* The volume now listens to parameter changes, and adapts itself automatically.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30061 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/bin/desklink/VolumeControl.cpp

@@ -103,6 +103,17 @@ VolumeControl::AttachedToWindow()
 	BSlider::AttachedToWindow();
 
 	SetEventMask(_IsReplicant() ? 0 : B_POINTER_EVENTS, B_NO_POINTER_HISTORY);
+
+	BMediaRoster::CurrentRoster()->StartWatching(this,
+		fMixerControl->GainNode(), B_MEDIA_NEW_PARAMETER_VALUE);
+}
+
+
+void
+VolumeControl::DetachedFromWindow()
+{
+	BMediaRoster::CurrentRoster()->StopWatching(this, fMixerControl->GainNode(),
+		B_MEDIA_NEW_PARAMETER_VALUE);
 }
 
 
@@ -164,6 +175,13 @@ VolumeControl::MessageReceived(BMessage* msg)
 			break;
 		}
 
+		case B_MEDIA_NEW_PARAMETER_VALUE:
+			if (IsTracking())
+				break;
+
+			SetValue((int32)fMixerControl->Volume());
+			break;
+
 		default:
 			return BView::MessageReceived(msg);
 	}

src/bin/desklink/VolumeControl.h

@@ -28,6 +28,7 @@ public:
 
 protected:
 	virtual	void			AttachedToWindow();
+	virtual	void			DetachedFromWindow();
 	virtual	void			MouseDown(BPoint where);
 	virtual	void			MessageReceived(BMessage* message);
 	virtual status_t		Invoke(BMessage* message = NULL);