QAbstractTextDocumentLayout

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

Inheritance diagram of PySide2.QtGui.QAbstractTextDocumentLayout

Inherited by: QPlainTextDocumentLayout

Synopsis

Functions

Virtual functions

Signals

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

class PySide2.QtGui.QAbstractTextDocumentLayout(doc)

Creates a new text document layout for the given document .

PySide2.QtGui.QAbstractTextDocumentLayout.anchorAt(pos)
Parameters:

pos – PySide2.QtCore.QPointF

Return type:

str

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

PySide2.QtGui.QAbstractTextDocumentLayout.blockBoundingRect(block)
Parameters:

block – PySide2.QtGui.QTextBlock

Return type:

PySide2.QtCore.QRectF

Returns the bounding rectangle of block .

PySide2.QtGui.QAbstractTextDocumentLayout.blockWithMarkerAt(pos)
Parameters:

pos – PySide2.QtCore.QPointF

Return type:

PySide2.QtGui.QTextBlock

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

PySide2.QtGui.QAbstractTextDocumentLayout.document()
Return type:

PySide2.QtGui.QTextDocument

Returns the text document that this layout is operating on.

PySide2.QtGui.QAbstractTextDocumentLayout.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

PySide2.QtGui.QAbstractTextDocumentLayout.documentSize()
Return type:

PySide2.QtCore.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

PySide2.QtGui.QAbstractTextDocumentLayout.documentSizeChanged(newSize)
Parameters:

newSize – PySide2.QtCore.QSizeF

PySide2.QtGui.QAbstractTextDocumentLayout.draw(painter, context)
Parameters:

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

PySide2.QtGui.QAbstractTextDocumentLayout.drawInlineObject(painter, rect, object, posInDocument, format)
Parameters:

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()

PySide2.QtGui.QAbstractTextDocumentLayout.format(pos)
Parameters:

pos – int

Return type:

PySide2.QtGui.QTextCharFormat

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

PySide2.QtGui.QAbstractTextDocumentLayout.formatAt(pos)
Parameters:

pos – PySide2.QtCore.QPointF

Return type:

PySide2.QtGui.QTextFormat

Returns the text format at the given position pos .

PySide2.QtGui.QAbstractTextDocumentLayout.formatIndex(pos)
Parameters:

pos – int

Return type:

int

Returns the index of the format at position pos .

PySide2.QtGui.QAbstractTextDocumentLayout.frameBoundingRect(frame)
Parameters:

frame – PySide2.QtGui.QTextFrame

Return type:

PySide2.QtCore.QRectF

Returns the bounding rectangle of frame .

PySide2.QtGui.QAbstractTextDocumentLayout.handlerForObject(objectType)
Parameters:

objectType – int

Return type:

PySide2.QtGui.QTextObjectInterface

Returns a handler for objects of the given objectType .

PySide2.QtGui.QAbstractTextDocumentLayout.hitTest(point, accuracy)
Parameters:
Return type:

int

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

PySide2.QtGui.QAbstractTextDocumentLayout.imageAt(pos)
Parameters:

pos – PySide2.QtCore.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.

PySide2.QtGui.QAbstractTextDocumentLayout.pageCount()
Return type:

int

Returns the number of pages contained in the layout.

See also

pageCountChanged()

PySide2.QtGui.QAbstractTextDocumentLayout.pageCountChanged(newPages)
Parameters:

newPages – int

PySide2.QtGui.QAbstractTextDocumentLayout.paintDevice()
Return type:

PySide2.QtGui.QPaintDevice

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

See also

setPaintDevice()

PySide2.QtGui.QAbstractTextDocumentLayout.positionInlineObject(item, posInDocument, format)
Parameters:

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()

PySide2.QtGui.QAbstractTextDocumentLayout.registerHandler(objectType, component)
Parameters:

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

Note

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 .

PySide2.QtGui.QAbstractTextDocumentLayout.resizeInlineObject(item, posInDocument, format)
Parameters:

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.

PySide2.QtGui.QAbstractTextDocumentLayout.setPaintDevice(device)
Parameters:

device – PySide2.QtGui.QPaintDevice

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

See also

paintDevice()

PySide2.QtGui.QAbstractTextDocumentLayout.unregisterHandler(objectType[, component=None])
Parameters:

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

PySide2.QtGui.QAbstractTextDocumentLayout.update([arg__1=QRectF(0., 0., 1000000000., 1000000000.)])
Parameters:

arg__1 – PySide2.QtCore.QRectF

PySide2.QtGui.QAbstractTextDocumentLayout.updateBlock(block)
Parameters:

block – PySide2.QtGui.QTextBlock