QSimpleRichText Class

Qt 3.0.5

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QSimpleRichText Class Reference

The QSimpleRichText class provides a small displayable piece of rich text. More...

#include <qsimplerichtext.h>

List of all member functions.

Public Members

QSimpleRichText ( const QString & text, const QFont & fnt, const QString & context = QString::null, const QStyleSheet * sheet = 0 )
QSimpleRichText ( const QString & text, const QFont & fnt, const QString & context, const QStyleSheet * sheet, const QMimeSourceFactory * factory, int pageBreak = -1, const QColor & linkColor = Qt::blue, bool linkUnderline = TRUE )
~QSimpleRichText ()
void setWidth ( int w )
void setWidth ( QPainter * p, int w )
void setDefaultFont ( const QFont & f )
int width () const
int widthUsed () const
int height () const
void adjustSize ()
void draw ( QPainter * p, int x, int y, const QRect & clipRect, const QColorGroup & cg, const QBrush * paper = 0 ) const
void draw ( QPainter * p, int x, int y, const QRegion & clipRegion, const QColorGroup & cg, const QBrush * paper = 0 ) const (obsolete)
QString context () const
QString anchorAt ( const QPoint & pos ) const
bool inText ( const QPoint & pos ) const

Detailed Description

The QSimpleRichText class provides a small displayable piece of rich text.

This class encapsulates simple rich text usage in which a string is interpreted as rich text and can be drawn. This is particularly useful if you want to display some rich text in a custom widget. A QStyleSheet is needed to interpret the tags and format the rich text. Qt provides a default HTML-like style sheet, but you may define custom style sheets.

Once created, the rich text object can be queried for its width(), height(), and the actual width used (see widthUsed()). Most importantly, it can be drawn on any given QPainter with draw(). QSimpleRichText can also be used to implement hypertext or active text facilities by using anchorAt(). A hit test through inText() makes it possible to use simple rich text for text objects in editable drawing canvases.

Once constructed from a string the contents cannot be changed, only resized. If the contents change, just throw the rich text object away and make a new one with the new contents.

For large documents use QTextEdit or QTextBrowser. For very small items of rich text you can use a QLabel.

Member Function Documentation

QSimpleRichText::QSimpleRichText ( const QString & text, const QFont & fnt, const QString & context = QString::null, const QStyleSheet * sheet = 0 )

Constructs a QSimpleRichText from the rich text string text and the font fnt.

The font is used as a basis for the text rendering. When using rich text rendering on a widget w, you would normally specify the widget's font, for example:

    QSimpleRichText myrichtext( contents, mywidget->font() );

context is the optional context of the rich text object. This becomes important if text contains relative references, for example within image tags. QSimpleRichText always uses the default mime source factory (see QMimeSourceFactory::defaultFactory()) to resolve those references. The context will then be used to calculate the absolute path. See QMimeSourceFactory::makeAbsolute() for details.

The sheet is an optional style sheet. If it is 0, the default style sheet will be used (see QStyleSheet::defaultSheet()).

QSimpleRichText::QSimpleRichText ( const QString & text, const QFont & fnt, const QString & context, const QStyleSheet * sheet, const QMimeSourceFactory * factory, int pageBreak = -1, const QColor & linkColor = Qt::blue, bool linkUnderline = TRUE )

Constructs a QSimpleRichText from the rich text string text and the font fnt.

This is a slightly more complex constructor for QSimpleRichText that takes an additional mime source factory factory, a page break parameter pageBreak and a bool linkUnderline. linkColor is only provided for compatibility, but has no effect, as QColorGroup's QColorGroup::link() color is used now.

The sheet is an optional style sheet. If it is 0, the default style sheet will be used (see QStyleSheet::defaultSheet()).

This constructor is useful for creating a QSimpleRichText object suitable for printing. Set pageBreak to be the height of the contents area of the pages.

QSimpleRichText::~QSimpleRichText ()

Destroys the rich text object, freeing memory.

void QSimpleRichText::adjustSize ()

Adjusts the richt text object to a reasonable size.

QString QSimpleRichText::anchorAt ( const QPoint & pos ) const

Returns the anchor at the requested position, pos. An empty string is returned if no anchor is specified for this position.

QString QSimpleRichText::context () const

Returns the context of the rich text object. If no context has been specified in the constructor, a null string is returned. The context is the path to use to look up relative links, such as image tags and anchor references.

void QSimpleRichText::draw ( QPainter * p, int x, int y, const QRect & clipRect, const QColorGroup & cg, const QBrush * paper = 0 ) const

Draws the formatted text with painter p, at position (x, y), clipped to clipRect. The clipping rectangle is given in the rich text object's coordinates translated by (x, y). Colors from the color group cg are used as needed, and if not 0, *paper is used as the background brush.

Note that the display code is highly optimized to reduce flicker, so passing a brush for paper is preferable to simply clearing the area to be painted and then calling this without a brush.

Example: helpviewer/helpwindow.cpp.

void QSimpleRichText::draw ( QPainter * p, int x, int y, const QRegion & clipRegion, const QColorGroup & cg, const QBrush * paper = 0 ) const

This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code.

Use the version with clipRect instead. The region version has problems with larger documents on some platforms (on X11 regions internally are represented with 16bit coordinates).

int QSimpleRichText::height () const

Returns the height of the rich text object in pixels.

bool QSimpleRichText::inText ( const QPoint & pos ) const

Returns TRUE if pos is within a text line of the rich text object; otherwise returns FALSE.

void QSimpleRichText::setDefaultFont ( const QFont & f )

Sets the default font for the rich text object to f

void QSimpleRichText::setWidth ( QPainter * p, int w )

Sets the width of the rich text object to w pixels, recalculating the layout as if it were to be drawn with painter p.

Passing a painter is useful when you intend drawing on devices other than the screen, for example a QPrinter.

void QSimpleRichText::setWidth ( int w )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Sets the width of the rich text object to w pixels.

int QSimpleRichText::width () const

Returns the set width of the rich text object in pixels.

int QSimpleRichText::widthUsed () const

Returns the width in pixels that is actually used by the rich text object. This can be smaller or wider than the set width.

It may be wider, for example, if the text contains images or non-breakable words that are already wider than the available space. It's smaller when the object only consists of lines that do not fill the width completely.