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QPicture Class Reference
^{[QtGui module]}

The QPicture class is a paint device that records and replays QPainter commands. More...

Inherits QPaintDevice.

Methods

• __init__ (self, int formatVersion = -1)
• __init__ (self, QPicture)
• QRect boundingRect (self)
• str data (self)
• detach (self)
• int devType (self)
• bool isDetached (self)
• bool isNull (self)
• bool load (self, QIODevice dev, str format = None)
• bool load (self, QString fileName, str format = None)
• int metric (self, QPaintDevice.PaintDeviceMetric m)
• QPaintEngine paintEngine (self)
• bool play (self, QPainter p)
• bool save (self, QIODevice dev, str format = None)
• bool save (self, QString fileName, str format = None)
• setBoundingRect (self, QRect r)
• setData (self, bytes data)
• int size (self)
• swap (self, QPicture other)

Static Methods

• QStringList inputFormatList ()
• unknown-type inputFormats ()
• QStringList outputFormatList ()
• unknown-type outputFormats ()
• str pictureFormat (QString fileName)

The QPicture class is a paint device that records and replays QPainter commands.

A picture serializes painter commands to an IO device in a platform-independent format. They are sometimes referred to as meta-files.

Qt pictures use a proprietary binary format. Unlike native picture (meta-file) formats on many window systems, Qt pictures have no limitations regarding their contents. Everything that can be painted on a widget or pixmap (e.g., fonts, pixmaps, regions, transformed graphics, etc.) can also be stored in a picture.

QPicture is resolution independent, i.e. a QPicture can be displayed on different devices (for example svg, pdf, ps, printer and screen) looking the same. This is, for instance, needed for WYSIWYG print preview. QPicture runs in the default system dpi, and scales the painter to match differences in resolution depending on the window system.

Example of how to record a picture:

         QPicture picture;
         QPainter painter;
         painter.begin(&picture);           // paint in picture
         painter.drawEllipse(10,20, 80,70); // draw an ellipse
         painter.end();                     // painting done
         picture.save("drawing.pic");       // save picture

Note that the list of painter commands is reset on each call to the QPainter.begin() function.

Example of how to replay a picture:

         QPicture picture;
         picture.load("drawing.pic");           // load picture
         QPainter painter;
         painter.begin(&myImage);               // paint in myImage
         painter.drawPicture(0, 0, picture);    // draw the picture at (0,0)
         painter.end();                         // painting done

Pictures can also be drawn using play(). Some basic data about a picture is available, for example, size(), isNull() and boundingRect().

Method Documentation

QPicture.__init__ (self, int formatVersion = -1)

Constructs an empty picture.

The formatVersion parameter may be used to create a QPicture that can be read by applications that are compiled with earlier versions of Qt.

Note that the default formatVersion is -1 which signifies the current release, i.e. for Qt 4.0 a formatVersion of 7 is the same as the default formatVersion of -1.

Reading pictures generated by earlier versions of Qt is not supported in Qt 4.0.

QPicture.__init__ (self, QPicture)

Constructs a copy of pic.

This constructor is fast thanks to implicit sharing.

QRect QPicture.boundingRect (self)

Returns the picture's bounding rectangle or an invalid rectangle if the picture contains no data.

See also setBoundingRect().

str QPicture.data (self)

Returns a pointer to the picture data. The pointer is only valid until the next non-const function is called on this picture. The returned pointer is 0 if the picture contains no data.

See also setData(), size(), and isNull().

QPicture.detach (self)

int QPicture.devType (self)

QStringList QPicture.inputFormatList ()

unknown-type QPicture.inputFormats ()

bool QPicture.isDetached (self)

bool QPicture.isNull (self)

Returns true if the picture contains no data; otherwise returns false.

bool QPicture.load (self, QIODevice dev, str format = None)

Loads a picture from the file specified by fileName and returns true if successful; otherwise returns false.

Please note that the format parameter has been deprecated and will have no effect.

See also save().

bool QPicture.load (self, QString fileName, str format = None)

This is an overloaded function.

int QPicture.metric (self, QPaintDevice.PaintDeviceMetric m)

QStringList QPicture.outputFormatList ()

unknown-type QPicture.outputFormats ()

QPaintEngine QPicture.paintEngine (self)

str QPicture.pictureFormat (QString fileName)

bool QPicture.play (self, QPainter p)

Replays the picture using painter, and returns true if successful; otherwise returns false.

This function does exactly the same as QPainter.drawPicture() with (x, y) = (0, 0).

bool QPicture.save (self, QIODevice dev, str format = None)

Saves a picture to the file specified by fileName and returns true if successful; otherwise returns false.

Please note that the format parameter has been deprecated and will have no effect.

See also load().

bool QPicture.save (self, QString fileName, str format = None)

This is an overloaded function.

QPicture.setBoundingRect (self, QRect r)

Sets the picture's bounding rectangle to r. The automatically calculated value is overridden.

See also boundingRect().

QPicture.setData (self, bytes data)

Sets the picture data directly from data and size. This function copies the input data.

See also data() and size().

int QPicture.size (self)

Returns the size of the picture data.

See also data().

QPicture.swap (self, QPicture other)

Swaps picture other with this picture. This operation is very fast and never fails.

This function was introduced in Qt 4.8.