gvcdll.c

GSview 4.6 PostScript previewer。Ghostscript在MS-Windows, OS/2 and Unix下的图形化接口

	    DEVICENAME, dmode, &view);
    if (!code && option.safer && (gsdll.revision_number > GS_UNSAFE))
	code = gs_printf("/.LockSafetyParams true\n");
    if (!code)
        code = send_prolog(IDR_VIEWER);
    if (!code)
        code = gs_printf(">> setpagedevice\n");
    if (!code) 	/* local/global bug in GS, see note above */
	code = gs_printf("setglobal\n");

    if (!code && option.safer && (gsdll.revision_number > GS_UNSAFE)) {
	if (gsdll.revision_number == 704) {
	    /* There is a local/global allocation problem in GS 7.04 */
	    /* which we try to avoid with the following */
	    code = gs_printf(
		"currentglobal true setglobal .locksafe setglobal\n");

	    /* .locksafe disabled ViewerPreProcess */
	    /* Put it back again */
	    if (!code)
		code = gs_printf("currentglobal true setglobal\n");
	    if (!code)
		code = gs_printf(
		    "currentpagedevice /ViewerPreProcess known not { <<\n");
	    if (!code)
		code = send_prolog(IDR_VIEWER);
	    if (!code)
		code = gs_printf(">> setpagedevice } if\n");
	    if (!code)
		code = gs_printf("setglobal\n");
        }
	else  {
	    /* code = gs_printf(".locksafe\n"); */
	    /* local/global bug in GS, see note above */
	    code = gs_printf(
		"currentglobal true setglobal .locksafe setglobal\n");
/* FIX: .locksafe in 7.06 pre-release is buggy and leaves items on the stack */
	    if (!code)
		code = gs_printf("clear\n");
	}
    }

    if (code) {
	char buf[256];
	sprintf(buf,"Failed to open device or install ViewerPreProcess hook: returns %d\n", code);
	gs_addmess(buf);
	pending.unload = TRUE;
	if ( (code == e_limitcheck)
	     || (code == e_invalidexit)
	     || (code == e_VMerror)
	   ) {
	    gs_addmess("Page size may have been too large or resolution too high.\nResetting page size and resolution\n");
	    if (option.xdpi > DEFAULT_RESOLUTION)
		option.xdpi = option.ydpi = DEFAULT_RESOLUTION;
	    if (zoom)
		option.zoom_xdpi = option.zoom_ydpi = 300;
	    post_img_message(WM_COMMAND, IDM_A4);
	}
    }

    if (!code)
	/* run Ghostscript with a stopped */
	code = gs_printf("\
/GSview_stopped\n\
{\n\
 { currentfile run } stopped\n\
 { $error /errorname get /VMerror eq\n\
  { $error begin command errorname end signalerror }\n\
  { handleerror quit }\n\
  ifelse\n\
 }\n\
 if\n\
}\n\
def\n\
GSview_stopped\n");

    if (!code)
	display.init = TRUE;
    return code;
}

int
d_pdf_page(int pagenum)
{
    int code;
    code = pdf_page_init(pagenum);
    if (code)
	gs_addmess("pdf_page_init failed\n");
    if (!zoom) {
	if (!code) {
	    code = d_resize(pagenum);
	    if (code)
		gs_addmess("d_resize failed\n");
	}
	if (!code) {
	    /* local/global bug in GS, see note above */
	    code = gs_printf("currentglobal true setglobal\n");
	    if (!code) {
		if (in_pstotext)
		    code = gs_printf("<< >> setpagedevice\n");
		else
		    code = gs_printf("<< >> //systemdict /setpagedevice get exec\n");
	    }
	    if (!code) 	/* local/global bug in GS, see note above */
		code = gs_printf("setglobal\n");
	    if (code)
		gs_addmess("setpagedevice failed\n");
	}
    }
    if (!code) {
	code = pdf_page();
	if (code)
	    gs_addmess("pdf_page failed\n");
    }
    return code;
}

/* input for Ghostscript DLL */
/* get_gs_input() copies/reads from gs_input[] to the supplied buffer */
/* copy/read at most blen bytes */
/* returns number of bytes copied to buffer */
int
get_gs_input(char *buf, int blen)
{
unsigned long len;
GSINPUT *entry;
GSDLL_INPUT *input = &view.input;


    if (input->index >= input->count) {
	return 0; /* no more */
    }

    entry = &input->section[input->index];
    len = entry->end - entry->ptr;
    len = min(len, (unsigned long)blen);

    if (entry->seek) {
	gfile_seek(psfile.file, entry->ptr, gfile_begin);
	entry->seek = FALSE;
    }

    len = gfile_read(psfile.file, buf, (int)len);
    entry->ptr += len;

    /* check if we need to move to next item */
    if (entry->ptr >= entry->end) {
        input->index++;
	/* do initial seek */
        if (input->index < input->count) {
	    gfile_seek(psfile.file, input->section[input->index].ptr, 
		gfile_begin);
	    input->section[input->index].seek = FALSE;
	}
    }
    return (int)len;
}


/* assume this is quick - don't check message loop */
int
send_trailer(void)
{
char buf[MAXSTR];
unsigned long len;
unsigned long ptr;
int code = 0;
int prevlen = 0;
CDSC *dsc = psfile.dsc;
    if (psfile.file == NULL)
	return 0;	/* file has been deleted */
    ptr = dsc->begintrailer;
    gfile_seek(psfile.file, ptr, gfile_begin);
    len = dsc->endtrailer - ptr;
    len = min(len, sizeof(buf));
    if (debug & DEBUG_GENERAL)
	gs_addmess("send_trailer\n");
    while (!code && len && (len = gfile_read(psfile.file, buf, (int)len))!=0) {
	code = gs_execute(buf, (int)len);
	prevlen = (int)len;
        ptr += len;
	len = dsc->endtrailer - ptr;
	len = min(len, sizeof(buf));
    }
#ifndef VIEWONLY
    if (code) {
	gs_addmess("\n---Error in document trailer---\n-------\n");
        gs_addmess_count(buf, prevlen);
	gs_addmess("\n-------\n");
    }
#endif
    return code;
}

/* This doesn't actually send anything to Ghostscript */
/* Instead it prepares a list of what will be sent */
int
send_document(void)
{
char filename[MAXSTR];
char buf[MAXSTR];
char *p;
CDSC *dsc = psfile.dsc;
GSDLL_INPUT *input = &view.input;
    if (debug & DEBUG_GENERAL)
	gs_addmess("send_document:\n");
    if (psfile.file == NULL)
	return -1;
    strcpy(filename, psfile.name);
    for (p=filename; *p; p++)
	if (*p == '\\')
	    *p = '/';

    if (dsc != (CDSC *)NULL) {
	if (dsc->page_count && (dsc->page != 0)) {
	    int i, page;
	    i = 0;
	    page = map_page(psfile.pagenum-1);
	    if (display.need_header) {
		sprintf(buf, "Displaying DSC file %s\n", filename);
		gs_addmess(buf);
		/* add header */
		if (dsc->endcomments - dsc->begincomments != 0) {
		    if (debug & DEBUG_GENERAL) {
			sprintf(buf, "adding header %ld %ld\n", 
			    (long)(dsc->begincomments), (long)(dsc->endcomments));
		 	gs_addmess(buf);
		    }
		    input->section[i].ptr = dsc->begincomments;
		    input->section[i].end = dsc->endcomments;
		    input->section[i].seek = TRUE;
		    i++;
		}
		/* add defaults */
		if (dsc->enddefaults - dsc->begindefaults != 0) {
		    if (debug & DEBUG_GENERAL) {
			sprintf(buf, "adding defaults %ld %ld\n", 
			    (long)(dsc->begindefaults), (long)(dsc->enddefaults));
		 	gs_addmess(buf);
		    }
		    input->section[i].ptr = dsc->begindefaults;
		    input->section[i].end = dsc->enddefaults;
		    input->section[i].seek = TRUE;
		    i++;
		}
		/* add prolog */
		if (dsc->endprolog - dsc->beginprolog != 0) {
		    if (debug & DEBUG_GENERAL) {
			sprintf(buf, "adding prolog %ld %ld\n", 
			    (long)(dsc->beginprolog), (long)(dsc->endprolog));
		 	gs_addmess(buf);
		    }
		    input->section[i].ptr = dsc->beginprolog;
		    input->section[i].end = dsc->endprolog;
		    input->section[i].seek = TRUE;
		    i++;
		}
		/* add setup */
		if (dsc->endsetup - dsc->beginsetup != 0) {
		    if (debug & DEBUG_GENERAL) {
			sprintf(buf, "adding setup %ld %ld\n", 
			    (long)(dsc->beginsetup), (long)(dsc->endsetup));
		 	gs_addmess(buf);
		    }
		    input->section[i].ptr = dsc->beginsetup;
		    input->section[i].end = dsc->endsetup;
		    input->section[i].seek = TRUE;
		    i++;
		}
		display.need_header = FALSE;
		/* remember if we need trailer later */
		if (dsc->endtrailer - dsc->begintrailer != 0)
		    display.need_trailer = TRUE;
	    }
	    /* add page */
	    sprintf(buf, "Displaying page %d\n", psfile.pagenum);
	    gs_addmess(buf);
	    if (debug & DEBUG_GENERAL) {
		sprintf(buf, "adding page %d %ld %ld\n", page,
		    (long)(dsc->page[page].begin), (long)(dsc->page[page].end));
		gs_addmess(buf);
	    }
	    input->section[i].ptr = dsc->page[page].begin;
	    input->section[i].end = dsc->page[page].end;
	    if (dsc->epsf && !dsc->dcs2) {
		int j;
		/* add everything except trailer */
		input->section[i].ptr = dsc->page[0].begin;
		for (j=0; j<(int)dsc->page_count; j++)
		    if (dsc->page[j].end)
			input->section[i].end = dsc->page[j].end;
		
		display.need_trailer = FALSE;
		if (dsc->endtrailer - dsc->begintrailer != 0)
		    display.need_trailer = TRUE;
	    }
	    input->section[i].seek = TRUE;
	    i++;
	    input->count = i;
	    input->index = 0;
	}
	else {
	    /* add complete file */
	    int i = 0;
	    sprintf(buf, "Displaying DSC file %s without pages\n", filename);
	    gs_addmess(buf);
	    /* add header */
	    if (dsc->endcomments - dsc->begincomments != 0) {
		if (debug & DEBUG_GENERAL) {
		    sprintf(buf, "adding header %ld %ld\n", 
			(long)(dsc->begincomments), (long)(dsc->endcomments));
		    gs_addmess(buf);
		}
		input->section[i].ptr = dsc->begincomments;
		input->section[i].end = dsc->endcomments;
		input->section[i].seek = TRUE;
		i++;
	    }
	    /* add defaults */
	    if (dsc->enddefaults - dsc->begindefaults != 0) {
		if (debug & DEBUG_GENERAL) {
		    sprintf(buf, "adding defaults %ld %ld\n", 
			(long)(dsc->begindefaults), (long)(dsc->enddefaults));
		    gs_addmess(buf);
		}
		input->section[i].ptr = dsc->begindefaults;
		input->section[i].end = dsc->enddefaults;
		input->section[i].seek = TRUE;
		i++;
	    }
	    /* add prolog */
	    if (dsc->endprolog - dsc->beginprolog != 0) {
		if (debug & DEBUG_GENERAL) {
		    sprintf(buf, "adding prolog %ld %ld\n", 
			(long)(dsc->beginprolog), (long)(dsc->endprolog));
		    gs_addmess(buf);
		}
		input->section[i].ptr = dsc->beginprolog;
		input->section[i].end = dsc->endprolog;
		input->section[i].seek = TRUE;
		i++;
	    }
	    /* add setup */
	    if (dsc->endsetup - dsc->beginsetup != 0) {
		if (debug & DEBUG_GENERAL) {
		    sprintf(buf, "adding setup %ld %ld\n", 
			(long)(dsc->beginsetup), (long)(dsc->endsetup));
		    gs_addmess(buf);
		}
		input->section[i].ptr = dsc->beginsetup;
		input->section[i].end = dsc->endsetup;
		input->section[i].seek = TRUE;
		i++;
	    }
	    /* add trailer */
	    if (dsc->endtrailer - dsc->begintrailer != 0) {
		if (debug & DEBUG_GENERAL) {
		    sprintf(buf, "adding trailer %ld %ld\n", 
			(long)(dsc->begintrailer), (long)(dsc->endtrailer));
		    gs_addmess(buf);
		}
		input->section[i].ptr = dsc->begintrailer;
		input->section[i].end = dsc->endtrailer;
		input->section[i].seek = TRUE;
		i++;
	    }
	    display.need_header = FALSE;
	    display.need_trailer = FALSE;
	    input->count = i;
	    input->index = 0;
	}
    }
    else {
	/* add complete file */
        sprintf(buf, "Displaying non DSC file %s\n", filename);
	gs_addmess(buf);
	input->section[0].ptr = 0;
	input->section[0].end = gfile_get_length(psfile.file);
	input->section[0].seek = TRUE;
	if (debug & DEBUG_GENERAL) {
	    sprintf(buf, "adding complete file %ld %ld\n", 
		(long)0, (long)(input->section[0].end));
	    gs_addmess(buf);
	}
	input->count = 1;
	input->index = 0;
        display.need_trailer = FALSE;
    }
/* this is done by get_gs_input
    gfile_seek(psfile.file, input->section[0].ptr, gfile_begin);
*/
    return 0;
}

BOOL
gs_process_trailer(void)
{
    if (display.need_trailer) {
	/* assume trailer is short, don't check message loop */	
	post_img_message(WM_GSWAIT, IDS_WAIT);
	if (!psfile.ispdf && (dfreopen() != 0)) {
	    pending.abort = TRUE;
	    return TRUE;
	}
	if (psfile.ispdf) {
	    if (pdf_trailer())
		return FALSE;
	}
	else {
	    BOOL old_now = pending.now;
	    pdf_free_link();
	    /* don't wait if we execute showpage in trailer */
	    pending.now = TRUE;
	    if (send_trailer()) {
		dfclose();
		pending.now = old_now;
		return FALSE;
	    }
	    dfclose();
	    pending.now = old_now;
	}
	display.need_trailer = FALSE;
    }
    return FALSE;
}


/* Prepare input to be written to Ghostscript (Unix)
 * or write header and prepare input (Windows)
 * Return code is 0 for OK, +ve for OK but exit enclosing loop,
 * -ve for Ghostscript error
 */
int
gs_process_prepare_input(PENDING *ppend)
{
    int code;
    int i;
    char buf[MAXSTR];
    GSDLL_INPUT *input = &view.input;
    code = dfreopen();
    if (code < 0) {
	/* file could not be opened */
	/* beep only */
	return 1;	/* error */
    }
    else if (code > 0) {
	/* document changed, so force a rescan */
	/* Cause the rescan to occur on main thread */
	request_mutex();
	pending.now = FALSE;
	pending.redisplay = TRUE; /* cause a redisplay after abort complete */
	pending.abort = TRUE;
	release_mutex();
	return 1;
    }

    code = 0;	/* GS return code */

    /* move to desired page */
    if (psfile.dsc != (CDSC *)NULL) {
	if (ppend->pagenum < 0)
	    ppend->pagenum = psfile.pagenum;
	if (psfile.dsc->page_count 
		&& (ppend->pagenum > (int)psfile.dsc->page_count))
	     ppend->pagenum = psfile.dsc->page_count;
	if (ppend->pagenum < 0)
	    ppend->pagenum = 1;
    }
    if (ppend->pagenum > 0)
	psfile.pagenum = ppend->pagenum;
    ppend->pagenum = 0;

    if (!display.init) {
	if (!code)
	    code = d_init1();	/* create GSview dict */
	if (!code)
	    code = d_resize(psfile.pagenum);  /* Set GSview dict entries */
	if (!code)
	    code = d_init2();	/* add ViewerPreProcess then setpagedevice */
    }
    else {
	if (ppend->resize) {
	    if (!code)
		code = d_resize(psfile.pagenum);
	    view.img->ignore_sync = TRUE;		/* ignore next sync */
	    if (!code) 	/* local/global bug in GS, see note above */
		code = gs_printf("currentglobal true setglobal\n");
	    if (!code) {
		if (in_pstotext)
		    code = gs_printf("<< >> setpagedevice\n");
		else
		    code = gs_printf("<< >> //systemdict /setpagedevice get exec\n");
	    }
	    if (!code) 	/* local/global bug in GS, see note above */
		code = gs_printf("setglobal\n");
	}
    }

    if (!code && option.epsf_warn)
	code = send_prolog(IDR_EPSFWARN);

    if (code) {
	/* error initializing GS */
	if (!psfile.ispdf)
	    dfclose();
	return code;
    }

    /* highlight search word if needed */
    if (psfile.text_bbox.valid) {
	display.show_find = TRUE;
	psfile.text_bbox.valid = FALSE;	/* don't do it on following pages */
    }
    else
	display.show_find = FALSE;

    if (psfile.ispdf) {
	post_img_message(WM_GSTEXTINDEX, 0);
	{
	    if (display.need_header) {
		gs_addmess("Scanning PDF file\n");
		if ( (code = pdf_head()) != 0 )
		    return code;
	    }
	    display.need_header = FALSE;
	    display.need_trailer = TRUE;
	    if (ppend->pagenum > 0)
		psfile.pagenum = ppend->pagenum;
	    ppend->pagenum = 0;