1 files changed, 50 insertions, 0 deletions
diff --git a/libs/audiographer/audiographer/listed_source.h b/libs/audiographer/audiographer/listed_source.h
new file mode 100644
index 0000000000..bc8f144d84
--- /dev/null
+++ b/libs/audiographer/audiographer/listed_source.h
@@ -0,0 +1,50 @@
+#ifndef AUDIOGRAPHER_LISTED_SOURCE_H
+#define AUDIOGRAPHER_LISTED_SOURCE_H
+
+#include "types.h"
+#include "source.h"
+
+#include <list>
+
+namespace AudioGrapher
+{
+
+template<typename T>
+class ListedSource : public Source<T>
+{
+  public:
+	void add_output (typename Source<T>::SinkPtr output) { outputs.push_back(output); }
+	void clear_outputs () { outputs.clear(); }
+	void remove_output (typename Source<T>::SinkPtr output) { outputs.remove(output); }
+	
+  protected:
+	
+	typedef std::list<typename Source<T>::SinkPtr> SinkList;
+	
+	/// Helper for derived classes
+	void output (ProcessContext<T> const & c)
+	{
+		for (typename SinkList::iterator i = outputs.begin(); i != outputs.end(); ++i) {
+			(*i)->process (c);
+		}
+	}
+
+	void output (ProcessContext<T> & c)
+	{
+		if (output_size_is_one()) {
+			// only one output, so we can keep this non-const
+			outputs.front()->process (c);
+		} else {
+			output (const_cast<ProcessContext<T> const &> (c));
+		}
+	}
+
+	inline bool output_size_is_one () { return (!outputs.empty() && ++outputs.begin() == outputs.end()); }
+
+	SinkList outputs;
+};
+
+} // namespace
+
+#endif //AUDIOGRAPHER_LISTED_SOURCE_H
+