Digikam::ThumbnailLoadThread Class Reference

Inheritance diagram for Digikam::ThumbnailLoadThread:

Signals
void	signalThumbnailLoaded (const LoadingDescription &loadingDescription, const QPixmap &pix)
void	ThumbnailLoaded (const LoadingDescription &, const QImage &)
void	thumbnailsAvailable ()
Signals inherited from Digikam::LoadSaveThread
void	signalImageLoaded (const LoadingDescription &loadingDescription, const DImg &img)
	This signal is emitted when the loading process has finished.
void	signalImageSaved (const QString &filePath, bool success)
void	signalImageStartedLoading (const LoadingDescription &loadingDescription)
	All signals are delivered to the thread from where the LoadSaveThread object has been created.
void	signalImageStartedSaving (const QString &filePath)
void	signalLoadingProgress (const LoadingDescription &loadingDescription, float progress)
	This signal is emitted whenever new progress info is available and the notification policy allows emitting the signal.
void	signalMoreCompleteLoadingAvailable (const LoadingDescription &oldLoadingDescription, const LoadingDescription &newLoadingDescription)
	This signal is emitted if.
void	signalQImageThumbnailLoaded (const LoadingDescription &loadingDescription, const QImage &img)
void	signalSavingProgress (const QString &filePath, float progress)
Signals inherited from Digikam::DynamicThread
void	finished ()
void	starting ()
	Emitted if emitSignals is enabled.

Public Member Functions
	ThumbnailLoadThread (QObject *const parent=nullptr)
void	find (const ThumbnailIdentifier &identifier)
	Find a thumbnail.
void	find (const ThumbnailIdentifier &identifier, const QRect &rect)
void	find (const ThumbnailIdentifier &identifier, const QRect &rect, int size)
bool	find (const ThumbnailIdentifier &identifier, const QRect &rect, QPixmap &pixmap)
	All tastes of find() methods, for loading the thumbnail of a detail.
bool	find (const ThumbnailIdentifier &identifier, const QRect &rect, QPixmap &pixmap, int size, bool onlyStorage=false)
void	find (const ThumbnailIdentifier &identifier, int size)
	Same as above, but does not use the global size, but an extra specified size.
bool	find (const ThumbnailIdentifier &identifier, QPixmap &pixmap)
	Find a thumbnail.
bool	find (const ThumbnailIdentifier &identifier, QPixmap &pixmap, int size, bool onlyStorage=false)
	Same as above, but does not use the global size, but an extra specified size.
bool	findBuffered (const ThumbnailIdentifier &identifier, const QRect &rect, QPixmap &pixmap, int size)
	Find the thumbnail pixmap in the buffered cache to avoid flickering while loading a new thumbnail.
void	findGroup (const QList< QPair< ThumbnailIdentifier, QRect > > &filePathAndRects)
void	findGroup (const QList< QPair< ThumbnailIdentifier, QRect > > &filePathsAndRects, int size)
void	findGroup (QList< ThumbnailIdentifier > &identifiers)
	Find a group of thumbnails.
void	findGroup (QList< ThumbnailIdentifier > &identifiers, int size)
QList< LoadingDescription >	lastDescriptions () const
	Returns the descriptions used by the last call to any of the above methods.
void	load (const LoadingDescription &description) override
	Load a thumbnail.
int	pixmapToThumbnailSize (int size) const
	Computes the thumbnail size for the give pixmap size.
void	pregenerateGroup (const QList< ThumbnailIdentifier > &identifiers)
	Pregenerate the thumbnail group.
void	pregenerateGroup (const QList< ThumbnailIdentifier > &identifiers, int size)
void	preload (const ThumbnailIdentifier &identifier)
	Preload the thumbnail or thumbnail group.
void	preload (const ThumbnailIdentifier &identifier, int size)
void	preloadGroup (QList< ThumbnailIdentifier > &identifiers)
void	preloadGroup (QList< ThumbnailIdentifier > &identifiers, int size)
void	setHighlightPixmap (bool highlight)
	If you enable this, a highlighting border will be drawn around the pixmap.
void	setPixmapRequested (bool wantPixmap)
	If you enable this, the signal thumbnailLoaded(LoadingDescription, QPixmap) will be emitted.
void	setSendSurrogatePixmap (bool send)
	If you enable this, the thread will try hard to send a pixmap if thumbnail loading failed.
void	setThumbnailSize (int size, bool forFace=false)
	Set the requested thumbnail size.
void	storeDetailThumbnail (const QString &filePath, const QRect &detailRect, const QImage &image, bool isFace=false)
	Stores the given detail thumbnail on disk.
int	storedSize () const
ThumbnailCreator *	thumbnailCreator () const
int	thumbnailToPixmapSize (int size) const
	Computes the pixmap size for the give thumbnail size.
Public Member Functions inherited from Digikam::ManagedLoadSaveThread
	ManagedLoadSaveThread (QObject *const parent=nullptr)
void	load (const LoadingDescription &description, LoadingPolicy policy)
LoadingPolicy	loadingPolicy () const
virtual void	save (const DImg &image, const QString &filePath, const QString &format) override
	Append a task to save the image to the task list.
void	setLoadingPolicy (LoadingPolicy policy)
	Set the loading policy.
void	setTerminationPolicy (TerminationPolicy terminationPolicy)
void	stopAllTasks ()
void	stopLoading (const LoadingDescription &desc, LoadingTaskFilter filter=LoadingTaskFilterAll)
	Same than previous method, but Stop and remove tasks filtered by LoadingDescription.
void	stopLoading (const QString &filePath=QString(), LoadingTaskFilter filter=LoadingTaskFilterAll)
	Stop and remove tasks filtered by filePath and policy.
void	stopSaving (const QString &filePath=QString())
	Stop and remove saving tasks filtered by filePath.
TerminationPolicy	terminationPolicy () const
Public Member Functions inherited from Digikam::LoadSaveThread
	LoadSaveThread (QObject *const parent=nullptr)
	~LoadSaveThread () override
	Destructor: The thread will execute all pending tasks and wait for this upon destruction.
void	imageLoaded (const LoadingDescription &loadingDescription, const DImg &img) override
void	imageSaved (const QString &filePath, bool success) override
void	imageStartedLoading (const LoadingDescription &loadingDescription) override
void	imageStartedSaving (const QString &filePath) override
void	loadingProgress (const LoadingDescription &loadingDescription, float progress) override
void	moreCompleteLoadingAvailable (const LoadingDescription &oldLoadingDescription, const LoadingDescription &newLoadingDescription) override
virtual bool	querySendNotifyEvent () const
void	savingProgress (const QString &filePath, float progress) override
void	setNotificationPolicy (NotificationPolicy notificationPolicy)
virtual void	taskHasFinished ()
Public Member Functions inherited from Digikam::DynamicThread
	DynamicThread (QObject *const parent=nullptr)
	This class extends QRunnable, so you have to reimplement virtual void run().
	~DynamicThread () override
	The destructor calls stop() and wait(), but if you, in your destructor, delete any data that is accessed by your run() method, you must call stop() and wait() before yourself.
bool	isFinished () const
bool	isRunning () const
QThread::Priority	priority () const
void	setEmitSignals (bool emitThem)
void	setPriority (QThread::Priority priority)
	Sets the priority for this dynamic thread.
State	state () const

Static Public Member Functions
static void	cleanUp ()
static ThumbnailLoadThread *	defaultIconViewThread ()
static ThumbnailLoadThread *	defaultThread ()
	Return application-wide default thumbnail threads.
static void	deleteThumbnail (const QString &filePath)
	This is a tool to force regeneration of thumbnails.
static void	initializeNoThumbnailStorage ()
	Disable storing thumbnails in the disk cache.
static void	initializeThumbnailDatabase (const DbEngineParameters &params, ThumbnailInfoProvider *const provider=nullptr)
	Enable loading of thumbnails from a thumbnail database.
static int	maximumThumbnailPixmapSize (bool withHighlighting)
static int	maximumThumbnailSize ()
	Returns the maximum possible size of a thumbnail.
static void	setDisplayingWidget (QWidget *const widget)
	For color management, this sets the widget the thumbnails will be color managed for.
static int	thumbnailToPixmapSize (bool withHighlight, int size)
Static Public Member Functions inherited from Digikam::LoadSaveThread
static int	exifOrientation (const QString &filePath, const DMetadata &metadata, bool isRaw, bool fromRawEmbeddedPreview)
	Retrieves the Exif orientation, either from the info provider if available, or from the metadata.
static LoadSaveFileInfoProvider *	infoProvider ()
static void	setInfoProvider (LoadSaveFileInfoProvider *const infoProvider)

Protected Member Functions
void	thumbnailLoaded (const LoadingDescription &loadingDescription, const QImage &img) override
	virtual method overridden from LoadSaveNotifier, implemented first by LoadSaveThread called by ThumbnailTask from working thread
Protected Member Functions inherited from Digikam::ManagedLoadSaveThread
void	load (const LoadingDescription &description, LoadingMode loadingMode, AccessMode mode=AccessModeReadWrite)
void	load (const LoadingDescription &description, LoadingMode loadingMode, LoadingPolicy policy, AccessMode mode=AccessModeReadWrite)
void	loadPreview (const LoadingDescription &description, LoadingPolicy policy)
void	loadThumbnail (const LoadingDescription &description)
void	preloadThumbnail (const LoadingDescription &description)
void	preloadThumbnailGroup (const QList< LoadingDescription > &descriptions)
void	prependThumbnailGroup (const QList< LoadingDescription > &descriptions)
void	shutDown () override
	If you are deleting data in your destructor which is accessed from the thread, do one of the following from your destructor to guarantee a safe shutdown: 1) Call this method 2) Call stop() and wait(), knowing that nothing will call start() anymore after this 3) Be sure the thread will never be running at destruction.
Protected Member Functions inherited from Digikam::LoadSaveThread
void	notificationReceived ()
void	run () override
	Implement this pure virtual function in your subclass.
Protected Member Functions inherited from Digikam::DynamicThread
bool	runningFlag () const volatile
	In you run() method, you shall regularly check for runningFlag() and cleanup and return if false.
void	start (QMutexLocker< QMutex > &locker)
	Doing the same as start(), stop() and wait above, provide it with a locked QMutexLocker on mutex().
void	stop (const QMutexLocker< QMutex > &locker)
QMutex *	threadMutex () const
	This is the non-recursive mutex used to protect state variables and waiting in this class.
void	wait (QMutexLocker< QMutex > &locker)

Additional Inherited Members
Public Types inherited from Digikam::ManagedLoadSaveThread
enum	LoadingMode { LoadingModeNormal , LoadingModeShared }
	used by SharedLoadSaveThread only More...
enum	LoadingPolicy {   LoadingPolicyFirstRemovePrevious , LoadingPolicyPrepend , LoadingPolicySimplePrepend , LoadingPolicyAppend ,   LoadingPolicySimpleAppend , LoadingPolicyPreload }
enum	LoadingTaskFilter { LoadingTaskFilterAll , LoadingTaskFilterPreloading }
enum	TerminationPolicy { TerminationPolicyTerminateLoading , TerminationPolicyTerminatePreloading , TerminationPolicyWait , TerminationPolicyTerminateAll }
Public Types inherited from Digikam::LoadSaveThread
enum	AccessMode { AccessModeRead , AccessModeReadWrite }
	used by SharedLoadSaveThread only More...
enum	NotificationPolicy { NotificationPolicyDirect , NotificationPolicyTimeLimited }
Public Types inherited from Digikam::DynamicThread
enum	State { Inactive , Scheduled , Running , Deactivating }
Public Slots inherited from Digikam::DynamicThread
void	start ()
void	stop ()
	Stop computation, sets the running flag to false.
void	wait ()
	Waits until the thread finishes.
Protected Attributes inherited from Digikam::ManagedLoadSaveThread
LoadingPolicy	m_loadingPolicy = LoadingPolicyAppend
TerminationPolicy	m_terminationPolicy = TerminationPolicyTerminateLoading
Protected Attributes inherited from Digikam::LoadSaveThread
LoadSaveTask *	m_currentTask = nullptr
QMutex	m_mutex
NotificationPolicy	m_notificationPolicy = NotificationPolicyTimeLimited
QList< LoadSaveTask * >	m_todo

Member Function Documentation

defaultThread()

ThumbnailLoadThread * Digikam::ThumbnailLoadThread::defaultThread ( )

static

It is perfectly all right to create an extra object of the class, but it is useful to have default object

deleteThumbnail()

void Digikam::ThumbnailLoadThread::deleteThumbnail ( const QString & filePath )

static

All thumbnail files for the given file will be removed from disk, and the cached instances will be removed as well. Use this method if you know that the contents of the file has changed. This method works independently from the multithreaded thumbnail loading.

find() [1/2]

void Digikam::ThumbnailLoadThread::find

(

const ThumbnailIdentifier &

identifier

)

This method sends the signals and does not return values like the method above. If you certainly need asynchronous return, connect with Qt::QueuedConnection to the signals. If you connect directly, the signals may be sent from within the method call.

find() [2/2]

bool Digikam::ThumbnailLoadThread::find	(	const ThumbnailIdentifier &	identifier,
		QPixmap &	pixmap )

If the pixmap is found in the cache, returns true and sets pixmap to the found QPixmap. If the pixmap is not found in the cache, load() is called to start the loading process, false is returned and pixmap is not touched.

findGroup()

void Digikam::ThumbnailLoadThread::findGroup

(

QList< ThumbnailIdentifier > &

identifiers

)

The items will be loaded in order and signals will be sent. Can be used to ensure that thumbnails are loaded in a particular order.

Note

: the signal signalThumbnailLoaded() is only fired once, after it has been loaded, this behavior is intentional. On all subsequent attempts, during the conversion from ThumbnailIdentifier to LoadingDescription, it checks whether the thumbnail is already in the cache. The load request is then discarded.

initializeNoThumbnailStorage()

void Digikam::ThumbnailLoadThread::initializeNoThumbnailStorage ( )

static

This shall be called once at application startup. This need not be called, then the FreeDesktop standard is used.

initializeThumbnailDatabase()

void Digikam::ThumbnailLoadThread::initializeThumbnailDatabase ( const DbEngineParameters & params, ThumbnailInfoProvider *const provider = nullptr )

static

This shall be called once at application startup. This need not be called, then the FreeDesktop standard is used. You can optionally provide a thumbnail info provider.

lastDescriptions()

QList< LoadingDescription > Digikam::ThumbnailLoadThread::lastDescriptions

(

)

const

After calling single-thumbnail methods (find, preload) the list will have size 1, after the group methods (findGroup, preloadGroup, pregenerateGroup) the list can be larger than 1. There is no information if the description was ever scheduled in the thread, already processed, skipped or canceled.

load()

void Digikam::ThumbnailLoadThread::load ( const LoadingDescription & description )

overridevirtual

You do not need to use this method directly, it will not access the pixmap cache. Use find(). The LoadingDescription shall be constructed with the constructor for preview/thumbnail jobs. (in the description constructor, you need to specify file path, thumbnail size and Exif rotation)

Reimplemented from Digikam::ManagedLoadSaveThread.

maximumThumbnailSize()

int Digikam::ThumbnailLoadThread::maximumThumbnailSize ( )

static

If you request a larger size, the thumbnail will not load. The size of the pixmap can slightly differ, especially when highlighting.

pregenerateGroup()

void Digikam::ThumbnailLoadThread::pregenerateGroup

(

const QList< ThumbnailIdentifier > &

identifiers

)

No signals will be emitted when these are loaded.

preload()

void Digikam::ThumbnailLoadThread::preload

(

const ThumbnailIdentifier &

identifier

)

This is essentially the same as loading, but with a lower priority.

setDisplayingWidget()

void Digikam::ThumbnailLoadThread::setDisplayingWidget ( QWidget *const widget )

static

(currently it is only possible to set one global widget)

setHighlightPixmap()

void Digikam::ThumbnailLoadThread::setHighlightPixmap

(

bool

highlight

)

This option has only an effect if pixmapRequested is true. Default value: Enabled.

setPixmapRequested()

void Digikam::ThumbnailLoadThread::setPixmapRequested

(

bool

wantPixmap

)

If you do not enable this, only the QImage-based signal (see LoadSaveThread) will be emitted.

If you disable this, pay attention to the (global) setting of the LoadingCache, which per default does not cache the images !!

Default value: Enabled.

setSendSurrogatePixmap()

void Digikam::ThumbnailLoadThread::setSendSurrogatePixmap

(

bool

send

)

It will use standard system icons to replace the real thumbnail. If you disable this, a null QPixmap will be sent. This does not influence the QImage-based signal; this signal will be emitted with a null QImage regardless of this setting here, if the loading failed. Default value: Enabled.

setThumbnailSize()

void Digikam::ThumbnailLoadThread::setThumbnailSize	(	int	size,
		bool	forFace = false )

Note

If the thread is currently loading thumbnails, there is no guarantee as to when the property change by one of the following methods takes effect. Default value: 128

signalThumbnailLoaded

void Digikam::ThumbnailLoadThread::signalThumbnailLoaded ( const LoadingDescription & loadingDescription, const QPixmap & pix )

signal

Note

See LoadSaveThread for a QImage-based thumbnailLoaded() signal.

storeDetailThumbnail()

void Digikam::ThumbnailLoadThread::storeDetailThumbnail	(	const QString &	filePath,
		const QRect &	detailRect,
		const QImage &	image,
		bool	isFace = false )

Use this if possible because generation of detail thumbnails is potentially slower. The image should at least have storedSize().

thumbnailCreator()

ThumbnailCreator * Digikam::ThumbnailLoadThread::thumbnailCreator

(

)

const

Note

For internal use - may only be used from the thread

thumbnailLoaded()

void Digikam::ThumbnailLoadThread::thumbnailLoaded ( const LoadingDescription & loadingDescription, const QImage & img )

overrideprotectedvirtual

Reimplemented from Digikam::LoadSaveThread.

thumbnailsAvailable

void Digikam::ThumbnailLoadThread::thumbnailsAvailable ( )

signal

Note

For internal use only.

thumbnailToPixmapSize()

int Digikam::ThumbnailLoadThread::thumbnailToPixmapSize

(

int

size

)

const

These can differ when highlighting is turned on.