Subversion Repositories SvarDOS

/* */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "mdr\cout.h"

#include "mdr\keyb.h"

#define COL_TXT        0

#define COL_STATUSBAR1 1

#define COL_STATUSBAR2 2

#define COL_SCROLLBAR  3

/* preload the mono scheme (to be overloaded at runtime if color adapter present) */

static unsigned char scheme[] = {0x07, 0x70, 0x70, 0x70};

#define SCROLL_CURSOR 0xB1

struct line {

  struct line *prev;

  struct line *next;

  unsigned short len;

  char payload[1];

};

struct linedb {

  struct line *topscreen;

  struct line *cursor;

  unsigned short xoffset;

};

void line_add(struct linedb *db, const char *line) {

  unsigned short slen = strlen(line);

  struct line *l;

  /* trim out CR/LF line endings */

  if ((slen >= 2) && (line[slen - 2] == '\r')) {

    slen -= 2;

  } else if ((slen >= 1) && (line[slen - 1] == '\n')) {

    slen--;

  }

  l =  calloc(1, sizeof(struct line) + slen + 1);

  l->prev = db->cursor;

  if (db->cursor) {

    l->next = db->cursor->next;

    db->cursor->next = l;

    l->next->prev = l;

  }

  db->cursor = l;

  memcpy(l->payload, line, slen);

  l->len = slen;

}

void db_rewind(struct linedb *db) {

  if (db->cursor == NULL) return;

  while (db->cursor->prev) db->cursor = db->cursor->prev;

  db->topscreen = db->cursor;

}

void load_colorscheme(void) {

  scheme[COL_TXT] = 0x17;

  scheme[COL_STATUSBAR1] = 0x70;

  scheme[COL_STATUSBAR2] = 0x78;

  scheme[COL_SCROLLBAR] = 0x70;

}

void ui_basic(unsigned char screenw, unsigned char screenh, const char *fname) {

  unsigned char i;

  const char *s = "HELP";

  unsigned char helpcol = screenw - (strlen(s) + 4);

  /* clear screen */

  mdr_cout_cls(scheme[COL_TXT]);

  /* status bar */

  for (i = 0; i < helpcol; i++) {

    mdr_cout_char(screenh - 1, i, *fname, scheme[COL_STATUSBAR1]);

    if (*fname != 0) fname++;

  }

  mdr_cout_str(screenh - 1, helpcol, " F1=", scheme[COL_STATUSBAR2], 40);

  mdr_cout_str(screenh - 1, helpcol + 4, s, scheme[COL_STATUSBAR2], 40);

  /* scroll bar */

  for (i = 0; i < (screenh - 1); i++) {

    mdr_cout_char(i, screenw - 1, SCROLL_CURSOR, scheme[COL_SCROLLBAR]);

  }

}

void ui_refresh(const struct linedb *db, unsigned char screenw, unsigned char screenh) {

  unsigned char y = 0;

  unsigned char len;

  struct line *l;

  for (l = db->topscreen; l != NULL; l = l->next) {

    if (db->xoffset < l->len) {

      len = mdr_cout_str(y, 0, l->payload + db->xoffset, scheme[COL_TXT], screenw - 1);

    } else {

      len = 0;

    }

    while (len < screenw - 1) mdr_cout_char(y, len++, ' ', scheme[COL_TXT]);

    if (y == screenh - 2) break;

    y++;

  }

}

static void check_cursor_not_after_eol(struct linedb *db, unsigned char *cursorpos) {

  if (db->xoffset + *cursorpos <= db->cursor->len) return;

  if (db->cursor->len < db->xoffset) {

    *cursorpos = 0;

    db->xoffset = db->cursor->len;

  } else {

    *cursorpos = db->cursor->len - db->xoffset;

  }

}

static void cursor_up(struct linedb *db, unsigned char *cursorposy) {

  if (db->cursor->prev != NULL) {

    db->cursor = db->cursor->prev;

    if (*cursorposy == 0) {

      db->topscreen = db->cursor;

    } else {

      *cursorposy -= 1;

    }

  }

}

static void cursor_eol(struct linedb *db, unsigned char *cursorposx, unsigned char screenw) {

  /* adjust xoffset to make sure eol is visible on screen */

  if (db->xoffset > db->cursor->len) db->xoffset = db->cursor->len - 1;

  if (db->xoffset + screenw - 1 <= db->cursor->len) db->xoffset = db->cursor->len - screenw + 2;

  *cursorposx = db->cursor->len - db->xoffset;

}

static void cursor_down(struct linedb *db, unsigned char *cursorposy, unsigned char screenh) {

  if (db->cursor->next != NULL) {

    db->cursor = db->cursor->next;

    if (*cursorposy < screenh - 2) {

      *cursorposy += 1;

    } else {

      db->topscreen = db->topscreen->next;

    }

  }

}

static void cursor_home(struct linedb *db, unsigned char *cursorposx) {

  *cursorposx = 0;

  db->xoffset = 0;

}

int main(int argc, char **argv) {

  FILE *fd;

  const char *fname = NULL;

  char buff[1024];

  struct linedb db;

  unsigned char screenw = 0, screenh = 0;

  unsigned char cursorposx = 0, cursorposy = 0;

  bzero(&db, sizeof(db));

  if ((argc != 2) || (argv[1][0] == '/')) {

    mdr_coutraw_puts("usage: sved file.txt");

    return(0);

  }

  fname = argv[1];

  printf("Loading %s...", fname);

  mdr_coutraw_puts("");

  fd = fopen(fname, "rb");

  if (fd == NULL) {

    printf("ERROR: failed to open file %s", fname);

    mdr_coutraw_puts("");

    return(1);

  }

  while (fgets(buff, sizeof(buff), fd) != NULL) {

    line_add(&db, buff);

  }

  /* add an empty line at end if not present already */

  if (db.cursor->len != 0) line_add(&db, "");

  fclose(fd);

  if (mdr_cout_init(&screenw, &screenh)) load_colorscheme();

  ui_basic(screenw, screenh, fname);

  db_rewind(&db);

  for (;;) {

    int k;

    check_cursor_not_after_eol(&db, &cursorposx);

    mdr_cout_locate(cursorposy, cursorposx);

    ui_refresh(&db, screenw, screenh);

    k = keyb_getkey();

    if (k == 0x150) { /* down */

      cursor_down(&db, &cursorposy, screenh);

    } else if (k == 0x148) { /* up */

      cursor_up(&db, &cursorposy);

    } else if (k == 0x14D) { /* right */

      if (db.cursor->len > db.xoffset + cursorposx) {

        if (cursorposx < screenw - 2) {

          cursorposx++;

        } else {

          db.xoffset++;

        }

      } else {

        cursor_down(&db, &cursorposy, screenh);

        cursor_home(&db, &cursorposx);

      }

    } else if (k == 0x14B) { /* left */

      if (cursorposx > 0) {

        cursorposx--;

      } else if (db.xoffset > 0) {

        db.xoffset--;

      } else if (db.cursor->prev != NULL) { /* jump to end of line above */

        cursor_up(&db, &cursorposy);

        cursor_eol(&db, &cursorposx, screenw);

      }

    } else if (k == 0x1B) { /* ESC */

      break;

    } else {

      printf("UNHANDLED KEY 0x%02X", k);

      keyb_getkey();

      break;

    }

  }

  mdr_cout_close();

  /* TODO free memory */

  return(0);

}