/*
 *  browse.c - Very simple file browser.
 *
 *  Syntax:
 *      browse file1 file2 ...
 */

#include <stdio.h>
#ifdef  __ZTC__     /* if MS-DOS/Zortech C */
#include <disp.h>
#else
#include <curses.h>
#define disp_printf printw
#define	disp_move   move
#endif

#define MAX_LINE    (80)
#define PAGE_SIZE   (20)


    main(argc, argv)
char    **argv;
{
int     i, c;
FILE    *fin;

#ifdef  __ZTC__
    disp_open();    /* Initialize display package */
    disp_move(0,0);
    disp_eeop();
    disp_flush();
#else
    initscr();
    noecho();
    scrollok(stdscr, TRUE);
    raw();          /* unbuffered character input  */
#endif

    for(i = 1; i < argc; ++i)
        if((fin=fopen(argv[i], "r")) == NULL)
            {
            c   = toupper(
                pause( "Can't open file for input. Continue (Y/n)? ", "yYnN" )
                         );
            if(c == 'N')
                break;
            }
        else if(!browse(fin))
            break;

#ifdef  __ZTC__
    disp_close();   /* wrap up display package  */
#else
    endwin();   /* set terminal to initial state    */
#endif
}

int     browse(fin)
FILE    *fin;
{
char    line[MAX_LINE];
int     c, nlines = 1, eof = 0, addlines = PAGE_SIZE;

#if __ZTC__
    disp_move(0, 0);
    disp_eeop();
    disp_move(1, 0);
#else
    clear();
    move(1, 0);    
#endif
    for(;;)
        {
        if(addlines)    /* wants to see more    */
            if(eof)
                putchar( 7 );   /* beep */
            else
                {
                while(fgets(line, MAX_LINE, fin))
                    {
                    if(nlines > PAGE_SIZE)
#ifdef __ZTC__
                        disp_scroll(1,0,0,PAGE_SIZE,79,DISP_NORMAL);
#else
                        scroll(stdscr);
#endif
                    else
                        ++nlines;
                    disp_move(nlines-1, 0);
                    disp_printf("%s", line);
                    if(--addlines <= 0)
                        break;
                    }
                if(addlines)    /* hit end of file  */
                    {
                    eof = 1, addlines = 0;
#if __ZTC__
                    disp_setattr(DISP_REVERSEVIDEO);
                    disp_printf( "End-of-File" );
                    disp_setattr(DISP_NORMAL);
#else
                    standout(); printw( "End-of-File" ); standend();
#endif
                    }
                }

        c   = pause("BROWSE: next File, Page, Line, or Quit (F,P,L,Q)? ",
                    "fFpPlLqQ");
        c   = toupper(c);
        if(c == 'F')
            {
            fclose(fin);
            return( 1 );
            }
        else if(c == 'P')
            addlines    = PAGE_SIZE;
        else if(c == 'L')
            addlines    = 1;
        else if(c == 'Q')
            {
            fclose(fin);
            return( 0 );
            }
        else
            putchar( 7 );   /* beep */
        }
}

int     pause(prompt, chars)
char    *prompt, *chars;
{
#if __ZTC__
extern  int disp_cursorrow, disp_cursorcol;
#endif
int     c, row, col;

#if __ZTC__
    row = disp_cursorrow, col = disp_cursorcol;
#endif

#if __ZTC__
    disp_move(0, 0);
    disp_setattr(DISP_REVERSEVIDEO);
    disp_printf( "%s", prompt );
    disp_flush();
#else
    getyx(stdscr, row, col);
    move(0, 0); standout();
    printw( "%s", prompt );
    refresh();
#endif
    while( !strchr(chars, (c=getch())) )
        putchar(7); /* beep */
#if __ZTC__
    disp_setattr(DISP_NORMAL);
    disp_move(row, col);
#else
    standend();
    move(row, col);
#endif
    return( c );
}