From 4bc704d7e3b1a03d5112327d55948ca375e427f8 Mon Sep 17 00:00:00 2001
From: David Sansome <davidsansome@gmail.com>
Date: Mon, 19 Apr 2010 12:04:35 +0000
Subject: [PATCH] Actually show error messages that come from gstreamer.  Fixes
 issue #230

---
 src/engines/gstengine.cpp         |  2 ++
 src/engines/gstenginepipeline.cpp | 32 +++++++++++++++++++------------
 src/engines/gstenginepipeline.h   |  2 ++
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/engines/gstengine.cpp b/src/engines/gstengine.cpp
index 403cb3339..2007fd3a0 100644
--- a/src/engines/gstengine.cpp
+++ b/src/engines/gstengine.cpp
@@ -435,6 +435,8 @@ void GstEngine::HandlePipelineError(const QString& message) {
   qWarning() << "Gstreamer error:" << message;
 
   current_pipeline_.reset();
+  emit Error(message);
+  emit StateChanged(Engine::Empty);
 }
 
 
diff --git a/src/engines/gstenginepipeline.cpp b/src/engines/gstenginepipeline.cpp
index 4f1630f2d..7cca4531a 100644
--- a/src/engines/gstenginepipeline.cpp
+++ b/src/engines/gstenginepipeline.cpp
@@ -72,8 +72,8 @@ bool GstEnginePipeline::Init(const QUrl &url) {
   } else {
     src_ = GstEngine::CreateElement("giosrc");
   }
-  if (!src_)
-    return false;
+  if (!src_)      // CreateElement will have shown an error dialog, so no need
+    return false; // one of our own.
 
   g_object_set(G_OBJECT(src_), "location", url.toEncoded().constData(), NULL);
   gst_bin_add(GST_BIN(pipeline_), src_);
@@ -135,7 +135,7 @@ bool GstEnginePipeline::Init(const QUrl &url) {
                         audioscale_, convert, audiosink_, NULL);
 
   gst_bus_set_sync_handler(gst_pipeline_get_bus(GST_PIPELINE(pipeline_)), BusCallbackSync, this);
-  gst_bus_add_watch(gst_pipeline_get_bus(GST_PIPELINE(pipeline_)), BusCallback, this);
+  bus_cb_id_ = gst_bus_add_watch(gst_pipeline_get_bus(GST_PIPELINE(pipeline_)), BusCallback, this);
 
   return true;
 }
@@ -149,6 +149,8 @@ GstEnginePipeline::~GstEnginePipeline() {
   }
 
   if (pipeline_) {
+    gst_bus_set_sync_handler(gst_pipeline_get_bus(GST_PIPELINE(pipeline_)), NULL, NULL);
+    g_source_remove(bus_cb_id_);
     gst_element_set_state(pipeline_, GST_STATE_NULL);
     gst_object_unref(GST_OBJECT(pipeline_));
   }
@@ -160,16 +162,9 @@ gboolean GstEnginePipeline::BusCallback(GstBus*, GstMessage* msg, gpointer self)
   GstEnginePipeline* instance = reinterpret_cast<GstEnginePipeline*>(self);
 
   switch ( GST_MESSAGE_TYPE(msg)) {
-    case GST_MESSAGE_ERROR: {
-      GError* error;
-      gchar* debugs;
-
-      gst_message_parse_error(msg, &error, &debugs);
-      qWarning() << "ERROR RECEIVED IN BUS_CB <" << error->message << ">" ;
-
-      emit instance->Error(QString::fromAscii(error->message));
+    case GST_MESSAGE_ERROR:
+      instance->ErrorMessageReceived(msg);
       break;
-    }
 
     case GST_MESSAGE_TAG:
       instance->TagMessageReceived(msg);
@@ -192,6 +187,10 @@ GstBusSyncReply GstEnginePipeline::BusCallbackSync(GstBus*, GstMessage* msg, gpo
       instance->TagMessageReceived(msg);
       break;
 
+    case GST_MESSAGE_ERROR:
+      instance->ErrorMessageReceived(msg);
+      break;
+
     default:
       break;
   }
@@ -199,6 +198,15 @@ GstBusSyncReply GstEnginePipeline::BusCallbackSync(GstBus*, GstMessage* msg, gpo
   return GST_BUS_PASS;
 }
 
+void GstEnginePipeline::ErrorMessageReceived(GstMessage* msg) {
+  GError* error;
+  gchar* debugs;
+
+  gst_message_parse_error(msg, &error, &debugs);
+
+  emit Error(QString::fromAscii(error->message));
+}
+
 void GstEnginePipeline::TagMessageReceived(GstMessage* msg) {
   GstTagList* taglist = NULL;
   gst_message_parse_tag(msg, &taglist);
diff --git a/src/engines/gstenginepipeline.h b/src/engines/gstenginepipeline.h
index 08037a74d..809137a7c 100644
--- a/src/engines/gstenginepipeline.h
+++ b/src/engines/gstenginepipeline.h
@@ -77,6 +77,7 @@ class GstEnginePipeline : public QObject {
   static void EventCallback(GstPad*, GstEvent*, gpointer);
   void TagMessageReceived(GstMessage*);
   QString ParseTag(GstTagList* list, const char* tag) const;
+  void ErrorMessageReceived(GstMessage*);
 
   void UpdateVolume();
 
@@ -112,6 +113,7 @@ class GstEnginePipeline : public QObject {
   GstElement* audiosink_;
 
   uint event_cb_id_;
+  uint bus_cb_id_;
 };
 
 #endif // GSTENGINEPIPELINE_H