- class QPicture#
The
QPicture
class is a paint device that records and replaysQPainter
commands. More…Synopsis#
Methods#
def
__init__()
def
boundingRect()
def
data()
def
isNull()
def
load()
def
play()
def
save()
def
size()
def
swap()
Virtual methods#
def
setData()
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
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. aQPicture
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:
picture = QPicture() painter = QPainter() 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:
picture = QPicture() picture.load("drawing.pic") # load picture painter = QPainter() 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()
andboundingRect()
.See also
Constructs a copy of
pic
.This constructor is fast thanks to implicit sharing.
- __init__([formatVersion=-1])
- Parameters:
formatVersion – int
Constructs an empty picture.
The
formatVersion
parameter may be used to create aQPicture
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.
Returns the picture’s bounding rectangle or an invalid rectangle if the picture contains no data.
See also
- data()#
- Return type:
PyObject
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.
- isNull()#
- Return type:
bool
Returns
true
if the picture contains no data; otherwise returns false.This is an overloaded function.
dev
is the device to use for loading.- load(fileName)
- Parameters:
fileName – str
- Return type:
bool
Loads a picture from the file specified by
fileName
and returns true if successful; otherwise invalidates the picture and returnsfalse
.See also
Replays the picture using
painter
, and returnstrue
if successful; otherwise returnsfalse
.This function does exactly the same as
drawPicture()
with (x, y) = (0, 0).Note
The state of the painter isn’t preserved by this function.
This is an overloaded function.
dev
is the device to use for saving.- save(fileName)
- Parameters:
fileName – str
- Return type:
bool
Saves a picture to the file specified by
fileName
and returns true if successful; otherwise returnsfalse
.See also
Sets the picture’s bounding rectangle to
r
. The automatically calculated value is overridden.See also
- setData(data)#
- Parameters:
data – str
Sets the picture data directly from
data
andsize
. This function copies the input data.- size()#
- Return type:
int
Returns the size of the picture data.
See also
Swaps picture
other
with this picture. This operation is very fast and never fails.