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QSvgGenerator Class

The QSvgGenerator class provides a paint device that is used to create SVG drawings. More...

Header: #include <QSvgGenerator>
CMake: find_package(Qt6 REQUIRED COMPONENTS Svg)
target_link_libraries(mytarget PRIVATE Qt6::Svg)
qmake: QT += svg
Inherits: QPaintDevice

Note: All functions in this class are reentrant.

Public Types

enum class SvgVersion { SvgTiny12, Svg11 }

Properties

Public Functions

QSvgGenerator()
QSvgGenerator(QSvgGenerator::SvgVersion version)
virtual ~QSvgGenerator()
QString description() const
QString fileName() const
QIODevice *outputDevice() const
int resolution() const
void setDescription(const QString &description)
void setFileName(const QString &fileName)
void setOutputDevice(QIODevice *outputDevice)
void setResolution(int dpi)
void setSize(const QSize &size)
void setTitle(const QString &title)
void setViewBox(const QRect &viewBox)
void setViewBox(const QRectF &viewBox)
QSize size() const
QSvgGenerator::SvgVersion svgVersion() const
QString title() const
QRect viewBox() const
QRectF viewBoxF() const

Reimplemented Protected Functions

virtual int metric(QPaintDevice::PaintDeviceMetric metric) const override
virtual QPaintEngine *paintEngine() const override

Detailed Description

This paint device represents a Scalable Vector Graphics (SVG) drawing. Like QPrinter, it is designed as a write-only device that generates output in a specific format.

To write an SVG file, you first need to configure the output by setting the fileName or outputDevice properties. It is usually necessary to specify the size of the drawing by setting the size property, and in some cases where the drawing will be included in another, the viewBox property also needs to be set.

    QSvgGenerator generator;
    generator.setFileName(path);
    generator.setSize(QSize(200, 200));
    generator.setViewBox(QRect(0, 0, 200, 200));
    generator.setTitle(tr("SVG Generator Example Drawing"));
    generator.setDescription(tr("An SVG drawing created by the SVG Generator "
                                "Example provided with Qt."));

Other meta-data can be specified by setting the title, description and resolution properties.

As with other QPaintDevice subclasses, a QPainter object is used to paint onto an instance of this class:

    QPainter painter;
    painter.begin(&generator);
    ...
    painter.end();

Painting is performed in the same way as for any other paint device. However, it is necessary to use the QPainter::begin() and end() to explicitly begin and end painting on the device.

The SVG Generator Example shows how the same painting commands can be used for painting a widget and writing an SVG file.

See also QSvgRenderer, QSvgWidget, and Qt SVG C++ Classes.

Member Type Documentation

[since 6.5] enum class QSvgGenerator::SvgVersion

This enumeration describes the version of the SVG output of the generator.

ConstantValueDescription
QSvgGenerator::SvgVersion::SvgTiny120The generated document follows the SVG Tiny 1.2 specification.
QSvgGenerator::SvgVersion::Svg111The generated document follows the SVG 1.1 specification.

This enum was introduced or modified in Qt 6.5.

Property Documentation

description : QString

This property holds the description of the generated SVG drawing

Access functions:

QString description() const
void setDescription(const QString &description)

See also title.

fileName : QString

This property holds the target filename for the generated SVG drawing

Access functions:

QString fileName() const
void setFileName(const QString &fileName)

See also outputDevice.

outputDevice : QIODevice*

This property holds the output device for the generated SVG drawing

If both output device and file name are specified, the output device will have precedence.

Access functions:

QIODevice *outputDevice() const
void setOutputDevice(QIODevice *outputDevice)

See also fileName.

resolution : int

This property holds the resolution of the generated output

The resolution is specified in dots per inch, and is used to calculate the physical size of an SVG drawing.

Access functions:

int resolution() const
void setResolution(int dpi)

See also size and viewBox.

size : QSize

This property holds the size of the generated SVG drawing

By default this property is set to QSize(-1, -1), which indicates that the generator should not output the width and height attributes of the <svg> element.

Note: It is not possible to change this property while a QPainter is active on the generator.

Access functions:

QSize size() const
void setSize(const QSize &size)

See also viewBox and resolution.

title : QString

This property holds the title of the generated SVG drawing

Access functions:

QString title() const
void setTitle(const QString &title)

See also description.

viewBox : QRectF

This property holds the viewBox of the generated SVG drawing

By default this property is set to QRect(0, 0, -1, -1), which indicates that the generator should not output the viewBox attribute of the <svg> element.

Note: It is not possible to change this property while a QPainter is active on the generator.

Access functions:

QRectF viewBoxF() const
void setViewBox(const QRect &viewBox)
void setViewBox(const QRectF &viewBox)

See also viewBox(), size, and resolution.

Member Function Documentation

QSvgGenerator::QSvgGenerator()

Constructs a new generator using the SVG Tiny 1.2 profile.

[explicit, since 6.5] QSvgGenerator::QSvgGenerator(QSvgGenerator::SvgVersion version)

Constructs a new generator that uses the SVG version version.

This function was introduced in Qt 6.5.

[virtual] QSvgGenerator::~QSvgGenerator()

Destroys the generator.

[override virtual protected] int QSvgGenerator::metric(QPaintDevice::PaintDeviceMetric metric) const

Reimplements: QPaintDevice::metric(QPaintDevice::PaintDeviceMetric metric) const.

[override virtual protected] QPaintEngine *QSvgGenerator::paintEngine() const

Reimplements: QPaintDevice::paintEngine() const.

Returns the paint engine used to render graphics to be converted to SVG format information.

[since 6.5] QSvgGenerator::SvgVersion QSvgGenerator::svgVersion() const

Returns the version of the SVG document that this generator is producing.

This function was introduced in Qt 6.5.

QRect QSvgGenerator::viewBox() const

Returns viewBoxF().toRect().

See also setViewBox() and viewBoxF().

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