From 9b224fd87da4da4cd9cf46bf08d8c6874a373a50 Mon Sep 17 00:00:00 2001
From: David Sansome <davidsansome@gmail.com>
Date: Wed, 19 May 2010 13:26:23 +0000
Subject: [PATCH] Fix the fader behaviour a bit

---
 src/engines/gstenginepipeline.cpp | 20 +++++++++++++++-----
 src/engines/gstenginepipeline.h   |  3 ++-
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/engines/gstenginepipeline.cpp b/src/engines/gstenginepipeline.cpp
index 63497664b..724193654 100644
--- a/src/engines/gstenginepipeline.cpp
+++ b/src/engines/gstenginepipeline.cpp
@@ -358,19 +358,28 @@ void GstEnginePipeline::UpdateVolume() {
 void GstEnginePipeline::StartFader(int duration_msec,
                                    QTimeLine::Direction direction,
                                    QTimeLine::CurveShape shape) {
-  delete fader_;
+  // If there's already another fader running then start from the same time
+  // that one was already at.
+  int start_time = direction == QTimeLine::Forward ? 0 : duration_msec;
+  if (fader_ && fader_->state() == QTimeLine::Running)
+    start_time = fader_->currentTime();
 
-  fader_ = new QTimeLine(duration_msec, this);
-  connect(fader_, SIGNAL(valueChanged(qreal)), SLOT(SetVolumeModifier(qreal)));
-  connect(fader_, SIGNAL(finished()), SLOT(FaderTimelineFinished()));
+  fader_.reset(new QTimeLine(duration_msec, this));
+  connect(fader_.get(), SIGNAL(valueChanged(qreal)), SLOT(SetVolumeModifier(qreal)));
+  connect(fader_.get(), SIGNAL(finished()), SLOT(FaderTimelineFinished()));
   fader_->setDirection(direction);
   fader_->setCurveShape(shape);
-  fader_->start();
+  fader_->setCurrentTime(start_time);
+  fader_->resume();
+
+  fader_fudge_timer_.stop();
 
   SetVolumeModifier(fader_->currentValue());
 }
 
 void GstEnginePipeline::FaderTimelineFinished() {
+  fader_.reset();
+
   // Wait a little while longer before emitting the finished signal (and
   // probably distroying the pipeline) to account for delays in the audio
   // server/driver.
@@ -379,6 +388,7 @@ void GstEnginePipeline::FaderTimelineFinished() {
 
 void GstEnginePipeline::timerEvent(QTimerEvent* e) {
   if (e->timerId() == fader_fudge_timer_.timerId()) {
+    fader_fudge_timer_.stop();
     emit FaderFinished();
     return;
   }
diff --git a/src/engines/gstenginepipeline.h b/src/engines/gstenginepipeline.h
index 6c2c037dd..507add6d4 100644
--- a/src/engines/gstenginepipeline.h
+++ b/src/engines/gstenginepipeline.h
@@ -23,6 +23,7 @@
 #include <QBasicTimer>
 
 #include <gst/gst.h>
+#include <boost/scoped_ptr.hpp>
 
 #include "engine_fwd.h"
 
@@ -115,7 +116,7 @@ class GstEnginePipeline : public QObject {
   int volume_percent_;
   qreal volume_modifier_;
 
-  QTimeLine* fader_;
+  boost::scoped_ptr<QTimeLine> fader_;
   QBasicTimer fader_fudge_timer_;
 
   GstElement* pipeline_;