io-svg.c: add "incremental load" scaffolding.

diff --git a/io-svg.c b/io-svg.c
index 13b692b2be1a93a68b59ae59228bdd4065032440..2d509c62b5b38319ea42399c26c86d9b440e2591 100644 (file)
--- a/io-svg.c
+++ b/io-svg.c
@@ -21,6 +21,14 @@ typedef struct svgtiny_diagram diagram_t;
 typedef struct svgtiny_shape shape_t;
 
 
+typedef struct {
+  GdkPixbufModuleUpdatedFunc  updated_func;
+  GdkPixbufModulePreparedFunc prepared_func;
+  GdkPixbufModuleSizeFunc     size_func;
+  gpointer                    user_data;
+} SvgTinyContext;
+
+
 /**
  * @brief Render an svgtiny path using cairo.
  *
@@ -303,8 +311,77 @@ static GdkPixbuf* gdk_pixbuf_from_svg_file_stream(FILE *fp, GError** error) {
 }
 
 
+static gpointer gdk_pixbuf_begin_load(GdkPixbufModuleSizeFunc size_func,
+                                     GdkPixbufModulePreparedFunc prep_func,
+                                     GdkPixbufModuleUpdatedFunc updated_func,
+                                     gpointer user_data,
+                                     GError **error)
+{
+        SvgTinyContext* context    = g_new0(SvgTinyContext, 1);
+
+        context->size_func     = size_func;
+        context->prepared_func = prep_func;
+        context->updated_func  = updated_func;
+        context->user_data     = user_data;
+
+        return context;
+}
+
+static gboolean gdk_pixbuf_load_increment(gpointer data,
+                                         const guchar* buf,
+                                         guint size,
+                                         GError** error) {
+  SvgTinyContext* context = (SvgTinyContext*)data;
+  /*
+  if (!rsvg_handle_write (context->handle, buf, size, error)) {
+    rsvg_propagate_error (error, _("Error writing"), ERROR_WRITING);
+    return FALSE;
+  }
+  */
+  return TRUE;
+}
+
+static void emit_updated(SvgTinyContext* context, GdkPixbuf* pixbuf) {
+  if (context->updated_func != NULL) {
+    (*context->updated_func)(pixbuf,
+                            0,
+                            0,
+                            gdk_pixbuf_get_width(pixbuf),
+                            gdk_pixbuf_get_height(pixbuf),
+                            context->user_data);
+  }
+}
+
+static void emit_prepared(SvgTinyContext* context, GdkPixbuf* pixbuf) {
+  if (context->prepared_func != NULL) {
+    (*context->prepared_func)(pixbuf, NULL, context->user_data);
+  }
+}
+
+static gboolean gdk_pixbuf_stop_load(gpointer data, GError **error) {
+  SvgTinyContext* context = (SvgTinyContext*)data;
+  GdkPixbuf* pixbuf = NULL;
+  gboolean result = TRUE;
+
+  if (pixbuf != NULL) {
+    emit_prepared(context, pixbuf);
+    emit_updated(context, pixbuf);
+    g_object_unref(pixbuf);
+  }
+  else {
+    result = FALSE;
+  }
+  g_free (context);
+
+  return result;
+}
+
+
 G_MODULE_EXPORT void fill_vtable(GdkPixbufModule* module);
 void fill_vtable(GdkPixbufModule* module) {
+  module->begin_load = gdk_pixbuf_begin_load;
+  module->load_increment = gdk_pixbuf_load_increment;
+  module->stop_load = gdk_pixbuf_stop_load;
   module->load = gdk_pixbuf_from_svg_file_stream;
 }