Add support for links and bookmarks in djvu documents. Thanks to Pauli

2006-09-17  Nickolay V. Shmyrev  <nshmyrev@yandex.ru>

	* djvu/Makefile.am:
	* djvu/djvu-document.c: (G_DEFINE_TYPE_WITH_CODE),
	(djvu_document_find_iface_init), (djvu_document_links_get_links),
	(djvu_document_document_links_iface_init):
	* djvu/djvu-links.c: (number_from_miniexp), (string_from_miniexp),
	(number_from_string_10), (get_djvu_link_dest),
	(get_djvu_link_action), (build_tree), (get_djvu_hyperlink_area),
	(get_djvu_hyperlink_mapping), (djvu_links_has_document_links),
	(djvu_links_get_links), (djvu_links_find_link_dest),
	(djvu_links_get_links_model):
	* djvu/djvu-links.h:

	Add support for links and bookmarks in djvu documents. Thanks
	to Pauli Virtanen <pauli.virtanen@iki.fi> for the wonderful
	patch.

5 files changed, 468 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index d785c84..baedb92 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@
+2006-09-17  Nickolay V. Shmyrev  <nshmyrev@yandex.ru>
+
+	* djvu/Makefile.am:
+	* djvu/djvu-document.c: (G_DEFINE_TYPE_WITH_CODE),
+	(djvu_document_find_iface_init), (djvu_document_links_get_links),
+	(djvu_document_document_links_iface_init):
+	* djvu/djvu-links.c: (number_from_miniexp), (string_from_miniexp),
+	(number_from_string_10), (get_djvu_link_dest),
+	(get_djvu_link_action), (build_tree), (get_djvu_hyperlink_area),
+	(get_djvu_hyperlink_mapping), (djvu_links_has_document_links),
+	(djvu_links_get_links), (djvu_links_find_link_dest),
+	(djvu_links_get_links_model):
+	* djvu/djvu-links.h:
+	
+	Add support for links and bookmarks in djvu documents. Thanks
+	to Pauli Virtanen <pauli.virtanen@iki.fi> for the wonderful
+	patch.
+
 2006-09-14  Nickolay V. Shmyrev  <nshmyrev@yandex.ru>
 
 	* shell/ev-application.c: (ev_application_open_uri_at_dest):
diff --git a/djvu/Makefile.am b/djvu/Makefile.am
index 630496a..62b76a5 100644
--- a/djvu/Makefile.am
+++ b/djvu/Makefile.am
@@ -12,6 +12,8 @@ libgtkdjvu_la_SOURCES = \
 	djvu-document.c	\
 	djvu-document.h \
 	djvu-document-private.h \
+	djvu-links.c	\
+	djvu-links.h	\
 	djvu-text.c	\
 	djvu-text.h	\
 	djvu-text-page.c \
diff --git a/djvu/djvu-document.c b/djvu/djvu-document.c
index e50fb8f..12f07bc 100644
--- a/djvu/djvu-document.c
+++ b/djvu/djvu-document.c
@@ -19,12 +19,15 @@
 
 #include "djvu-document.h"
 #include "djvu-text.h"
+#include "djvu-links.h"
 #include "djvu-document-private.h"
 #include "ev-document-thumbnails.h"
 #include "ev-document-misc.h"
 #include "ev-document-find.h"
+#include "ev-document-links.h"
 
 #include <libdjvu/ddjvuapi.h>
+#include <libdjvu/miniexp.h>
 #include <gtk/gtk.h>
 #include <gdk-pixbuf/gdk-pixbuf-core.h>
 #include <glib/gunicode.h>
@@ -47,6 +50,7 @@ typedef struct _DjvuDocumentClass DjvuDocumentClass;
 static void djvu_document_document_iface_init (EvDocumentIface *iface);
 static void djvu_document_document_thumbnails_iface_init (EvDocumentThumbnailsIface *iface);
 static void djvu_document_find_iface_init (EvDocumentFindIface *iface);
+static void djvu_document_document_links_iface_init  (EvDocumentLinksIface *iface);
 
 G_DEFINE_TYPE_WITH_CODE 
     (DjvuDocument, djvu_document, G_TYPE_OBJECT, 
@@ -54,6 +58,7 @@ G_DEFINE_TYPE_WITH_CODE
       G_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT, djvu_document_document_iface_init);    
       G_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_THUMBNAILS, djvu_document_document_thumbnails_iface_init)
       G_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_FIND, djvu_document_find_iface_init);
+      G_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_LINKS, djvu_document_document_links_iface_init);
      });
 
 
@@ -451,3 +456,19 @@ djvu_document_find_iface_init (EvDocumentFindIface *iface)
 	iface->get_progress = djvu_document_find_get_progress;
         iface->cancel = djvu_document_find_cancel;
 }
+
+static GList *
+djvu_document_links_get_links (EvDocumentLinks *document_links,
+			       gint             page)
+{
+	return djvu_links_get_links (document_links, page, SCALE_FACTOR);
+}
+
+static void
+djvu_document_document_links_iface_init  (EvDocumentLinksIface *iface)
+{
+	iface->has_document_links = djvu_links_has_document_links;
+	iface->get_links_model = djvu_links_get_links_model;
+	iface->get_links = djvu_document_links_get_links;
+	iface->find_link_dest = djvu_links_find_link_dest;
+}
diff --git a/djvu/djvu-links.c b/djvu/djvu-links.c
new file mode 100644
index 0000000..e2fc23e
--- /dev/null
+++ b/djvu/djvu-links.c
@@ -0,0 +1,392 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
+/*
+ * Implements hyperlink functionality for Djvu files.
+ * Copyright (C) 2006 Pauli Virtanen <pav@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "djvu-document.h"
+#include "djvu-links.h"
+#include "djvu-document-private.h"
+#include "ev-document-links.h"
+
+#include <libdjvu/ddjvuapi.h>
+#include <libdjvu/miniexp.h>
+#include <glib.h>
+#include <string.h>
+
+static gboolean number_from_miniexp(miniexp_t sexp, int *number)
+{
+	if (miniexp_numberp (sexp)) {
+		*number = miniexp_to_int (sexp);
+		return TRUE;
+	} else {
+		return FALSE;
+	}
+}
+
+static gboolean string_from_miniexp(miniexp_t sexp, const char **str)
+{
+	if (miniexp_stringp (sexp)) {
+		*str = miniexp_to_str (sexp);
+		return TRUE;
+	} else {
+		return FALSE;
+	}
+}
+
+static gboolean number_from_string_10(const gchar *str, guint64 *number)
+{
+	gchar *end_ptr;
+
+	*number = g_ascii_strtoull(str, &end_ptr, 10);
+	if (*end_ptr == '\0') {
+		return TRUE;
+	} else {
+		return FALSE;
+	}
+}
+
+static EvLinkDest *
+get_djvu_link_dest (const DjvuDocument *djvu_document, const gchar *link_name, int base_page)
+{
+	guint64 page_num = 0;
+	gchar *end_ptr;
+
+	/* #pagenum, #+pageoffset, #-pageoffset */
+	if (g_str_has_prefix (link_name, "#")) {
+		if (base_page > 0 && g_str_has_prefix (link_name+1, "+")) {
+			if (number_from_string_10 (link_name + 2, &page_num)) {
+				return ev_link_dest_new_page (base_page + page_num);
+			}
+		} else if (base_page > 0 && g_str_has_prefix (link_name+1, "-")) {
+			if (number_from_string_10 (link_name + 2, &page_num)) {
+				return ev_link_dest_new_page (base_page - page_num);
+			}
+		} else {
+			if (number_from_string_10 (link_name + 1, &page_num)) {
+				return ev_link_dest_new_page (page_num - 1);
+			}
+		}
+	} else {
+		/* FIXME: component file identifiers */
+	}
+
+	return NULL;
+}
+
+static EvLinkAction *
+get_djvu_link_action (const DjvuDocument *djvu_document, const gchar *link_name, int base_page)
+{
+	EvLinkDest *ev_dest = NULL;
+	EvLinkAction *ev_action = NULL;
+
+	ev_dest = get_djvu_link_dest (djvu_document, link_name, base_page);
+
+	if (ev_dest) {
+		ev_action = ev_link_action_new_dest (ev_dest);
+	} else if (strstr(link_name, "://") != NULL) {
+		/* It's probably an URI */
+		ev_action = ev_link_action_new_external_uri (link_name);
+	} else {
+		/* FIXME: component file identifiers */
+	}
+
+	return ev_action;
+}
+
+/**
+ * Builds the index GtkTreeModel from DjVu s-expr
+ *
+ * (bookmarks
+ *   ("title1" "dest1"
+ *     ("title12" "dest12"
+ *       ... )
+ *     ... )
+ *   ("title2" "dest2"
+ *     ... )
+ *   ... )
+ */
+static void
+build_tree (const DjvuDocument *djvu_document,
+	    GtkTreeModel       *model,
+	    GtkTreeIter        *parent,
+	    miniexp_t           iter)
+{
+	const char *title, *link_dest;
+	char *title_markup;
+
+	EvLinkAction *ev_action = NULL;
+	EvLink *ev_link = NULL;
+	GtkTreeIter tree_iter;
+
+	if (miniexp_car (iter) == miniexp_symbol ("bookmarks")) {
+		/* The (bookmarks) cons */
+		iter = miniexp_cdr (iter);
+	} else if ( miniexp_length (iter) >= 2 ) {
+		/* An entry */
+		if (!string_from_miniexp (miniexp_car (iter), &title)) goto unknown_entry;
+		if (!string_from_miniexp (miniexp_cadr (iter), &link_dest)) goto unknown_entry;
+
+		title_markup = g_markup_escape_text (title, -1);
+		ev_action = get_djvu_link_action (djvu_document, link_dest, -1);
+		
+		if (g_str_has_suffix (link_dest, ".djvu")) {
+			/* FIXME: component file identifiers */
+		} else if (ev_action) {
+			ev_link = ev_link_new (title, ev_action);
+			gtk_tree_store_append (GTK_TREE_STORE (model), &tree_iter, parent);
+			gtk_tree_store_set (GTK_TREE_STORE (model), &tree_iter,
+					    EV_DOCUMENT_LINKS_COLUMN_MARKUP, title_markup,
+					    EV_DOCUMENT_LINKS_COLUMN_LINK, ev_link,
+					    EV_DOCUMENT_LINKS_COLUMN_EXPAND, FALSE,
+					    -1);
+		} else {
+			gtk_tree_store_append (GTK_TREE_STORE (model), &tree_iter, parent);
+			gtk_tree_store_set (GTK_TREE_STORE (model), &tree_iter,
+					    EV_DOCUMENT_LINKS_COLUMN_MARKUP, title_markup,
+					    EV_DOCUMENT_LINKS_COLUMN_EXPAND, FALSE,
+					    -1);
+		}
+
+		g_free (title_markup);
+		
+		iter = miniexp_cddr (iter);
+		parent = &tree_iter;
+	} else {
+		goto unknown_entry;
+	}
+
+	for (; iter != miniexp_nil; iter = miniexp_cdr (iter)) {
+		build_tree (djvu_document, model, parent, miniexp_car (iter));
+	}
+	return;
+
+ unknown_entry:
+	g_warning ("DjvuLibre error: Unknown entry in bookmarks");
+	return;
+}
+
+static gboolean
+get_djvu_hyperlink_area (ddjvu_pageinfo_t   *page_info,
+			 miniexp_t           sexp,
+			 EvLinkMapping      *ev_link_mapping)
+{
+	miniexp_t iter;
+        ddjvu_pageinfo_t info;
+
+	iter = sexp;
+	
+	if ((miniexp_car (iter) == miniexp_symbol ("rect") || miniexp_car (iter) == miniexp_symbol ("oval"))
+	    && miniexp_length (iter) == 5) {
+		/* FIXME: get bounding box for (oval) since Evince doesn't support shaped links */
+		int minx, miny, width, height;
+
+		iter = miniexp_cdr (iter);
+		if (!number_from_miniexp (miniexp_car (iter), &minx)) goto unknown_link;
+		iter = miniexp_cdr (iter);
+		if (!number_from_miniexp (miniexp_car (iter), &miny)) goto unknown_link;
+		iter = miniexp_cdr (iter);
+		if (!number_from_miniexp (miniexp_car (iter), &width)) goto unknown_link;
+		iter = miniexp_cdr (iter);
+		if (!number_from_miniexp (miniexp_car (iter), &height)) goto unknown_link;
+
+		ev_link_mapping->x1 = minx;
+		ev_link_mapping->x2 = (minx + width);
+		ev_link_mapping->y1 = (page_info->height - (miny + height));
+		ev_link_mapping->y2 = (page_info->height - miny);
+	} else if (miniexp_car (iter) == miniexp_symbol ("poly")
+		   && miniexp_length (iter) >= 5 && miniexp_length (iter) % 2 == 1) {
+		
+		/* FIXME: get bounding box since Evince doesn't support shaped links */
+		int minx = G_MAXINT, miny = G_MAXINT;
+		int maxx = G_MININT, maxy = G_MININT;
+
+		iter = miniexp_cdr(iter);
+		while (iter != miniexp_nil) {
+			int x, y;
+
+			if (!number_from_miniexp (miniexp_car(iter), &x)) goto unknown_link;
+			iter = miniexp_cdr (iter);
+			if (!number_from_miniexp (miniexp_car(iter), &y)) goto unknown_link;
+			iter = miniexp_cdr (iter);
+
+			minx = MIN (minx, x);
+			miny = MIN (miny, y);
+			maxx = MAX (maxx, x);
+			maxy = MAX (maxy, y);
+		}
+
+		ev_link_mapping->x1 = minx;
+		ev_link_mapping->x2 = maxx;
+		ev_link_mapping->y1 = (page_info->height - maxy);
+		ev_link_mapping->y2 = (page_info->height - miny);
+	} else {
+		/* unknown */
+		goto unknown_link;
+	}
+
+	return TRUE;
+	
+ unknown_link:
+	g_warning("DjvuLibre error: Unknown hyperlink area %s", miniexp_to_name(miniexp_car(sexp)));
+	return FALSE;
+}
+
+static EvLinkMapping *
+get_djvu_hyperlink_mapping (DjvuDocument     *djvu_document,
+			    int               page,
+			    ddjvu_pageinfo_t *page_info,
+			    miniexp_t         sexp)
+{
+	EvLinkMapping *ev_link_mapping = NULL;
+	EvLinkAction *ev_action = NULL;
+	miniexp_t iter;
+	const char *url, *url_target, *comment;
+
+	ev_link_mapping = g_new (EvLinkMapping, 1);
+
+	iter = sexp;
+
+	if (miniexp_car (iter) != miniexp_symbol ("maparea")) goto unknown_mapping;
+
+	iter = miniexp_cdr(iter);
+
+	if (miniexp_caar(iter) == miniexp_symbol("url")) {
+		if (!string_from_miniexp (miniexp_cadr (miniexp_car (iter)), &url)) goto unknown_mapping;
+		if (!string_from_miniexp (miniexp_caddr (miniexp_car (iter)), &url_target)) goto unknown_mapping;
+	} else {
+		if (!string_from_miniexp (miniexp_car(iter), &url)) goto unknown_mapping;
+		url_target = NULL;
+	}
+
+	iter = miniexp_cdr (iter);
+	if (!string_from_miniexp (miniexp_car(iter), &comment)) goto unknown_mapping;
+
+	iter = miniexp_cdr (iter);
+	if (!get_djvu_hyperlink_area (page_info, miniexp_car(iter), ev_link_mapping)) goto unknown_mapping;
+
+	iter = miniexp_cdr (iter);
+	/* FIXME: DjVu hyperlink attributes are ignored */
+
+	ev_action = get_djvu_link_action (djvu_document, url, page);
+	if (!ev_action) goto unknown_mapping;
+
+	ev_link_mapping->link = ev_link_new (comment, ev_action);
+			
+	return ev_link_mapping;
+
+ unknown_mapping:
+	if (ev_link_mapping) g_free(ev_link_mapping);
+	g_warning("DjvuLibre error: Unknown hyperlink %s", miniexp_to_name(miniexp_car(sexp)));
+	return NULL;
+}
+
+
+gboolean
+djvu_links_has_document_links (EvDocumentLinks *document_links)
+{
+	DjvuDocument *djvu_document = DJVU_DOCUMENT (document_links);
+	miniexp_t outline;
+
+	while ((outline = ddjvu_document_get_outline (djvu_document->d_document)) == miniexp_dummy)
+		djvu_handle_events (djvu_document, TRUE);
+
+	if (outline) {
+		ddjvu_miniexp_release (djvu_document->d_document, outline);
+		return TRUE;
+	}
+	
+	return FALSE;
+}
+
+GList *
+djvu_links_get_links (EvDocumentLinks *document_links,
+                      gint             page,
+                      double           scale_factor)
+{
+	DjvuDocument *djvu_document = DJVU_DOCUMENT (document_links);
+	GList *retval = NULL;
+	miniexp_t page_annotations = miniexp_nil;
+	miniexp_t *hyperlinks = NULL, *iter = NULL;
+	EvLinkMapping *ev_link_mapping;
+        ddjvu_pageinfo_t page_info;
+
+	while ((page_annotations = ddjvu_document_get_pageanno (djvu_document->d_document, page)) == miniexp_dummy)
+		djvu_handle_events (djvu_document, TRUE);
+
+	while (ddjvu_document_get_pageinfo (djvu_document->d_document, page, &page_info) < DDJVU_JOB_OK)
+		djvu_handle_events(djvu_document, TRUE);
+
+	if (page_annotations) {
+		hyperlinks = ddjvu_anno_get_hyperlinks (page_annotations);
+		if (hyperlinks) {
+			for (iter = hyperlinks; *iter; ++iter) {
+				ev_link_mapping = get_djvu_hyperlink_mapping (djvu_document, page, &page_info, *iter);
+				if (ev_link_mapping) {
+					ev_link_mapping->x1 *= scale_factor;
+					ev_link_mapping->x2 *= scale_factor;
+					ev_link_mapping->y1 *= scale_factor;
+					ev_link_mapping->y2 *= scale_factor;
+					retval = g_list_prepend (retval, ev_link_mapping);
+				}
+			}
+			free (hyperlinks);
+		}
+		ddjvu_miniexp_release (djvu_document->d_document, page_annotations);
+	}
+	
+	return retval;
+}
+
+EvLinkDest *
+djvu_links_find_link_dest (EvDocumentLinks  *document_links,
+                           const gchar      *link_name)
+{
+	DjvuDocument *djvu_document = DJVU_DOCUMENT (document_links);
+	EvLinkDest *ev_dest = NULL;
+	
+	ev_dest = get_djvu_link_dest (DJVU_DOCUMENT (document_links), link_name, -1);
+
+	if (!ev_dest) {
+		g_warning ("DjvuLibre error: unknown link destination %s", link_name);
+	}
+	
+	return ev_dest;
+}
+
+GtkTreeModel *
+djvu_links_get_links_model (EvDocumentLinks *document_links)
+{
+	DjvuDocument *djvu_document = DJVU_DOCUMENT (document_links);
+	GtkTreeModel *model = NULL;
+	miniexp_t outline = miniexp_nil;
+
+	while ((outline = ddjvu_document_get_outline (djvu_document->d_document)) == miniexp_dummy)
+		djvu_handle_events (djvu_document, TRUE);
+
+	if (outline) {
+		model = (GtkTreeModel *) gtk_tree_store_new (EV_DOCUMENT_LINKS_COLUMN_NUM_COLUMNS,
+							     G_TYPE_STRING,
+							     G_TYPE_OBJECT,
+							     G_TYPE_BOOLEAN);
+		build_tree (djvu_document, model, NULL, outline);
+
+		ddjvu_miniexp_release (djvu_document->d_document, outline);
+	}
+	
+	return model;
+}
diff --git a/djvu/djvu-links.h b/djvu/djvu-links.h
new file mode 100644
index 0000000..fdbfdeb
--- /dev/null
+++ b/djvu/djvu-links.h
@@ -0,0 +1,35 @@
+/* 
+ * Copyright (C) 2006 Pauli Virtanen <pav@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __DJVU_LINK_H__
+#define __DJVU_LINK_H__
+
+#include "ev-document-links.h"
+#include "djvu-document.h"
+
+#include <glib.h>
+
+GtkTreeModel *djvu_links_get_links_model    (EvDocumentLinks *document_links);
+GList        *djvu_links_get_links          (EvDocumentLinks *document_links,
+                                             gint             page,
+                                             double           scale_factor);
+EvLinkDest   *djvu_links_find_link_dest     (EvDocumentLinks *document_links,
+                                             const gchar     *link_name);
+gboolean      djvu_links_has_document_links (EvDocumentLinks *document_links);
+
+#endif /* __DJVU_LINK_H__ */