class QAbstractTextDocumentLayout#

The QAbstractTextDocumentLayout class is an abstract base class used to implement custom layouts for QTextDocuments. More…

Inherited by: QPlainTextDocumentLayout

Synopsis#

Methods#

def __init__()
def anchorAt()
def blockWithMarkerAt()
def document()
def format()
def formatAt()
def formatIndex()
def handlerForObject()
def imageAt()
def paintDevice()
def registerHandler()
def setPaintDevice()
def unregisterHandler()

Signals#

def documentSizeChanged()
def pageCountChanged()
def update()
def updateBlock()

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#

The standard layout provided by Qt can handle simple word processing including inline images, lists and tables.

Some applications, e.g., a word processor or a DTP application might need more features than the ones provided by Qt’s layout engine, in which case you can subclass QAbstractTextDocumentLayout to provide custom layout behavior for your text documents.

An instance of the QAbstractTextDocumentLayout subclass can be installed on a QTextDocument object with the setDocumentLayout() function.

You can insert custom objects into a QTextDocument ; see the QTextObjectInterface class description for details.

See also

QTextObjectInterface

__init__(doc)#

Parameters:: doc – QTextDocument

Creates a new text document layout for the given document.

anchorAt(pos)#

Parameters:: pos – QPointF
Return type:: str

Returns the reference of the anchor the given position, or an empty string if no anchor exists at that point.

abstract blockBoundingRect(block)#

Parameters:: block – QTextBlock
Return type:: QRectF

Returns the bounding rectangle of block.

blockWithMarkerAt(pos)#

Parameters:: pos – QPointF
Return type:: QTextBlock

Returns the block (probably a list item) whose marker is found at the given position pos.

document()#

Return type:: QTextDocument

Returns the text document that this layout is operating on.

abstract documentChanged(from, charsRemoved, charsAdded)#

Parameters:

from – int
charsRemoved – int
charsAdded – int

This function is called whenever the contents of the document change. A change occurs when text is inserted, removed, or a combination of these two. The change is specified by position, charsRemoved, and charsAdded corresponding to the starting character position of the change, the number of characters removed from the document, and the number of characters added.

For example, when inserting the text “Hello” into an empty document, charsRemoved would be 0 and charsAdded would be 5 (the length of the string).

Replacing text is a combination of removing and inserting. For example, if the text “Hello” gets replaced by “Hi”, charsRemoved would be 5 and charsAdded would be 2.

For subclasses of QAbstractTextDocumentLayout , this is the central function where a large portion of the work to lay out and position document contents is done.

For example, in a subclass that only arranges blocks of text, an implementation of this function would have to do the following:

Determine the list of changed QTextBlock (s) using the parameters provided.

Each QTextBlock object’s corresponding QTextLayout object needs to be processed. You can access the QTextBlock ‘s layout using the layout() function. This processing should take the document’s page size into consideration.

If the total number of pages changed, the pageCountChanged() signal should be emitted.

If the total size changed, the documentSizeChanged() signal should be emitted.

The update() signal should be emitted to schedule a repaint of areas in the layout that require repainting.

See also

QTextLayout

abstract documentSize()#

Return type:: QSizeF

Returns the total size of the document’s layout.

This information can be used by display widgets to update their scroll bars correctly.

See also

documentSizeChanged() pageSize

documentSizeChanged(newSize)#

Parameters:: newSize – QSizeF

This signal is emitted when the size of the document layout changes to newSize.

Subclasses of QAbstractTextDocumentLayout should emit this signal when the document’s entire layout size changes. This signal is useful for widgets that display text documents since it enables them to update their scroll bars correctly.

See also

documentSize()

abstract draw(painter, context)#

Parameters:

painter – QPainter
context – PaintContext

Draws the layout with the given painter using the given context.

drawInlineObject(painter, rect, object, posInDocument, format)#

Parameters:

painter – QPainter
rect – QRectF
object – QTextInlineObject
posInDocument – int
format – QTextFormat

This function is called to draw the inline object, object, with the given painter within the rectangle specified by rect using the specified text format.

posInDocument specifies the position of the object within the document.

The default implementation calls drawObject() on the object handlers. This function is called only within Qt. Subclasses can reimplement this function to customize the drawing of inline objects.

See also

draw()

format(pos)#

Parameters:: pos – int
Return type:: QTextCharFormat

Returns the character format that is applicable at the given position.

formatAt(pos)#

Parameters:: pos – QPointF
Return type:: QTextFormat

Returns the text format at the given position pos.

formatIndex(pos)#

Parameters:: pos – int
Return type:: int

abstract frameBoundingRect(frame)#

Parameters:: frame – QTextFrame
Return type:: QRectF

Returns the bounding rectangle of frame.

handlerForObject(objectType)#

Parameters:: objectType – int
Return type:: QTextObjectInterface

Returns a handler for objects of the given objectType.

abstract hitTest(point, accuracy)#

Parameters:

point – QPointF
accuracy – HitTestAccuracy

Return type:

int

Returns the cursor position for the given point with the specified accuracy. Returns -1 if no valid cursor position was found.

imageAt(pos)#

Parameters:: pos – QPointF
Return type:: str

Returns the source of the image at the given position pos, or an empty string if no image exists at that point.

abstract pageCount()#

Return type:: int

Returns the number of pages contained in the layout.

See also

pageCountChanged()

pageCountChanged(newPages)#

Parameters:: newPages – int

This signal is emitted when the number of pages in the layout changes; newPages is the updated page count.

Subclasses of QAbstractTextDocumentLayout should emit this signal when the number of pages in the layout has changed. Changes to the page count are caused by changes to the layout or the document content itself.

See also

pageCount()

paintDevice()#

Return type:: QPaintDevice

Returns the paint device used to render the document’s layout.

See also

setPaintDevice()

positionInlineObject(item, posInDocument, format)#

Parameters:

item – QTextInlineObject
posInDocument – int
format – QTextFormat

Lays out the inline object item using the given text format.

posInDocument specifies the position of the object within the document.

The default implementation does nothing. This function is called only within Qt. Subclasses can reimplement this function to customize the position of inline objects.

See also

drawInlineObject()

registerHandler(objectType, component)#

Parameters:

objectType – int
component – QObject

Registers the given component as a handler for items of the given objectType.

Note

registerHandler() has to be called once for each object type. This means that there is only one handler for multiple replacement characters of the same object type.

The text document layout does not take ownership of component.

resizeInlineObject(item, posInDocument, format)#

Parameters:

item – QTextInlineObject
posInDocument – int
format – QTextFormat

Sets the size of the inline object item corresponding to the text format.

posInDocument specifies the position of the object within the document.

The default implementation resizes the item to the size returned by the object handler’s intrinsicSize() function. This function is called only within Qt. Subclasses can reimplement this function to customize the resizing of inline objects.

setPaintDevice(device)#

Parameters:: device – QPaintDevice

Sets the paint device used for rendering the document’s layout to the given device.

See also

paintDevice()

unregisterHandler(objectType[, component=None])#

Parameters:

objectType – int
component – QObject

Unregisters the given component as a handler for items of the given objectType, or any handler if the component is not specified.

update([arg__1=QRectF(0., 0., 1000000000., 1000000000.)])#

Parameters:: arg__1 – QRectF

This signal is emitted when the rectangle rect has been updated.

Subclasses of QAbstractTextDocumentLayout should emit this signal when the layout of the contents change in order to repaint.

updateBlock(block)#

Parameters:: block – QTextBlock

This signal is emitted when the specified block has been updated.

Subclasses of QAbstractTextDocumentLayout should emit this signal when the layout of block has changed in order to repaint.