updatehandler.h

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 //------------------------------------------------------------------------
// Project     : SDK Base
// Version     : 1.0
//
// Category    : Helpers
// Filename    : base/source/updatehandler.h
// Created by  : Steinberg, 2008
// Description :
//
//-----------------------------------------------------------------------------
// LICENSE
// (c) 2023, Steinberg Media Technologies GmbH, All Rights Reserved
//-----------------------------------------------------------------------------
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
// 
//   * Redistributions of source code must retain the above copyright notice, 
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation 
//     and/or other materials provided with the distribution.
//   * Neither the name of the Steinberg Media Technologies nor the names of its
//     contributors may be used to endorse or promote products derived from this 
//     software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
// IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE  OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
//-----------------------------------------------------------------------------
 
#pragma once
 
#include "base/source/fobject.h"
#include "base/thread/include/flock.h"
#include "pluginterfaces/base/iupdatehandler.h"
 
namespace Steinberg {
 
namespace Update { struct Table; }
 
//------------------------------------------------------------------------
//------------------------------------------------------------------------
class IUpdateManager : public FUnknown
{
public:
//------------------------------------------------------------------------
    virtual tresult PLUGIN_API cancelUpdates (FUnknown* object) = 0;
    virtual tresult PLUGIN_API triggerDeferedUpdates (FUnknown* object = nullptr) = 0;
    static const FUID iid;
};
 
DECLARE_CLASS_IID (IUpdateManager, 0x030B780C, 0xD6E6418D, 0x8CE00BC2, 0x09C834D4)
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
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;
    tresult PLUGIN_API addDependent (FUnknown* object, IDependent* dependent) SMTG_OVERRIDE;
    tresult PLUGIN_API removeDependent (FUnknown* object, IDependent* dependent, size_t& earseCount);
    tresult PLUGIN_API removeDependent (FUnknown* object,
                                                IDependent* dependent) SMTG_OVERRIDE;
public:
    tresult PLUGIN_API triggerUpdates (FUnknown* object, int32 message) SMTG_OVERRIDE;
    tresult PLUGIN_API deferUpdates (FUnknown* object, int32 message) SMTG_OVERRIDE;
 
    // IUpdateManager
    tresult PLUGIN_API cancelUpdates (FUnknown* object) SMTG_OVERRIDE;
    tresult PLUGIN_API triggerDeferedUpdates (FUnknown* object = nullptr) SMTG_OVERRIDE;
 
    // 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
    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