Returns a copy of the pixmap that is transformed using the given transformation transform and transformation mode. More...

#include <qpixmap.h>

Inheritance diagram for QPixmap:

Collaboration diagram for QPixmap:

Public Types
typedef QExplicitlySharedDataPointer< QPlatformPixmap >	DataPtr

Public Types inherited from QPaintDevice
enum	PaintDeviceMetric { PdmWidth = 1 , PdmHeight , PdmWidthMM , PdmHeightMM , PdmNumColors , PdmDepth , PdmDpiX , PdmDpiY , PdmPhysicalDpiX , PdmPhysicalDpiY , PdmDevicePixelRatio , PdmDevicePixelRatioScaled , PdmDevicePixelRatioF_EncodedA , PdmDevicePixelRatioF_EncodedB }

Public Member Functions
	QPixmap ()
	Constructs a null pixmap.

	QPixmap (QPlatformPixmap *data)

	QPixmap (int w, int h)
	Constructs a pixmap with the given width and height.

	QPixmap (const QSize &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Constructs a pixmap of the given size.

	QPixmap (const QString &fileName, const char *format=nullptr, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Constructs a pixmap from the file with the given fileName.

	QPixmap (const char *const xpm[])
	Constructs a pixmap from the given xpm data, which must be a valid XPM image.

	QPixmap (const QPixmap &)
	Constructs a pixmap that is a copy of the given pixmap.

	QPixmap (QPixmap &&other) noexcept
	Move-constructs a QPixmap instance from other.

	~QPixmap ()
	Destroys the pixmap.

QPixmap &	operator= (const QPixmap &)
	Assigns the given pixmap to this pixmap and returns a reference to this pixmap.

void	swap (QPixmap &other) noexcept
	\memberswap{pixmap}

bool	operator== (const QPixmap &) const =delete

bool	operator!= (const QPixmap &) const =delete

	operator QVariant () const
	Returns the pixmap as a QVariant.

bool	isNull () const
	Returns `true` if this is a null pixmap; otherwise returns `false`.

int	devType () const override

int	width () const
	Returns the width of the pixmap.

int	height () const
	Returns the height of the pixmap.

QSize	size () const
	Returns the size of the pixmap.

QRect	rect () const
	Returns the pixmap's enclosing rectangle.

int	depth () const
	Returns the depth of the pixmap.

void	fill (const QColor &fillColor=Qt::white)
	Fills the pixmap with the given color.

QBitmap	mask () const
	Returns `true` if this pixmap has an alpha channel, or has a mask, otherwise returns `false`.

void	setMask (const QBitmap &)
	Sets a mask bitmap.

qreal	devicePixelRatio () const
	Returns the device pixel ratio for the pixmap.

void	setDevicePixelRatio (qreal scaleFactor)
	Sets the device pixel ratio for the pixmap.

QSizeF	deviceIndependentSize () const
	Returns the size of the pixmap in device independent pixels.

bool	hasAlpha () const

bool	hasAlphaChannel () const

QBitmap	createHeuristicMask (bool clipTight=true) const
	Creates and returns a heuristic mask for this pixmap.

QBitmap	createMaskFromColor (const QColor &maskColor, Qt::MaskMode mode=Qt::MaskInColor) const
	Creates and returns a mask for this pixmap based on the given maskColor.

QPixmap	scaled (int w, int h, Qt::AspectRatioMode aspectMode=Qt::IgnoreAspectRatio, Qt::TransformationMode mode=Qt::FastTransformation) const

QPixmap	scaled (const QSize &s, Qt::AspectRatioMode aspectMode=Qt::IgnoreAspectRatio, Qt::TransformationMode mode=Qt::FastTransformation) const

QPixmap	scaledToWidth (int w, Qt::TransformationMode mode=Qt::FastTransformation) const
	Returns a scaled copy of the image.

QPixmap	scaledToHeight (int h, Qt::TransformationMode mode=Qt::FastTransformation) const
	Returns a scaled copy of the image.

QPixmap	transformed (const QTransform &, Qt::TransformationMode mode=Qt::FastTransformation) const

QImage	toImage () const
	Converts the pixmap to a QImage.

bool	load (const QString &fileName, const char *format=nullptr, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Loads a pixmap from the file with the given fileName.

bool	loadFromData (const uchar buf, uint len, const char format=nullptr, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Loads a pixmap from the len first bytes of the given binary data.

bool	loadFromData (const QByteArray &data, const char *format=nullptr, Qt::ImageConversionFlags flags=Qt::AutoColor)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Loads a pixmap from the binary data using the specified format and conversion flags.

bool	save (const QString &fileName, const char *format=nullptr, int quality=-1) const
	Saves the pixmap to the file with the given fileName using the specified image file format and quality factor.

bool	save (QIODevice device, const char format=nullptr, int quality=-1) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This function writes a QPixmap to the given device using the specified image file format and quality factor.

bool	convertFromImage (const QImage &img, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Replaces this pixmap's data with the given image using the specified flags to control the conversion.

QPixmap	copy (int x, int y, int width, int height) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns a deep copy of the subset of the pixmap that is specified by the rectangle QRect( x, y, width, height).

QPixmap	copy (const QRect &rect=QRect()) const
	Returns a deep copy of the subset of the pixmap that is specified by the given rectangle.

void	scroll (int dx, int dy, int x, int y, int width, int height, QRegion *exposed=nullptr)
	This convenience function is equivalent to calling QPixmap::scroll(dx, dy, QRect(x, y, width, height), exposed).

void	scroll (int dx, int dy, const QRect &rect, QRegion *exposed=nullptr)
	Scrolls the area rect of this pixmap by (dx, dy).

qint64	cacheKey () const
	Returns a number that identifies this QPixmap.

bool	isDetached () const

void	detach ()
	Detaches the pixmap from shared pixmap data.

bool	isQBitmap () const
	Returns `true` if this is a QBitmap; otherwise returns `false`.

QPaintEngine *	paintEngine () const override

bool	operator! () const
	Returns `true` if this is a null pixmap; otherwise returns `false`.

QPlatformPixmap *	handle () const

DataPtr &	data_ptr ()

Public Member Functions inherited from QPaintDevice
virtual	~QPaintDevice ()

bool	paintingActive () const

int	width () const

int	height () const

int	widthMM () const

int	heightMM () const

int	logicalDpiX () const

int	logicalDpiY () const

int	physicalDpiX () const

int	physicalDpiY () const

qreal	devicePixelRatio () const

qreal	devicePixelRatioF () const

int	colorCount () const

int	depth () const

Static Public Member Functions
static int	defaultDepth ()

static QTransform	trueMatrix (const QTransform &m, int w, int h)
	Returns the actual matrix used for transforming a pixmap with the given width, height and matrix.

static QPixmap	fromImage (const QImage &image, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Converts the given image to a pixmap using the specified flags to control the conversion.

static QPixmap	fromImageReader (QImageReader *imageReader, Qt::ImageConversionFlags flags=Qt::AutoColor)
	Create a QPixmap from an image read directly from an imageReader.

static QPixmap	fromImage (QImage &&image, Qt::ImageConversionFlags flags=Qt::AutoColor)

Static Public Member Functions inherited from QPaintDevice
static qreal	devicePixelRatioFScale ()

static int	encodeMetricF (PaintDeviceMetric metric, double value)

Protected Member Functions
int	metric (PaintDeviceMetric) const override

Protected Member Functions inherited from QPaintDevice
	QPaintDevice () noexcept

virtual void	initPainter (QPainter *painter) const

virtual QPaintDevice *	redirected (QPoint *offset) const

virtual QPainter *	sharedPainter () const

double	getDecodedMetricF (PaintDeviceMetric metricA, PaintDeviceMetric metricB) const

Static Protected Member Functions
static QPixmap	fromImageInPlace (QImage &image, Qt::ImageConversionFlags flags=Qt::AutoColor)

Friends
class	QPlatformPixmap

class	QBitmap

class	QPaintDevice

class	QPainter

class	QOpenGLWidget

class	QWidgetPrivate

class	QRasterBuffer

Q_GUI_EXPORT QDataStream &	operator>> (QDataStream &, QPixmap &)
	Reads an image from the given stream into the given pixmap.

Related Symbols
(Note that these are not member symbols.)
QDataStream &	operator<< (QDataStream &stream, const QPixmap &pixmap)
	Writes the given pixmap to the given stream as a PNG image.

Additional Inherited Members
Protected Attributes inherited from QPaintDevice
ushort	painters

Detailed Description

Returns a copy of the pixmap that is transformed using the given transformation transform and transformation mode.

The original pixmap is not changed.

The transformation transform is internally adjusted to compensate for unwanted translation; i.e. the pixmap produced is the smallest pixmap that contains all the transformed points of the original pixmap. Use the trueMatrix() function to retrieve the actual matrix used for transforming the pixmap.

This function is slow because it involves transformation to a QImage, non-trivial computations and a transformation back to a QPixmap.

See also: trueMatrix(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}

\inmodule QtGui

The QPixmap class is an off-screen image representation that can be used as a paint device.

Qt provides four classes for handling image data: QImage, QPixmap, QBitmap and QPicture. QImage is designed and optimized for I/O, and for direct pixel access and manipulation, while QPixmap is designed and optimized for showing images on screen. QBitmap is only a convenience class that inherits QPixmap, ensuring a depth of 1. The isQBitmap() function returns true if a QPixmap object is really a bitmap, otherwise returns false. Finally, the QPicture class is a paint device that records and replays QPainter commands.

A QPixmap can easily be displayed on the screen using QLabel or one of QAbstractButton's subclasses (such as QPushButton and QToolButton). QLabel has a pixmap property, whereas QAbstractButton has an icon property.

QPixmap objects can be passed around by value since the QPixmap class uses implicit data sharing. For more information, see the \l {Implicit Data Sharing} documentation. QPixmap objects can also be streamed.

Note that the pixel data in a pixmap is internal and is managed by the underlying window system. Because QPixmap is a QPaintDevice subclass, QPainter can be used to draw directly onto pixmaps. Pixels can only be accessed through QPainter functions or by converting the QPixmap to a QImage. However, the fill() function is available for initializing the entire pixmap with a given color.

There are functions to convert between QImage and QPixmap. Typically, the QImage class is used to load an image file, optionally manipulating the image data, before the QImage object is converted into a QPixmap to be shown on screen. Alternatively, if no manipulation is desired, the image file can be loaded directly into a QPixmap.

QPixmap provides a collection of functions that can be used to obtain a variety of information about the pixmap. In addition, there are several functions that enables transformation of the pixmap.

Definition at line 26 of file qpixmap.h.

Member Typedef Documentation

◆ DataPtr

typedef QExplicitlySharedDataPointer<QPlatformPixmap> QPixmap::DataPtr

Definition at line 147 of file qpixmap.h.

Constructor & Destructor Documentation

◆ QPixmap() [1/8]

QPixmap::QPixmap ( )

Constructs a null pixmap.

See also: isNull()

Definition at line 78 of file qpixmap.cpp.

◆ QPixmap() [2/8]

QPixmap::QPixmap ( QPlatformPixmap * d )

explicit

Definition at line 133 of file qpixmap.cpp.

◆ QPixmap() [3/8]

QPixmap::QPixmap	(	int	width,
		int	height )

Constructs a pixmap with the given width and height.

If either width or height is zero, a null pixmap is constructed.

Warning: This will create a QPixmap with uninitialized data. Call fill() to fill the pixmap with an appropriate color before drawing onto it with QPainter.

See also: isNull()

Definition at line 99 of file qpixmap.cpp.

◆ QPixmap() [4/8]

QPixmap::QPixmap ( const QSize & size )

explicit

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Constructs a pixmap of the given size.

Warning: This will create a QPixmap with uninitialized data. Call fill() to fill the pixmap with an appropriate color before drawing onto it with QPainter.

Definition at line 114 of file qpixmap.cpp.

◆ QPixmap() [5/8]

QPixmap::QPixmap	(	const QString &	fileName,
		const char *	format = nullptr,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

Constructs a pixmap from the file with the given fileName.

If the file does not exist or is of an unknown format, the pixmap becomes a null pixmap.

The loader attempts to read the pixmap using the specified format. If the format is not specified (which is the default), the loader probes the file for a header to guess the file format.

The file name can either refer to an actual file on disk or to one of the application's embedded resources. See the \l{resources.html}{Resource System} overview for details on how to embed images and other resource files in the application's executable.

If the image needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

The fileName, format and flags parameters are passed on to load(). This means that the data in fileName is not compiled into the binary. If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory.

See also: {QPixmap#Reading and Writing Image Files}{Reading and Writing Image Files}

Definition at line 167 of file qpixmap.cpp.

◆ QPixmap() [6/8]

QPixmap::QPixmap ( const char *const xpm[] )

explicit

Constructs a pixmap from the given xpm data, which must be a valid XPM image.

Errors are silently ignored.

Note that it's possible to squeeze the XPM variable a little bit by using an unusual declaration:

static const char * const start_xpm[] = {
    "16 15 8 1",
    "a c #cec6bd",
    // etc.
};

The extra const makes the entire definition read-only, which is slightly more efficient (for example, when the code is in a shared library) and ROMable when the application is to be stored in ROM.

Definition at line 221 of file qpixmap.cpp.

◆ QPixmap() [7/8]

QPixmap::QPixmap ( const QPixmap & pixmap )

Constructs a pixmap that is a copy of the given pixmap.

See also: copy()

Definition at line 183 of file qpixmap.cpp.

◆ QPixmap() [8/8]

QPixmap::QPixmap ( QPixmap && other )

inlinenoexcept

Move-constructs a QPixmap instance from other.

See also: swap() operator=(QPixmap&&)

Definition at line 38 of file qpixmap.h.

◆ ~QPixmap()

QPixmap::~QPixmap ( )

Destroys the pixmap.

Definition at line 243 of file qpixmap.cpp.

Member Function Documentation

◆ cacheKey()

qint64 QPixmap::cacheKey ( ) const

Returns a number that identifies this QPixmap.

Distinct QPixmap objects can only have the same cache key if they refer to the same contents.

The cacheKey() will change when the pixmap is altered.

Definition at line 882 of file qpixmap.cpp.

◆ convertFromImage()

bool QPixmap::convertFromImage	(	const QImage &	image,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

Replaces this pixmap's data with the given image using the specified flags to control the conversion.

The flags argument is a bitwise-OR of the \l{Qt::ImageConversionFlags}. Passing 0 for flags sets all the default options. Returns true if the result is that this pixmap is not null.

See also: fromImage()

Definition at line 969 of file qpixmap.cpp.

◆ copy() [1/2]

QPixmap QPixmap::copy ( const QRect & rectangle = QRect() ) const

Returns a deep copy of the subset of the pixmap that is specified by the given rectangle.

For more information on deep copies, see the \l {Implicit Data Sharing} documentation.

If the given rectangle is empty, the whole image is copied.

See also: operator=(), QPixmap(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}

Definition at line 276 of file qpixmap.cpp.

◆ copy() [2/2]

QPixmap QPixmap::copy	(	int	x,
		int	y,
		int	width,
		int	height ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns a deep copy of the subset of the pixmap that is specified by the rectangle QRect( x, y, width, height).

Definition at line 153 of file qpixmap.h.

◆ createHeuristicMask()

QBitmap QPixmap::createHeuristicMask ( bool clipTight = true ) const

Creates and returns a heuristic mask for this pixmap.

The function works by selecting a color from one of the corners and then chipping away pixels of that color, starting at all the edges. If clipTight is true (the default) the mask is just large enough to cover the pixels; otherwise, the mask is larger than the data pixels.

The mask may not be perfect but it should be reasonable, so you can do things such as the following:

QPixmap myPixmap;

myPixmap.setMask(myPixmap.createHeuristicMask());

This function is slow because it involves converting to/from a QImage, and non-trivial computations.

See also: QImage::createHeuristicMask(), createMaskFromColor()

Definition at line 651 of file qpixmap.cpp.

◆ createMaskFromColor()

QBitmap QPixmap::createMaskFromColor	(	const QColor &	maskColor,
		Qt::MaskMode	mode = Qt::MaskInColor ) const

Creates and returns a mask for this pixmap based on the given maskColor.

If the mode is Qt::MaskInColor, all pixels matching the maskColor will be transparent. If mode is Qt::MaskOutColor, all pixels matching the maskColor will be opaque.

This function is slow because it involves converting to/from a QImage.

See also: createHeuristicMask(), QImage::createMaskFromColor()

Definition at line 669 of file qpixmap.cpp.

◆ data_ptr()

DataPtr & QPixmap::data_ptr ( )

inline

Definition at line 148 of file qpixmap.h.

◆ defaultDepth()

static int QPixmap::defaultDepth ( )

static

◆ depth()

int QPixmap::depth ( ) const

Returns the depth of the pixmap.

The pixmap depth is also called bits per pixel (bpp) or bit planes of a pixmap. A null pixmap has depth 0.

See also: defaultDepth(), {QPixmap#Pixmap Information}{Pixmap Information}

Definition at line 519 of file qpixmap.cpp.

◆ detach()

void QPixmap::detach ( )

Detaches the pixmap from shared pixmap data.

A pixmap is automatically detached by Qt whenever its contents are about to change. This is done in almost all QPixmap member functions that modify the pixmap (fill(), fromImage(), load(), etc.), and in QPainter::begin() on a pixmap.

There are two exceptions in which detach() must be called explicitly, that is when calling the handle() or the x11PictureHandle() function (only available on X11). Otherwise, any modifications done using system calls, will be performed on the shared data.

The detach() function returns immediately if there is just a single reference or if the pixmap has not been initialized yet.

Definition at line 1395 of file qpixmap.cpp.

◆ deviceIndependentSize()

QSizeF QPixmap::deviceIndependentSize ( ) const

Returns the size of the pixmap in device independent pixels.

This value should be used when using the pixmap size in user interface size calculations.

The return value is equivalent to pixmap.size() / pixmap.devicePixelRatio().

Since: 6.2

Definition at line 624 of file qpixmap.cpp.

◆ devicePixelRatio()

qreal QPixmap::devicePixelRatio ( ) const

Returns the device pixel ratio for the pixmap.

This is the ratio between {device pixels} and {device independent pixels}.

Use this function when calculating layout geometry based on the pixmap size: QSize layoutSize = image.size() / image.devicePixelRatio()

The default value is 1.0.

See also: setDevicePixelRatio(), QImageReader

Definition at line 574 of file qpixmap.cpp.

◆ devType()

int QPixmap::devType ( ) const

overridevirtual

Reimplemented from QPaintDevice.

Definition at line 251 of file qpixmap.cpp.

◆ fill()

void QPixmap::fill ( const QColor & color = Qt::white )

Fills the pixmap with the given color.

The effect of this function is undefined when the pixmap is being painted on.

See also: {QPixmap#Pixmap Transformations}{Pixmap Transformations}

Definition at line 848 of file qpixmap.cpp.

◆ fromImage() [1/2]

QPixmap QPixmap::fromImage	(	const QImage &	image,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

static

Converts the given image to a pixmap using the specified flags to control the conversion.

The flags argument is a bitwise-OR of the \l{Qt::ImageConversionFlags}. Passing 0 for flags sets all the default options.

In case of monochrome and 8-bit images, the image is first converted to a 32-bit pixmap and then filled with the colors in the color table. If this is too expensive an operation, you can use QBitmap::fromImage() instead.

See also: fromImageReader(), toImage(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}

Definition at line 1433 of file qpixmap.cpp.

◆ fromImage() [2/2]

static QPixmap QPixmap::fromImage	(	QImage &&	image,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

inlinestatic

Since: 5.3 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Converts the given image to a pixmap without copying if possible.

Definition at line 91 of file qpixmap.h.

◆ fromImageInPlace()

QPixmap QPixmap::fromImageInPlace	(	QImage &	image,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

staticprotected

Definition at line 1460 of file qpixmap.cpp.

◆ fromImageReader()

QPixmap QPixmap::fromImageReader	(	QImageReader *	imageReader,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

static

Create a QPixmap from an image read directly from an imageReader.

The flags argument is a bitwise-OR of the \l{Qt::ImageConversionFlags}. Passing 0 for flags sets all the default options.

On some systems, reading an image directly to QPixmap can use less memory than reading a QImage to convert it to QPixmap.

See also: fromImage(), toImage(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}

Definition at line 1487 of file qpixmap.cpp.

◆ handle()

QPlatformPixmap * QPixmap::handle ( ) const

Definition at line 1502 of file qpixmap.cpp.

◆ hasAlpha()

bool QPixmap::hasAlpha ( ) const

◆ hasAlphaChannel()

bool QPixmap::hasAlphaChannel ( ) const

◆ height()

int QPixmap::height ( ) const

Returns the height of the pixmap.

See also: size(), {QPixmap#Pixmap Information}{Pixmap Information}

Definition at line 478 of file qpixmap.cpp.

◆ isDetached()

bool QPixmap::isDetached ( ) const

Definition at line 955 of file qpixmap.cpp.

◆ isNull()

bool QPixmap::isNull ( ) const

Returns true if this is a null pixmap; otherwise returns false.

A null pixmap has zero width, zero height and no contents. You cannot draw in a null pixmap.

Definition at line 454 of file qpixmap.cpp.

◆ isQBitmap()

bool QPixmap::isQBitmap ( ) const

Returns true if this is a QBitmap; otherwise returns false.

Definition at line 441 of file qpixmap.cpp.

◆ load()

bool QPixmap::load	(	const QString &	fileName,
		const char *	format = nullptr,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

Loads a pixmap from the file with the given fileName.

Returns true if the pixmap was successfully loaded; otherwise invalidates the pixmap and returns false.

The loader attempts to read the pixmap using the specified format. If the format is not specified (which is the default), the loader probes the file for a header to guess the file format.

The file name can either refer to an actual file on disk or to one of the application's embedded resources. See the \l{resources.html}{Resource System} overview for details on how to embed pixmaps and other resource files in the application's executable.

If the data needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

Note that QPixmaps are automatically added to the QPixmapCache when loaded from a file in main thread; the key used is internal and cannot be acquired.

See also: loadFromData(), {QPixmap#Reading and Writing Image Files}{Reading and Writing Image Files}

Definition at line 702 of file qpixmap.cpp.

◆ loadFromData() [1/2]

bool QPixmap::loadFromData	(	const QByteArray &	data,
		const char *	format = nullptr,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Loads a pixmap from the binary data using the specified format and conversion flags.

Definition at line 163 of file qpixmap.h.

◆ loadFromData() [2/2]

bool QPixmap::loadFromData	(	const uchar *	data,
		uint	len,
		const char *	format = nullptr,
		Qt::ImageConversionFlags	flags = Qt::AutoColor )

Loads a pixmap from the len first bytes of the given binary data.

Returns true if the pixmap was loaded successfully; otherwise invalidates the pixmap and returns false.

The loader attempts to read the pixmap using the specified format. If the format is not specified (which is the default), the loader probes the file for a header to guess the file format.

If the data needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

See also: load(), {QPixmap#Reading and Writing Image Files}{Reading and Writing Image Files}

Definition at line 759 of file qpixmap.cpp.

◆ mask()

QBitmap QPixmap::mask ( ) const

Returns true if this pixmap has an alpha channel, or has a mask, otherwise returns false.

See also: hasAlphaChannel(), mask()

Returns true if the pixmap has a format that respects the alpha channel, otherwise returns false.

See also: hasAlpha()

Extracts a bitmap mask from the pixmap's alpha channel.

Warning: This is potentially an expensive operation. The mask of the pixmap is extracted dynamically from the pixeldata.

See also: setMask(), {QPixmap#Pixmap Information}{Pixmap Information}

◆ metric()

int QPixmap::metric ( PaintDeviceMetric ) const

overrideprotectedvirtual

Reimplemented from QPaintDevice.

◆ operator QVariant()

QPixmap::operator QVariant ( ) const

Returns the pixmap as a QVariant.

Definition at line 377 of file qpixmap.cpp.

◆ operator!()

bool QPixmap::operator! ( ) const

inline

Returns true if this is a null pixmap; otherwise returns false.

See also: isNull()

Definition at line 119 of file qpixmap.h.

◆ operator!=()

bool QPixmap::operator!= ( const QPixmap & ) const

delete

◆ operator=()

QPixmap & QPixmap::operator= ( const QPixmap & pixmap )

Assigns the given pixmap to this pixmap and returns a reference to this pixmap.

Move-assigns other to this QPixmap instance.

See also: copy(), QPixmap()

Since: 5.2

Definition at line 347 of file qpixmap.cpp.

◆ operator==()

bool QPixmap::operator== ( const QPixmap & ) const

delete

◆ paintEngine()

QPaintEngine * QPixmap::paintEngine ( ) const

overridevirtual

Implements QPaintDevice.

◆ rect()

QRect QPixmap::rect ( ) const

Returns the pixmap's enclosing rectangle.

See also: {QPixmap#Pixmap Information}{Pixmap Information}

Definition at line 503 of file qpixmap.cpp.

◆ save() [1/2]

bool QPixmap::save	(	const QString &	fileName,
		const char *	format = nullptr,
		int	quality = -1 ) const

Saves the pixmap to the file with the given fileName using the specified image file format and quality factor.

Returns true if successful; otherwise returns false.

The quality factor must be in the range [0,100] or -1. Specify 0 to obtain small compressed files, 100 for large uncompressed files, and -1 to use the default settings.

If format is \nullptr, an image format will be chosen from fileName's suffix.

See also: {QPixmap#Reading and Writing Image Files}{Reading and Writing Image Files}

Definition at line 801 of file qpixmap.cpp.

◆ save() [2/2]

bool QPixmap::save	(	QIODevice *	device,
		const char *	format = nullptr,
		int	quality = -1 ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This function writes a QPixmap to the given device using the specified image file format and quality factor.

This can be used, for example, to save a pixmap directly into a QByteArray:

QPixmap pixmap;
QByteArray bytes;
QBuffer buffer(&bytes);
buffer.open(QIODevice::WriteOnly);
pixmap.save(&buffer, "PNG"); // writes pixmap into bytes in PNG format

Definition at line 819 of file qpixmap.cpp.

◆ scaled() [1/2]

QPixmap QPixmap::scaled	(	const QSize &	s,
		Qt::AspectRatioMode	aspectMode = Qt::IgnoreAspectRatio,
		Qt::TransformationMode	mode = Qt::FastTransformation ) const

◆ scaled() [2/2]

QPixmap QPixmap::scaled	(	int	w,
		int	h,
		Qt::AspectRatioMode	aspectMode = Qt::IgnoreAspectRatio,
		Qt::TransformationMode	mode = Qt::FastTransformation ) const

inline

Definition at line 78 of file qpixmap.h.

◆ scaledToHeight()

QPixmap QPixmap::scaledToHeight	(	int	height,
		Qt::TransformationMode	mode = Qt::FastTransformation ) const

Returns a scaled copy of the image.

The returned image is scaled to the given height using the specified transformation mode. The width of the pixmap is automatically calculated so that the aspect ratio of the pixmap is preserved.

If height is 0 or negative, a null pixmap is returned.

See also: isNull(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}

◆ scaledToWidth()

QPixmap QPixmap::scaledToWidth	(	int	w,
		Qt::TransformationMode	mode = Qt::FastTransformation ) const

Returns a scaled copy of the image.

The returned image is scaled to the given width using the specified transformation mode. The height of the pixmap is automatically calculated so that the aspect ratio of the pixmap is preserved.

If width is 0 or negative, a null pixmap is returned.

See also: isNull(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}

Definition at line 1052 of file qpixmap.cpp.

◆ scroll() [1/2]

void QPixmap::scroll	(	int	dx,
		int	dy,
		const QRect &	rect,
		QRegion *	exposed = nullptr )

Scrolls the area rect of this pixmap by (dx, dy).

The exposed region is left unchanged. You can optionally pass a pointer to an empty QRegion to get the region that is exposed by the scroll operation.

QPixmap pixmap("background.png");
QRegion exposed;
pixmap.scroll(10, 10, pixmap.rect(), &exposed);

You cannot scroll while there is an active painter on the pixmap.

See also: QWidget::scroll(), QGraphicsItem::scroll()

Definition at line 310 of file qpixmap.cpp.

◆ scroll() [2/2]

void QPixmap::scroll	(	int	dx,
		int	dy,
		int	x,
		int	y,
		int	width,
		int	height,
		QRegion *	exposed = nullptr )

inline

This convenience function is equivalent to calling QPixmap::scroll(dx, dy, QRect(x, y, width, height), exposed).

See also: QWidget::scroll(), QGraphicsItem::scroll()

Definition at line 158 of file qpixmap.h.

◆ setDevicePixelRatio()

void QPixmap::setDevicePixelRatio ( qreal scaleFactor )

Sets the device pixel ratio for the pixmap.

This is the ratio between image pixels and device-independent pixels.

The default scaleFactor is 1.0. Setting it to something else has two effects:

QPainters that are opened on the pixmap will be scaled. For example, painting on a 200x200 image if with a ratio of 2.0 will result in effective (device-independent) painting bounds of 100x100.

Code paths in Qt that calculate layout geometry based on the pixmap size will take the ratio into account: QSize layoutSize = pixmap.size() / pixmap.devicePixelRatio() The net effect of this is that the pixmap is displayed as high-DPI pixmap rather than a large pixmap (see \l{Drawing High Resolution Versions of Pixmaps and Images}).

See also: devicePixelRatio(), deviceIndependentSize()

Definition at line 602 of file qpixmap.cpp.

◆ setMask()

void QPixmap::setMask ( const QBitmap & mask )

Sets a mask bitmap.

This function merges the mask with the pixmap's alpha channel. A pixel value of 1 on the mask means the pixmap's pixel is unchanged; a value of 0 means the pixel is transparent. The mask must have the same size as this pixmap.

Setting a null mask resets the mask, leaving the previously transparent pixels black. The effect of this function is undefined when the pixmap is being painted on.

Warning: This is potentially an expensive operation.

See also: mask(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}, QBitmap

Definition at line 541 of file qpixmap.cpp.

◆ size()

QSize QPixmap::size ( ) const

Returns the size of the pixmap.

See also: width(), height(), {QPixmap#Pixmap Information}{Pixmap Information}

Definition at line 491 of file qpixmap.cpp.

◆ swap()

void QPixmap::swap ( QPixmap & other )

inlinenoexcept

\memberswap{pixmap}

Definition at line 43 of file qpixmap.h.

◆ toImage()

QImage QPixmap::toImage ( ) const

Converts the pixmap to a QImage.

Returns a null image if the conversion fails.

If the pixmap has 1-bit depth, the returned image will also be 1 bit deep. Images with more bits will be returned in a format closely represents the underlying system. Usually this will be QImage::Format_ARGB32_Premultiplied for pixmaps with an alpha and QImage::Format_RGB32 or QImage::Format_RGB16 for pixmaps without alpha.

Note that for the moment, alpha masks on monochrome images are ignored.

See also: fromImage(), {QImage#Image Formats}{Image Formats}

Definition at line 406 of file qpixmap.cpp.

◆ transformed()

QPixmap QPixmap::transformed	(	const QTransform &	,
		Qt::TransformationMode	mode = Qt::FastTransformation ) const

◆ trueMatrix()

QTransform QPixmap::trueMatrix	(	const QTransform &	matrix,
		int	width,
		int	height )

static

Returns the actual matrix used for transforming a pixmap with the given width, height and matrix.

When transforming a pixmap using the transformed() function, the transformation matrix is internally adjusted to compensate for unwanted translation, i.e. transformed() returns the smallest pixmap containing all transformed points of the original pixmap. This function returns the modified matrix, which maps points correctly from the original pixmap into the new pixmap.

See also: transformed(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}

Definition at line 430 of file qpixmap.cpp.

◆ width()

int QPixmap::width ( ) const

Returns the width of the pixmap.

See also: size(), {QPixmap#Pixmap Information}{Pixmap Information}

Definition at line 466 of file qpixmap.cpp.

Friends And Related Symbol Documentation

◆ operator<<()

QDataStream & operator<<	(	QDataStream &	stream,
		const QPixmap &	pixmap )

Writes the given pixmap to the given stream as a PNG image.

Note that writing the stream to a file will not produce a valid image file.

See also: QPixmap::save(), {Serializing Qt Data Types}

Definition at line 921 of file qpixmap.cpp.

◆ operator>>

QDataStream & operator>>	(	QDataStream &	stream,
		QPixmap &	pixmap )

friend

Reads an image from the given stream into the given pixmap.

See also: QPixmap::load(), {Serializing Qt Data Types}

Definition at line 934 of file qpixmap.cpp.

◆ QBitmap

friend class QBitmap

friend

Definition at line 133 of file qpixmap.h.

◆ QOpenGLWidget

friend class QOpenGLWidget

friend

Definition at line 136 of file qpixmap.h.

◆ QPaintDevice

friend class QPaintDevice

friend

Definition at line 134 of file qpixmap.h.

◆ QPainter

friend class QPainter

friend

Definition at line 135 of file qpixmap.h.

◆ QPlatformPixmap

friend class QPlatformPixmap

friend

Definition at line 132 of file qpixmap.h.

◆ QRasterBuffer

friend class QRasterBuffer

friend

Definition at line 138 of file qpixmap.h.

◆ QWidgetPrivate

friend class QWidgetPrivate

friend

Definition at line 137 of file qpixmap.h.

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

qtbase/src/gui/image/qpixmap.h (6ff4c3d787ecc2e6d2740f22d0406b34346faede)
qtbase/src/gui/image/qpixmap.cpp (6fb39ca2cbb111469ce09c8342997eb5375e3239)

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Friends

Related Symbols

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ DataPtr

Constructor & Destructor Documentation

◆ QPixmap() [1/8]

◆ QPixmap() [2/8]

◆ QPixmap() [3/8]

◆ QPixmap() [4/8]

◆ QPixmap() [5/8]

◆ QPixmap() [6/8]

◆ QPixmap() [7/8]

◆ QPixmap() [8/8]

◆ ~QPixmap()

Member Function Documentation

◆ cacheKey()

◆ convertFromImage()

◆ copy() [1/2]

◆ copy() [2/2]

◆ createHeuristicMask()

◆ createMaskFromColor()

◆ data_ptr()

◆ defaultDepth()

◆ depth()

◆ detach()

◆ deviceIndependentSize()

◆ devicePixelRatio()

◆ devType()

◆ fill()

◆ fromImage() [1/2]

◆ fromImage() [2/2]

◆ fromImageInPlace()

◆ fromImageReader()

◆ handle()

◆ hasAlpha()

◆ hasAlphaChannel()

◆ height()

◆ isDetached()

◆ isNull()

◆ isQBitmap()

◆ load()

◆ loadFromData() [1/2]

◆ loadFromData() [2/2]

◆ mask()

◆ metric()

◆ operator QVariant()

◆ operator!()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ paintEngine()

◆ rect()

◆ save() [1/2]

◆ save() [2/2]

◆ scaled() [1/2]

◆ scaled() [2/2]

◆ scaledToHeight()

◆ scaledToWidth()

◆ scroll() [1/2]

◆ scroll() [2/2]

◆ setDevicePixelRatio()

◆ setMask()

◆ size()

◆ swap()

◆ toImage()

◆ transformed()

◆ trueMatrix()

◆ width()

Friends And Related Symbol Documentation

◆ operator<<()

◆ operator>>

◆ QBitmap

◆ QOpenGLWidget