Added easy method to retrieve the playback position (of the seek slider [0..1]).

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36417 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/mediaplayer/TransportControlGroup.cpp

@@ -464,6 +464,13 @@ TransportControlGroup::SetPosition(float value, bigtime_t position,
 }
 
 
+float
+TransportControlGroup::Position() const
+{
+	return fSeekSlider->Position();
+}
+
+
 void
 TransportControlGroup::SetDisabledString(const char* string)
 {

src/apps/mediaplayer/TransportControlGroup.h

@@ -68,6 +68,7 @@ public:
 			void				SetVolume(float value);
 			void				SetPosition(float value, bigtime_t position,
 									bigtime_t duration);
+			float				Position() const;
 
 			PeakView*			GetPeakView() const
 									{ return fPeakView; }

src/apps/mediaplayer/interface/SeekSlider.cpp

@@ -299,6 +299,16 @@ SeekSlider::SetPosition(float position)
 }
 
 
+float
+SeekSlider::Position() const
+{
+	int32 range = fMaxValue - fMinValue;
+	if (range == 0)
+		return 0;
+	return (float)(Value() - fMinValue) / range;
+}
+
+
 bool
 SeekSlider::IsTracking() const
 {

src/apps/mediaplayer/interface/SeekSlider.h

@@ -32,6 +32,7 @@ public:
 
 	// SeekSlider
 			void				SetPosition(float position);
+			float				Position() const;
 			bool				IsTracking() const;
 			void				SetDisabledString(const char* string);