AudioDeviceHandle.h

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// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
 
#include "UObject/WeakObjectPtr.h"
 
// Set this to one if you'd like to check who owns
// handles to an audio device.
#ifndef INSTRUMENT_AUDIODEVICE_HANDLES
#define INSTRUMENT_AUDIODEVICE_HANDLES 0
#endif
 
namespace Audio
{
    class FMixerDevice;
 
    using FDeviceId = uint32;
}
 
class FAudioDevice;
class UWorld;
 
 
// Strong handle to an audio device. Guarantees that the audio device it references will stay alive while it is in scope.
class FAudioDeviceHandle
{
public:
    ENGINE_API FAudioDeviceHandle();
    ENGINE_API FAudioDeviceHandle(const FAudioDeviceHandle& Other);
    ENGINE_API FAudioDeviceHandle(FAudioDeviceHandle&& Other);
 
    ENGINE_API FAudioDeviceHandle& operator=(const FAudioDeviceHandle& Other);
    ENGINE_API FAudioDeviceHandle& operator=(FAudioDeviceHandle&& Other);
 
 
    ENGINE_API ~FAudioDeviceHandle();
 
    // gets a pointer to the audio device.
    ENGINE_API FAudioDevice* GetAudioDevice() const;
 
    // Returns the device ID for the audio device referenced by this handle.
    ENGINE_API Audio::FDeviceId GetDeviceID() const;
 
    // Returns world set when handle was created
    ENGINE_API TWeakObjectPtr<UWorld> GetWorld() const;
 
    // Checks whether this points to a valid AudioDevice.
    ENGINE_API bool IsValid() const;
 
    // Resets handle to invalid state
    ENGINE_API void Reset();
 
private:
    // This constructor should only be called by FAudioDeviceManager.
    ENGINE_API FAudioDeviceHandle(FAudioDevice* InDevice, Audio::FDeviceId InID, UWorld* InWorld);
 
    // The world that this FAudioDeviceHandle was requested with.
    // Null if this device handle wasn't generated by RequestAudioDevice.
    TWeakObjectPtr<UWorld> World;
 
    FAudioDevice* Device;
    Audio::FDeviceId DeviceId;
 
#if INSTRUMENT_AUDIODEVICE_HANDLES
    uint32 StackWalkID;
    ENGINE_API void AddStackDumpToAudioDeviceContainer();
#endif
 
    friend class FAudioDeviceManager;
 
public:
    // These are convenience operators to use an FAudioDeviceHandle like an FAudioDevice* or an Audio::FDeviceId.
    // For safety, we still require explicit casting to an FAudioDevice* to ensure ownership isn't lost due to programmer error.
    const FAudioDevice& operator*() const
    {
        check(IsValid());
        return *Device;
    }
 
    FAudioDevice& operator*()
    {
        check(IsValid());
        return *Device;
    }
 
    const FAudioDevice* operator->() const
    {
        check(IsValid());
        return Device;
    }
 
    FAudioDevice* operator->()
    {
        check(IsValid());
        return Device;
    }
 
    inline explicit operator bool() const
    {
        return IsValid();
    }
 
    inline bool operator==(const FAudioDeviceHandle& Other) const
    {
        return DeviceId == Other.DeviceId;
    }
 
    inline bool operator==(const FAudioDevice*& Other) const
    {
        return Device == Other;
    }
 
    inline bool operator==(FAudioDevice*& Other) const
    {
        return Device == Other;
    }
 
    inline bool operator==(const Audio::FDeviceId& Other) const
    {
        return DeviceId == Other;
    }
 
    explicit operator FAudioDevice*() const
    {
        check(IsValid());
        return Device;
    }
 
    explicit operator Audio::FDeviceId() const
    {
        return DeviceId;
    }
};