Add EngineBase, a pure virtual public interface for the engine.

git-svn-id: http://svn.drobilla.net/lad/trunk/ingen@3155 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 67 insertions, 0 deletions

diff --git a/include/ingen/EngineBase.hpp b/include/ingen/EngineBase.hpp
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+++ b/include/ingen/EngineBase.hpp
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+/* This file is part of Ingen.
+ * Copyright 2007-2011 David Robillard <http://drobilla.net>
+ *
+ * Ingen 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.
+ *
+ * Ingen is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef INGEN_ENGINE_BASE_HPP
+#define INGEN_ENGINE_BASE_HPP
+
+#include "raul/SharedPtr.hpp"
+
+namespace Raul { class Maid; }
+
+namespace Ingen {
+
+namespace Shared { class World; }
+
+/**
+   The engine which executes the process graph.
+
+   @ingroup interface
+*/
+class EngineBase
+{
+public:
+	virtual ~EngineBase() {}
+
+	virtual bool activate() = 0;
+
+	virtual void deactivate() = 0;
+
+	/**
+	   Indicate that a quit is desired
+
+	   This function simply sets a flag which affects the return value of
+	   main_iteration, it does not actually force the engine to stop running or
+	   block.  The code driving the engine is responsible for stopping and
+	   cleaning up when main_iteration returns false.
+	*/
+	virtual void quit() = 0;
+
+	/**
+	   Run a single iteration of the main context.
+
+	   The main context post-processes events and performs housekeeping duties
+	   like collecting garbage.  This should be called regularly, e.g. a few
+	   times per second.  The return value indicates whether execution should
+	   continue; i.e. if false is returned, a quit has been requested and the
+	   caller should cease calling main_iteration() and stop the engine.
+	*/
+	virtual bool main_iteration() = 0;
+};
+
+} // namespace Ingen
+
+#endif // INGEN_ENGINE_BASE_HPP