juce::AudioThumbnailCache Class Reference

Detailed Description

An instance of this class is used to manage multiple AudioThumbnail objects.

The cache runs a single background thread that is shared by all the thumbnails that need it, and it maintains a set of low-res previews in memory, to avoid having to re-scan audio files too often.

See also

AudioThumbnail

Public Member Functions
	AudioThumbnailCache (int maxNumThumbsToStore)
	Creates a cache object.
virtual	~AudioThumbnailCache ()
	Destructor.
void	clear ()
	Clears out any stored thumbnails.
bool	loadThumb (AudioThumbnailBase &thumb, int64 hashCode)
	Reloads the specified thumb if this cache contains the appropriate stored data.
void	storeThumb (const AudioThumbnailBase &thumb, int64 hashCode)
	Stores the cacheable data from the specified thumb in this cache.
void	removeThumb (int64 hashCode)
	Tells the cache to forget about the thumb with the given hashcode.
bool	readFromStream (InputStream &source)
	Attempts to re-load a saved cache of thumbnails from a stream.
void	writeToStream (OutputStream &stream)
	Writes all currently-loaded cache data to a stream.
TimeSliceThread &	getTimeSliceThread () noexcept
	Returns the thread that client thumbnails can use.

Protected Member Functions
virtual void	saveNewlyFinishedThumbnail (const AudioThumbnailBase &, int64 hashCode)
	This can be overridden to provide a custom callback for saving thumbnails once they have finished being loaded.
virtual bool	loadNewThumb (AudioThumbnailBase &, int64 hashCode)
	This can be overridden to provide a custom callback for loading thumbnails from pre-saved files to save the cache the trouble of having to create them.

Constructors and Destructors

AudioThumbnailCache()

juce::AudioThumbnailCache::AudioThumbnailCache ( int maxNumThumbsToStore )

explicit

Creates a cache object.

The maxNumThumbsToStore parameter lets you specify how many previews should be kept in memory at once.

Referenced by loadNewThumb().

~AudioThumbnailCache()

virtual juce::AudioThumbnailCache::~AudioThumbnailCache ( )

virtual

Destructor.

Member Functions

clear()

void juce::AudioThumbnailCache::clear

(

)

Clears out any stored thumbnails.

loadThumb()

bool juce::AudioThumbnailCache::loadThumb	(	AudioThumbnailBase &	thumb,
		int64	hashCode )

Reloads the specified thumb if this cache contains the appropriate stored data.

This is called automatically by the AudioThumbnail class, so you shouldn't normally need to call it directly.

storeThumb()

void juce::AudioThumbnailCache::storeThumb	(	const AudioThumbnailBase &	thumb,
		int64	hashCode )

Stores the cacheable data from the specified thumb in this cache.

This is called automatically by the AudioThumbnail class, so you shouldn't normally need to call it directly.

removeThumb()

void juce::AudioThumbnailCache::removeThumb

(

int64

hashCode

)

Tells the cache to forget about the thumb with the given hashcode.

readFromStream()

bool juce::AudioThumbnailCache::readFromStream

(

InputStream &

source

)

Attempts to re-load a saved cache of thumbnails from a stream.

The cache data must have been written by the writeToStream() method. This will replace all currently-loaded thumbnails with the new data.

writeToStream()

void juce::AudioThumbnailCache::writeToStream

(

OutputStream &

stream

)

Writes all currently-loaded cache data to a stream.

The resulting data can be re-loaded with readFromStream().

getTimeSliceThread()

TimeSliceThread & juce::AudioThumbnailCache::getTimeSliceThread ( )

noexcept

Returns the thread that client thumbnails can use.

saveNewlyFinishedThumbnail()

virtual void juce::AudioThumbnailCache::saveNewlyFinishedThumbnail ( const AudioThumbnailBase & , int64 hashCode )

protectedvirtual

This can be overridden to provide a custom callback for saving thumbnails once they have finished being loaded.

loadNewThumb()

virtual bool juce::AudioThumbnailCache::loadNewThumb ( AudioThumbnailBase & , int64 hashCode )

protectedvirtual

This can be overridden to provide a custom callback for loading thumbnails from pre-saved files to save the cache the trouble of having to create them.

References AudioThumbnailCache().