SlideBuffer Class Reference

Provides a queue/pool of slides. More...

#include <galleryslide.h>

Inheritance diagram for SlideBuffer:

Collaboration diagram for SlideBuffer:

Signals
void	SlideReady (int count)
	Signals that buffer has (count) loaded slides awaiting display. More...

Public Member Functions
	SlideBuffer ()=default
	~SlideBuffer () override
void	Initialise (MythUIImage &image)
	Construct buffer. More...
void	Teardown ()
bool	Load (const ImagePtrK &im, int direction)
	Assign an image to next available slide, start loading and signal when done. More...
void	Preload (const ImagePtrK &im)
	Load an image in next available slide. More...
void	ReleaseCurrent ()
	Move head slide to back of queue and flush waiting slides. More...
Slide &	GetCurrent ()
Slide &	GetNext ()

Protected Member Functions
QString	BufferState ()
	Determines buffer state for debug logging. More...

Protected Attributes
QRecursiveMutex	m_mutexQ
	Queue protection. More...
QQueue< Slide * >	m_queue
	Queue of slides. More...
int	m_nextLoad {0}
	Index of first spare slide, (or last slide if none spare) More...

Private Slots
void	Flush (Slide *slide, const QString &reason)
	Signal if any slides are waiting to be displayed. More...
void	Flush (Slide *slide)

Detailed Description

Provides a queue/pool of slides.

Slides are cloned from a theme-provided image definition, so are created at start-up and re-used (a pool). Image requests are assigned to successive slides. When loaded a slide becomes available for display in requested order (a queue). The head slide is the one displayed, its successor is also displayed during a transition. When a transition completes the head slide is removed and returned to the tail for re-use. If a rapid batch of requests fill the buffer then subsequent requests overwrite the last slide, discarding the previous image (jumping behaviour).

Definition at line 215 of file galleryslide.h.

Constructor & Destructor Documentation

SlideBuffer()

SlideBuffer::SlideBuffer ( )

default

~SlideBuffer()

SlideBuffer::~SlideBuffer ( )

override

Definition at line 573 of file galleryslide.cpp.

Member Function Documentation

Initialise()

void SlideBuffer::Initialise

(

MythUIImage &

image

)

Construct buffer.

Slides are cloned from an XML image and become children of it.

Parameters

image

Parent image used as a template for slides

Definition at line 593 of file galleryslide.cpp.

Referenced by GallerySlideView::Create().

Teardown()

void SlideBuffer::Teardown

(

)

Definition at line 579 of file galleryslide.cpp.

Referenced by GallerySlideView::Close().

Load()

bool SlideBuffer::Load	(	const ImagePtrK &	im,
		int	direction
	)

Assign an image to next available slide, start loading and signal when done.

Parameters

im	Image to load
direction	Navigation causing the load

Returns

bool True if image is already loaded

Definition at line 654 of file galleryslide.cpp.

Referenced by GallerySlideView::ShowSlide().

Preload()

void SlideBuffer::Preload

(

const ImagePtrK &

im

)

Load an image in next available slide.

Parameters

im	Image to load

Definition at line 679 of file galleryslide.cpp.

Referenced by GallerySlideView::TransitionComplete().

ReleaseCurrent()

void SlideBuffer::ReleaseCurrent

(

)

Move head slide to back of queue and flush waiting slides.

Returns

int Number of slides waiting for display at head

Definition at line 701 of file galleryslide.cpp.

Referenced by GallerySlideView::TransitionComplete().

GetCurrent()

Slide& SlideBuffer::GetCurrent ( )

inline

Definition at line 227 of file galleryslide.h.

Referenced by GallerySlideView::MenuMain(), GallerySlideView::MenuTransforms(), GallerySlideView::Pan(), GallerySlideView::PlayVideo(), GallerySlideView::ShowInfo(), GallerySlideView::ShowNextSlide(), GallerySlideView::SlideAvailable(), GallerySlideView::TransitionComplete(), and GallerySlideView::Zoom().

GetNext()

Slide& SlideBuffer::GetNext ( )

inline

Definition at line 233 of file galleryslide.h.

Referenced by GallerySlideView::SlideAvailable().

SlideReady

void SlideBuffer::SlideReady ( int  count )

signal

Signals that buffer has (count) loaded slides awaiting display.

Referenced by GallerySlideView::Create(), and Flush().

Flush [1/2]

void SlideBuffer::Flush ( Slide *  slide, const QString &  reason  )

privateslot

Signal if any slides are waiting to be displayed.

Parameters

slide	The slide that has loaded or being tested
reason	Debug text describing reason for test

Returns

int Number of slides available for display

Definition at line 729 of file galleryslide.cpp.

Referenced by Flush(), Initialise(), and ReleaseCurrent().

Flush [2/2]

void SlideBuffer::Flush ( Slide *  slide )

privateslot

Definition at line 753 of file galleryslide.cpp.

BufferState()

QString SlideBuffer::BufferState ( )

protected

Determines buffer state for debug logging.

Returns

String showing state of each slide

Definition at line 633 of file galleryslide.cpp.

Referenced by Flush(), Load(), and Preload().

Member Data Documentation

m_mutexQ

QRecursiveMutex SlideBuffer::m_mutexQ

protected

Queue protection.

Definition at line 254 of file galleryslide.h.

Referenced by BufferState(), Flush(), GetCurrent(), GetNext(), Load(), Preload(), ReleaseCurrent(), and Teardown().

m_queue

QQueue<Slide*> SlideBuffer::m_queue

protected

Queue of slides.

Definition at line 256 of file galleryslide.h.

Referenced by BufferState(), Flush(), GetCurrent(), GetNext(), Initialise(), Load(), Preload(), ReleaseCurrent(), and Teardown().

m_nextLoad

int SlideBuffer::m_nextLoad {0}

protected

Index of first spare slide, (or last slide if none spare)

Definition at line 257 of file galleryslide.h.

Referenced by BufferState(), Initialise(), Load(), Preload(), and ReleaseCurrent().

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The documentation for this class was generated from the following files:

• galleryslide.h
• galleryslide.cpp