53 lines
1.0 KiB
C++
53 lines
1.0 KiB
C++
#pragma once
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#include <cstddef>
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#include <memory>
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#include "QObjectPtr.h"
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class Usable;
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/**
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* Base class for things that can be used by multiple other things and we want to track the use count.
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*
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* @see UseLock
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*/
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class Usable {
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friend class UseLock;
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public:
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virtual ~Usable() {}
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std::size_t useCount() const { return m_useCount; }
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bool isInUse() const { return m_useCount > 0; }
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protected:
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virtual void decrementUses() { m_useCount--; }
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virtual void incrementUses() { m_useCount++; }
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private:
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std::size_t m_useCount = 0;
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};
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/**
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* Lock class to use for keeping track of uses of other things derived from Usable
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*
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* @see Usable
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*/
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class UseLock
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{
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public:
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UseLock(shared_qobject_ptr<Usable> usable)
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: m_usable(usable)
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{
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// this doesn't use shared pointer use count, because that wouldn't be correct. this count is separate.
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m_usable->incrementUses();
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}
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~UseLock()
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{
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m_usable->decrementUses();
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}
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private:
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shared_qobject_ptr<Usable> m_usable;
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};
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