comparison plugin/transform/ModelTransformer.h @ 331:f620ce48c950

* Further naming change: Transformer -> ModelTransformer.
  The Transform class now describes a thing that can be done, and the
  ModelTransformer does it to a Model.

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2006 Chris Cannam.
+   
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef _TRANSFORMER_H_
+#define _TRANSFORMER_H_
+
+#include "base/Thread.h"
+
+#include "data/model/Model.h"
+
+/**
+ * A ModelTransformer turns one data model into another.
+ *
+ * Typically in this application, a ModelTransformer might have a
+ * DenseTimeValueModel as its input (e.g. an audio waveform) and a
+ * SparseOneDimensionalModel (e.g. detected beats) as its output.
+ *
+ * The ModelTransformer typically runs in the background, as a
+ * separate thread populating the output model.  The model is
+ * available to the user of the ModelTransformer immediately, but may
+ * be initially empty until the background thread has populated it.
+ */
+
+class ModelTransformer : public Thread
+{
+public:
+    virtual ~ModelTransformer();
+
+    // Just a hint to the processing thread that it should give up.
+    // Caller should still wait() and/or delete the transform before
+    // assuming its input and output models are no longer required.
+    void abandon() { m_abandoned = true; }
+
+    Model *getInputModel()  { return m_input; }
+    Model *getOutputModel() { return m_output; }
+    Model *detachOutputModel() { m_detached = true; return m_output; }
+
+protected:
+    ModelTransformer(Model *m);
+
+    Model *m_input; // I don't own this
+    Model *m_output; // I own this, unless...
+    bool m_detached; // ... this is true.
+    bool m_abandoned;
+};
+
+#endif