Constructs a new text document layout for the given doc.

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

Returns the bounding rectangle of block.

Implemented in QPlainTextDocumentLayout::blockBoundingRect()

Returns the text document that this layout is operating on.

This method 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.

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. 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 QTextBlock::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

Implemented in QPlainTextDocumentLayout::documentChanged()

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(), QTextDocument::pageSize

Implemented in QPlainTextDocumentLayout::documentSize()

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()

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

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 internally. Subclasses can reimplement this function to customize the drawing of inline objects.

See also

draw()

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

Returns the bounding rectangle of frame.

Implemented in QPlainTextDocumentLayout::frameBoundingRect()

Returns a handler for objects of the given objectType.

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

Implemented in QPlainTextDocumentLayout::hitTest()

Returns the number of pages contained in the layout.

See also

pageCountChanged()

Implemented in QPlainTextDocumentLayout::pageCount()

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()

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

See also

setPaintDevice()

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 internally. Subclasses can reimplement this function to customize the position of inline objects.

See also

drawInlineObject()

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.

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 internally. Subclasses can reimplement this function to customize the resizing of inline objects.

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

See also

paintDevice()

Unregisters the given component as handler for items of the given objectType. Unregisters all handlers if the component is a nullptr.

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.

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.