You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

198 lines
4.1 KiB
C

#include <stdio.h>
#include <ncurses.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
typedef struct Buffer_struct Buffer;
struct Buffer_struct {
char* text;
char* start;
char* end;
int size;
int gap_size;
};
Buffer* new_buffer(int size) {
Buffer* buffer = malloc(sizeof(Buffer));
buffer->size = size;
buffer->text = malloc(buffer->size);
buffer->gap_size = size;
buffer->start = buffer->text;
buffer->end = buffer->start + buffer->gap_size;
return buffer;
}
void buffer_grow(Buffer* buffer) {
int old_size = buffer->size; /* I am making use of the fact that, whenever this
function is called, the strlen of the string must
equal the size of the buffer (since the gap size is zero) */
int start_offset = buffer->start - buffer->text;
buffer->size += 10;
buffer->text = realloc(buffer->text,buffer->size);
buffer->start = buffer->text + start_offset;
buffer->gap_size = 10;
for (int i= (old_size - start_offset) - 1; i >= 0; i--) {
*(buffer->start + i + buffer->gap_size) = *(buffer->start + i);
*(buffer->start + i) = 0;
}
buffer->end = buffer->start + buffer->gap_size;
}
void buffer_insert(char ch, Buffer* buffer) {
*(buffer->start) = ch;
buffer->start++;
buffer->gap_size--;
if (buffer->gap_size == 0) {
buffer_grow(buffer);
}
}
void buffer_delete(Buffer* buffer) {
if (buffer->start != buffer->text) {
buffer->start--;
buffer->gap_size++;
}
}
void buffer_right(Buffer* buffer) {
if (buffer->end != buffer->text + buffer->size) {
char c = *(buffer->end);
buffer->start++;
buffer->end++;
*(buffer->start -1) = c;
}
}
void buffer_left(Buffer* buffer) {
if (buffer->start != buffer->text) {
char c = *(buffer->start - 1);
buffer->start--;
buffer->end--;
*(buffer->end) = c;
*(buffer->start) = 0;
}
}
void init_curses() {
initscr();
noecho();
keypad(stdscr,TRUE);
cbreak();
// scrollok(stdscr,TRUE);
}
void sigint_handler(int dummy) {
endwin();
exit(130);
}
int main(int argc, char** argv) {
signal(SIGINT,sigint_handler);
Buffer* buffer = new_buffer(10);
FILE* logfile = fopen("logfile.txt","w");
if (argc == 2) {
int num_of_chars = 0;
if (access(argv[1],F_OK) == 0) { /* If the file exists */
FILE* file = fopen(argv[1],"r");
char c;
while ((c = fgetc(file)) != EOF) {
buffer_insert(c,buffer);
num_of_chars++;
}
} else {
printf("File does not exist.\n");
return -10;
}
while (num_of_chars > 0) {
buffer_left(buffer);
num_of_chars--;
}
}
init_curses();
int ch;
int y, x;
while (true) {
clear();
int i=0;
if ((buffer->start != buffer->text) || (buffer->gap_size != buffer->size)) { /* We don't want to print the string, if the
gap starts at the first index of the string, and continues till the end */
while (i < buffer->size) {
if ((buffer->start - buffer->text) == i) { /* If we have encountered
the start of the gap */
getyx(stdscr,y,x);
i += buffer->gap_size;
}
if (i >= buffer->size) {
break;
}
addch(*(buffer->text + i));
i++;
fprintf(logfile,"At line %d of %d\n",getcury(stdscr),getmaxy(stdscr));
if (*(buffer->text + i) == '\n' && (getcury(stdscr) == getmaxy(stdscr))) {
fprintf(logfile,"Read newline\n");
break;
}
}
move(y,x);
}
ch = getch();
switch(ch) {
case KEY_BACKSPACE:
buffer_delete(buffer);
break;
case KEY_LEFT:
buffer_left(buffer);
break;
case KEY_RIGHT:
buffer_right(buffer);
break;
case 10: /* Enter key */
buffer_insert('\n',buffer); /* Why handle this separately?
Because, by default, curses seems to send '\r\n',
which is technically two characters. I should
probably add some code to deal with this scenario
in the 'insert' method (instead of creating an
exception here), but that's a problem for another day. */
break;
break;
default:
buffer_insert(ch,buffer);
}
continue_while_loop:
}
endwin();
}