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.
If you are using QSimpleRichText to print in high resolution you
should call setWidth(QPainter, int) so that the content will be
laid out properly on the page.
See also Text Related Classes.
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.
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()).
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.
See also setWidth().
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). Passing
an null rectangle results in no clipping. 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.
Examples: action/application.cpp, application/application.cpp, helpviewer/helpwindow.cpp, and mdi/application.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.
See also setWidth().
Examples: action/application.cpp, application/application.cpp, helpviewer/helpwindow.cpp, and mdi/application.cpp.
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.
See also height() and adjustSize().
Examples: action/application.cpp, application/application.cpp, helpviewer/helpwindow.cpp, and mdi/application.cpp.
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.
See also height() and adjustSize().
int QSimpleRichText::width () const
Returns the set width of the rich text object in pixels.
See also widthUsed().
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.
See also width().
This file is part of the Qt toolkit.
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