QAbstractTextDocumentLayout Class Reference

#include <qabstracttextdocumentlayout.h>

Inheritance diagram for QAbstractTextDocumentLayout:

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Collaboration diagram for QAbstractTextDocumentLayout:

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List of all members.

Detailed Description

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

The standard layout provided by Qt can handle simple word processing including inline layouts, 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 your own custom layout behavior for your text documents.

Definition at line 42 of file qabstracttextdocumentlayout.h.

Signals

void update (const QRectF &=QRectF(0., 0., 1000000000., 1000000000.))
void documentSizeChanged (const QSizeF &newSize)
void pageCountChanged (int newPages)

Public Member Functions

 QAbstractTextDocumentLayout (QTextDocument *doc)
 ~QAbstractTextDocumentLayout ()
virtual void draw (QPainter *painter, const PaintContext &context)=0
virtual int hitTest (const QPointF &point, Qt::HitTestAccuracy accuracy) const =0
QString anchorAt (const QPointF &pos) const
virtual int pageCount () const=0
virtual QSizeF documentSize () const=0
virtual QRectF frameBoundingRect (QTextFrame *frame) const=0
virtual QRectF blockBoundingRect (const QTextBlock &block) const=0
void setPaintDevice (QPaintDevice *device)
QPaintDevice * paintDevice () const
QTextDocument * document () const
void registerHandler (int objectType, QObject *component)
QTextObjectInterface * handlerForObject (int objectType) const

Protected Member Functions

 QAbstractTextDocumentLayout (QAbstractTextDocumentLayoutPrivate &, QTextDocument *)
virtual void documentChanged (int from, int charsRemoved, int charsAdded)=0
virtual void resizeInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format)
virtual void positionInlineObject (QTextInlineObject item, int posInDocument, const QTextFormat &format)
virtual void drawInlineObject (QPainter *painter, const QRectF &rect, QTextInlineObject object, int posInDocument, const QTextFormat &format)
int formatIndex (int pos)
QTextCharFormat format (int pos)

Private Member Functions

 Q_PRIVATE_SLOT (d_func(), void _q_handlerDestroyed(QObject *obj)) Q_PRIVATE_SLOT(d_func()
int _q_dynamicPageCountSlot ()) Q_PRIVATE_SLOT(d_func()

Friends

class QTextDocument
class QTextDocumentPrivate
class QTextEngine
class QTextLayout
class QTextLine

Classes

class  PaintContext
 The QAbstractTextDocumentLayout::PaintContext class is a convenience class defining the parameters of a painter context. More...
class  Selection
 the position within the document, where the cursor line should be drawn.the default color that is used for the text, when no color is specified in the text.a hint to the layout avoiding that paragraphs, frames or text that are clearly outside the specified rectangle, are drawnthe collection of selections that will be rendered when passing this painter context to QAbstractTextDocumentLayout's draw() function.The QAbstractTextDocumentLayout::Selection class is a convenience class defining the parameters of a selection. More...

Constructor & Destructor Documentation

QAbstractTextDocumentLayout::QAbstractTextDocumentLayout ( QTextDocument *  document  )  [explicit]

the format of the selectionthe selection's cursor

Creates a new text document layout for the given document.

Definition at line 222 of file qabstracttextdocumentlayout.cpp.

00223     : QObject(*new QAbstractTextDocumentLayoutPrivate, document)
00224 {
00225 }

QAbstractTextDocumentLayout::~QAbstractTextDocumentLayout (  ) 

Definition at line 238 of file qabstracttextdocumentlayout.cpp.

00239 {
00240 }

QAbstractTextDocumentLayout::QAbstractTextDocumentLayout ( QAbstractTextDocumentLayoutPrivate &  ,
QTextDocument *   
) [protected]

Definition at line 230 of file qabstracttextdocumentlayout.cpp.

00231     :QObject(p, document)
00232 {
00233 }

Member Function Documentation

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

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

Referenced by DocumentShape::DocumentShape(), QTextDocument::drawContents(), ArthurFrame::paintDescription(), QWhatsThat::paintEvent(), and PreviewView::paintPage().

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

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

Referenced by anchorAt(), QTextControlPrivate::dragMoveEvent(), QTextControlPrivate::mouseMoveEvent(), QTextControlPrivate::mousePressEvent(), and QTextControlPrivate::setCursorPosition().

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

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

Definition at line 410 of file qabstracttextdocumentlayout.cpp.

References QTextCharFormat::anchorHref(), QTextFormatCollection::charFormat(), Qt::ExactHit, QTextDocumentPrivate::find(), QTextDocumentPrivate::formatCollection(), hitTest(), and QObject::parent().

Referenced by QLabelPrivate::createStandardContextMenu(), QWhatsThat::mouseMoveEvent(), QWhatsThat::mousePressEvent(), and QWhatsThat::mouseReleaseEvent().

00411 {
00412     int cursorPos = hitTest(pos, Qt::ExactHit);
00413     if (cursorPos == -1)
00414         return QString();
00415 
00416     QTextDocumentPrivate *pieceTable = qobject_cast<const QTextDocument *>(parent())->docHandle();
00417     QTextDocumentPrivate::FragmentIterator it = pieceTable->find(cursorPos);
00418     QTextCharFormat fmt = pieceTable->formatCollection()->charFormat(it->format);
00419     return fmt.anchorHref();
00420 }

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int QAbstractTextDocumentLayout::pageCount (  )  const [pure virtual]

Returns the number of pages required by the layout.

See also:
pageCountChanged()

Referenced by QTextDocument::pageCount().

QSizeF QAbstractTextDocumentLayout::documentSize (  )  const [pure virtual]

Returns the total size of the document. This is useful to display widgets since they can use to information to update their scroll bars correctly

See also:
documentSizeChanged(), QTextDocument::pageSize

Referenced by QTextDocument::adjustSize(), TransEditor::calculateFieldHeight(), EditorPage::calculateFieldHeight(), DocumentShape::DocumentShape(), QLabelPrivate::layoutRect(), and QTextDocument::size().

QRectF QAbstractTextDocumentLayout::frameBoundingRect ( QTextFrame *  frame  )  const [pure virtual]

Returns the bounding rectacle of frame.

Returns the bounding rectangle of frame.

Referenced by QTextControlPrivate::selectionRect().

QRectF QAbstractTextDocumentLayout::blockBoundingRect ( const QTextBlock &  block  )  const [pure virtual]

Returns the bounding rectangle of block.

Referenced by QTextControlPrivate::extendWordwiseSelection(), QAccessibleTextEdit::rect(), QTextControlPrivate::rectForPosition(), and QTextControlPrivate::selectionRect().

void QAbstractTextDocumentLayout::setPaintDevice ( QPaintDevice *  device  ) 

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

See also:
paintDevice()

Definition at line 439 of file qabstracttextdocumentlayout.cpp.

References d.

Referenced by DocumentShape::DocumentShape(), QTextEditPrivate::init(), QTextDocument::print(), and PrintPreview::PrintPreview().

00440 {
00441     Q_D(QAbstractTextDocumentLayout);
00442     d->paintDevice = device;
00443 }

QPaintDevice * QAbstractTextDocumentLayout::paintDevice (  )  const

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

See also:
setPaintDevice()

Definition at line 450 of file qabstracttextdocumentlayout.cpp.

References d.

Referenced by QTextEngine::font(), QTextEngine::fontEngine(), getPixmapSize(), QTextDocument::print(), and QScriptLine::setDefaultHeight().

00451 {
00452     Q_D(const QAbstractTextDocumentLayout);
00453     return d->paintDevice;
00454 }

QTextDocument * QAbstractTextDocumentLayout::document (  )  const

Returns the text document that this layout is operating on.

Definition at line 399 of file qabstracttextdocumentlayout.cpp.

References QObject::parent().

Referenced by QTextDocumentLayout::blockBoundingRect(), QTextDocumentLayout::documentChanged(), QTextDocumentLayout::doLayout(), QTextDocumentLayout::draw(), drawInlineObject(), QTextDocumentLayout::drawInlineObject(), QTextDocumentLayout::dynamicDocumentSize(), QTextDocumentLayout::dynamicPageCount(), QTextDocumentLayout::hitTest(), QTextDocumentLayout::layoutStatus(), QTextDocumentLayout::positionInlineObject(), resizeInlineObject(), and QTextDocumentLayout::resizeInlineObject().

00400 {
00401     return qobject_cast<QTextDocument *>(parent());
00402 }

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

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

Definition at line 246 of file qabstracttextdocumentlayout.cpp.

References QObject::connect(), d, QObject::destroyed(), h, SIGNAL, and SLOT.

Referenced by QTextDocumentLayout::QTextDocumentLayout().

00247 {
00248     Q_D(QAbstractTextDocumentLayout);
00249 
00250     QTextObjectInterface *iface = qobject_cast<QTextObjectInterface *>(component);
00251     if (!iface)
00252         return; // ### print error message on terminal?
00253 
00254     connect(component, SIGNAL(destroyed(QObject*)), this, SLOT(_q_handlerDestroyed(QObject*)));
00255 
00256     QTextObjectHandler h;
00257     h.iface = iface;
00258     h.component = component;
00259     d->handlers.insert(formatType, h);
00260 }

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QTextObjectInterface * QAbstractTextDocumentLayout::handlerForObject ( int  objectType  )  const

Returns a handler for objects of the given objectType.

Definition at line 265 of file qabstracttextdocumentlayout.cpp.

References d, and handler.

00266 {
00267     Q_D(const QAbstractTextDocumentLayout);
00268 
00269     QTextObjectHandler handler = d->handlers.value(objectType);
00270     if (!handler.component)
00271         return 0;
00272 
00273     return handler.iface;
00274 }

void QAbstractTextDocumentLayout::update ( const QRectF &  rect = QRectF(0., 0., 1000000000., 1000000000.)  )  [signal]

This signal is emitted when the rectangle rect has been updated.

Referenced by QTextDocumentLayout::documentChanged().

void QAbstractTextDocumentLayout::documentSizeChanged ( const QSizeF &  newSize  )  [signal]

This signal is emitted when the size of the document changes. The new size is specified by newSize.

This information is useful to widgets that display text documents since it enables them to update their scroll bars correctly.

See also:
documentSize()

Referenced by QTextDocumentLayout::documentChanged(), and QTextDocumentLayout::timerEvent().

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.

Changes to the page count are due to the changes to the layout or the document content itself.

See also:
pageCount()

Referenced by QTextDocumentLayout::timerEvent().

void QAbstractTextDocumentLayout::documentChanged ( int  position,
int  charsRemoved,
int  charsAdded 
) [protected, pure virtual]

This function is called whenever the contents of the document change. A change occurs when text is inserted, removed, or a combination of the two types of operation. The change is specified by position, charsRemoved, and charsAdded corresponding to the starting character position of the change, the number of character 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 the combination of removal and insertion. For example, if the text "Hello" gets replaced by "Hi", charsRemoved would be 5 and charsAdded would be 2.

Referenced by QTextDocumentPrivate::clear(), QTextDocumentPrivate::endEditBlock(), and QTextDocumentPrivate::setLayout().

void QAbstractTextDocumentLayout::resizeInlineObject ( QTextInlineObject  item,
int  posInDocument,
const QTextFormat &  format 
) [protected, virtual]

Sets the size of the inline object item in accordance with the text format. posInDocument specifies the position of the object within the document.

Definition at line 281 of file qabstracttextdocumentlayout.cpp.

References d, document(), format(), handler, QTextCharFormat::isValid(), QTextFormat::objectType(), s, QTextInlineObject::setAscent(), QTextInlineObject::setDescent(), QTextInlineObject::setWidth(), and QTextFormat::toCharFormat().

Referenced by QTextEngine::shape().

00282 {
00283     Q_D(QAbstractTextDocumentLayout);
00284 
00285     QTextCharFormat f = format.toCharFormat();
00286     Q_ASSERT(f.isValid());
00287     QTextObjectHandler handler = d->handlers.value(f.objectType());
00288     if (!handler.component)
00289         return;
00290 
00291     QSizeF s = handler.iface->intrinsicSize(document(), posInDocument, format);
00292     item.setWidth(s.width());
00293     item.setAscent(s.height());
00294     item.setDescent(0);
00295 }

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void QAbstractTextDocumentLayout::positionInlineObject ( QTextInlineObject  item,
int  posInDocument,
const QTextFormat &  format 
) [protected, virtual]

Lays out the inline object item using the given text format. The base class implementation does nothing. posInDocument specifies the position of the object within the document.

See also:
drawInlineObject()

Definition at line 304 of file qabstracttextdocumentlayout.cpp.

References format().

Referenced by QTextLine::layout_helper().

00305 {
00306     Q_UNUSED(item);
00307     Q_UNUSED(posInDocument);
00308     Q_UNUSED(format);
00309 }

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

Called to draw the inline object object on the given painter within the rectangle specified by rect using the text format specified by format. posInDocument specifies the position of the object within the document.

See also:
draw()

Definition at line 321 of file qabstracttextdocumentlayout.cpp.

References QColor::blue, d, Qt::Dense4Pattern, document(), format(), QColor::green, handler, image, QPixmap::isNull(), QTextCharFormat::isValid(), QTextFormat::objectType(), p, QColor::red, QBrush::setTexture(), and QTextFormat::toCharFormat().

Referenced by QTextLine::draw(), and QTextDocumentLayout::drawInlineObject().

00323 {
00324     Q_UNUSED(item);
00325     Q_D(QAbstractTextDocumentLayout);
00326 
00327     QTextCharFormat f = format.toCharFormat();
00328     Q_ASSERT(f.isValid());
00329     QTextObjectHandler handler = d->handlers.value(f.objectType());
00330     if (!handler.component)
00331         return;
00332 
00333     handler.iface->drawObject(p, rect, document(), posInDocument, format);
00334 
00335 #if 0
00336     if (selType == QTextLayout::Highlight && item.engine()->pal) {
00337 #if defined (Q_WS_WIN)
00338         static QPixmap tile;
00339         if (tile.isNull()) {
00340             QImage image(128, 128, 32);
00341             image.fill((item.engine()->pal->highlight().color().rgb() & 0x00ffffff) | 0x7f000000);
00342             image.setAlphaBuffer(true);
00343             tile = QPixmap(image);
00344         }
00345         p->drawTiledPixmap(rect, tile);
00346 #elif defined (Q_WS_MAC)
00347         QColor hl = item.engine()->pal->highlight().color();
00348         QBrush brush(QColor(hl.red(), hl.green(), hl.blue(), 127));
00349         QPixmap texture = item.engine()->pal->highlight().texture();
00350         if(!texture.isNull())
00351             brush.setTexture(texture);
00352         p->fillRect(rect, brush);
00353 #else
00354         QBrush brush(item.engine()->pal->highlight().color(), Qt::Dense4Pattern);
00355         p->fillRect(rect, brush);
00356 #endif
00357     }
00358 #endif
00359 }

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int QAbstractTextDocumentLayout::formatIndex ( int  pos  )  [protected]

Definition at line 376 of file qabstracttextdocumentlayout.cpp.

References QTextDocumentPrivate::find(), and QObject::parent().

00377 {
00378     QTextDocumentPrivate *pieceTable = qobject_cast<QTextDocument *>(parent())->docHandle();
00379     return pieceTable->find(pos).value()->format;
00380 }

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QTextCharFormat QAbstractTextDocumentLayout::format ( int  position  )  [protected]

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

Definition at line 387 of file qabstracttextdocumentlayout.cpp.

References QTextFormatCollection::charFormat(), QTextDocumentPrivate::find(), QTextDocumentPrivate::formatCollection(), and QObject::parent().

Referenced by drawInlineObject(), QTextDocumentLayout::drawInlineObject(), positionInlineObject(), QTextDocumentLayout::positionInlineObject(), resizeInlineObject(), and QTextDocumentLayout::resizeInlineObject().

00388 {
00389     QTextDocumentPrivate *pieceTable = qobject_cast<QTextDocument *>(parent())->docHandle();
00390     int idx = pieceTable->find(pos).value()->format;
00391     return pieceTable->formatCollection()->charFormat(idx);
00392 }

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QAbstractTextDocumentLayout::Q_PRIVATE_SLOT ( d_func()  ,
void   _q_handlerDestroyed(QObject *obj) 
) [private]

int QAbstractTextDocumentLayout::_q_dynamicPageCountSlot (  )  [private]

Friends And Related Function Documentation

friend class QTextDocument [friend]

Definition at line 104 of file qabstracttextdocumentlayout.h.

friend class QTextDocumentPrivate [friend]

Definition at line 105 of file qabstracttextdocumentlayout.h.

friend class QTextEngine [friend]

Definition at line 106 of file qabstracttextdocumentlayout.h.

friend class QTextLayout [friend]

Definition at line 107 of file qabstracttextdocumentlayout.h.

friend class QTextLine [friend]

Definition at line 108 of file qabstracttextdocumentlayout.h.

The documentation for this class was generated from the following files:
Generated on Thu Mar 15 16:45:08 2007 for Qt 4.2 User's Guide by  doxygen 1.5.1