Subversion Repositories Kolibri OS

#include "fitz.h"

#include "mupdf.h"

#include "pdfapp.h"

#include "kolibri.h"

#include  /* for tolower() */

#define ZOOMSTEP 1.142857

#define BEYOND_THRESHHOLD 40

enum panning

{

	DONT_PAN = 0,

	PAN_TO_TOP,

	PAN_TO_BOTTOM

};

static void pdfapp_showpage(pdfapp_t *app, int loadpage, int drawpage, int repaint);

static void pdfapp_warn(pdfapp_t *app, const char *fmt, ...)

{

	char buf[1024];

	va_list ap;

	va_start(ap, fmt);

	vsprintf(buf, fmt, ap);

	va_end(ap);

	winwarn(app, buf);

}

static void pdfapp_error(pdfapp_t *app, fz_error error)

{

	winerror(app, error);

}

char *pdfapp_version(pdfapp_t *app)

{

	return

		"MuPDF 0.9\n"

		"Copyright 2006-2011 Artifex Sofware, Inc.\n";

}

char *pdfapp_usage(pdfapp_t *app)

{

	return " ";

	/*

		"L\t\t-- rotate left\n"

		"R\t\t-- rotate right\n"

		"h\t\t-- scroll left\n"

		"j down\t\t-- scroll down\n"

		"k up\t\t-- scroll up\n"

		"l\t\t-- scroll right\n"

		"+\t\t-- zoom in\n"

		"-\t\t-- zoom out\n"

		"w\t\t-- shrinkwrap\n"

		"r\t\t-- reload file\n"

		". pgdn right space\t-- next page\n"

		", pgup left b\t-- previous page\n"

		">\t\t-- next 10 pages\n"

		"<\t\t-- back 10 pages\n"

		"m\t\t-- mark page for snap back\n"

		"t\t\t-- pop back to latest mark\n"

		"1m\t\t-- mark page in register 1\n"

		"1t\t\t-- go to page in register 1\n"

		"123g\t\t-- go to page 123\n"

		"/\t\t-- search for text\n"

		"n\t\t-- find next search result\n"

		"N\t\t-- find previous search result\n"

		"c\t\t-- toggle between color and grayscale\n"

	;

	*/

}

void pdfapp_init(pdfapp_t *app)

{

	memset(app, 0, sizeof(pdfapp_t));

	app->scrw = 640;

	app->scrh = 480;

	app->resolution = 72;

}

void pdfapp_invert(pdfapp_t *app, fz_bbox rect)

{

	unsigned char *p;

	int x, y, n;

	int x0 = CLAMP(rect.x0 - app->image->x, 0, app->image->w - 1);

	int x1 = CLAMP(rect.x1 - app->image->x, 0, app->image->w - 1);

	int y0 = CLAMP(rect.y0 - app->image->y, 0, app->image->h - 1);

	int y1 = CLAMP(rect.y1 - app->image->y, 0, app->image->h - 1);

	for (y = y0; y < y1; y++)

	{

		p = app->image->samples + (y * app->image->w + x0) * app->image->n;

		for (x = x0; x < x1; x++)

		{

			for (n = app->image->n; n > 0; n--, p++)

				*p = 255 - *p;

		}

	}

}

static void pdfapp_open_pdf(pdfapp_t *app, char *filename, int fd)

{

	fz_error error;

	fz_stream *file;

	char *password = "";

	fz_obj *obj;

	fz_obj *info;

	/*

	 * Open PDF and load xref table

	 */

kol_board_puts("FZ OPEN\n");

	//file = fz_open_fd(fd);

	kol_board_puts("FZ ready\n");

	error = pdf_open_xref(&app->xref, filename, NULL);

	if (error){

	kol_board_puts("FZ can't open\n");

		pdfapp_error(app, fz_rethrow(error, "cannot open document '%s'", filename));}

	fz_close(file);

	/*

	 * Handle encrypted PDF files

	 */

/*

	if (pdf_needs_password(app->xref))

	{

		int okay = pdf_authenticate_password(app->xref, password);

		while (!okay)

		{

			password = winpassword(app, filename);

			if (!password)

				exit(1);

			okay = pdf_authenticate_password(app->xref, password);

			if (!okay)

				pdfapp_warn(app, "Invalid password.");

		}

	}

	* */

	/*

	 * Load meta information

	 */

/*

	app->outline = pdf_load_outline(app->xref);

	app->doctitle = filename;

	if (strrchr(app->doctitle, '\\'))

		app->doctitle = strrchr(app->doctitle, '\\') + 1;

	if (strrchr(app->doctitle, '/'))

		app->doctitle = strrchr(app->doctitle, '/') + 1;

	info = fz_dict_gets(app->xref->trailer, "Info");

	if (info)

	{

		obj = fz_dict_gets(info, "Title");

		if (obj)

			app->doctitle = pdf_to_utf8(obj);

	} */

	/*

	 * Start at first page

	 */

	 kol_board_puts("Start at first page\n");

	error = pdf_load_page_tree(app->xref);

	if (error) {

		kol_board_puts("Can't load tree\n");

		pdfapp_error(app, fz_rethrow(error, "cannot load page tree"));}

kol_board_puts("Page counter\n");

	app->pagecount = pdf_count_pages(app->xref);

	kol_board_puts("All is set!\n");

}

void pdfapp_open(pdfapp_t *app, char *filename, int fd, int reload)

{

	pdfapp_open_pdf(app, filename, fd);

	app->cache = fz_new_glyph_cache();

	if (app->pageno < 1)

		app->pageno = 1;

	if (app->pageno > app->pagecount)

		app->pageno = app->pagecount;

	if (app->resolution < MINRES)

		app->resolution = MINRES;

	if (app->resolution > MAXRES)

		app->resolution = MAXRES;

	if (!reload)

	{

		app->shrinkwrap = 1;

		app->rotate = 0;

		app->panx = 0;

		app->pany = 0;

	}

	pdfapp_showpage(app, 1, 1, 1);

}

void pdfapp_close(pdfapp_t *app)

{

	if (app->cache)

		fz_free_glyph_cache(app->cache);

	app->cache = NULL;

	if (app->image)

		fz_drop_pixmap(app->image);

	app->image = NULL;

	if (app->outline)

		pdf_free_outline(app->outline);

	app->outline = NULL;

	if (app->xref)

	{

		if (app->xref->store)

			pdf_free_store(app->xref->store);

		app->xref->store = NULL;

		pdf_free_xref(app->xref);

		app->xref = NULL;

	}

	fz_flush_warnings();

}

static fz_matrix pdfapp_viewctm(pdfapp_t *app)

{

	fz_matrix ctm;

	ctm = fz_identity;

	ctm = fz_concat(ctm, fz_translate(0, -app->page_bbox.y1));

	if (app->xref)

		ctm = fz_concat(ctm, fz_scale(app->resolution/72.0f, -app->resolution/72.0f));

	else

		ctm = fz_concat(ctm, fz_scale(app->resolution/96.0f, app->resolution/96.0f));

	ctm = fz_concat(ctm, fz_rotate(app->rotate + app->page_rotate));

	return ctm;

}

static void pdfapp_panview(pdfapp_t *app, int newx, int newy)

{

	if (newx < 0)

		newx = 0;

	if (newy < 0)

		newy = 0;

	if (newx + app->image->w < app->winw)

		newx = app->winw - app->image->w;

	if (newy + app->image->h < app->winh)

		newy = app->winh - app->image->h;

	if (app->winw >= app->image->w)

		newx = (app->winw - app->image->w) / 2;

	if (app->winh >= app->image->h)

		newy = (app->winh - app->image->h) / 2;

	if (newx != app->panx || newy != app->pany)

		winrepaint(app);

	if (newy > app->image->h) {

		app->pageno++;

	if (app->pageno > app->pagecount)

		app->pageno = app->pagecount;

			newy = 0;

				app->pany = newy;

		pdfapp_showpage(app, 1, 1, 1);

	}

	app->panx = newx;

	app->pany = newy;

}

static void pdfapp_loadpage_pdf(pdfapp_t *app)

{

	pdf_page *page;

	fz_error error;

	fz_device *mdev;

	error = pdf_load_page(&page, app->xref, app->pageno - 1);

	if (error)

		pdfapp_error(app, error);

	app->page_bbox = page->mediabox;

	app->page_rotate = page->rotate;

	app->page_links = page->links;

	page->links = NULL;

	/* Create display list */

	app->page_list = fz_new_display_list();

	mdev = fz_new_list_device(app->page_list);

	error = pdf_run_page(app->xref, page, mdev, fz_identity);

	if (error)

	{

		error = fz_rethrow(error, "cannot draw page %d in '%s'", app->pageno, app->doctitle);

		pdfapp_error(app, error);

	}

	fz_free_device(mdev);

	pdf_free_page(page);

	pdf_age_store(app->xref->store, 3);

}

static void pdfapp_showpage(pdfapp_t *app, int loadpage, int drawpage, int repaint)

{

	char buf[256];

	fz_device *idev;

	fz_device *tdev;

	fz_colorspace *colorspace;

	fz_matrix ctm;

	fz_bbox bbox;

	wincursor(app, WAIT);

	if (loadpage)

	{

		if (app->page_list)

			fz_free_display_list(app->page_list);

		if (app->page_text)

			fz_free_text_span(app->page_text);

		if (app->page_links)

			pdf_free_link(app->page_links);

		if (app->xref)

			pdfapp_loadpage_pdf(app);

		/* Zero search hit position */

		app->hit = -1;

		app->hitlen = 0;

		/* Extract text */

		app->page_text = fz_new_text_span();

		tdev = fz_new_text_device(app->page_text);

		fz_execute_display_list(app->page_list, tdev, fz_identity, fz_infinite_bbox);

		fz_free_device(tdev);

	}

	if (drawpage)

	{

		sprintf(buf, "%s - %d/%d (%d dpi)", app->doctitle,

				app->pageno, app->pagecount, app->resolution);

		wintitle(app, buf);

		ctm = pdfapp_viewctm(app);

		bbox = fz_round_rect(fz_transform_rect(ctm, app->page_bbox));

		/* Draw */

		if (app->image)

			fz_drop_pixmap(app->image);

		if (app->grayscale)

			colorspace = fz_device_gray;

		else

//#ifdef _WIN32

			colorspace = fz_device_bgr;

//#else

	//		colorspace = fz_device_rgb;

//#endif

		app->image = fz_new_pixmap_with_rect(colorspace, bbox);

		fz_clear_pixmap_with_color(app->image, 255);

		idev = fz_new_draw_device(app->cache, app->image);

		fz_execute_display_list(app->page_list, idev, ctm, bbox);

		fz_free_device(idev);

	}

	if (repaint)

	{

		pdfapp_panview(app, app->panx, app->pany);

		if (app->shrinkwrap)

		{

			kol_board_puts ("SHRINK\n");

			int w = app->image->w;

			int h = app->image->h;

			if (app->winw == w)

				app->panx = 0;

			if (app->winh == h)

				app->pany = 0;

			if (w > app->scrw * 90 / 100)

				w = app->scrw * 90 / 100;

			if (h > app->scrh * 90 / 100)

				h = app->scrh * 90 / 100;

			if (w != app->winw || h != app->winh)

				winresize(app, w, h);

		}

		winrepaint(app);

		wincursor(app, ARROW);

	}

	fz_flush_warnings();

}

static void pdfapp_gotouri(pdfapp_t *app, fz_obj *uri)

{

	char *buf;

	buf = fz_malloc(fz_to_str_len(uri) + 1);

	memcpy(buf, fz_to_str_buf(uri), fz_to_str_len(uri));

	buf[fz_to_str_len(uri)] = 0;

	winopenuri(app, buf);

	fz_free(buf);

}

static void pdfapp_gotopage(pdfapp_t *app, fz_obj *obj)

{

	int number;

	number = pdf_find_page_number(app->xref, obj);

	if (number < 0)

		return;

	if (app->histlen + 1 == 256)

	{

		memmove(app->hist, app->hist + 1, sizeof(int) * 255);

		app->histlen --;

	}

	app->hist[app->histlen++] = app->pageno;

	app->pageno = number + 1;

	pdfapp_showpage(app, 1, 1, 1);

}

static inline fz_bbox bboxcharat(fz_text_span *span, int idx)

{

	int ofs = 0;

	while (span)

	{

		if (idx < ofs + span->len)

			return span->text[idx - ofs].bbox;

		if (span->eol)

		{

			if (idx == ofs + span->len)

				return fz_empty_bbox;

			ofs ++;

		}

		ofs += span->len;

		span = span->next;

	}

	return fz_empty_bbox;

}

void pdfapp_inverthit(pdfapp_t *app)

{

	fz_bbox hitbox, bbox;

	fz_matrix ctm;

	int i;

	if (app->hit < 0)

		return;

	hitbox = fz_empty_bbox;

	ctm = pdfapp_viewctm(app);

	for (i = app->hit; i < app->hit + app->hitlen; i++)

	{

		bbox = bboxcharat(app->page_text, i);

		if (fz_is_empty_rect(bbox))

		{

			if (!fz_is_empty_rect(hitbox))

				pdfapp_invert(app, fz_transform_bbox(ctm, hitbox));

			hitbox = fz_empty_bbox;

		}

		else

		{

			hitbox = fz_union_bbox(hitbox, bbox);

		}

	}

	if (!fz_is_empty_rect(hitbox))

		pdfapp_invert(app, fz_transform_bbox(ctm, hitbox));

}

static inline int charat(fz_text_span *span, int idx)

{

	int ofs = 0;

	while (span)

	{

		if (idx < ofs + span->len)

			return span->text[idx - ofs].c;

		if (span->eol)

		{

			if (idx == ofs + span->len)

				return ' ';

			ofs ++;

		}

		ofs += span->len;

		span = span->next;

	}

	return 0;

}

static int textlen(fz_text_span *span)

{

	int len = 0;

	while (span)

	{

		len += span->len;

		if (span->eol)

			len ++;

		span = span->next;

	}

	return len;

}

static int match(char *s, fz_text_span *span, int n)

{

	int orig = n;

	int c;

	while ((c = *s++))

	{

		if (c == ' ' && charat(span, n) == ' ')

		{

			while (charat(span, n) == ' ')

				n++;

		}

		else

		{

			if (tolower(c) != tolower(charat(span, n)))

				return 0;

			n++;

		}

	}

	return n - orig;

}

static void pdfapp_searchforward(pdfapp_t *app, enum panning *panto)

{

	int matchlen;

	int test;

	int len;

	int startpage;

	wincursor(app, WAIT);

	startpage = app->pageno;

	do

	{

		len = textlen(app->page_text);

		if (app->hit >= 0)

			test = app->hit + strlen(app->search);

		else

			test = 0;

		while (test < len)

		{

			matchlen = match(app->search, app->page_text, test);

			if (matchlen)

			{

				app->hit = test;

				app->hitlen = matchlen;

				wincursor(app, HAND);

				winrepaint(app);

				return;

			}

			test++;

		}

		app->pageno++;

		if (app->pageno > app->pagecount)

			app->pageno = 1;

		pdfapp_showpage(app, 1, 0, 0);

		*panto = PAN_TO_TOP;

	} while (app->pageno != startpage);

	if (app->pageno == startpage)

	{

		pdfapp_warn(app, "String '%s' not found.", app->search);

		winrepaintsearch(app);

	}

	else

		winrepaint(app);

	wincursor(app, HAND);

}

static void pdfapp_searchbackward(pdfapp_t *app, enum panning *panto)

{

	int matchlen;

	int test;

	int len;

	int startpage;

	wincursor(app, WAIT);

	startpage = app->pageno;

	do

	{

		len = textlen(app->page_text);

		if (app->hit >= 0)

			test = app->hit - 1;

		else

			test = len;

		while (test >= 0)

		{

			matchlen = match(app->search, app->page_text, test);

			if (matchlen)

			{

				app->hit = test;

				app->hitlen = matchlen;

				wincursor(app, HAND);

				winrepaint(app);

				return;

			}

			test--;

		}

		app->pageno--;

		if (app->pageno < 1)

			app->pageno = app->pagecount;

		pdfapp_showpage(app, 1, 0, 0);

		*panto = PAN_TO_BOTTOM;

	} while (app->pageno != startpage);

	if (app->pageno == startpage)

	{

		pdfapp_warn(app, "String '%s' not found.", app->search);

		winrepaintsearch(app);

	}

	else

		winrepaint(app);

	wincursor(app, HAND);

}

void pdfapp_onresize(pdfapp_t *app, int w, int h)

{

	if (app->winw != w || app->winh != h)

	{

		app->winw = w;

		app->winh = h;

		pdfapp_panview(app, app->panx, app->pany);

		winrepaint(app);

	}

}

void pdfapp_onkey(pdfapp_t *app, int c)

{

	int oldpage = app->pageno;

	enum panning panto = PAN_TO_TOP;

	int loadpage = 1;

	if (app->isediting)

	{

		int n = strlen(app->search);

		if (c < ' ')

		{

			if (c == '\b' && n > 0)

			{

				app->search[n - 1] = 0;

				winrepaintsearch(app);

			}

			if (c == '\n' || c == '\r')

			{

				app->isediting = 0;

				if (n > 0)

				{

					winrepaintsearch(app);

					pdfapp_onkey(app, 'n');

				}

				else

					winrepaint(app);

			}

			if (c == '\033')

			{

				app->isediting = 0;

				winrepaint(app);

			}

		}

		else

		{

			if (n + 2 < sizeof app->search)

			{

				app->search[n] = c;

				app->search[n + 1] = 0;

				winrepaintsearch(app);

			}

		}

		return;

	}

	/*

	 * Save numbers typed for later

	 */

	if (c >= '0' && c <= '9')

	{

		app->number[app->numberlen++] = c;

		app->number[app->numberlen] = '\0';

	}

	switch (c)

	{

	case '?':

		winhelp(app);

		break;

	case 'q':

		winclose(app);

		break;

	/*

	 * Zoom and rotate

	 */

	case '+':

	case '=':

		app->resolution *= ZOOMSTEP;

		if (app->resolution > MAXRES)

			app->resolution = MAXRES;

		pdfapp_showpage(app, 0, 1, 1);

		break;

	case '-':

		app->resolution /= ZOOMSTEP;

		if (app->resolution < MINRES)

			app->resolution = MINRES;

		pdfapp_showpage(app, 0, 1, 1);

		break;

	case 'L':

		app->rotate -= 90;

		pdfapp_showpage(app, 0, 1, 1);

		break;

	case 'R':

		app->rotate += 90;

		pdfapp_showpage(app, 0, 1, 1);

		break;

	case 'c':

		app->grayscale ^= 1;

		pdfapp_showpage(app, 0, 1, 1);

		break;

#ifndef NDEBUG

	case 'a':

		app->rotate -= 15;

		pdfapp_showpage(app, 0, 1, 1);

		break;

	case 's':

		app->rotate += 15;

		pdfapp_showpage(app, 0, 1, 1);

		break;

#endif

	/*

	 * Pan view, but dont need to repaint image

	 */

	case 'w':

		app->shrinkwrap = 1;

		app->panx = app->pany = 0;

		pdfapp_showpage(app, 0, 0, 1);

		break;

	case 'h':

		app->panx += app->image->w / 10;

		pdfapp_showpage(app, 0, 0, 1);

		break;

	case 'j':

		app->pany -= app->image->h / 10;

		pdfapp_showpage(app, 0, 0, 1);

		break;

	case 'k':

		app->pany += app->image->h / 10;

		pdfapp_showpage(app, 0, 0, 1);

		break;

	case 'l':

		app->panx -= app->image->w / 10;

		pdfapp_showpage(app, 0, 0, 1);

		break;

	/*

	 * Page navigation

	 */

	case 'g':

	case '\n':

	case '\r':

		if (app->numberlen > 0)

			app->pageno = atoi(app->number);

		else

			app->pageno = 1;

		break;

	case 'G':

		app->pageno = app->pagecount;

		break;

	case 'm':

		if (app->numberlen > 0)

		{

			int idx = atoi(app->number);

			if (idx >= 0 && idx < nelem(app->marks))

				app->marks[idx] = app->pageno;

		}

		else

		{

			if (app->histlen + 1 == 256)

			{

				memmove(app->hist, app->hist + 1, sizeof(int) * 255);

				app->histlen --;

			}

			app->hist[app->histlen++] = app->pageno;

		}

		break;

	case 't':

		if (app->numberlen > 0)

		{

			int idx = atoi(app->number);

			if (idx >= 0 && idx < nelem(app->marks))

				if (app->marks[idx] > 0)

					app->pageno = app->marks[idx];

		}

		else if (app->histlen > 0)

			app->pageno = app->hist[--app->histlen];

		break;

	/*

	 * Back and forth ...

	 */

	case ',':

		panto = PAN_TO_BOTTOM;

		if (app->numberlen > 0)

			app->pageno -= atoi(app->number);

		else

			app->pageno--;

		break;

	case '.':

		panto = PAN_TO_TOP;

		if (app->numberlen > 0)

			app->pageno += atoi(app->number);

		else

			app->pageno++;

		break;

	case 'b':

		panto = DONT_PAN;

		if (app->numberlen > 0)

			app->pageno -= atoi(app->number);

		else

			app->pageno--;

		break;

	case ' ':

		panto = DONT_PAN;

		if (app->numberlen > 0)

			app->pageno += atoi(app->number);

		else

			app->pageno++;

		break;

case ']':

		panto = PAN_TO_TOP;

			app->pageno++;

		break;

case '[':

		panto = PAN_TO_TOP;

			app->pageno--;

		break;

	case '<':

		panto = PAN_TO_TOP;

		app->pageno -= 10;

		break;

	case '>':

		panto = PAN_TO_TOP;

		app->pageno += 10;

		break;

	/*

	 * Reloading the file...

	 */

	case 'r':

		panto = DONT_PAN;

		oldpage = -1;

		winreloadfile(app);

		break;

	/*

	 * Searching

	 */

	case '/':

		app->isediting = 1;

		app->search[0] = 0;

		app->hit = -1;

		app->hitlen = 0;

		winrepaintsearch(app);

		break;

	case 'n':

		pdfapp_searchforward(app, &panto);

		loadpage = 0;

		break;

	case 'N':

		pdfapp_searchbackward(app, &panto);

		loadpage = 0;

		break;

	}

	if (c < '0' || c > '9')

		app->numberlen = 0;

	if (app->pageno < 1)

		app->pageno = 1;

	if (app->pageno > app->pagecount)

		app->pageno = app->pagecount;

	if (app->pageno != oldpage)

	{

		switch (panto)

		{

		case PAN_TO_TOP:

			app->pany = 0;

			break;

		case PAN_TO_BOTTOM:

			app->pany = -2000;

			break;

		case DONT_PAN:

			break;

		}

		pdfapp_showpage(app, loadpage, 1, 1);

	}

}

void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int modifiers, int state)

{

	pdf_link *link;

	fz_matrix ctm;

	fz_point p;

	p.x = x - app->panx + app->image->x;

	p.y = y - app->pany + app->image->y;

	ctm = pdfapp_viewctm(app);

	ctm = fz_invert_matrix(ctm);

	p = fz_transform_point(ctm, p);

	for (link = app->page_links; link; link = link->next)

	{

		if (p.x >= link->rect.x0 && p.x <= link->rect.x1)

			if (p.y >= link->rect.y0 && p.y <= link->rect.y1)

				break;

	}

	if (link)

	{

		wincursor(app, HAND);

		if (btn == 1 && state == 1)

		{

			if (link->kind == PDF_LINK_URI)

				pdfapp_gotouri(app, link->dest);

			else if (link->kind == PDF_LINK_GOTO)

				pdfapp_gotopage(app, fz_array_get(link->dest, 0)); /* [ pageobj ... ] */

			return;

		}

	}

	else

	{

		wincursor(app, ARROW);

	}

	if (state == 1)

	{

		if (btn == 1 && !app->iscopying)

		{

			app->ispanning = 1;

			app->selx = x;

			app->sely = y;

			app->beyondy = 0;

		}

		if (btn == 3 && !app->ispanning)

		{

			app->iscopying = 1;

			app->selx = x;

			app->sely = y;

			app->selr.x0 = x;

			app->selr.x1 = x;

			app->selr.y0 = y;

			app->selr.y1 = y;

		}

		if (btn == 4 || btn == 5) /* scroll wheel */

		{

			int dir = btn == 4 ? 1 : -1;

			app->ispanning = app->iscopying = 0;

			if (modifiers & (1<<2))

			{

				/* zoom in/out if ctrl is pressed */

				if (dir > 0)

					app->resolution *= ZOOMSTEP;

				else

					app->resolution /= ZOOMSTEP;

				if (app->resolution > MAXRES)

					app->resolution = MAXRES;

				if (app->resolution < MINRES)

					app->resolution = MINRES;

				pdfapp_showpage(app, 0, 1, 1);

			}

			else

			{

				/* scroll up/down, or left/right if

				shift is pressed */

				int isx = (modifiers & (1<<0));

				int xstep = isx ? 20 * dir : 0;

				int ystep = !isx ? 20 * dir : 0;

				pdfapp_panview(app, app->panx + xstep, app->pany + ystep);

			}

		}

	}

	else if (state == -1)

	{

		if (app->iscopying)

		{

			app->iscopying = 0;

			app->selr.x0 = MIN(app->selx, x) - app->panx + app->image->x;

			app->selr.x1 = MAX(app->selx, x) - app->panx + app->image->x;

			app->selr.y0 = MIN(app->sely, y) - app->pany + app->image->y;

			app->selr.y1 = MAX(app->sely, y) - app->pany + app->image->y;

			winrepaint(app);

			if (app->selr.x0 < app->selr.x1 && app->selr.y0 < app->selr.y1)

				windocopy(app);

		}

		if (app->ispanning)

			app->ispanning = 0;

	}

	else if (app->ispanning)

	{

		int newx = app->panx + x - app->selx;

		int newy = app->pany + y - app->sely;

		/* Scrolling beyond limits implies flipping pages */

		/* Are we requested to scroll beyond limits? */

		if (newy + app->image->h < app->winh || newy > 0)

		{

			/* Yes. We can assume that deltay != 0 */

			int deltay = y - app->sely;

			/* Check whether the panning has occured in the

			 * direction that we are already crossing the

			 * limit it. If not, we can conclude that we

			 * have switched ends of the page and will thus

			 * start over counting.

			 */

			if( app->beyondy == 0 || (app->beyondy ^ deltay) >= 0 )

			{

				/* Updating how far we are beyond and

				 * flipping pages if beyond threshhold

				 */

				app->beyondy += deltay;

				if (app->beyondy > BEYOND_THRESHHOLD)

				{

					if( app->pageno > 1 )

					{

						app->pageno--;

						pdfapp_showpage(app, 1, 1, 1);

						newy = -app->image->h;

					}

					app->beyondy = 0;

				}

				else if (app->beyondy < -BEYOND_THRESHHOLD)

				{

					if( app->pageno < app->pagecount )

					{

						app->pageno++;

						pdfapp_showpage(app, 1, 1, 1);

						newy = 0;

					}

					app->beyondy = 0;

				}

			}

			else

				app->beyondy = 0;

		}

		/* Although at this point we've already determined that

		 * or that no scrolling will be performed in

		 * y-direction, the x-direction has not yet been taken

		 * care off. Therefore

		 */

		pdfapp_panview(app, newx, newy);

		app->selx = x;

		app->sely = y;

	}

	else if (app->iscopying)

	{

		app->selr.x0 = MIN(app->selx, x) - app->panx + app->image->x;

		app->selr.x1 = MAX(app->selx, x) - app->panx + app->image->x;

		app->selr.y0 = MIN(app->sely, y) - app->pany + app->image->y;

		app->selr.y1 = MAX(app->sely, y) - app->pany + app->image->y;

		winrepaint(app);

	}

}