[evince] font properties: say whether fonts are pdf standard

[Carlos Garcia Campos <carlosgc src gnome org>]

commit bda8ab9cfb8c1b808ab22c5059e530b10ffed0e0
Author: Alban Crequy <alban crequy collabora co uk>
Date:   Tue Nov 27 18:07:57 2012 +0000

    font properties: say whether fonts are pdf standard
    
    In the font property dialog, say for each non-embedded font whether it is one
    of the 14 standard fonts.
    
    Backends can also implement get_fonts_summary() to return a summary line to
    display before the tree view to say whether there is any non-embedded and
    non-standard font.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=527222

 backend/pdf/ev-poppler.cc       |   85 +++++++++++++++++++++++++++++++++++---
 libdocument/ev-document-fonts.c |   11 +++++
 libdocument/ev-document-fonts.h |   26 ++++++-----
 shell/ev-properties-fonts.c     |   24 ++++++++++-
 4 files changed, 126 insertions(+), 20 deletions(-)
---
diff --git a/backend/pdf/ev-poppler.cc b/backend/pdf/ev-poppler.cc
index 6f29caa..e8f36c6 100644
--- a/backend/pdf/ev-poppler.cc
+++ b/backend/pdf/ev-poppler.cc
@@ -106,6 +106,7 @@ struct _PdfDocument
 	PopplerFontInfo *font_info;
 	PopplerFontsIter *fonts_iter;
 	int fonts_scanned_pages;
+	gboolean missing_fonts;
 
 	PdfPrintContext *print_ctx;
 
@@ -1047,6 +1048,54 @@ font_type_to_string (PopplerFontType type)
 	}
 }
 
+static gboolean
+is_standard_font (const gchar *name, PopplerFontType type)
+{
+	/* list borrowed from Poppler: poppler/GfxFont.cc */
+	static const char *base_14_subst_fonts[14] = {
+	  "Courier",
+	  "Courier-Oblique",
+	  "Courier-Bold",
+	  "Courier-BoldOblique",
+	  "Helvetica",
+	  "Helvetica-Oblique",
+	  "Helvetica-Bold",
+	  "Helvetica-BoldOblique",
+	  "Times-Roman",
+	  "Times-Italic",
+	  "Times-Bold",
+	  "Times-BoldItalic",
+	  "Symbol",
+	  "ZapfDingbats"
+	};
+	unsigned int i;
+
+	/* The Standard 14 fonts are all Type 1 fonts. A non embedded TrueType
+	 * font with the same name is not a Standard 14 font. */
+	if (type != POPPLER_FONT_TYPE_TYPE1)
+		return FALSE;
+
+	for (i = 0; i < G_N_ELEMENTS (base_14_subst_fonts); i++) {
+		if (g_str_equal (name, base_14_subst_fonts[i]))
+			return TRUE;
+	}
+	return FALSE;
+}
+
+static const gchar *
+pdf_document_fonts_get_fonts_summary (EvDocumentFonts *document_fonts)
+{
+	PdfDocument *pdf_document = PDF_DOCUMENT (document_fonts);
+
+	if (pdf_document->missing_fonts)
+		return _("This document contains non-embedded fonts that are not from the "
+			 "PDF Standard 14 fonts. If the substitute fonts selected by fontconfig "
+			 "are not the same as the fonts used to create the PDF, the rendering may "
+			 "not be correct.");
+	else
+		return _("All fonts are either standard or embedded.");
+}
+
 static void
 pdf_document_fonts_fill_model (EvDocumentFonts *document_fonts,
 			       GtkTreeModel    *model)
@@ -1062,8 +1111,10 @@ pdf_document_fonts_fill_model (EvDocumentFonts *document_fonts,
 	do {
 		GtkTreeIter list_iter;
 		const char *name;
-		const char *type;
+		PopplerFontType type;
+		const char *type_str;
 		const char *embedded;
+		const char *standard_str = "";
 		const gchar *substitute;
 		const gchar *substitute_text;
 		const gchar *filename;
@@ -1081,8 +1132,8 @@ pdf_document_fonts_fill_model (EvDocumentFonts *document_fonts,
 		if (!encoding)
 			encoding = _("None");
 
-		type = font_type_to_string (
-			poppler_fonts_iter_get_font_type (iter));
+		type = poppler_fonts_iter_get_font_type (iter);
+		type_str = font_type_to_string (type);
 
 		if (poppler_fonts_iter_is_embedded (iter)) {
 			if (poppler_fonts_iter_is_subset (iter))
@@ -1091,19 +1142,38 @@ pdf_document_fonts_fill_model (EvDocumentFonts *document_fonts,
 				embedded = _("Embedded");
 		} else {
 			embedded = _("Not embedded");
+			if (is_standard_font (name, type)) {
+				/* Translators: string starting with a space
+				 * because it is directly appended to the font
+				 * type. Example:
+				 * "Type 1 (One of the Standard 14 Fonts)"
+				 */
+				standard_str = _(" (One of the Standard 14 Fonts)");
+			} else {
+				/* Translators: string starting with a space
+				 * because it is directly appended to the font
+				 * type. Example:
+				 * "TrueType (Not one of the Standard 14 Fonts)"
+				 */
+				standard_str = _(" (Not one of the Standard 14 Fonts)");
+				pdf_document->missing_fonts = TRUE;
+			}
 		}
 
 		substitute = poppler_fonts_iter_get_substitute_name (iter);
 		filename = poppler_fonts_iter_get_file_name (iter);
 		encoding_text = _("Encoding");
-		substitute_text = _("substituting with");
+		substitute_text = _("Substituting with");
 
 		if (substitute && filename)
-			details = g_markup_printf_escaped ("%s\n%s: %s\n%s, %s <b>%s</b>\n(%s)",
-							   type, encoding_text, encoding, embedded,
+			details = g_markup_printf_escaped ("%s%s\n%s: %s\n%s\n%s <b>%s</b>\n(%s)",
+							   type_str, standard_str,
+							   encoding_text, encoding, embedded,
 							   substitute_text, substitute, filename);
 		else
-			details = g_markup_printf_escaped ("%s\n%s: %s\n%s", type, encoding_text, encoding, embedded);
+			details = g_markup_printf_escaped ("%s%s\n%s: %s\n%s",
+							   type_str, standard_str,
+							   encoding_text, encoding, embedded);
 
 		gtk_list_store_append (GTK_LIST_STORE (model), &list_iter);
 		gtk_list_store_set (GTK_LIST_STORE (model), &list_iter,
@@ -1119,6 +1189,7 @@ static void
 pdf_document_document_fonts_iface_init (EvDocumentFontsInterface *iface)
 {
 	iface->fill_model = pdf_document_fonts_fill_model;
+	iface->get_fonts_summary = pdf_document_fonts_get_fonts_summary;
 	iface->scan = pdf_document_fonts_scan;
 	iface->get_progress = pdf_document_fonts_get_progress;
 }
diff --git a/libdocument/ev-document-fonts.c b/libdocument/ev-document-fonts.c
index 7622f72..8587625 100644
--- a/libdocument/ev-document-fonts.c
+++ b/libdocument/ev-document-fonts.c
@@ -57,3 +57,14 @@ ev_document_fonts_fill_model (EvDocumentFonts *document_fonts,
 
 	iface->fill_model (document_fonts, model);
 }
+
+const gchar *
+ev_document_fonts_get_fonts_summary (EvDocumentFonts *document_fonts)
+{
+	EvDocumentFontsInterface *iface = EV_DOCUMENT_FONTS_GET_IFACE (document_fonts);
+
+        if (!iface->get_fonts_summary)
+                return NULL;
+
+	return iface->get_fonts_summary (document_fonts);
+}
diff --git a/libdocument/ev-document-fonts.h b/libdocument/ev-document-fonts.h
index 8cabe35..4edc92d 100644
--- a/libdocument/ev-document-fonts.h
+++ b/libdocument/ev-document-fonts.h
@@ -58,20 +58,22 @@ struct _EvDocumentFontsInterface
 {
 	GTypeInterface base_iface;
 
-	/* Methods */
-	gboolean (* scan)         (EvDocumentFonts *document_fonts,
-				   int              n_pages);
-	double   (* get_progress) (EvDocumentFonts *document_fonts);
-	void     (* fill_model)   (EvDocumentFonts *document_fonts,
-				   GtkTreeModel    *model);
+        /* Methods */
+        gboolean     (* scan)              (EvDocumentFonts *document_fonts,
+                                            int              n_pages);
+        double       (* get_progress)      (EvDocumentFonts *document_fonts);
+        void         (* fill_model)        (EvDocumentFonts *document_fonts,
+                                            GtkTreeModel    *model);
+        const gchar *(* get_fonts_summary) (EvDocumentFonts *document_fonts);
 };
 
-GType     ev_document_fonts_get_type     (void);
-gboolean  ev_document_fonts_scan         (EvDocumentFonts *document_fonts,
-				          int              n_pages);
-double	  ev_document_fonts_get_progress (EvDocumentFonts *document_fonts);
-void      ev_document_fonts_fill_model   (EvDocumentFonts *document_fonts,
-				          GtkTreeModel    *model);
+GType        ev_document_fonts_get_type          (void);
+gboolean     ev_document_fonts_scan              (EvDocumentFonts *document_fonts,
+                                                  int              n_pages);
+double       ev_document_fonts_get_progress      (EvDocumentFonts *document_fonts);
+void         ev_document_fonts_fill_model        (EvDocumentFonts *document_fonts,
+                                                  GtkTreeModel    *model);
+const gchar *ev_document_fonts_get_fonts_summary (EvDocumentFonts *document_fonts);
 
 G_END_DECLS
 
diff --git a/shell/ev-properties-fonts.c b/shell/ev-properties-fonts.c
index bb2c24f..f4d4438 100644
--- a/shell/ev-properties-fonts.c
+++ b/shell/ev-properties-fonts.c
@@ -35,6 +35,7 @@ struct _EvPropertiesFonts {
 
 	GtkWidget *fonts_treeview;
 	GtkWidget *fonts_progress_label;
+	GtkWidget *fonts_summary;
 	EvJob     *fonts_job;
 
 	EvDocument *document;
@@ -112,10 +113,19 @@ ev_properties_fonts_init (EvPropertiesFonts *properties)
 	gtk_container_set_border_width (GTK_CONTAINER (properties), 12);
 	gtk_box_set_spacing (GTK_BOX (properties), 6);
 	
+	properties->fonts_summary = gtk_label_new (NULL);
+	g_object_set (G_OBJECT (properties->fonts_summary),
+		      "xalign", 0.0,
+		      NULL);
+	gtk_label_set_line_wrap (GTK_LABEL (properties->fonts_summary), TRUE);
+	gtk_box_pack_start (GTK_BOX (properties),
+			    properties->fonts_summary,
+			    FALSE, FALSE, 0);
+
 	swindow = gtk_scrolled_window_new (NULL, NULL);
 	gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (swindow),
 					     GTK_SHADOW_IN);
-	
+
 	properties->fonts_treeview = gtk_tree_view_new ();
 	gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (properties->fonts_treeview),
 					   FALSE);
@@ -169,9 +179,21 @@ update_progress_label (GtkWidget *label, double progress)
 static void
 job_fonts_finished_cb (EvJob *job, EvPropertiesFonts *properties)
 {
+	EvDocumentFonts *document_fonts = EV_DOCUMENT_FONTS (properties->document);
+	const gchar     *font_summary;
+
 	g_signal_handlers_disconnect_by_func (job, job_fonts_finished_cb, properties);
 	g_object_unref (properties->fonts_job);
 	properties->fonts_job = NULL;
+
+	font_summary = ev_document_fonts_get_fonts_summary (document_fonts);
+	if (font_summary) {
+		gtk_label_set_text (GTK_LABEL (properties->fonts_summary),
+				    font_summary);
+		/* show the label only when fonts are scanned, so the label
+		 * does not take space while it is loading */
+		gtk_widget_show (properties->fonts_summary);
+	}
 }
 
 static void