First Commit

libui-ng/unix/future.c

@@ -0,0 +1,60 @@
+// 29 june 2016
+#include "uipriv_unix.h"
+
+// functions FROM THE FUTURE!
+// in some cases, because being held back by LTS releases sucks :/
+// in others, because parts of GTK+ being unstable until recently also sucks :/
+
+// added in pango 1.38; we need 1.36
+static PangoAttribute *(*newFeaturesAttr)(const gchar *features) = NULL;
+static PangoAttribute *(*newFGAlphaAttr)(guint16 alpha) = NULL;
+static PangoAttribute *(*newBGAlphaAttr)(guint16 alpha) = NULL;
+
+// added in GTK+ 3.20; we need 3.10
+static void (*gwpIterSetObjectName)(GtkWidgetPath *path, gint pos, const char *name) = NULL;
+
+// note that we treat any error as "the symbols aren't there" (and don't care if dlclose() failed)
+void uiprivLoadFutures(void)
+{
+	void *handle;
+
+	// dlsym() walks the dependency chain, so opening the current process should be sufficient
+	handle = dlopen(NULL, RTLD_LAZY);
+	if (handle == NULL)
+		return;
+#define GET(var, fn) *((void **) (&var)) = dlsym(handle, #fn)
+	GET(newFeaturesAttr, pango_attr_font_features_new);
+	GET(newFGAlphaAttr, pango_attr_foreground_alpha_new);
+	GET(newBGAlphaAttr, pango_attr_background_alpha_new);
+	GET(gwpIterSetObjectName, gtk_widget_path_iter_set_object_name);
+	dlclose(handle);
+}
+
+PangoAttribute *uiprivFUTURE_pango_attr_font_features_new(const gchar *features)
+{
+	if (newFeaturesAttr == NULL)
+		return NULL;
+	return (*newFeaturesAttr)(features);
+}
+
+PangoAttribute *uiprivFUTURE_pango_attr_foreground_alpha_new(guint16 alpha)
+{
+	if (newFGAlphaAttr == NULL)
+		return NULL;
+	return (*newFGAlphaAttr)(alpha);
+}
+
+PangoAttribute *uiprivFUTURE_pango_attr_background_alpha_new(guint16 alpha)
+{
+	if (newBGAlphaAttr == NULL)
+		return NULL;
+	return (*newBGAlphaAttr)(alpha);
+}
+
+gboolean uiprivFUTURE_gtk_widget_path_iter_set_object_name(GtkWidgetPath *path, gint pos, const char *name)
+{
+	if (gwpIterSetObjectName == NULL)
+		return FALSE;
+	(*gwpIterSetObjectName)(path, pos, name);
+	return TRUE;
+}