\reentrant More...

#include <qabstracttextdocumentlayout.h>

Inheritance diagram for QAbstractTextDocumentLayout:

Collaboration diagram for QAbstractTextDocumentLayout:

Classes
class	PaintContext
	\reentrant \inmodule QtGui More...

class	Selection
	\variable QAbstractTextDocumentLayout::PaintContext::cursorPosition More...

Signals
void	update (const QRectF &=QRectF(0., 0., 1000000000., 1000000000.))
	This signal is emitted when the rectangle rect has been updated.

void	updateBlock (const QTextBlock &block)

void	documentSizeChanged (const QSizeF &newSize)
	This signal is emitted when the size of the document layout changes to newSize.

void	pageCountChanged (int newPages)
	This signal is emitted when the number of pages in the layout changes; newPages is the updated page count.

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QAbstractTextDocumentLayout (QTextDocument *doc)
	\variable QAbstractTextDocumentLayout::Selection::format

	~QAbstractTextDocumentLayout ()

virtual void	draw (QPainter *painter, const PaintContext &context)=0
	Draws the layout with the given painter using the given context.

virtual int	hitTest (const QPointF &point, Qt::HitTestAccuracy accuracy) const =0
	Returns the cursor position for the given point with the specified accuracy.

QString	anchorAt (const QPointF &pos) const
	Returns the reference of the anchor the given position, or an empty string if no anchor exists at that point.

QString	imageAt (const QPointF &pos) const

QTextFormat	formatAt (const QPointF &pos) const

QTextBlock	blockWithMarkerAt (const QPointF &pos) const

virtual int	pageCount () const =0
	Returns the number of pages contained in the layout.

virtual QSizeF	documentSize () const =0
	Returns the total size of the document's layout.

virtual QRectF	frameBoundingRect (QTextFrame *frame) const =0
	Returns the bounding rectangle of frame.

virtual QRectF	blockBoundingRect (const QTextBlock &block) const =0
	Returns the bounding rectangle of block.

void	setPaintDevice (QPaintDevice *device)
	Sets the paint device used for rendering the document's layout to the given device.

QPaintDevice *	paintDevice () const
	Returns the paint device used to render the document's layout.

QTextDocument *	document () const
	Returns the text document that this layout is operating on.

void	registerHandler (int objectType, QObject *component)
	Registers the given component as a handler for items of the given objectType.

void	unregisterHandler (int objectType, QObject *component=nullptr)

QTextObjectInterface *	handlerForObject (int objectType) const
	Returns a handler for objects of the given objectType.

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

virtual bool	eventFilter (QObject watched, QEvent event)
	Filters events if this object has been installed as an event filter for the watched object.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Protected Member Functions
	QAbstractTextDocumentLayout (QAbstractTextDocumentLayoutPrivate &, QTextDocument *)

virtual void	documentChanged (int from, int charsRemoved, int charsAdded)=0
	This function is called whenever the contents of the document change.

virtual void	resizeInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format)
	Sets the size of the inline object item corresponding to the text format.

virtual void	positionInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format)
	Lays out the inline object item using the given text format.

virtual void	drawInlineObject (QPainter *painter, const QRectF &rect, QTextInlineObject object, int posInDocument, const QTextFormat &format)
	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.

int	formatIndex (int pos)

QTextCharFormat	format (int pos)
	Returns the character format that is applicable at the given position.

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Friends
class	QWidgetTextControl

class	QTextDocument

class	QTextDocumentPrivate

class	QTextEngine

class	QTextLayout

class	QTextLine

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

\reentrant

The QAbstractTextDocumentLayout class is an abstract base class used to implement custom layouts for QTextDocuments. \inmodule QtGui

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 \l{QTextDocument::}{setDocumentLayout()} function.

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

See also: QTextObjectInterface

Definition at line 22 of file qabstracttextdocumentlayout.h.

Constructor & Destructor Documentation

◆ QAbstractTextDocumentLayout() [1/2]

QAbstractTextDocumentLayout::QAbstractTextDocumentLayout ( QTextDocument * document )

explicit

\variable QAbstractTextDocumentLayout::Selection::format

the format of the selection

The default value is QTextFormat::InvalidFormat.

\variable QAbstractTextDocumentLayout::Selection::cursor

the selection's cursor

The default value is a null cursor.

Creates a new text document layout for the given document.

Definition at line 361 of file qabstracttextdocumentlayout.cpp.

◆ ~QAbstractTextDocumentLayout()

QAbstractTextDocumentLayout::~QAbstractTextDocumentLayout ( )

Definition at line 381 of file qabstracttextdocumentlayout.cpp.

◆ QAbstractTextDocumentLayout() [2/2]

QAbstractTextDocumentLayout::QAbstractTextDocumentLayout	(	QAbstractTextDocumentLayoutPrivate &	p,
		QTextDocument *	document )

protected

Definition at line 371 of file qabstracttextdocumentlayout.cpp.

Member Function Documentation

◆ anchorAt()

QString QAbstractTextDocumentLayout::anchorAt ( const QPointF & pos ) const

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

Definition at line 569 of file qabstracttextdocumentlayout.cpp.

◆ blockBoundingRect()

virtual QRectF QAbstractTextDocumentLayout::blockBoundingRect ( const QTextBlock & block ) const

pure virtual

Returns the bounding rectangle of block.

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ blockWithMarkerAt()

QTextBlock QAbstractTextDocumentLayout::blockWithMarkerAt ( const QPointF & pos ) const

Since: 5.14

Returns the block (probably a list item) whose \l{QTextBlockFormat::marker()}{marker} is found at the given position pos.

Definition at line 624 of file qabstracttextdocumentlayout.cpp.

◆ document()

QTextDocument * QAbstractTextDocumentLayout::document ( ) const

Returns the text document that this layout is operating on.

Definition at line 557 of file qabstracttextdocumentlayout.cpp.

◆ documentChanged()

virtual void QAbstractTextDocumentLayout::documentChanged	(	int	position,
		int	charsRemoved,
		int	charsAdded )

protectedpure virtual

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:

\list

Determine the list of changed \l{QTextBlock}(s) using the parameters provided.
Each QTextBlock object's corresponding QTextLayout object needs to be processed. You can access the \l{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. \endlist

See also: QTextLayout

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ documentSize()

virtual QSizeF QAbstractTextDocumentLayout::documentSize ( ) const

pure virtual

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, and QTextDocumentLayout.

◆ documentSizeChanged

void QAbstractTextDocumentLayout::documentSizeChanged ( const QSizeF & newSize )

signal

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()

◆ draw()

virtual void QAbstractTextDocumentLayout::draw	(	QPainter *	painter,
		const PaintContext &	context )

pure virtual

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

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ drawInlineObject()

void QAbstractTextDocumentLayout::drawInlineObject	(	QPainter *	painter,
		const QRectF &	rect,
		QTextInlineObject	object,
		int	posInDocument,
		const QTextFormat &	format )

protectedvirtual

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()

Reimplemented in QTextDocumentLayout.

Definition at line 504 of file qabstracttextdocumentlayout.cpp.

◆ format()

QTextCharFormat QAbstractTextDocumentLayout::format ( int pos )

protected

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

Definition at line 545 of file qabstracttextdocumentlayout.cpp.

◆ formatAt()

QTextFormat QAbstractTextDocumentLayout::formatAt ( const QPointF & pos ) const

Since: 5.8

Returns the text format at the given position pos.

Definition at line 592 of file qabstracttextdocumentlayout.cpp.

◆ formatIndex()

int QAbstractTextDocumentLayout::formatIndex ( int pos )

protected

Returns the index of the format at position pos.

Definition at line 534 of file qabstracttextdocumentlayout.cpp.

◆ frameBoundingRect()

virtual QRectF QAbstractTextDocumentLayout::frameBoundingRect ( QTextFrame * frame ) const

pure virtual

Returns the bounding rectangle of frame.

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ handlerForObject()

QTextObjectInterface * QAbstractTextDocumentLayout::handlerForObject ( int objectType ) const

Returns a handler for objects of the given objectType.

Definition at line 433 of file qabstracttextdocumentlayout.cpp.

◆ hitTest()

virtual int QAbstractTextDocumentLayout::hitTest	(	const QPointF &	point,
		Qt::HitTestAccuracy	accuracy ) const

pure virtual

Returns the cursor position for the given point with the specified accuracy.

Returns -1 if no valid cursor position was found.

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ imageAt()

QString QAbstractTextDocumentLayout::imageAt ( const QPointF & pos ) const

Since: 5.8

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

Definition at line 581 of file qabstracttextdocumentlayout.cpp.

◆ pageCount()

virtual int QAbstractTextDocumentLayout::pageCount ( ) const

pure virtual

Returns the number of pages contained in the layout.

See also: pageCountChanged()

Implemented in QPlainTextDocumentLayout, and QTextDocumentLayout.

◆ pageCountChanged

void QAbstractTextDocumentLayout::pageCountChanged ( int newPages )

signal

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()

QPaintDevice * QAbstractTextDocumentLayout::paintDevice ( ) const

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

See also: setPaintDevice()

Definition at line 677 of file qabstracttextdocumentlayout.cpp.

◆ positionInlineObject()

void QAbstractTextDocumentLayout::positionInlineObject	(	QTextInlineObject	item,
		int	posInDocument,
		const QTextFormat &	format )

protectedvirtual

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()

Reimplemented in QTextDocumentLayout.

Definition at line 482 of file qabstracttextdocumentlayout.cpp.

◆ registerHandler()

void QAbstractTextDocumentLayout::registerHandler	(	int	objectType,
		QObject *	component )

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.

Definition at line 394 of file qabstracttextdocumentlayout.cpp.

◆ resizeInlineObject()

void QAbstractTextDocumentLayout::resizeInlineObject	(	QTextInlineObject	item,
		int	posInDocument,
		const QTextFormat &	format )

protectedvirtual

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.

Reimplemented in QTextDocumentLayout.

Definition at line 455 of file qabstracttextdocumentlayout.cpp.