ui: use envvar to activate debug prints if enabled at configure

3 files changed, 22 insertions, 2 deletions

diff --git a/README b/README
index 9622923..d658ac5 100644
--- a/README
+++ b/README
@@ -79,6 +79,12 @@ make some noise:
 Instead of the UI one can also use netcat again:
   netcat -l -p 8765 127.0.0.1
   netcat -l 127.0.0.1 8765
+  
+If the package is configured with --enable-trace one can get debug prints from the UI:
+  GSTTLUI_DEBUG=1 gsttlui
+  
+If the UI crashes it is most likely grphviz :/
+graphviz version 2.26.3 (20100126.1600)
 
 === In the future ===
 pygtk ui using mathplotlib
diff --git a/src/ui/gsttlui.c b/src/ui/gsttlui.c
index 0f5cee5..d4020e7 100644
--- a/src/ui/gsttlui.c
+++ b/src/ui/gsttlui.c
@@ -57,7 +57,10 @@ on_window_destroy (GtkWidget *widget, gpointer user_data)
 }
 
 #ifdef ENABLE_TRACE
-void _log_printf(const gchar *file, guint line, const gchar *func, const gchar *fmt,...) {
+
+void (*_log_printf)(const gchar *file, guint line, const gchar *func, const gchar *fmt,...);
+
+static void _log_printf_stdout(const gchar *file, guint line, const gchar *func, const gchar *fmt,...) {
     va_list args;
 
     va_start(args, fmt);
@@ -67,6 +70,9 @@ void _log_printf(const gchar *file, guint line, const gchar *func, const gchar *
     fflush(stdout);
     va_end(args);
 }
+
+static void _log_printf_null(const gchar *file, guint line, const gchar *func, const gchar *fmt,...) {
+}
 #endif
 
 gint
@@ -99,6 +105,14 @@ main (gint argc, gchar *argv[])
     g_option_context_free (ctx);
     exit (1);
   }
+  
+#ifdef ENABLE_TRACE
+  if (getenv("GSTTLUI_DEBUG")) {
+    _log_printf = _log_printf_stdout;
+  } else {
+    _log_printf = _log_printf_null;
+  }
+#endif
 
   /* take log filename from remaining args if there are any and we have no
    * filename yet */
diff --git a/src/ui/gsttlui.h b/src/ui/gsttlui.h
index 920e938..1a6e56e 100644
--- a/src/ui/gsttlui.h
+++ b/src/ui/gsttlui.h
@@ -107,7 +107,7 @@ extern GQuark log_event_type_topo_link_rem;
 
 /* debug logging */
 #ifdef ENABLE_TRACE
-extern void _log_printf(const gchar *file, const guint line, const gchar *func, const gchar *fmt, ...);
+extern void (*_log_printf)(const gchar *file, const guint line, const gchar *func, const gchar *fmt, ...);
 #  define TRACE(...) _log_printf(__FILE__,__LINE__,__FUNCTION__,__VA_ARGS__)
 #else
 #  define TRACE(...)