Initial release

engine/vendor/vst3sdk/base/source/updatehandler.h

@@ -0,0 +1,130 @@
+//------------------------------------------------------------------------
+// Project     : SDK Base
+// Version     : 1.0
+//
+// Category    : Helpers
+// Filename    : base/source/updatehandler.h
+// Created by  : Steinberg, 2008
+// Description :
+//
+//-----------------------------------------------------------------------------
+// This file is part of a Steinberg SDK. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this distribution
+// and at www.steinberg.net/sdklicenses. 
+// No part of the SDK, including this file, may be copied, modified, propagated,
+// or distributed except according to the terms contained in the LICENSE file.
+//-----------------------------------------------------------------------------
+
+#pragma once
+
+#include "base/source/fobject.h"
+#include "base/thread/include/flock.h"
+#include "pluginterfaces/base/iupdatehandler.h"
+
+namespace Steinberg {
+
+/// @cond ignore
+namespace Update { struct Table; }
+/// @endcond
+
+//------------------------------------------------------------------------
+/** Handle Send and Cancel pending message for a given object*/
+//------------------------------------------------------------------------
+class IUpdateManager : public FUnknown
+{
+public:
+//------------------------------------------------------------------------
+	/** cancel pending messages send by \param object or by any if object is 0 */
+	virtual tresult PLUGIN_API cancelUpdates (FUnknown* object) = 0;
+	/** send pending messages send by \param object or by any if object is 0 */
+	virtual tresult PLUGIN_API triggerDeferedUpdates (FUnknown* object = nullptr) = 0;
+	static const FUID iid;
+};
+
+DECLARE_CLASS_IID (IUpdateManager, 0x030B780C, 0xD6E6418D, 0x8CE00BC2, 0x09C834D4)
+
+//------------------------------------------------------------------------------
+/**
+UpdateHandler implements IUpdateManager and IUpdateHandler to handle dependencies
+between objects to store and forward messages to dependent objects.
+
+This implementation is thread save, so objects can send message, add or remove
+dependents from different threads.
+Do do so it uses mutex, so be aware of locking.
+*/
+//------------------------------------------------------------------------------
+class UpdateHandler : public FObject, public IUpdateHandler, public IUpdateManager
+{
+public:
+//------------------------------------------------------------------------------
+	UpdateHandler ();
+	~UpdateHandler () SMTG_OVERRIDE;
+
+	using FObject::addDependent;
+	using FObject::removeDependent;
+	using FObject::deferUpdate;
+
+	// IUpdateHandler
+//private:
+	friend class FObject;
+	/** register \param dependent to get messages from \param object */
+	tresult PLUGIN_API addDependent (FUnknown* object, IDependent* dependent) SMTG_OVERRIDE;
+	/** unregister \param dependent to get no messages from \param object */
+	tresult PLUGIN_API removeDependent (FUnknown* object, IDependent* dependent, size_t& earseCount);
+	tresult PLUGIN_API removeDependent (FUnknown* object,
+	                                            IDependent* dependent) SMTG_OVERRIDE;
+public:
+	/** send \param message to all dependents of \param object immediately */
+	tresult PLUGIN_API triggerUpdates (FUnknown* object, int32 message) SMTG_OVERRIDE;
+	/** send \param message to all dependents of \param object when idle */
+	tresult PLUGIN_API deferUpdates (FUnknown* object, int32 message) SMTG_OVERRIDE;
+
+	// IUpdateManager
+	/** cancel pending messages send by \param object or by any if object is 0 */
+	tresult PLUGIN_API cancelUpdates (FUnknown* object) SMTG_OVERRIDE;
+	/** send pending messages send by \param object or by any if object is 0 */
+	tresult PLUGIN_API triggerDeferedUpdates (FUnknown* object = nullptr) SMTG_OVERRIDE;
+
+	/// @cond ignore
+	// obsolete functions kept for compatibility
+	void checkUpdates (FObject* object = nullptr)
+	{
+		triggerDeferedUpdates (object ? object->unknownCast () : nullptr);
+	}
+	void flushUpdates (FObject* object)
+	{
+		if (object)
+			cancelUpdates (object->unknownCast ());
+	}
+	void deferUpdate (FObject* object, int32 message)
+	{
+		if (object)
+			deferUpdates (object->unknownCast (), message);
+	}
+	void signalChange (FObject* object, int32 message, bool suppressUpdateDone = false)
+	{
+		if (object)
+			doTriggerUpdates (object->unknownCast (), message, suppressUpdateDone);
+	}
+#if DEVELOPMENT
+	bool checkDeferred (FUnknown* object);
+	bool hasDependencies (FUnknown* object);
+	void printForObject (FObject* object) const;
+#endif
+	/// @endcond
+	size_t countDependencies (FUnknown* object = nullptr);
+	
+	OBJ_METHODS (UpdateHandler, FObject)
+	FUNKNOWN_METHODS2 (IUpdateHandler, IUpdateManager, FObject)
+	SINGLETON (UpdateHandler)
+//------------------------------------------------------------------------------
+private:
+	tresult doTriggerUpdates (FUnknown* object, int32 message, bool suppressUpdateDone);
+
+	Steinberg::Base::Thread::FLock lock;
+	Update::Table* table = nullptr;
+};
+
+
+//------------------------------------------------------------------------
+} // namespace Steinberg