Qt 5.9 | Qt SVG | C++ Classes | QSvgGenerator

Qt 5.9.2 Reference Documentation

# QSvgGenerator Class

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

Header: | #include <QSvgGenerator>
qmake: | QT += svg
Since: | Qt 4.3

- List of all members, including inherited members

Note: All functions in this class are reentrant.

## Properties

description : QString fileName : QString outputDevice : QIODevice * resolution : int | size : QSize title : QString viewBox : QRectF

## Public Functions

| QSvgGenerator()
| ~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
QString | title() const
QRect | viewBox() const
QRectF | viewBoxF() const

## Protected Functions

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

## Detailed Description

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

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.

## Property Documentation

### description : QString

This property holds the description of the generated SVG drawing

This property was introduced in Qt 4.5.

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

This property was introduced in Qt 4.5.

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.

This property was introduced in Qt 4.5.

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.

This property was introduced in Qt 4.5.

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.

This property was introduced in Qt 4.5.

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

This property was introduced in Qt 4.5.

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.

This property was introduced in Qt 4.5.

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.

### QSvgGenerator::~QSvgGenerator()

Destroys the generator.

### `[protected]` int QSvgGenerator::metric(QPaintDevice::PaintDeviceMetric metric) const

### `[protected]` QPaintEngine *QSvgGenerator::paintEngine() const

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

### QRect QSvgGenerator::viewBox() const

Returns viewBoxF().toRect().

This function was introduced in Qt 4.5.

See also setViewBox() and viewBoxF().