JUCE/modules/juce_audio_basics/sources/juce_PositionableAudioSource.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

  ==============================================================================
*/

#pragma once


//==============================================================================
/**
    A type of AudioSource which can be repositioned.

    The basic AudioSource just streams continuously with no idea of a current
    time or length, so the PositionableAudioSource is used for a finite stream
    that has a current read position.

    @see AudioSource, AudioTransportSource
*/
class JUCE_API  PositionableAudioSource  : public AudioSource
{
protected:
    //==============================================================================
    /** Creates the PositionableAudioSource. */
    PositionableAudioSource() noexcept  {}

public:
    /** Destructor */
    ~PositionableAudioSource()          {}

    //==============================================================================
    /** Tells the stream to move to a new position.

        Calling this indicates that the next call to AudioSource::getNextAudioBlock()
        should return samples from this position.

        Note that this may be called on a different thread to getNextAudioBlock(),
        so the subclass should make sure it's synchronised.
    */
    virtual void setNextReadPosition (int64 newPosition) = 0;

    /** Returns the position from which the next block will be returned.

        @see setNextReadPosition
    */
    virtual int64 getNextReadPosition() const = 0;

    /** Returns the total length of the stream (in samples). */
    virtual int64 getTotalLength() const = 0;

    /** Returns true if this source is actually playing in a loop. */
    virtual bool isLooping() const = 0;

    /** Tells the source whether you'd like it to play in a loop. */
    virtual void setLooping (bool shouldLoop)       { ignoreUnused (shouldLoop); }
};