Inverted colors(night) viewing mode for ePub

Added the capability to view and epub document with inverted colors, yet to test for documents where we write the stylesheet, although the code is there.

1 files changed, 135 insertions, 0 deletions

diff --git a/backend/epub/epub-document.c b/backend/epub/epub-document.c
index d0dce118..9caa8432 100644
--- a/backend/epub/epub-document.c
+++ b/backend/epub/epub-document.c
@@ -1267,6 +1267,139 @@ epub_document_get_page(EvDocument *document,
 	return page ;
 }
 
+static void
+change_to_night_sheet(contentListNode *nodedata,gpointer user_data)
+{
+    gchar *filename = g_filename_from_uri(nodedata->value,NULL,NULL);
+    open_xml_document(filename);
+    set_xml_root_node(NULL);
+    xmlNodePtr head =xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"rel",(xmlChar*)"stylesheet");
+
+    xmlNodePtr day = xmlretval;
+    xmlSetProp(day,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"night");
+    xmlSetProp(xmlretval,(xmlChar*)"rel",(xmlChar*)"stylesheet");
+    xmlSaveFormatFile (filename, xmldocument, 0);
+    xml_free_doc();
+    g_free(filename);
+}
+
+static void
+change_to_day_sheet(contentListNode *nodedata,gpointer user_data)
+{
+    gchar *filename = g_filename_from_uri(nodedata->value,NULL,NULL);
+    open_xml_document(filename);
+    set_xml_root_node(NULL);
+    xmlNodePtr head =xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"rel",(xmlChar*)"stylesheet");
+
+    xmlNodePtr day = xmlretval;
+    xmlSetProp(day,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"day");
+    xmlSetProp(xmlretval,(xmlChar*)"rel",(xmlChar*)"stylesheet");
+    xmlSaveFormatFile (filename, xmldocument, 0);
+    xml_free_doc();
+    g_free(filename);
+}
+
+static gchar*
+epub_document_get_alternate_stylesheet(gchar *docuri)
+{
+    gchar *filename = g_filename_from_uri(docuri,NULL,NULL);
+    open_xml_document(filename);
+
+    set_xml_root_node(NULL);
+
+    xmlNodePtr head= xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+
+    xmlretval = NULL;
+
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"night");
+
+    if (xmlretval != NULL) {
+        return (gchar*)xml_get_data_from_node(xmlretval,XML_ATTRIBUTE,(xmlChar*)"href");
+    }
+    g_free(filename);
+    xml_free_doc();
+    return NULL;
+}
+
+static void
+add_night_sheet(contentListNode *listdata,gchar *sheet)
+{
+    gchar *sheeturi = g_filename_to_uri(sheet,NULL,NULL);
+    open_xml_document(listdata->value);
+
+    set_xml_root_node(NULL);
+    xmlNodePtr head = xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+    
+    xmlNodePtr link = xmlNewTextChild(head,NULL,(xmlChar*)"link",NULL);
+    xmlAttrPtr href = xmlNewProp(link,(xmlChar*)"href",(xmlChar*)sheeturi);
+    xmlAttrPtr rel = xmlNewProp(link,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+    xmlAttrPtr class =  xmlNewProp(link,(xmlChar*)"class",(xmlChar*)"night");
+
+    xmlSaveFormatFile (listdata->value, xmldocument, 0);
+    xml_free_doc();
+    g_free(sheeturi);
+}
+
+static void
+epub_document_check_add_night_sheet(EvDocument *document)
+{
+    EpubDocument *epub_document = EPUB_DOCUMENT(document);
+
+    g_return_if_fail(EPUB_IS_DOCUMENT(epub_document));
+
+    /*
+     * We'll only check the first page for a supplied night mode stylesheet.
+     * Odds are, if this one has it, all others have it too.
+     */
+	contentListNode *node = epub_document->contentList->data;
+    gchar* stylesheetfilename = epub_document_get_alternate_stylesheet((gchar*)node->value) ;
+
+    if (stylesheetfilename == NULL) {
+        gchar *style = "body {color:rgb(255,255,255);background-color:rgb(0,0,0);text-align:justify;line-spacing:1.8; margin-top:0px;margin-bottom:4px;margin-right:50px;\
+        margin-left:50px;text-indent:3em;";
+
+        gchar *csspath = g_strdup_printf("%s/atrilnightstyle.css",epub_document->documentdir);
+
+        
+        GFile *styles = g_file_new_for_path (csspath);
+        GOutputStream *outstream = (GOutputStream*)g_file_create(styles,G_FILE_CREATE_PRIVATE,NULL,NULL);
+        if ( g_output_stream_write((GOutputStream*)outstream,style,strlen(style),NULL,NULL) == -1 )
+        {
+            return ;
+        }
+        g_output_stream_close((GOutputStream*)outstream,NULL,NULL);
+        g_object_unref(styles) ;
+        g_object_unref(outstream) ;
+        //add this stylesheet to each document, for later.
+        g_list_foreach(epub_document->contentList,(GFunc)add_night_sheet,csspath);
+        g_free(csspath);
+    }
+    g_free(stylesheetfilename);
+}
+
+static void
+epub_document_toggle_night_mode(EvDocument *document,gboolean night)
+{
+    EpubDocument *epub_document = EPUB_DOCUMENT(document);
+
+    g_return_if_fail(EPUB_IS_DOCUMENT(epub_document));
+    if (night) 
+        g_list_foreach(epub_document->contentList,(GFunc)change_to_night_sheet,NULL);
+    else
+        g_list_foreach(epub_document->contentList,(GFunc)change_to_day_sheet,NULL);
+}
 
 static gboolean
 epub_document_load (EvDocument* document,
@@ -1388,4 +1521,6 @@ epub_document_class_init (EpubDocumentClass *klass)
 	ev_document_class->get_n_pages = epub_document_get_n_pages;
 	ev_document_class->get_info = epub_document_get_info; 
 	ev_document_class->get_page = epub_document_get_page;
+	ev_document_class->toggle_night_mode = epub_document_toggle_night_mode;
+    ev_document_class->check_add_night_sheet = epub_document_check_add_night_sheet;
 }
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