qt_demoe/third/3rd_qwt/qwt_text_engine.cpp

347 lines
8.6 KiB
C++

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
* Qwt Widget Library
* Copyright (C) 1997 Josef Wilgen
* Copyright (C) 2002 Uwe Rathmann
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the Qwt License, Version 1.0
*****************************************************************************/
#include "qwt_text_engine.h"
#include "qwt_math.h"
#include "qwt_painter.h"
#include <qpainter.h>
#include <qpixmap.h>
#include <qimage.h>
#include <qmap.h>
#include <qwidget.h>
#include <qtextobject.h>
#include <qtextdocument.h>
#include <qabstracttextdocumentlayout.h>
static QString taggedRichText( const QString &text, int flags )
{
QString richText = text;
// By default QSimpleRichText is Qt::AlignLeft
if ( flags & Qt::AlignJustify )
{
richText.prepend( QString::fromLatin1( "<div align=\"justify\">" ) );
richText.append( QString::fromLatin1( "</div>" ) );
}
else if ( flags & Qt::AlignRight )
{
richText.prepend( QString::fromLatin1( "<div align=\"right\">" ) );
richText.append( QString::fromLatin1( "</div>" ) );
}
else if ( flags & Qt::AlignHCenter )
{
richText.prepend( QString::fromLatin1( "<div align=\"center\">" ) );
richText.append( QString::fromLatin1( "</div>" ) );
}
return richText;
}
class QwtRichTextDocument: public QTextDocument
{
public:
QwtRichTextDocument( const QString &text, int flags, const QFont &font )
{
setUndoRedoEnabled( false );
setDefaultFont( font );
setHtml( text );
// make sure we have a document layout
( void )documentLayout();
QTextOption option = defaultTextOption();
if ( flags & Qt::TextWordWrap )
option.setWrapMode( QTextOption::WordWrap );
else
option.setWrapMode( QTextOption::NoWrap );
option.setAlignment( static_cast<Qt::Alignment>( flags ) );
setDefaultTextOption( option );
QTextFrame *root = rootFrame();
QTextFrameFormat fm = root->frameFormat();
fm.setBorder( 0 );
fm.setMargin( 0 );
fm.setPadding( 0 );
fm.setBottomMargin( 0 );
fm.setLeftMargin( 0 );
root->setFrameFormat( fm );
adjustSize();
}
};
class QwtPlainTextEngine::PrivateData
{
public:
int effectiveAscent( const QFont &font ) const
{
const QString fontKey = font.key();
QMap<QString, int>::const_iterator it =
d_ascentCache.constFind( fontKey );
if ( it != d_ascentCache.constEnd() )
return *it;
const int ascent = findAscent( font );
d_ascentCache.insert( fontKey, ascent );
return ascent;
}
private:
int findAscent( const QFont &font ) const
{
static const QString dummy( "E" );
static const QColor white( Qt::white );
const QFontMetrics fm( font );
QPixmap pm( fm.width( dummy ), fm.height() );
pm.fill( white );
QPainter p( &pm );
p.setFont( font );
p.drawText( 0, 0, pm.width(), pm.height(), 0, dummy );
p.end();
const QImage img = pm.toImage();
int row = 0;
for ( row = 0; row < img.height(); row++ )
{
const QRgb *line = reinterpret_cast<const QRgb *>(
img.scanLine( row ) );
const int w = pm.width();
for ( int col = 0; col < w; col++ )
{
if ( line[col] != white.rgb() )
return fm.ascent() - row + 1;
}
}
return fm.ascent();
}
mutable QMap<QString, int> d_ascentCache;
};
//! Constructor
QwtTextEngine::QwtTextEngine()
{
}
//! Destructor
QwtTextEngine::~QwtTextEngine()
{
}
//! Constructor
QwtPlainTextEngine::QwtPlainTextEngine()
{
d_data = new PrivateData;
}
//! Destructor
QwtPlainTextEngine::~QwtPlainTextEngine()
{
delete d_data;
}
/*!
Find the height for a given width
\param font Font of the text
\param flags Bitwise OR of the flags used like in QPainter::drawText
\param text Text to be rendered
\param width Width
\return Calculated height
*/
double QwtPlainTextEngine::heightForWidth( const QFont& font, int flags,
const QString& text, double width ) const
{
const QFontMetricsF fm( font );
const QRectF rect = fm.boundingRect(
QRectF( 0, 0, width, QWIDGETSIZE_MAX ), flags, text );
return rect.height();
}
/*!
Returns the size, that is needed to render text
\param font Font of the text
\param flags Bitwise OR of the flags used like in QPainter::drawText
\param text Text to be rendered
\return Calculated size
*/
QSizeF QwtPlainTextEngine::textSize( const QFont &font,
int flags, const QString& text ) const
{
const QFontMetricsF fm( font );
const QRectF rect = fm.boundingRect(
QRectF( 0, 0, QWIDGETSIZE_MAX, QWIDGETSIZE_MAX ), flags, text );
return rect.size();
}
/*!
Return margins around the texts
\param font Font of the text
\param left Return 0
\param right Return 0
\param top Return value for the top margin
\param bottom Return value for the bottom margin
*/
void QwtPlainTextEngine::textMargins( const QFont &font, const QString &,
double &left, double &right, double &top, double &bottom ) const
{
left = right = top = 0;
const QFontMetricsF fm( font );
top = fm.ascent() - d_data->effectiveAscent( font );
bottom = fm.descent();
}
/*!
\brief Draw the text in a clipping rectangle
A wrapper for QPainter::drawText.
\param painter Painter
\param rect Clipping rectangle
\param flags Bitwise OR of the flags used like in QPainter::drawText
\param text Text to be rendered
*/
void QwtPlainTextEngine::draw( QPainter *painter, const QRectF &rect,
int flags, const QString& text ) const
{
QwtPainter::drawText( painter, rect, flags, text );
}
/*!
Test if a string can be rendered by this text engine.
\return Always true. All texts can be rendered by QwtPlainTextEngine
*/
bool QwtPlainTextEngine::mightRender( const QString & ) const
{
return true;
}
#ifndef QT_NO_RICHTEXT
//! Constructor
QwtRichTextEngine::QwtRichTextEngine()
{
}
/*!
Find the height for a given width
\param font Font of the text
\param flags Bitwise OR of the flags used like in QPainter::drawText()
\param text Text to be rendered
\param width Width
\return Calculated height
*/
double QwtRichTextEngine::heightForWidth( const QFont& font, int flags,
const QString& text, double width ) const
{
QwtRichTextDocument doc( text, flags, font );
doc.setPageSize( QSizeF( width, QWIDGETSIZE_MAX ) );
return doc.documentLayout()->documentSize().height();
}
/*!
Returns the size, that is needed to render text
\param font Font of the text
\param flags Bitwise OR of the flags used like in QPainter::drawText()
\param text Text to be rendered
\return Calculated size
*/
QSizeF QwtRichTextEngine::textSize( const QFont &font,
int flags, const QString& text ) const
{
QwtRichTextDocument doc( text, flags, font );
QTextOption option = doc.defaultTextOption();
if ( option.wrapMode() != QTextOption::NoWrap )
{
option.setWrapMode( QTextOption::NoWrap );
doc.setDefaultTextOption( option );
doc.adjustSize();
}
return doc.size();
}
/*!
Draw the text in a clipping rectangle
\param painter Painter
\param rect Clipping rectangle
\param flags Bitwise OR of the flags like in for QPainter::drawText()
\param text Text to be rendered
*/
void QwtRichTextEngine::draw( QPainter *painter, const QRectF &rect,
int flags, const QString& text ) const
{
QwtRichTextDocument doc( text, flags, painter->font() );
QwtPainter::drawSimpleRichText( painter, rect, flags, doc );
}
/*!
Wrap text into <div align=...> </div> tags according flags
\param text Text
\param flags Bitwise OR of the flags like in for QPainter::drawText()
\return Tagged text
*/
QString QwtRichTextEngine::taggedText( const QString &text, int flags ) const
{
return taggedRichText( text, flags );
}
/*!
Test if a string can be rendered by this text engine
\param text Text to be tested
\return Qt::mightBeRichText(text);
*/
bool QwtRichTextEngine::mightRender( const QString &text ) const
{
return Qt::mightBeRichText( text );
}
/*!
Return margins around the texts
\param left Return 0
\param right Return 0
\param top Return 0
\param bottom Return 0
*/
void QwtRichTextEngine::textMargins( const QFont &, const QString &,
double &left, double &right, double &top, double &bottom ) const
{
left = right = top = bottom = 0;
}
#endif // !QT_NO_RICHTEXT