Track changes in FontMaps using a serial

This adds the pango_font_map_get_serial method that lets you see
if a fontmap has changes since the last check. It adds implementations
to all current fontmaps.

https://bugzilla.gnome.org/show_bug.cgi?id=340066

1 files changed, 24 insertions, 1 deletions

diff --git a/pango/pangoxft-fontmap.c b/pango/pangoxft-fontmap.c
index 9d210b50..aa891c54 100644
--- a/pango/pangoxft-fontmap.c
+++ b/pango/pangoxft-fontmap.c
@@ -41,6 +41,8 @@ struct _PangoXftFontMap
 {
   PangoFcFontMap parent_instance;
 
+  guint serial;
+
   Display *display;
   int screen;
 
@@ -59,6 +61,7 @@ struct _PangoXftFontMapClass
   PangoFcFontMapClass parent_class;
 };
 
+static guint         pango_xft_font_map_get_serial         (PangoFontMap         *fontmap);
 static void          pango_xft_font_map_default_substitute (PangoFcFontMap       *fcfontmap,
 							    FcPattern            *pattern);
 static PangoFcFont * pango_xft_font_map_new_font           (PangoFcFontMap       *fcfontmap,
@@ -74,16 +77,21 @@ static void
 pango_xft_font_map_class_init (PangoXftFontMapClass *class)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
+  PangoFontMapClass *fontmap_class = PANGO_FONT_MAP_CLASS (class);
   PangoFcFontMapClass *fcfontmap_class = PANGO_FC_FONT_MAP_CLASS (class);
 
   gobject_class->finalize  = pango_xft_font_map_finalize;
+
+  fontmap_class->get_serial = pango_xft_font_map_get_serial;
+
   fcfontmap_class->default_substitute = pango_xft_font_map_default_substitute;
   fcfontmap_class->new_font = pango_xft_font_map_new_font;
 }
 
 static void
-pango_xft_font_map_init (PangoXftFontMap *xftfontmap G_GNUC_UNUSED)
+pango_xft_font_map_init (PangoXftFontMap *xftfontmap)
 {
+  xftfontmap->serial = 1;
 }
 
 static void
@@ -105,6 +113,14 @@ pango_xft_font_map_finalize (GObject *object)
 }
 
 
+static guint
+pango_xft_font_map_get_serial (PangoFontMap *fontmap)
+{
+  PangoXftFontMap *xftfontmap = PANGO_XFT_FONT_MAP (fontmap);
+
+  return xftfontmap->serial;
+}
+
 static PangoFontMap *
 pango_xft_find_font_map (Display *display,
 			 int      screen)
@@ -283,6 +299,10 @@ pango_xft_set_default_substitute (Display                *display,
 {
   PangoXftFontMap *xftfontmap = (PangoXftFontMap *)pango_xft_get_font_map (display, screen);
 
+  xftfontmap->serial++;
+  if (xftfontmap->serial == 0)
+    xftfontmap->serial++;
+
   if (xftfontmap->substitute_destroy)
     xftfontmap->substitute_destroy (xftfontmap->substitute_data);
 
@@ -312,6 +332,9 @@ pango_xft_substitute_changed (Display *display,
 {
   PangoXftFontMap *xftfontmap = (PangoXftFontMap *)pango_xft_get_font_map (display, screen);
 
+  xftfontmap->serial++;
+  if (xftfontmap->serial == 0)
+    xftfontmap->serial++;
   pango_fc_font_map_cache_clear (PANGO_FC_FONT_MAP (xftfontmap));
 }