Qt 5.7 | Qt Quick | C++ Classes | QQuickTextureFactory

Qt 5.7.1 Reference Documentation

# QQuickTextureFactory Class

The QQuickTextureFactory class provides an interface for loading custom textures from QML. More...

Header: | #include <QQuickTextureFactory>
qmake: | QT += quick
Since: | Qt 5.0

- List of all members, including inherited members

## Public Functions

| QQuickTextureFactory()
virtual | ~QQuickTextureFactory()
virtual QSGTexture * | createTexture(QQuickWindow *window) const = 0
virtual QImage | image() const
virtual int | textureByteCount() const = 0
virtual QSize | textureSize() const = 0

## Static Public Members

QQuickTextureFactory * | textureFactoryForImage(const QImage &image)

## Detailed Description

The QQuickTextureFactory class provides an interface for loading custom textures from QML.

The purpose of the texture factory is to provide a placeholder for a image data that can be converted into an OpenGL texture.

Creating a texture directly is not possible as there is rarely an OpenGL context available in the thread that is responsible for loading the image data.

## Member Function Documentation

### QQuickTextureFactory::QQuickTextureFactory()

Constructs a texture factory. Since QQuickTextureFactory is abstract, it cannot be instantiated directly.

### `[virtual]` QQuickTextureFactory::~QQuickTextureFactory()

Destroys the texture factory.

### `[pure virtual]` QSGTexture *QQuickTextureFactory::createTexture(QQuickWindow *window) const

This function is called on the scene graph rendering thread to create a QSGTexture instance from the factory. window provides the context which this texture is created in.

QML will internally cache the returned texture as needed. Each call to this function should return a unique instance.

The OpenGL context used for rendering is bound when this function is called.

### `[virtual]` QImage QQuickTextureFactory::image() const

Returns an image version of this texture.

The lifespan of the returned image is unknown, so the implementation should return a self contained QImage, not make use of the QImage(uchar *, ...) constructor.

This function is not commonly used and is expected to be slow.

### `[pure virtual]` int QQuickTextureFactory::textureByteCount() const

Returns the number of bytes of memory the texture consumes.

### `[static]` QQuickTextureFactory *QQuickTextureFactory::textureFactoryForImage(const QImage &image)

Returns a QQuickTextureFactory holding the given image.

This is typically used as a helper in QQuickImageResponse::textureFactory.

This function was introduced in Qt 5.6.

### `[pure virtual]` QSize QQuickTextureFactory::textureSize() const

Returns the size of the texture. This function will be called from arbitrary threads and should not rely on an OpenGL context bound.