- class QTextObjectInterface#
The
QTextObjectInterface
class allows drawing of custom text objects inQTextDocument
s. More…Synopsis#
Virtual methods#
def
drawObject()
def
intrinsicSize()
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 text object describes the structure of one or more elements in a text document; for instance, images imported from HTML are implemented using text objects. A text object knows how to lay out and draw its elements when a document is being rendered.
Qt allows custom text objects to be inserted into a document by registering a custom
object type
withQTextCharFormat
. AQTextObjectInterface
must also be implemented for this type and beregistered
with theQAbstractTextDocumentLayout
of the document. When the object type is encountered while rendering aQTextDocument
, theintrinsicSize()
anddrawObject()
functions of the interface are called.The following list explains the required steps of inserting a custom text object into a document:
Choose an
objectType
. TheobjectType
is an integer with a value greater or equal toUserObject
.Create a
QTextCharFormat
object and set the object type to the chosen type using the setObjectType() function.Implement the
QTextObjectInterface
class.Call
registerHandler()
with an instance of yourQTextObjectInterface
subclass to register your object type.Insert QChar::ObjectReplacementCharacter with the aforementioned
QTextCharFormat
of the chosen object type into the document. As mentioned, the functions ofQTextObjectInterface
intrinsicSize()
anddrawObject()
will then be called with theQTextFormat
as parameter whenever the replacement character is encountered.
A class implementing a text object needs to inherit both QObject and
QTextObjectInterface
. QObject must be the first class inherited. For instance:class SvgTextObject(QObject, QTextObjectInterface): Q_OBJECT Q_INTERFACES(QTextObjectInterface)
The data of a text object is usually stored in the
QTextCharFormat
usingsetProperty()
, and then retrieved withproperty()
.- abstract drawObject(painter, rect, doc, posInDocument, format)#
- Parameters:
painter –
QPainter
rect –
QRectF
doc –
QTextDocument
posInDocument – int
format –
QTextFormat
Draws this text object using the specified
painter
.The size of the rectangle,
rect
, to draw in is the size previously calculated byintrinsicSize()
. The rectangles position is relative to thepainter
.You also get the document (
doc
) and the position (posInDocument
) of theformat
in that document.See also
- abstract intrinsicSize(doc, posInDocument, format)#
- Parameters:
doc –
QTextDocument
posInDocument – int
format –
QTextFormat
- Return type:
The intrinsicSize() function returns the size of the text object represented by
format
in the given document (doc
) at the given position (posInDocument
).The size calculated will be used for subsequent calls to
drawObject()
for thisformat
.See also