QPicture露

PyQt5.QtGui.QPicture: Inherits from QPaintDevice.

Description露

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 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().

Methods露

__init__(formatVersion: int = -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.

__init__(QPicture)

Constructs a copy of pic.

This constructor is fast thanks to implicit sharing.

boundingRect() → QRect: Returns the picture鈥檚 bounding rectangle or an invalid rectangle if the picture contains no data.

See also

setBoundingRect().

data() → str: See also

setData().

detach(): TODO

devType() → int: TODO

isDetached() → bool: TODO

isNull() → bool: TODO

load(QIODevice, format: str = None) → bool

This is an overloaded function.

dev is the device to use for loading.

load(str, format: str = None) → bool

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

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