/*
 * page.c
 *
 * map page numbers to file position
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <X11/IntrinsicP.h>
#include <X11/StringDefs.h>
#include <X11/Xos.h>
#include <stdio.h>
#include <ctype.h>
#include "DviP.h"

static DviFileMap *
MapPageNumberToFileMap(DviWidget dw, int number)
{
    DviFileMap *m;

    for (m = dw->dvi.file_map; m; m = m->next) {
        if (m->page_number == number)
            break;
    }
    return m;
}

void
DestroyFileMap(DviFileMap *m)
{
    DviFileMap *next;

    for (; m; m = next) {
        next = m->next;
        XtFree((char *) m);
    }
}

void
ForgetPagePositions(DviWidget dw)
{
    DestroyFileMap(dw->dvi.file_map);
    dw->dvi.file_map = NULL;
}

void
RememberPagePosition(DviWidget dw, int number)
{
    DviFileMap *m = MapPageNumberToFileMap(dw, number);

    if (!m) {
        m = (DviFileMap *) XtMalloc(sizeof *m);
        m->page_number = number;
        m->next = dw->dvi.file_map;
        dw->dvi.file_map = m;
    }
    if (dw->dvi.tmpFile)
        m->position = ftell(dw->dvi.tmpFile);
    else
        m->position = ftell(dw->dvi.file);
}

long
SearchPagePosition(DviWidget dw, int number)
{
    DviFileMap *m = MapPageNumberToFileMap(dw, number);

    if (!m)
        return -1;
    return m->position;
}

void
FileSeek(DviWidget dw, long position)
{
    if (dw->dvi.tmpFile) {
        dw->dvi.readingTmp = 1;
        fseek(dw->dvi.tmpFile, position, SEEK_SET);
    }
    else
        fseek(dw->dvi.file, position, SEEK_SET);
}