source: vendor/trolltech/current/src/kernel/qstylesheet.cpp

/****************************************************************************
** $Id: qstylesheet.cpp 2 2005-11-16 15:49:26Z dmik $
**
** Implementation of the QStyleSheet class
**
** Created : 990101
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

#include "qstylesheet.h"

#ifndef QT_NO_RICHTEXT

#include "private/qrichtext_p.h"
#include "qlayout.h"
#include "qpainter.h"
#include "qcleanuphandler.h"

#include <stdio.h>

class QStyleSheetItemData
{
public:
    QStyleSheetItem::DisplayMode disp;
    int fontitalic;
    int fontunderline;
    int fontstrikeout;
    int fontweight;
    int fontsize;
    int fontsizelog;
    int fontsizestep;
    int lineSpacing;
    QString fontfamily;
    QStyleSheetItem *parentstyle;
    QString stylename;
    int ncolumns;
    QColor col;
    bool anchor;
    int align;
    QStyleSheetItem::VerticalAlignment valign;
    int margin[5];
    QStyleSheetItem::ListStyle list;
    QStyleSheetItem::WhiteSpaceMode whitespacemode;
    QString contxt;
    bool selfnest;
    QStyleSheet* sheet;
};

/*!
    \class QStyleSheetItem qstylesheet.h
    \brief The QStyleSheetItem class provides an encapsulation of a set of text styles.

    \ingroup text

    A style sheet item consists of a name and a set of attributes that
    specifiy its font, color, etc. When used in a \link QStyleSheet
    style sheet\endlink (see styleSheet()), items define the name() of
    a rich text tag and the display property changes associated with
    it.

    The \link QStyleSheetItem::DisplayMode display mode\endlink
    attribute indicates whether the item is a block, an inline element
    or a list element; see setDisplayMode(). The treatment of
    whitespace is controlled by the \link
    QStyleSheetItem::WhiteSpaceMode white space mode\endlink; see
    setWhiteSpaceMode(). An item's margins are set with setMargin(),
    In the case of list items, the list style is set with
    setListStyle(). An item may be a hypertext link anchor; see
    setAnchor(). Other attributes are set with setAlignment(),
    setVerticalAlignment(), setFontFamily(), setFontSize(),
    setFontWeight(), setFontItalic(), setFontUnderline(),
    setFontStrikeOut and setColor().
*/

/*! \enum QStyleSheetItem::AdditionalStyleValues
    \internal
*/

/*!
    \enum QStyleSheetItem::WhiteSpaceMode

    This enum defines the ways in which QStyleSheet can treat
    whitespace.

    \value WhiteSpaceNormal  any sequence of whitespace (including
        line-breaks) is equivalent to a single space.

    \value WhiteSpacePre  whitespace must be output exactly as given
        in the input.

    \value WhiteSpaceNoWrap  multiple spaces are collapsed as with
        WhiteSpaceNormal, but no automatic line-breaks occur. To break
        lines manually, use the \c{<br>} tag.

*/

/*!
    \enum QStyleSheetItem::Margin

    \value MarginLeft  left margin
    \value MarginRight  right margin
    \value MarginTop  top margin
    \value MarginBottom  bottom margin
    \value MarginAll  all margins (left, right, top and bottom)
    \value MarginVertical  top and bottom margins
    \value MarginHorizontal  left and right margins
    \value MarginFirstLine  margin (indentation) of the first line of
        a paragarph (in addition to the MarginLeft of the paragraph)
*/

/*!
    Constructs a new style called \a name for the stylesheet \a
    parent.

    All properties in QStyleSheetItem are initially in the "do not
    change" state, except \link QStyleSheetItem::DisplayMode display
    mode\endlink, which defaults to \c DisplayInline.
*/
QStyleSheetItem::QStyleSheetItem( QStyleSheet* parent, const QString& name )
{
    d = new QStyleSheetItemData;
    d->stylename = name.lower();
    d->sheet = parent;
    init();
    if (parent)
        parent->insert( this );
}

/*!
    Copy constructor. Constructs a copy of \a other that is not bound
    to any style sheet.
*/
QStyleSheetItem::QStyleSheetItem( const QStyleSheetItem & other )
{
    d = new QStyleSheetItemData;
    *d = *other.d;
}


/*!
    Destroys the style. Note that QStyleSheetItem objects become
    owned by QStyleSheet when they are created.
*/
QStyleSheetItem::~QStyleSheetItem()
{
    delete d;
}

/*!
  Assignment. Assings a copy of \a other that is not bound to any style sheet.
  Unbounds first from previous style sheet.
 */
QStyleSheetItem& QStyleSheetItem::operator=( const QStyleSheetItem& other )
{
    if ( &other == this )
        return *this;
    delete d;
    d = new QStyleSheetItemData;
    *d = *other.d;
    return *this;
}

/*!
    Returns the style sheet this item is in.
*/
QStyleSheet* QStyleSheetItem::styleSheet()
{
    return d->sheet;
}

/*!
    \overload

    Returns the style sheet this item is in.
*/
const QStyleSheet* QStyleSheetItem::styleSheet() const
{
    return d->sheet;
}

/*!
  \internal
  Internal initialization
 */
void QStyleSheetItem::init()
{
    d->disp = DisplayInline;

    d->fontitalic = Undefined;
    d->fontunderline = Undefined;
    d->fontstrikeout = Undefined;
    d->fontweight = Undefined;
    d->fontsize = Undefined;
    d->fontsizelog = Undefined;
    d->fontsizestep = 0;
    d->ncolumns = Undefined;
    d->col = QColor(); // !isValid()
    d->anchor = FALSE;
    d->align = Undefined;
    d->valign = VAlignBaseline;
    d->margin[0] = Undefined;
    d->margin[1] = Undefined;
    d->margin[2] = Undefined;
    d->margin[3] = Undefined;
    d->margin[4] = Undefined;
    d->list = ListStyleUndefined;
    d->whitespacemode = WhiteSpaceModeUndefined;
    d->selfnest = TRUE;
    d->lineSpacing = Undefined;
}

/*!
    Returns the name of the style item.
*/
QString QStyleSheetItem::name() const
{
    return d->stylename;
}

/*!
    Returns the \link QStyleSheetItem::DisplayMode display
    mode\endlink of the style.

    \sa setDisplayMode()
*/
QStyleSheetItem::DisplayMode QStyleSheetItem::displayMode() const
{
    return d->disp;
}

/*!
    \enum QStyleSheetItem::DisplayMode

    This enum type defines the way adjacent elements are displayed.

    \value DisplayBlock  elements are displayed as a rectangular block
        (e.g. \c{<p>...</p>}).

    \value DisplayInline  elements are displayed in a horizontally
        flowing sequence (e.g. \c{<em>...</em>}).

    \value DisplayListItem  elements are displayed in a vertical
        sequence (e.g. \c{<li>...</li>}).

    \value DisplayNone  elements are not displayed at all.
*/

/*!
    Sets the display mode of the style to \a m.

    \sa displayMode()
 */
void QStyleSheetItem::setDisplayMode(DisplayMode m)
{
    d->disp=m;
}


/*!
    Returns the alignment of this style. Possible values are \c
    AlignAuto, \c AlignLeft, \c AlignRight, \c AlignCenter or \c
    AlignJustify.

    \sa setAlignment(), Qt::AlignmentFlags
*/
int QStyleSheetItem::alignment() const
{
    return d->align;
}

/*!
    Sets the alignment to \a f. This only makes sense for styles with
    a \link QStyleSheetItem::DisplayMode display mode\endlink of
    DisplayBlock. Possible values are \c AlignAuto, \c AlignLeft,
    \c AlignRight, \c AlignCenter or \c AlignJustify.

    \sa alignment(), displayMode(), Qt::AlignmentFlags
*/
void QStyleSheetItem::setAlignment( int f )
{
    d->align = f;
}


/*!
    Returns the vertical alignment of the style. Possible values are
    \c VAlignBaseline, \c VAlignSub or \c VAlignSuper.

    \sa setVerticalAlignment()
*/
QStyleSheetItem::VerticalAlignment QStyleSheetItem::verticalAlignment() const
{
    return d->valign;
}

/*!
    \enum QStyleSheetItem::VerticalAlignment

    This enum type defines the way elements are aligned vertically.
    This is only supported for text elements.

    \value VAlignBaseline align the baseline of the element (or the
        bottom, if the element doesn't have a baseline) with the
        baseline of the parent

    \value VAlignSub subscript the element

    \value VAlignSuper superscript the element

*/


/*!
    Sets the vertical alignment to \a valign. Possible values are
    \c VAlignBaseline, \c VAlignSub or \c VAlignSuper.

    The vertical alignment property is not inherited.

    \sa verticalAlignment()
*/
void QStyleSheetItem::setVerticalAlignment( VerticalAlignment valign )
{
    d->valign = valign;
}


/*!
    Returns TRUE if the style sets an italic font; otherwise returns
    FALSE.

    \sa setFontItalic(), definesFontItalic()
*/
bool QStyleSheetItem::fontItalic() const
{
    return d->fontitalic > 0;
}

/*!
    If \a italic is TRUE sets italic for the style; otherwise sets
    upright.

    \sa fontItalic(), definesFontItalic()
*/
void QStyleSheetItem::setFontItalic(bool italic)
{
    d->fontitalic = italic?1:0;
}

/*!
    Returns TRUE if the style defines a font shape; otherwise returns
    FALSE. A style does not define any shape until setFontItalic() is
    called.

    \sa setFontItalic(), fontItalic()
*/
bool QStyleSheetItem::definesFontItalic() const
{
    return d->fontitalic != Undefined;
}

/*!
    Returns TRUE if the style sets an underlined font; otherwise
    returns FALSE.

    \sa setFontUnderline(), definesFontUnderline()
*/
bool QStyleSheetItem::fontUnderline() const
{
    return d->fontunderline > 0;
}

/*!
    If \a underline is TRUE, sets underline for the style; otherwise
    sets no underline.

    \sa fontUnderline(), definesFontUnderline()
*/
void QStyleSheetItem::setFontUnderline(bool underline)
{
    d->fontunderline = underline?1:0;
}

/*!
    Returns TRUE if the style defines a setting for the underline
    property of the font; otherwise returns FALSE. A style does not
    define this until setFontUnderline() is called.

    \sa setFontUnderline(), fontUnderline()
*/
bool QStyleSheetItem::definesFontUnderline() const
{
    return d->fontunderline != Undefined;
}


/*!
    Returns TRUE if the style sets a strike out font; otherwise
    returns FALSE.

    \sa setFontStrikeOut(), definesFontStrikeOut()
*/
bool QStyleSheetItem::fontStrikeOut() const
{
    return d->fontstrikeout > 0;
}

/*!
    If \a strikeOut is TRUE, sets strike out for the style; otherwise
    sets no strike out.

    \sa fontStrikeOut(), definesFontStrikeOut()
*/
void QStyleSheetItem::setFontStrikeOut(bool strikeOut)
{
    d->fontstrikeout = strikeOut?1:0;
}

/*!
    Returns TRUE if the style defines a setting for the strikeOut
    property of the font; otherwise returns FALSE. A style does not
    define this until setFontStrikeOut() is called.

    \sa setFontStrikeOut(), fontStrikeOut()
*/
bool QStyleSheetItem::definesFontStrikeOut() const
{
    return d->fontstrikeout != Undefined;
}


/*!
    Returns the font weight setting of the style. This is either a
    valid \c QFont::Weight or the value \c QStyleSheetItem::Undefined.

    \sa setFontWeight(), QFont
*/
int QStyleSheetItem::fontWeight() const
{
    return d->fontweight;
}

/*!
    Sets the font weight setting of the style to \a w. Valid values
    are those defined by \c QFont::Weight.

    \sa QFont, fontWeight()
*/
void QStyleSheetItem::setFontWeight(int w)
{
    d->fontweight = w;
}

/*!
    Returns the logical font size setting of the style. This is either
    a valid size between 1 and 7 or \c QStyleSheetItem::Undefined.

    \sa setLogicalFontSize(), setLogicalFontSizeStep(), QFont::pointSize(), QFont::setPointSize()
*/
int QStyleSheetItem::logicalFontSize() const
{
    return d->fontsizelog;
}


/*!
    Sets the logical font size setting of the style to \a s. Valid
    logical sizes are 1 to 7.

    \sa logicalFontSize(), QFont::pointSize(), QFont::setPointSize()
*/
void QStyleSheetItem::setLogicalFontSize(int s)
{
    d->fontsizelog = s;
}

/*!
    Returns the logical font size step of this style.

    The default is 0. Tags such as \c big define \c +1; \c small
    defines \c -1.

    \sa setLogicalFontSizeStep()
*/
int QStyleSheetItem::logicalFontSizeStep() const
{
    return d->fontsizestep;
}

/*!
    Sets the logical font size step of this style to \a s.

    \sa logicalFontSizeStep()
*/
void QStyleSheetItem::setLogicalFontSizeStep( int s )
{
    d->fontsizestep = s;
}



/*!
    Sets the font size setting of the style to \a s points.

    \sa fontSize(), QFont::pointSize(), QFont::setPointSize()
*/
void QStyleSheetItem::setFontSize(int s)
{
    d->fontsize = s;
}

/*!
    Returns the font size setting of the style. This is either a valid
    point size or \c QStyleSheetItem::Undefined.

    \sa setFontSize(), QFont::pointSize(), QFont::setPointSize()
*/
int QStyleSheetItem::fontSize() const
{
    return d->fontsize;
}


/*!
    Returns the font family setting of the style. This is either a
    valid font family or QString::null if no family has been set.

    \sa setFontFamily(), QFont::family(), QFont::setFamily()
*/
QString QStyleSheetItem::fontFamily() const
{
    return d->fontfamily;
}

/*!
    Sets the font family setting of the style to \a fam.

    \sa fontFamily(), QFont::family(), QFont::setFamily()
*/
void QStyleSheetItem::setFontFamily( const QString& fam)
{
    d->fontfamily = fam;
}


/*!\obsolete
  Returns the number of columns for this style.

  \sa setNumberOfColumns(), displayMode(), setDisplayMode()

 */
int QStyleSheetItem::numberOfColumns() const
{
    return d->ncolumns;
}


/*!\obsolete
  Sets the number of columns for this style. Elements in the style
  are divided into columns.

  This makes sense only if the style uses a block display mode
  (see QStyleSheetItem::DisplayMode).

  \sa numberOfColumns()
 */
void QStyleSheetItem::setNumberOfColumns(int ncols)
{
    if (ncols > 0)
        d->ncolumns = ncols;
}


/*!
    Returns the text color of this style or an invalid color if no
    color has been set.

    \sa setColor() QColor::isValid()
*/
QColor QStyleSheetItem::color() const
{
    return d->col;
}

/*!
    Sets the text color of this style to \a c.

    \sa color()
*/
void QStyleSheetItem::setColor( const QColor &c)
{
    d->col = c;
}

/*!
    Returns whether this style is an anchor.

    \sa setAnchor()
*/
bool QStyleSheetItem::isAnchor() const
{
    return d->anchor;
}

/*!
    If \a anc is TRUE, sets this style to be an anchor (hypertext
    link); otherwise sets it to not be an anchor. Elements in this
    style link to other documents or anchors.

    \sa isAnchor()
*/
void QStyleSheetItem::setAnchor(bool anc)
{
    d->anchor = anc;
}


/*!
    Returns the whitespace mode.

    \sa setWhiteSpaceMode() WhiteSpaceMode
*/
QStyleSheetItem::WhiteSpaceMode QStyleSheetItem::whiteSpaceMode() const
{
    return d->whitespacemode;
}

/*!
    Sets the whitespace mode to \a m.

    \sa WhiteSpaceMode
*/
void QStyleSheetItem::setWhiteSpaceMode(WhiteSpaceMode m)
{
    d->whitespacemode = m;
}


/*!
    Returns the width of margin \a m in pixels.

    The margin, \a m, can be \c MarginLeft, \c MarginRight, \c
    MarginTop, \c MarginBottom, \c MarginAll, \c MarginVertical or \c
    MarginHorizontal.

    \sa setMargin() Margin
*/
int QStyleSheetItem::margin(Margin m) const
{
    return d->margin[m];
}


/*!
    Sets the width of margin \a m to \a v pixels.

    The margin, \a m, can be \c MarginLeft, \c MarginRight, \c
    MarginTop, \c MarginBottom, \c MarginAll, \c MarginVertical or \c
    MarginHorizontal. The value \a v must be >= 0.

    \sa margin()
*/
void QStyleSheetItem::setMargin(Margin m, int v)
{
    if (m == MarginAll ) {
        d->margin[0] = v;
        d->margin[1] = v;
        d->margin[2] = v;
        d->margin[3] = v;
    } else if (m == MarginVertical ) {
        d->margin[MarginTop] = v;
        d->margin[MarginBottom] = v;
    } else if (m == MarginHorizontal ) {
        d->margin[MarginLeft] = v;
        d->margin[MarginRight] = v;
    } else {
        d->margin[m] = v;
    }
}


/*!
    Returns the list style of the style.

    \sa setListStyle() ListStyle
 */
QStyleSheetItem::ListStyle QStyleSheetItem::listStyle() const
{
    return d->list;
}

/*!
    \enum QStyleSheetItem::ListStyle

    This enum type defines how the items in a list are prefixed when
    displayed.

    \value ListDisc  a filled circle (i.e. a bullet)
    \value ListCircle  an unfilled circle
    \value ListSquare  a filled square
    \value ListDecimal  an integer in base 10: \e 1, \e 2, \e 3, ...
    \value ListLowerAlpha  a lowercase letter: \e a, \e b, \e c, ...
    \value ListUpperAlpha  an uppercase letter: \e A, \e B, \e C, ...
*/

/*!
    Sets the list style of the style to \a s.

    This is used by nested elements that have a display mode of \c
    DisplayListItem.

    \sa listStyle() DisplayMode ListStyle
*/
void QStyleSheetItem::setListStyle(ListStyle s)
{
    d->list=s;
}


/*!
    Returns a space-separated list of names of styles that may contain
    elements of this style. If nothing has been set, contexts()
    returns an empty string, which indicates that this style can be
    nested everywhere.

    \sa setContexts()
*/
QString QStyleSheetItem::contexts() const
{
    return d->contxt;
}

/*!
    Sets a space-separated list of names of styles that may contain
    elements of this style. If \a c is empty, the style can be nested
    everywhere.

    \sa contexts()
*/
void QStyleSheetItem::setContexts( const QString& c)
{
    d->contxt = QChar(' ') + c + QChar(' ');
}

/*!
    Returns TRUE if this style can be nested into an element of style
    \a s; otherwise returns FALSE.

    \sa contexts(), setContexts()
*/
bool QStyleSheetItem::allowedInContext( const QStyleSheetItem* s) const
{
    if ( d->contxt.isEmpty() )
        return TRUE;
    return d->contxt.find( QChar(' ')+s->name()+QChar(' ')) != -1;
}


/*!
    Returns TRUE if this style has self-nesting enabled; otherwise
    returns FALSE.

    \sa setSelfNesting()
*/
bool QStyleSheetItem::selfNesting() const
{
    return d->selfnest;
}

/*!
    Sets the self-nesting property for this style to \a nesting.

    In order to support "dirty" HTML, paragraphs \c{<p>} and list
    items \c{<li>} are not self-nesting. This means that starting a
    new paragraph or list item automatically closes the previous one.

    \sa selfNesting()
*/
void QStyleSheetItem::setSelfNesting( bool nesting )
{
    d->selfnest = nesting;
}

/*!
   \internal
    Sets the linespacing to be at least \a ls pixels.

    For compatibility with previous Qt releases, small values get
    treated differently: If \a ls is smaller than the default font
    line spacing in pixels at parse time, the resulting line spacing
    is the sum of the default line spacing plus \a ls. We recommend
    not relying on this behavior.
*/

void QStyleSheetItem::setLineSpacing( int ls )
{
    d->lineSpacing = ls;
}

/*!
  \obsolete

  Returns the linespacing
*/

int QStyleSheetItem::lineSpacing() const
{
    return d->lineSpacing;
}

//************************************************************************




//************************************************************************


/*!
    \class QStyleSheet qstylesheet.h
    \ingroup text
    \brief The QStyleSheet class is a collection of styles for rich text
    rendering and a generator of tags.

    \ingroup graphics
    \ingroup helpsystem

    By creating QStyleSheetItem objects for a style sheet you build a
    definition of a set of tags. This definition will be used by the
    internal rich text rendering system to parse and display text
    documents to which the style sheet applies. Rich text is normally
    visualized in a QTextEdit or a QTextBrowser. However, QLabel,
    QWhatsThis and QMessageBox also support it, and other classes are
    likely to follow. With QSimpleRichText it is possible to use the
    rich text renderer for custom widgets as well.

    The default QStyleSheet object has the following style bindings,
    sorted by structuring bindings, anchors, character style bindings
    (i.e. inline styles), special elements such as horizontal lines or
    images, and other tags. In addition, rich text supports simple
    HTML tables.

    The structuring tags are
    \table
    \header \i Structuring tags \i Notes
    \row \i \c{<qt>}...\c{</qt>}
         \i A Qt rich text document. It understands the following
            attributes:
            \list
            \i \c title -- The caption of the document. This attribute is
                easily accessible with QTextEdit::documentTitle().
            \i \c type -- The type of the document. The default type is \c
                page. It indicates that the document is displayed in a
                page of its own. Another style is \c detail, which can be
                used to explain certain expressions in more detail in a
                few sentences. For \c detail, QTextBrowser will then keep
                the current page and display the new document in a small
                popup similar to QWhatsThis. Note that links will not work
                in documents with \c{<qt type="detail">...</qt>}.
            \i \c bgcolor -- The background color, for example \c
                bgcolor="yellow" or \c bgcolor="#0000FF".
            \i \c background -- The background pixmap, for example \c
                background="granite.xpm". The pixmap name will be resolved
                by a QMimeSourceFactory().
            \i \c text -- The default text color, for example \c text="red".
            \i \c link -- The link color, for example \c link="green".
            \endlist
    \row \i \c{<h1>...</h1>}
         \i A top-level heading.
    \row \i \c{<h2>...</h2>}
         \i A sublevel heading.
    \row \i \c{<h3>...</h3>}
         \i A sub-sublevel heading.
    \row \i \c{<p>...</p>}
         \i A left-aligned paragraph. Adjust the alignment with the \c
            align attribute. Possible values are \c left, \c right and
            \c center.
    \row \i \c{<center>...}<br>\c{</center>}
         \i A centered paragraph.
    \row \i \c{<blockquote>...}<br>\c{</blockquote>}
         \i An indented paragraph that is useful for quotes.
    \row \i \c{<ul>...</ul>}
         \i An unordered list. You can also pass a type argument to
            define the bullet style. The default is \c type=disc;
            other types are \c circle and \c square.
    \row \i \c{<ol>...</ol>}
         \i An ordered list. You can also pass a type argument to
            define the enumeration label style. The default is \c
            type="1"; other types are \c "a" and \c "A".
    \row \i \c{<li>...</li>}
         \i A list item. This tag can be used only within the context
            of \c{<ol>} or \c{<ul>}.
    \row \i \c{<pre>...</pre>}
         \i For larger chunks of code. Whitespaces in the contents are
            preserved. For small bits of code use the inline-style \c
            code.
    \endtable

    Anchors and links are done with a single tag:
    \table
    \header \i Anchor tags \i Notes
    \row \i \c{<a>...</a>}
         \i An anchor or link.
            \list
            \i A link is created by using an \c href
                attribute, for example
                <br>\c{<a href="target.qml">Link Text</a>}. Links to
                targets within a document are achieved in the same way
                as for HTML, e.g.
                <br>\c{<a href="target.qml#subtitle">Link Text</a>}.
            \i A target is created by using a \c name
                attribute, for example
                <br>\c{<a name="subtitle"><h2>Sub Title</h2></a>}.
            \endlist
    \endtable

    The default character style bindings are
    \table
    \header \i Style tags \i Notes
    \row \i \c{<em>...</em>}
         \i Emphasized. By default this is the same as \c{<i>...</i>}
            (italic).
    \row \i \c{<strong>...</strong>}
         \i Strong. By default this is the same as \c{<b>...</b>}
            (bold).
    \row \i \c{<i>...</i>}
         \i Italic font style.
    \row \i \c{<b>...</b>}
         \i Bold font style.
    \row \i \c{<u>...</u>}
         \i Underlined font style.
    \row \i \c{<s>...</s>}
         \i Strike out font style.
    \row \i \c{<big>...</big>}
         \i A larger font size.
    \row \i \c{<small>...</small>}
         \i A smaller font size.
    \row \i \c{<sub>...</sub>}
         \i Subscripted text
    \row \i \c{<sup>...</sup>}
         \i Superscripted text
    \row \i \c{<code>...</code>}
         \i Indicates code. By default this is the same as
            \c{<tt>...</tt>} (typewriter). For larger chunks of code
            use the block-tag \c{<}\c{pre>}.
    \row \i \c{<tt>...</tt>}
         \i Typewriter font style.
    \row \i \c{<font>...</font>}
         \i Customizes the font size, family  and text color. The tag
            understands the following  attributes:
            \list
            \i \c color -- The text color, for example \c color="red" or
                \c color="#FF0000".
            \i \c size -- The logical size of the font. Logical sizes 1
                to 7 are supported. The value may either be absolute
                (for example, \c size=3) or relative (\c size=-2). In
                the latter case the sizes are simply added.
            \i \c face -- The family of the font, for example \c face=times.
            \endlist
    \endtable

    Special elements are:
    \table
    \header \i Special tags \i Notes
    \row \i \c{<img>}
         \i An image. The image name for the mime source factory is
            given in the source attribute, for example
            \c{<img src="qt.xpm">} The image tag also understands the
            attributes \c width and \c height that determine the size
            of the image. If the pixmap does not fit the specified
            size it will be scaled automatically (by using
            QImage::smoothScale()).
            <br>
            The \c align attribute determines where the image is
            placed. By default, an image is placed inline just like a
            normal character. Specify \c left or \c right to place the
            image at the respective side.
    \row \i \c{<hr>}
         \i A horizontal line.
    \row \i \c{<br>}
         \i A line break.
    \row \i \c{<nobr>...</nobr>}
         \i No break. Prevents word wrap.
    \endtable

    In addition, rich text supports simple HTML tables. A table
    consists of one or more rows each of which contains one or more
    cells. Cells are either data cells or header cells, depending on
    their content. Cells which span rows and columns are supported.

    \table
    \header \i Table tags \i Notes
    \row \i \c{<table>...</table>}
         \i A table. Tables support the following attributes:
            \list
            \i \c bgcolor -- The background color.
            \i \c width -- The table width. This is either an absolute
                pixel width or a relative percentage of the table's
                width, for example \c width=80%.
            \i \c border -- The width of the table border. The default is
                0 (= no border).
            \i \c cellspacing -- Additional space around the table cells.
                The default is 2.
            \i \c cellpadding -- Additional space around the contents of
                table cells. The default is 1.
            \endlist
    \row \i \c{<tr>...</tr>}
         \i A table row. This is only valid within a \c table. Rows
            support the following attribute:
            \list
            \i \c bgcolor -- The background color.
            \endlist
    \row \i \c{<th>...</th>}
         \i A table header cell. Similar to \c td, but defaults to
            center alignment and a bold font.
    \row \i \c{<td>...</td>}
         \i A table data cell. This is only valid within a \c tr.
            Cells support the following attributes:
            \list
            \i \c bgcolor -- The background color.
            \i \c width -- The cell width. This is either an absolute
                pixel width or a relative percentage of table's width,
                for example \c width=50%.
            \i \c colspan -- Specifies how many columns this cell spans.
                The default is 1.
            \i \c rowspan -- Specifies how many rows this cell spans. The
                default is 1.
            \i \c align -- Alignment; possible values are \c left, \c
                right, and \c center. The default is \c left.
            \i \c valign -- Vertical alignment; possible values are \c
            top, \c middle, and \c bottom. The default is \c middle.
            \endlist
    \endtable
*/

/*!
    Creates a style sheet called \a name, with parent \a parent. Like
    any QObject it will be deleted when its parent is destroyed (if
    the child still exists).

    By default the style sheet has the tag definitions defined above.
*/
QStyleSheet::QStyleSheet( QObject *parent, const char *name )
    : QObject( parent, name )
{
    init();
}

/*!
    Destroys the style sheet. All styles inserted into the style sheet
    will be deleted.
*/
QStyleSheet::~QStyleSheet()
{
}

/*!
  \internal
  Initialized the style sheet to the basic Qt style.
*/
void QStyleSheet::init()
{
    styles.setAutoDelete( TRUE );

    nullstyle  = new QStyleSheetItem( this,
        QString::fromLatin1("") );

    QStyleSheetItem*  style;

    style = new QStyleSheetItem( this, "qml" ); // compatibility
    style->setDisplayMode( QStyleSheetItem::DisplayBlock );

    style = new QStyleSheetItem( this, QString::fromLatin1("qt") );
    style->setDisplayMode( QStyleSheetItem::DisplayBlock );

    style = new QStyleSheetItem( this, QString::fromLatin1("a") );
    style->setAnchor( TRUE );

    style = new QStyleSheetItem( this, QString::fromLatin1("em") );
    style->setFontItalic( TRUE );

    style = new QStyleSheetItem( this, QString::fromLatin1("i") );
    style->setFontItalic( TRUE );

    style = new QStyleSheetItem( this, QString::fromLatin1("big") );
    style->setLogicalFontSizeStep( 1 );
    style = new QStyleSheetItem( this, QString::fromLatin1("large") ); // compatibility
    style->setLogicalFontSizeStep( 1 );

    style = new QStyleSheetItem( this, QString::fromLatin1("small") );
    style->setLogicalFontSizeStep( -1 );

    style = new QStyleSheetItem( this, QString::fromLatin1("strong") );
    style->setFontWeight( QFont::Bold);

    style = new QStyleSheetItem( this, QString::fromLatin1("b") );
    style->setFontWeight( QFont::Bold);

    style = new QStyleSheetItem( this, QString::fromLatin1("h1") );
    style->setFontWeight( QFont::Bold);
    style->setLogicalFontSize(6);
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginTop, 18);
    style-> setMargin(QStyleSheetItem::MarginBottom, 12);

    style = new QStyleSheetItem( this, QString::fromLatin1("h2") );
    style->setFontWeight( QFont::Bold);
    style->setLogicalFontSize(5);
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginTop, 16);
    style-> setMargin(QStyleSheetItem::MarginBottom, 12);

    style = new QStyleSheetItem( this, QString::fromLatin1("h3") );
    style->setFontWeight( QFont::Bold);
    style->setLogicalFontSize(4);
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginTop, 14);
    style-> setMargin(QStyleSheetItem::MarginBottom, 12);

    style = new QStyleSheetItem( this, QString::fromLatin1("h4") );
    style->setFontWeight( QFont::Bold);
    style->setLogicalFontSize(3);
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginVertical, 12);

    style = new QStyleSheetItem( this, QString::fromLatin1("h5") );
    style->setFontWeight( QFont::Bold);
    style->setLogicalFontSize(2);
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginTop, 12);
    style-> setMargin(QStyleSheetItem::MarginBottom, 4);

    style = new QStyleSheetItem( this, QString::fromLatin1("p") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style-> setMargin(QStyleSheetItem::MarginVertical, 12);
    style->setSelfNesting( FALSE );

    style = new QStyleSheetItem( this, QString::fromLatin1("center") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setAlignment( AlignCenter );

    style = new QStyleSheetItem( this, QString::fromLatin1("twocolumn") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setNumberOfColumns( 2 );

    style =  new QStyleSheetItem( this, QString::fromLatin1("multicol") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    (void) new QStyleSheetItem( this, QString::fromLatin1("font") );

    style = new QStyleSheetItem( this, QString::fromLatin1("ul") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setListStyle( QStyleSheetItem::ListDisc );
    style-> setMargin(QStyleSheetItem::MarginVertical, 12);
    style->setMargin( QStyleSheetItem::MarginLeft, 40 );

    style = new QStyleSheetItem( this, QString::fromLatin1("ol") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setListStyle( QStyleSheetItem::ListDecimal );
    style-> setMargin(QStyleSheetItem::MarginVertical, 12);
    style->setMargin( QStyleSheetItem::MarginLeft, 40 );

    style = new QStyleSheetItem( this, QString::fromLatin1("li") );
    style->setDisplayMode(QStyleSheetItem::DisplayListItem);
    style->setSelfNesting( FALSE );

    style = new QStyleSheetItem( this, QString::fromLatin1("code") );
    style->setFontFamily( QString::fromLatin1("Courier New,courier") );

    style = new QStyleSheetItem( this, QString::fromLatin1("tt") );
    style->setFontFamily( QString::fromLatin1("Courier New,courier") );

    new QStyleSheetItem(this, QString::fromLatin1("img"));
    new QStyleSheetItem(this, QString::fromLatin1("br"));
    new QStyleSheetItem(this, QString::fromLatin1("hr"));

    style = new QStyleSheetItem(this, QString::fromLatin1("sub"));
    style->setVerticalAlignment( QStyleSheetItem::VAlignSub );
    style = new QStyleSheetItem(this, QString::fromLatin1("sup"));
    style->setVerticalAlignment( QStyleSheetItem::VAlignSuper );

    style = new QStyleSheetItem( this, QString::fromLatin1("pre") );
    style->setFontFamily( QString::fromLatin1("Courier New,courier") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setWhiteSpaceMode(QStyleSheetItem::WhiteSpacePre);
    style-> setMargin(QStyleSheetItem::MarginVertical, 12);

    style = new QStyleSheetItem( this, QString::fromLatin1("blockquote") );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setMargin(QStyleSheetItem::MarginHorizontal, 40 );

     style = new QStyleSheetItem( this, QString::fromLatin1("head") );
     style->setDisplayMode(QStyleSheetItem::DisplayNone);
     style = new QStyleSheetItem( this, QString::fromLatin1("body") );
     style->setDisplayMode(QStyleSheetItem::DisplayBlock);
     style = new QStyleSheetItem( this, QString::fromLatin1("div") );
     style->setDisplayMode(QStyleSheetItem::DisplayBlock) ;
     style = new QStyleSheetItem( this, QString::fromLatin1("span") );
     style = new QStyleSheetItem( this, QString::fromLatin1("dl") );
    style-> setMargin(QStyleSheetItem::MarginVertical, 8);
     style->setDisplayMode(QStyleSheetItem::DisplayBlock);
     style = new QStyleSheetItem( this, QString::fromLatin1("dt") );
     style->setDisplayMode(QStyleSheetItem::DisplayBlock);
     style->setContexts(QString::fromLatin1("dl") );
     style = new QStyleSheetItem( this, QString::fromLatin1("dd") );
     style->setDisplayMode(QStyleSheetItem::DisplayBlock);
     style->setMargin(QStyleSheetItem::MarginLeft, 30);
     style->setContexts(QString::fromLatin1("dt dl") );
     style = new QStyleSheetItem( this, QString::fromLatin1("u") );
     style->setFontUnderline( TRUE);
     style = new QStyleSheetItem( this, QString::fromLatin1("s") );
     style->setFontStrikeOut( TRUE);
     style = new QStyleSheetItem( this, QString::fromLatin1("nobr") );
     style->setWhiteSpaceMode( QStyleSheetItem::WhiteSpaceNoWrap );

     // compatibily with some minor 3.0.x Qt versions that had an
     // undocumented <wsp> tag. ### Remove 3.1
     style = new QStyleSheetItem( this, QString::fromLatin1("wsp") );
     style->setWhiteSpaceMode( QStyleSheetItem::WhiteSpacePre );

     // tables
     style = new QStyleSheetItem( this, QString::fromLatin1("table") );
     style = new QStyleSheetItem( this, QString::fromLatin1("tr") );
     style->setContexts(QString::fromLatin1("table"));
     style = new QStyleSheetItem( this, QString::fromLatin1("td") );
     style->setContexts(QString::fromLatin1("tr"));
     style = new QStyleSheetItem( this, QString::fromLatin1("th") );
     style->setFontWeight( QFont::Bold );
     style->setAlignment( Qt::AlignCenter );
     style->setContexts(QString::fromLatin1("tr"));

     style = new QStyleSheetItem( this, QString::fromLatin1("html") );
}



static QStyleSheet* defaultsheet = 0;
static QSingleCleanupHandler<QStyleSheet> qt_cleanup_stylesheet;

/*!
    Returns the application-wide default style sheet. This style sheet
    is used by rich text rendering classes such as QSimpleRichText,
    QWhatsThis and QMessageBox to define the rendering style and
    available tags within rich text documents. It also serves as the
    initial style sheet for the more complex render widgets, QTextEdit
    and QTextBrowser.

    \sa setDefaultSheet()
*/
QStyleSheet* QStyleSheet::defaultSheet()
{
    if (!defaultsheet) {
        defaultsheet = new QStyleSheet();
        qt_cleanup_stylesheet.set( &defaultsheet );
    }
    return defaultsheet;
}

/*!
    Sets the application-wide default style sheet to \a sheet,
    deleting any style sheet previously set. The ownership is
    transferred to QStyleSheet.

    \sa defaultSheet()
*/
void QStyleSheet::setDefaultSheet( QStyleSheet* sheet)
{
    if ( defaultsheet != sheet ) {
        if ( defaultsheet )
            qt_cleanup_stylesheet.reset();
        delete defaultsheet;
    }
    defaultsheet = sheet;
    if ( defaultsheet )
        qt_cleanup_stylesheet.set( &defaultsheet );
}

/*!\internal
  Inserts \a style. Any tags generated after this time will be
  bound to this style. Note that \a style becomes owned by the
  style sheet and will be deleted when the style sheet is destroyed.
*/
void QStyleSheet::insert( QStyleSheetItem* style )
{
    styles.insert(style->name(), style);
}


/*!
    Returns the style called \a name or 0 if there is no such style.
*/
QStyleSheetItem* QStyleSheet::item( const QString& name)
{
    if ( name.isNull() )
        return 0;
    return styles[name];
}

/*!
    \overload

    Returns the style called \a name or 0 if there is no such style
    (const version)
*/
const QStyleSheetItem* QStyleSheet::item( const QString& name) const
{
    if ( name.isNull() )
        return 0;
    return styles[name];
}


/*!
    \preliminary

    Generates an internal object for the tag called \a name, given the
    attributes \a attr, and using additional information provided by
    the mime source factory \a factory.

    \a context is the optional context of the document, i.e. the path
    to look for relative links. This becomes important if the text
    contains relative references, for example within image tags.
    QSimpleRichText always uses the default mime source factory (see
    \l{QMimeSourceFactory::defaultFactory()}) to resolve these
    references. The context will then be used to calculate the
    absolute path. See QMimeSourceFactory::makeAbsolute() for details.

    \a emptyTag and \a doc are for internal use only.

    This function should not be used in application code.
*/
#ifndef QT_NO_TEXTCUSTOMITEM
QTextCustomItem* QStyleSheet::tag(  const QString& name,
                                   const QMap<QString, QString> &attr,
                                   const QString& context,
                                   const QMimeSourceFactory& factory,
                                   bool /*emptyTag */, QTextDocument *doc ) const
{
    const QStyleSheetItem* style = item( name );
    // first some known  tags
    if ( !style )
        return 0;
    if ( style->name() == "img" )
        return new QTextImage( doc, attr, context, (QMimeSourceFactory&)factory );
    if ( style->name() == "hr" )
        return new QTextHorizontalLine( doc, attr, context, (QMimeSourceFactory&)factory  );
   return 0;
}
#endif


/*!  Auxiliary function. Converts the plain text string \a plain to a
    rich text formatted paragraph while preserving most of its look.

    \a mode defines the whitespace mode. Possible values are \c
    QStyleSheetItem::WhiteSpacePre (no wrapping, all whitespaces
    preserved) and \c QStyleSheetItem::WhiteSpaceNormal (wrapping,
    simplified whitespaces).

    \sa escape()
*/
QString QStyleSheet::convertFromPlainText( const QString& plain, QStyleSheetItem::WhiteSpaceMode mode )
{
    int col = 0;
    QString rich;
    rich += "<p>";
    for ( int i = 0; i < int(plain.length()); ++i ) {
        if ( plain[i] == '\n' ){
            int c = 1;
            while ( i+1 < int(plain.length()) && plain[i+1] == '\n' ) {
                i++;
                c++;
            }
            if ( c == 1)
                rich += "<br>\n";
            else {
                rich += "</p>\n";
                while ( --c > 1 )
                    rich += "<br>\n";
                rich += "<p>";
            }
            col = 0;
        } else {
            if ( mode == QStyleSheetItem::WhiteSpacePre && plain[i] == '\t' ){
                rich += 0x00a0U;
                ++col;
                while ( col % 8 ) {
                    rich += 0x00a0U;
                    ++col;
                }
            }
            else if ( mode == QStyleSheetItem::WhiteSpacePre && plain[i].isSpace() )
                rich += 0x00a0U;
            else if ( plain[i] == '<' )
                rich +="&lt;";
            else if ( plain[i] == '>' )
                rich +="&gt;";
            else if ( plain[i] == '&' )
                rich +="&amp;";
            else
                rich += plain[i];
            ++col;
        }
    }
    if ( col != 0 )
        rich += "</p>";
    return rich;
}

/*!
    Auxiliary function. Converts the plain text string \a plain to a
    rich text formatted string with any HTML meta-characters escaped.

    \sa convertFromPlainText()
*/
QString QStyleSheet::escape( const QString& plain)
{
    QString rich;
    for ( int i = 0; i < int(plain.length()); ++i ) {
        if ( plain[i] == '<' )
            rich +="&lt;";
        else if ( plain[i] == '>' )
            rich +="&gt;";
        else if ( plain[i] == '&' )
            rich +="&amp;";
        else
            rich += plain[i];
    }
    return rich;
}

// Must doc this enum somewhere, and it is logically related to QStyleSheet

/*!
    \enum Qt::TextFormat

    This enum is used in widgets that can display both plain text and
    rich text, e.g. QLabel. It is used for deciding whether a text
    string should be interpreted as one or the other. This is normally
    done by passing one of the enum values to a setTextFormat()
    function.

    \value PlainText  The text string is interpreted as a plain text
        string.

    \value RichText The text string is interpreted as a rich text
        string using the current QStyleSheet::defaultSheet().

    \value AutoText The text string is interpreted as for \c RichText
        if QStyleSheet::mightBeRichText() returns TRUE, otherwise as
        \c PlainText.

    \value LogText A special, limited text format which is only used
    by QTextEdit in an optimized mode.
*/

/*!
    Returns TRUE if the string \a text is likely to be rich text;
    otherwise returns FALSE.

    This function uses a fast and therefore simple heuristic. It
    mainly checks whether there is something that looks like a tag
    before the first line break. Although the result may be correct
    for common cases, there is no guarantee.
*/
bool QStyleSheet::mightBeRichText( const QString& text)
{
    if ( text.isEmpty() )
        return FALSE;
    int start = 0;

    while ( start < int(text.length()) && text[start].isSpace() )
        ++start;
    if ( text.mid( start, 5 ).lower() == "<!doc" )
        return TRUE;
    int open = start;
    while ( open < int(text.length()) && text[open] != '<'
            && text[open] != '\n' ) {
        if ( text[open] == '&' &&  text.mid(open+1,3) == "lt;" )
            return TRUE; // support desperate attempt of user to see <...>
        ++open;
    }
    if ( open < (int)text.length() && text[open] == '<' ) {
        int close = text.find('>', open);
        if ( close > -1 ) {
            QString tag;
            for (int i = open+1; i < close; ++i) {
                if ( text[i].isDigit() || text[i].isLetter() )
                    tag += text[i];
                else if ( !tag.isEmpty() && text[i].isSpace() )
                    break;
                else if ( !text[i].isSpace() && (!tag.isEmpty() || text[i] != '!' ) )
                    return FALSE; // that's not a tag
            }
            return defaultSheet()->item( tag.lower() ) != 0;
        }
    }
    return FALSE;
}


/*!
    \fn void QStyleSheet::error( const QString& msg) const

    This virtual function is called when an error occurs when
    processing rich text. Reimplement it if you need to catch error
    messages.

    Errors might occur if some rich text strings contain tags that are
    not understood by the stylesheet, if some tags are nested
    incorrectly, or if tags are not closed properly.

    \a msg is the error message.
*/
void QStyleSheet::error( const QString& ) const
{
}


/*!
    Scales the font \a font to the appropriate physical point size
    corresponding to the logical font size \a logicalSize.

    When calling this function, \a font has a point size corresponding
    to the logical font size 3.

    Logical font sizes range from 1 to 7, with 1 being the smallest.

    \sa QStyleSheetItem::logicalFontSize(), QStyleSheetItem::logicalFontSizeStep(), QFont::setPointSize()
 */
void QStyleSheet::scaleFont( QFont& font, int logicalSize ) const
{
    if ( logicalSize < 1 )
        logicalSize = 1;
    if ( logicalSize > 7 )
        logicalSize = 7;
    int baseSize = font.pointSize();
    bool pixel = FALSE;
    if ( baseSize == -1 ) {
        baseSize = font.pixelSize();
        pixel = TRUE;
    }
    int s;
    switch ( logicalSize ) {
    case 1:
        s =  7*baseSize/10;
        break;
    case 2:
        s = (8 * baseSize) / 10;
        break;
    case 4:
        s =  (12 * baseSize) / 10;
        break;
    case 5:
        s = (15 * baseSize) / 10;
        break;
    case 6:
        s = 2 * baseSize;
        break;
    case 7:
        s = (24 * baseSize) / 10;
        break;
    default:
        s = baseSize;
    }
    if ( pixel )
        font.setPixelSize( s );
    else
        font.setPointSize( s );
}

#endif // QT_NO_RICHTEXT