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Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
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QTextDocumentLayout Class Reference

#include <qtextdocumentlayout_p.h>

Inheritance diagram for QTextDocumentLayout:
Collaboration diagram for QTextDocumentLayout:

Public Member Functions

 QTextDocumentLayout (QTextDocument *doc)
void draw (QPainter *painter, const PaintContext &context) override
 Draws the layout with the given painter using the given context.
int hitTest (const QPointF &point, Qt::HitTestAccuracy accuracy) const override
 Returns the cursor position for the given point with the specified accuracy.
int pageCount () const override
 Returns the number of pages contained in the layout.
QSizeF documentSize () const override
 Returns the total size of the document's layout.
void setCursorWidth (int width)
int cursorWidth () const
void setFixedColumnWidth (int width)
void setViewport (const QRectF &viewport)
virtual QRectF frameBoundingRect (QTextFrame *frame) const override
 Returns the bounding rectangle of frame.
virtual QRectF blockBoundingRect (const QTextBlock &block) const override
 Returns the bounding rectangle of block.
QRectF tableBoundingRect (QTextTable *table) const
QRectF tableCellBoundingRect (QTextTable *table, const QTextTableCell &cell) const
int layoutStatus () const
int dynamicPageCount () const
QSizeF dynamicDocumentSize () const
void ensureLayouted (qreal)
qreal idealWidth () const
bool contentHasAlignment () const
Public Member Functions inherited from QAbstractTextDocumentLayout
 QAbstractTextDocumentLayout (QTextDocument *doc)
 \variable QAbstractTextDocumentLayout::Selection::format
 ~QAbstractTextDocumentLayout ()
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
void setPaintDevice (QPaintDevice *device)
 Sets the paint device used for rendering the document's layout to the given device.
QPaintDevicepaintDevice () const
 Returns the paint device used to render the document's layout.
QTextDocumentdocument () 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)
QTextObjectInterfacehandlerForObject (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< QStringbindableObjectName ()
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 isQmlObjectType () const
 Returns whether the object has been created by the QML engine or ownership has been explicitly set via QJSEngine::setObjectOwnership().
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).
QThreadthread () 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>
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>
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 QObjectListchildren () 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< QByteArraydynamicPropertyNames () const
QBindingStoragebindingStorage ()
const QBindingStoragebindingStorage () const
QObjectparent () 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

void documentChanged (int from, int oldLength, int length) override
 This function is called whenever the contents of the document change.
void resizeInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format) override
 Sets the size of the inline object item corresponding to the text format.
void positionInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format) override
 Lays out the inline object item using the given text format.
void drawInlineObject (QPainter *p, const QRectF &rect, QTextInlineObject item, int posInDocument, const QTextFormat &format) override
 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.
virtual void timerEvent (QTimerEvent *e) override
 This event handler can be reimplemented in a subclass to receive timer events for the object.
Protected Member Functions inherited from QAbstractTextDocumentLayout
 QAbstractTextDocumentLayout (QAbstractTextDocumentLayoutPrivate &, QTextDocument *)
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
QObjectsender () 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 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)

Properties

int cursorWidth
qreal idealWidth
bool contentHasAlignment
Properties inherited from QObject
QString objectName
 the name of this object

Additional Inherited Members

Public Slots inherited from QObject
void deleteLater ()
 \threadsafe
Signals inherited from QAbstractTextDocumentLayout
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.
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< QObjectDatad_ptr

Detailed Description

Definition at line 32 of file qtextdocumentlayout_p.h.

Constructor & Destructor Documentation

◆ QTextDocumentLayout()

QTextDocumentLayout::QTextDocumentLayout ( QTextDocument * doc)
explicit

Definition at line 3698 of file qtextdocumentlayout.cpp.

Member Function Documentation

◆ blockBoundingRect()

QRectF QTextDocumentLayout::blockBoundingRect ( const QTextBlock & block) const
overridevirtual

Returns the bounding rectangle of block.

Implements QAbstractTextDocumentLayout.

Definition at line 4112 of file qtextdocumentlayout.cpp.

◆ contentHasAlignment()

bool QTextDocumentLayout::contentHasAlignment ( ) const

Definition at line 4195 of file qtextdocumentlayout.cpp.

◆ cursorWidth()

int QTextDocumentLayout::cursorWidth ( ) const

Definition at line 4031 of file qtextdocumentlayout.cpp.

◆ documentChanged()

void QTextDocumentLayout::documentChanged ( int position,
int charsRemoved,
int charsAdded )
overrideprotectedvirtual

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

Implements QAbstractTextDocumentLayout.

Definition at line 3759 of file qtextdocumentlayout.cpp.

◆ documentSize()

QSizeF QTextDocumentLayout::documentSize ( ) const
overridevirtual

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

Implements QAbstractTextDocumentLayout.

Definition at line 3984 of file qtextdocumentlayout.cpp.

◆ draw()

void QTextDocumentLayout::draw ( QPainter * painter,
const PaintContext & context )
overridevirtual

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

Implements QAbstractTextDocumentLayout.

Definition at line 3705 of file qtextdocumentlayout.cpp.

◆ drawInlineObject()

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

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 from QAbstractTextDocumentLayout.

Definition at line 3948 of file qtextdocumentlayout.cpp.

◆ dynamicDocumentSize()

QSizeF QTextDocumentLayout::dynamicDocumentSize ( ) const

Definition at line 3971 of file qtextdocumentlayout.cpp.

◆ dynamicPageCount()

int QTextDocumentLayout::dynamicPageCount ( ) const

Definition at line 3962 of file qtextdocumentlayout.cpp.

◆ ensureLayouted()

void QTextDocumentLayout::ensureLayouted ( qreal y)

Definition at line 4183 of file qtextdocumentlayout.cpp.

◆ frameBoundingRect()

QRectF QTextDocumentLayout::frameBoundingRect ( QTextFrame * frame) const
overridevirtual

Returns the bounding rectangle of frame.

Implements QAbstractTextDocumentLayout.

Definition at line 4083 of file qtextdocumentlayout.cpp.

◆ hitTest()

int QTextDocumentLayout::hitTest ( const QPointF & point,
Qt::HitTestAccuracy accuracy ) const
overridevirtual

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

Returns -1 if no valid cursor position was found.

Implements QAbstractTextDocumentLayout.

Definition at line 3849 of file qtextdocumentlayout.cpp.

◆ idealWidth()

qreal QTextDocumentLayout::idealWidth ( ) const

Definition at line 4188 of file qtextdocumentlayout.cpp.

◆ layoutStatus()

int QTextDocumentLayout::layoutStatus ( ) const

Definition at line 4141 of file qtextdocumentlayout.cpp.

◆ pageCount()

int QTextDocumentLayout::pageCount ( ) const
overridevirtual

Returns the number of pages contained in the layout.

See also
pageCountChanged()

Implements QAbstractTextDocumentLayout.

Definition at line 3977 of file qtextdocumentlayout.cpp.

◆ positionInlineObject()

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

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 from QAbstractTextDocumentLayout.

Definition at line 3921 of file qtextdocumentlayout.cpp.

◆ resizeInlineObject()

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

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 from QAbstractTextDocumentLayout.

Definition at line 3875 of file qtextdocumentlayout.cpp.

◆ setCursorWidth()

void QTextDocumentLayout::setCursorWidth ( int width)

Definition at line 4025 of file qtextdocumentlayout.cpp.

◆ setFixedColumnWidth()

void QTextDocumentLayout::setFixedColumnWidth ( int width)

Definition at line 4037 of file qtextdocumentlayout.cpp.

◆ setViewport()

void QTextDocumentLayout::setViewport ( const QRectF & viewport)

Definition at line 3733 of file qtextdocumentlayout.cpp.

◆ tableBoundingRect()

QRectF QTextDocumentLayout::tableBoundingRect ( QTextTable * table) const

Definition at line 4056 of file qtextdocumentlayout.cpp.

◆ tableCellBoundingRect()

QRectF QTextDocumentLayout::tableCellBoundingRect ( QTextTable * table,
const QTextTableCell & cell ) const

Definition at line 4043 of file qtextdocumentlayout.cpp.

◆ timerEvent()

void QTextDocumentLayout::timerEvent ( QTimerEvent * event)
overrideprotectedvirtual

This event handler can be reimplemented in a subclass to receive timer events for the object.

QChronoTimer provides higher-level interfaces to the timer functionality, and also more general information about timers. The timer event is passed in the event parameter.

See also
startTimer(), killTimer(), event()

Reimplemented from QObject.

Definition at line 4150 of file qtextdocumentlayout.cpp.

Property Documentation

◆ contentHasAlignment

bool QTextDocumentLayout::contentHasAlignment
read

Definition at line 38 of file qtextdocumentlayout_p.h.

◆ cursorWidth

int QTextDocumentLayout::cursorWidth
readwrite

Definition at line 36 of file qtextdocumentlayout_p.h.

◆ idealWidth

qreal QTextDocumentLayout::idealWidth
read

Definition at line 37 of file qtextdocumentlayout_p.h.


The documentation for this class was generated from the following files: