QAbstractTextDocumentLayout ¶

概要 ¶

详细描述 ¶

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() 函数。

You can insert custom objects into a QTextDocument ; see the QTextObjectInterface 类描述了解细节。

另请参阅

QTextObjectInterface

class QAbstractTextDocumentLayout ( doc ) ¶

param doc

QTextDocument

Creates a new text document layout for the given document .

PySide2.QtGui.QAbstractTextDocumentLayout. anchorAt ( pos ) ¶

参数

pos – QPointF

返回类型

unicode

Returns the reference of the anchor the given position ，或空字符串若该点不存在锚点。

PySide2.QtGui.QAbstractTextDocumentLayout. blockBoundingRect ( block ) ¶

参数

block – QTextBlock

返回类型

QRectF

Returns the bounding rectangle of block .

PySide2.QtGui.QAbstractTextDocumentLayout. blockWithMarkerAt ( pos ) ¶

参数

pos – QPointF

返回类型

QTextBlock

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

PySide2.QtGui.QAbstractTextDocumentLayout. document ( ) ¶

返回类型

QTextDocument

Returns the text document that this layout is operating on.

PySide2.QtGui.QAbstractTextDocumentLayout. documentChanged ( from , charsRemoved , charsAdded ) ¶

参数

• 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 ，和 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.

• 每 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.

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

另请参阅

QTextLayout

PySide2.QtGui.QAbstractTextDocumentLayout. documentSize ( ) ¶

返回类型

QSizeF

Returns the total size of the document’s layout.

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

另请参阅

documentSizeChanged() pageSize

PySide2.QtGui.QAbstractTextDocumentLayout. documentSizeChanged ( newSize ) ¶

参数

newSize – QSizeF

PySide2.QtGui.QAbstractTextDocumentLayout. draw ( painter , context ) ¶

参数

• painter – QPainter

• context – PaintContext

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

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

参数

• painter – QPainter

• rect – QRectF

• object – QTextInlineObject

• posInDocument – int

• format – QTextFormat

This function is called to draw the inline object, object ，采用给定 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.

另请参阅

draw()

PySide2.QtGui.QAbstractTextDocumentLayout. format ( pos ) ¶

参数

pos – int

返回类型

QTextCharFormat

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

PySide2.QtGui.QAbstractTextDocumentLayout. formatAt ( pos ) ¶

参数

pos – QPointF

返回类型

QTextFormat

Returns the text format at the given position pos .

PySide2.QtGui.QAbstractTextDocumentLayout. formatIndex ( pos ) ¶

参数

pos – int

返回类型

int

Returns the index of the format at position pos .

PySide2.QtGui.QAbstractTextDocumentLayout. frameBoundingRect ( frame ) ¶

参数

frame – QTextFrame

返回类型

QRectF

Returns the bounding rectangle of frame .

PySide2.QtGui.QAbstractTextDocumentLayout. handlerForObject ( objectType ) ¶

参数

objectType – int

返回类型

QTextObjectInterface

Returns a handler for objects of the given objectType .

PySide2.QtGui.QAbstractTextDocumentLayout. hitTest ( point , accuracy ) ¶

参数

• point – QPointF

• accuracy – HitTestAccuracy

返回类型

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 ) ¶

参数

pos – QPointF

返回类型

unicode

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 ( ) ¶

返回类型

int

Returns the number of pages contained in the layout.

另请参阅

pageCountChanged()

PySide2.QtGui.QAbstractTextDocumentLayout. pageCountChanged ( newPages ) ¶

参数

newPages – int

PySide2.QtGui.QAbstractTextDocumentLayout. paintDevice ( ) ¶

返回类型

QPaintDevice

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

另请参阅

setPaintDevice()

PySide2.QtGui.QAbstractTextDocumentLayout. positionInlineObject ( item , posInDocument , format ) ¶

参数

• 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.

另请参阅

drawInlineObject()

PySide2.QtGui.QAbstractTextDocumentLayout. registerHandler ( objectType , component ) ¶

参数

• objectType – int

• component – QObject

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

注意

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 ) ¶

参数

• 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.

PySide2.QtGui.QAbstractTextDocumentLayout. setPaintDevice ( device ) ¶

参数

device – QPaintDevice

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

另请参阅

paintDevice()

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

参数

• 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.

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

参数

arg__1 – QRectF

PySide2.QtGui.QAbstractTextDocumentLayout. updateBlock ( block ) ¶

参数

block – QTextBlock