) {
putchar(BELL);
continue;
}
switch (c) {
case RETURN:
goto done;
case BACKSPACE:
case DELETE:
if (i > 0) {
putchar(BACKSPACE);
putchar(' ');
putchar(BACKSPACE);
--i;
} else
putchar(BELL);
break;
default:
putchar(c);
userentry[i++] = c;
}
if (i == 79)
goto done;
}
done:
userentry[i] = '\0';
putchar(CLRLINE);
gotoxy(curscol, cursrow);
cursor(1);
return i;
}
/*
* Prompt ok?
*/
char prompt_okay(char *msg) {
char c;
goto_prompt_row();
printf("%c%sSure? (y/n)", INVERSE, msg);
while (1) {
c = cgetc();
if ((c == 'y') || (c == 'Y') || (c == 'n') || (c == 'N'))
break;
putchar(BELL);
}
if ((c == 'y') || (c == 'Y'))
c = 1;
else
c = 0;
putchar(CLRLINE);
return c;
}
/*
* Error message
*/
void show_error(char *msg) {
goto_prompt_row();
putchar(BELL);
printf("%c%s [Press Any Key]%c", INVERSE, msg, NORMAL);
cgetc();
}
/*
* Insert a character into gapbuf at current position
* c - character to insert
* Returns 0 on success, 1 on failure (insufficient space)
*/
uint8_t insert_char(char c) {
if (FREESPACE()) {
gapbuf[gapbegin++] = c;
return 0;
}
return 1;
}
/*
* Delete the character to the left of the current position
* Returns 0 on success, 1 on failure (nothing to delete)
*/
uint8_t delete_char(void) {
if (gapbegin == 0)
return 1;
--gapbegin;
}
/*
* Delete the character to the right of the current position
* Returns 0 on success, 1 on failure (nothing to delete)
*/
uint8_t delete_char_right(void) {
if (gapend == BUFSZ - 1)
return 1;
++gapend;
}
/*
* Obtain the next character (to the right of the current position)
* and advance the position.
* c - character is returned throught this pointer
* Returns 0 on success, 1 if at end of the buffer.
*/
uint8_t get_char(char *c) {
if (gapend == BUFSZ - 1)
return 1;
*c = gapbuf[gapbegin++] = gapbuf[++gapend];
return 0;
}
/*
* Move the current position
* pos - position to which to move
* Returns 0 on success, 1 if pos is invalid
*/
uint8_t jump_pos(uint16_t pos) {
if (pos > BUFSZ - 1)
return 1;
if (pos == GETPOS())
return 0;
if (pos > GETPOS())
do {
gapbuf[gapbegin++] = gapbuf[++gapend];
} while (pos > GETPOS());
else
do {
gapbuf[gapend--] = gapbuf[--gapbegin];
} while (pos < GETPOS());
return 0;
}
/*
* Go to next tabstop
*/
uint8_t next_tabstop(uint8_t col) {
return (col / 8) * 8 + 8;
}
/*
* Load a file from disk into the gapbuf
* filename - name of file to load
* Returns 0 on success
* 1 if file can't be opened
*/
uint8_t load_file(char *filename) {
char c;
uint8_t i;
FILE *fp = fopen(filename, "r");
if (!fp)
return 1;
gapbegin = 0;
gapend = BUFSZ - 1;
col = 0;
while (!feof(fp)) {
c = fgetc(fp);
switch (c) {
case '\r': // Native Apple2 files
case '\n': // UNIX files
col = 0;
gapbuf[gapbegin++] = '\r';
break;
case '\t':
c = next_tabstop(col) - col;
for (i = 0; i < c; ++i)
gapbuf[gapbegin++] = ' ';
col += c;
break;
default:
++col;
gapbuf[gapbegin++] = c;
}
if (FREESPACE() < 1000) {
fclose(fp);
show_error("File truncated");
return 0;
}
if ((gapbegin % 1000) == 0)
putchar('.');
}
--gapbegin; // Eat EOF character
fclose(fp);
return 0;
}
/*
* Save gapbuf to file
* filename - name of file to load
* Returns 0 on success
* 1 if file can't be opened
* 2 gapbuf is corrupt
*/
uint8_t save_file(char *filename) {
char c;
FILE *fp = fopen(filename, "w");
if (!fp)
return 1;
if (jump_pos(0))
return 2;
while (get_char(&c) == 0)
fputc(c, fp);
fclose(fp);
return 0;
}
/*
* Read next char from gapbuf[] and update state.
* Returns 1 on EOL, 0 otherwise
* If do_print is set, print char on the screen.
* Interface is via the following globals:
* do_print - if 1, update screen
* pos - position in buffer, advanced by one
* row, col - position on screen
* rowlen[] - length of each screen row in chars
*/
uint8_t read_char_update_pos(void) {
char c;
if ((c = gapbuf[pos++]) == EOL) {
if (do_print) {
rowlen[row] = col + 1;
putchar(CLREOL);
putchar('\r');
}
++row;
col = 0;
return 1;
}
if (do_print)
putchar(c);
++col;
if (do_print)
rowlen[row] = col;
if (col == NCOLS) {
++row;
col = 0;
}
return 0;
}
/*
* Draw screenful of text
*/
void draw_screen(void) {
uint16_t startpos;
uint8_t rowsabove, cursorrow;
// Initialize all rows to length 0 to cover those rows that may have
// no text and would otherwise be unitialized.
for (rowsabove = 0; rowsabove < NROWS; ++rowsabove)
rowlen[rowsabove] = 0;
revers(0);
// First we have to scan back to work out where in the buffer to
// start drawing on the screen at the top left. This is at most
// NROWS * NCOLS chars.
startpos = gapbegin;
if (startpos > NROWS * NCOLS)
startpos -= NROWS * NCOLS;
else
startpos = 0;
// Format the text and work out the number of rows it takes up
pos = startpos;
row = col = 0;
do_print = 0;
while (pos < gapbegin)
read_char_update_pos();
rowsabove = row; // Number of complete rows above cursor
if (rowsabove <= CURSORROW) {
pos = 0;
cursorrow = rowsabove;
} else {
cursorrow = CURSORROW;
// Now repeat the formatting of the text, eating the first
// (rowsabove - cursorrow) lines
pos = startpos;
row = col = 0;
while (row < (rowsabove - cursorrow))
read_char_update_pos();
}
// Finally actually write the text to the screen!
videomode(VIDEOMODE_80COL);
clrscr();
row = col = 0;
do_print = 1;
while (pos < gapbegin)
read_char_update_pos();
curscol = col;
cursrow = row;
// Now write the text after the cursor up to the end of the screen
pos = gapend + 1;
while ((pos < BUFSZ) && (row < NROWS))
read_char_update_pos();
gotoxy(0, NROWS + 1);
revers(1);
printf(" ");
revers(0);
gotoxy(curscol, cursrow);
cursor(1);
}
/*
* Scroll screen up and update rowlen[]
*/
void scroll_up() {
draw_screen();
}
/*
* Scroll screen down and update rowlen[]
*/
void scroll_down() {
draw_screen();
}
/*
* Update screen after delete_char_right()
*/
void update_after_delete_char_right(void) {
uint8_t eol = 0;
uint8_t i;
col = curscol;
row = cursrow;
do_print = 1;
// Print rest of line up to EOL
pos = gapend + 1;
while (!eol && (pos < BUFSZ) && (row < NROWS)) {
i = col;
eol = read_char_update_pos();
}
// If necessary, print rest of screen
if ((gapbuf[gapend] == EOL) || (i == NCOLS - 1))
while ((pos < BUFSZ) && (row < NROWS))
read_char_update_pos();
// Erase the rest of the screen (if any)
for (i = row; i < NROWS; ++i) {
gotoxy(0, eol);
putchar(CLREOL);
}
gotoxy(curscol, cursrow);
cursor(1);
}
/*
* Update screen after delete_char()
*/
void update_after_delete_char(void) {
uint8_t eol = 0;
uint8_t i;
col = curscol;
row = cursrow;
if (gapbuf[gapbegin] == EOL) {
// Special handling if we deleted an EOL
if (row > 0)
col = rowlen[--row] - 1;
else {
scroll_up();
return;
}
} else {
// Erase char to left of cursor & update row, col
putchar(BACKSPACE);
if (col > 0)
--col;
else {
col = 0;
if (row > 0)
--row;
else {
scroll_up();
return;
}
}
}
curscol = col;
cursrow = row;
gotoxy(curscol, cursrow);
do_print = 1;
// Print rest of line up to EOL
pos = gapend + 1;
while (!eol && (pos < BUFSZ) && (row < NROWS)) {
i = col;
eol = read_char_update_pos();
}
// If necessary, print rest of screen
if ((gapbuf[gapbegin] == EOL) || (i == NCOLS - 1))
while ((pos < BUFSZ) && (row < NROWS))
read_char_update_pos();
// Erase the rest of the screen (if any)
for (i = row; i < NROWS; ++i) {
gotoxy(0, i);
putchar(CLREOL);
}
gotoxy(curscol, cursrow);
cursor(1);
}
/*
* Update screen after insert_char()
*/
void update_after_insert_char(void) {
uint8_t eol = 0;
uint8_t prevcol;
col = curscol;
row = cursrow;
// Print character just inserted
pos = gapbegin - 1;
do_print = 1;
read_char_update_pos();
curscol = col;
cursrow = row;
if (cursrow == NROWS) {
scroll_down();
return;
}
// Print rest of line up to EOL
pos = gapend + 1;
while (!eol && (pos < BUFSZ) && (row < NROWS)) {
prevcol = col;
eol = read_char_update_pos();
}
// If necessary, print rest of screen
if ((gapbuf[gapbegin - 1] == EOL) || (prevcol == 0))
while ((pos < BUFSZ) && (row < NROWS))
read_char_update_pos();
gotoxy(curscol, cursrow);
cursor(1);
}
/*
* Move the cursor left
*/
void cursor_left(void) {
if (gapbegin > 0)
gapbuf[gapend--] = gapbuf[--gapbegin];
else {
putchar(BELL);
return;
}
if (curscol == 0) {
if (cursrow == 0) {
scroll_up();
if (cursrow == 0) {
putchar(BELL);
return;
}
}
--cursrow;
curscol = rowlen[cursrow];
} else
--curscol;
gotoxy(curscol, cursrow);
}
/*
* Move the cursor right
*/
void cursor_right(void) {
if (gapbegin < DATASIZE())
gapbuf[gapbegin++] = gapbuf[++gapend];
else {
putchar(BELL);
return;
}
++curscol;
if (curscol == rowlen[cursrow]) {
if (cursrow == NROWS - 1) {
scroll_down();
if (cursrow == NROWS - 1) {
putchar(BELL);
return;
}
}
++cursrow;
curscol = 0;
}
gotoxy(curscol, cursrow);
}
/*
* Move the cursor up
* Returns 1 if at top, 0 otherwise
*/
uint8_t cursor_up(void) {
uint8_t i;
if (cursrow == 0) {
scroll_up();
if (cursrow == 0) {
putchar(BELL);
gotoxy(curscol, cursrow);
return 1;
}
}
for (i = 0; i < curscol; ++i)
gapbuf[gapend--] = gapbuf[--gapbegin];
--cursrow;
// Short line ...
if (curscol > rowlen[cursrow] - 1)
curscol = rowlen[cursrow] - 1;
for (i = 0; i < rowlen[cursrow] - curscol; ++i)
if (gapbegin > 0)
gapbuf[gapend--] = gapbuf[--gapbegin];
gotoxy(curscol, cursrow);
return 0;
}
/*
* Move the cursor down
* Returns 1 if at bottom, 0 otherwise
*/
uint8_t cursor_down(void) {
uint8_t i;
if (cursrow == NROWS - 1) {
scroll_down();
if (cursrow == NROWS - 1) {
putchar(BELL);
return 1;
}
}
// if (gapbuf[rowlen[cursrow] - 1] == EOL) {
for (i = 0; i < rowlen[cursrow] - curscol; ++i) {
if (gapbegin < DATASIZE()) // TODO Not sure this is necessary now
gapbuf[gapbegin++] = gapbuf[++gapend];
else {
putchar(BELL);
return 1;
}
}
++cursrow;
// }
// Short line ...
if (curscol > rowlen[cursrow] - 1)
curscol = rowlen[cursrow] - 1;
for (i = 0; i < curscol; ++i)
if (gapbegin < DATASIZE()) // TODO Not sure this is necessary now
gapbuf[gapbegin++] = gapbuf[++gapend];
gotoxy(curscol, cursrow);
return 0;
}
/*
* Goto beginning of line
*/
void goto_bol(void) {
while (curscol > 0)
cursor_left();
}
/*
* Goto end of line
*/
void goto_eol(void) {
while (curscol < rowlen[cursrow] - 1)
cursor_right();
}
/*
* Jump forward 15 screen lines
*/
void page_down(void) {
uint8_t i;
for (i = 0; i < 15; ++i)
if (cursor_down() == 1)
break;
}
/*
* Jump back 15 screen lines
*/
void page_up(void) {
uint8_t i;
for (i = 0; i < 15; ++i)
if (cursor_up() == 1)
break;
}
/*
* Delete from cursor to EOL.
* If at EOL, delete EOL char.
*/
void kill_line(void) {
// TODO
}
/*
* Load EMAIL.SYSTEM to $2000 and jump to it
* (This code is in language card space so it can't possibly be trashed)
*/
#pragma code-name (push, "LC")
void load_email(void) {
revers(0);
clrscr();
exec("/IP65/EMAIL.SYSTEM", NULL);
}
#pragma code-name (pop)
/*
* Main editor routine
*/
int edit(char *filename) {
char c;
uint16_t pos;
uint8_t i;
videomode(VIDEOMODE_80COL);
if (filename) {
printf("Loading file %s ", filename);
if (load_file(filename)) {
sprintf(userentry, "%cCan't load %s", filename);
show_error(userentry);
}
}
jump_pos(0);
pos = 0;
draw_screen();
while (1) {
cursor(1);
c = cgetc();
switch (c) {
case 0x88: // OA-Left "Home"
goto_bol();
break;
case 0x8b: // OA-Up "Page Up"
page_up();
break;
case 0x95: // OA-Right "End"
goto_eol();
break;
case 0x8a: // OA-Down "Page Down"
page_down();
break;
case 0x80 + 'L': // OA-L "Load"
case 0x80 + 'l':
prompt_for_name("File", 1);
strcpy(filename, userentry);
gapbegin = 0;
gapend = BUFSZ - 1;
if (load_file(filename)) {
sprintf(userentry, "%cCan't load %s", filename);
show_error(userentry);
}
jump_pos(0);
pos = 0;
draw_screen();
break;
case 0x80 + 'N': // OA-N "New"
case 0x80 + 'n': // OA-n
if (prompt_okay("Erase buffer -")) {
gapbegin = 0;
gapend = BUFSZ - 1;
jump_pos(0);
pos = 0;
draw_screen();
}
break;
case 0x80 + 'Q': // OA-Q "Quit"
case 0x80 + 'q': // OA-q
if (quit_to_email) {
if (prompt_okay("Quit to EMAIL - "))
load_email();
} else {
if (prompt_okay("Quit to ProDOS - ")) {
revers(0);
clrscr();
exit(0);
}
}
break;
case 0x80 + 'S': // OA-S "Save"
case 0x80 + 's': // OA-s
if (save_file(filename)) {
sprintf(userentry, "%cCan't save %s", filename);
show_error(userentry);
draw_screen();
}
break;
case 0x80 + DELETE: // OA-Backspace
case 0x04: // Ctrl-D "DELETE"
delete_char_right();
update_after_delete_char_right();
2020-07-16 00:46:43 +00:00
break;
case 0x0c: // Ctrl-L "REFRESH"
draw_screen();
break;
case DELETE: // DEL "BACKSPACE"
delete_char();
update_after_delete_char();
break;
case 0x09: // Tab
c = next_tabstop(curscol) - curscol;
for (i = 0; i < c; ++i) {
insert_char(' ');
update_after_insert_char();
}
break;
case 0x08: // Left
cursor_left();
break;
case 0x15: // Right
cursor_right();
break;
case 0x0b: // Up
cursor_up();
break;
case 0x0a: // Down
cursor_down();
break;
default:
//printf("**%02x**", c);
if ((c >= 0x20) && (c < 0x80) || (c == EOL)) {
insert_char(c);
update_after_insert_char();
}
}
}
}
int main(int argc, char *argv[]) {
if (argc == 2) {
quit_to_email = 1;
edit(argv[1]);
} else {
quit_to_email = 0;
edit(NULL);
}
}