qwt_text_engine.cpp
/******************************************************************************
* 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_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( QLatin1String( "<div align=\"justify\">" ) );
richText.append( QLatin1String ( "</div>" ) );
}
else if ( flags & Qt::AlignRight )
{
richText.prepend( QLatin1String ( "<div align=\"right\">" ) );
richText.append( QLatin1String ( "</div>" ) );
}
else if ( flags & Qt::AlignHCenter )
{
richText.prepend( QLatin1String ( "<div align=\"center\">" ) );
richText.append( QLatin1String ( "</div>" ) );
}
return richText;
}
namespace
{
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 =
m_ascentCache.constFind( fontKey );
if ( it != m_ascentCache.constEnd() )
return *it;
const int ascent = findAscent( font );
m_ascentCache.insert( fontKey, ascent );
return ascent;
}
private:
static int findAscent( const QFont& font )
{
static const QString dummy( "E" );
static const QColor white( Qt::white );
const QFontMetrics fm( font );
QPixmap pm( QwtPainter::horizontalAdvance( fm, 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 > m_ascentCache;
};
QwtTextEngine::QwtTextEngine()
{
}
QwtTextEngine::~QwtTextEngine()
{
}
QwtPlainTextEngine::QwtPlainTextEngine()
{
m_data = new PrivateData;
}
QwtPlainTextEngine::~QwtPlainTextEngine()
{
delete m_data;
}
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();
}
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();
}
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() - m_data->effectiveAscent( font );
bottom = fm.descent();
}
void QwtPlainTextEngine::draw( QPainter* painter, const QRectF& rect,
int flags, const QString& text ) const
{
QwtPainter::drawText( painter, rect, flags, text );
}
bool QwtPlainTextEngine::mightRender( const QString& ) const
{
return true;
}
#ifndef QT_NO_RICHTEXT
QwtRichTextEngine::QwtRichTextEngine()
{
}
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();
}
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();
}
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 );
}
QString QwtRichTextEngine::taggedText( const QString& text, int flags ) const
{
return taggedRichText( text, flags );
}
bool QwtRichTextEngine::mightRender( const QString& text ) const
{
return Qt::mightBeRichText( text );
}
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
QMap
Definition: qwt_compass.h:19
QwtPainter::drawSimpleRichText
static void drawSimpleRichText(QPainter *, const QRectF &, int flags, const QTextDocument &)
Definition: qwt_painter.cpp:489
QwtPainter::drawText
static void drawText(QPainter *, qreal x, qreal y, const QString &)
Wrapper for QPainter::drawText()
Definition: qwt_painter.cpp:438
QwtPainter::horizontalAdvance
static int horizontalAdvance(const QFontMetrics &, const QString &)
Definition: qwt_painter.cpp:1379
QwtPlainTextEngine::heightForWidth
virtual double heightForWidth(const QFont &font, int flags, const QString &text, double width) const override
Definition: qwt_text_engine.cpp:172
QwtPlainTextEngine::QwtPlainTextEngine
QwtPlainTextEngine()
Constructor.
Definition: qwt_text_engine.cpp:151
QwtPlainTextEngine::~QwtPlainTextEngine
virtual ~QwtPlainTextEngine()
Destructor.
Definition: qwt_text_engine.cpp:157
QwtPlainTextEngine::textMargins
virtual void textMargins(const QFont &, const QString &, double &left, double &right, double &top, double &bottom) const override
Definition: qwt_text_engine.cpp:210
QwtPlainTextEngine::textSize
virtual QSizeF textSize(const QFont &font, int flags, const QString &text) const override
Definition: qwt_text_engine.cpp:191
QwtPlainTextEngine::draw
virtual void draw(QPainter *, const QRectF &rect, int flags, const QString &text) const override
Draw the text in a clipping rectangle.
Definition: qwt_text_engine.cpp:230
QwtPlainTextEngine::mightRender
virtual bool mightRender(const QString &) const override
Definition: qwt_text_engine.cpp:240
QwtRichTextEngine::textSize
virtual QSizeF textSize(const QFont &font, int flags, const QString &text) const override
Definition: qwt_text_engine.cpp:281
QwtRichTextEngine::textMargins
virtual void textMargins(const QFont &, const QString &, double &left, double &right, double &top, double &bottom) const override
Definition: qwt_text_engine.cpp:344
QwtRichTextEngine::mightRender
virtual bool mightRender(const QString &) const override
Definition: qwt_text_engine.cpp:331
QwtRichTextEngine::heightForWidth
virtual double heightForWidth(const QFont &font, int flags, const QString &text, double width) const override
Definition: qwt_text_engine.cpp:262
QwtRichTextEngine::QwtRichTextEngine
QwtRichTextEngine()
Constructor.
Definition: qwt_text_engine.cpp:248
QwtRichTextEngine::draw
virtual void draw(QPainter *, const QRectF &rect, int flags, const QString &text) const override
Definition: qwt_text_engine.cpp:305
QwtTextEngine::QwtTextEngine
QwtTextEngine()
Constructor.
Definition: qwt_text_engine.cpp:141
QwtTextEngine::~QwtTextEngine
virtual ~QwtTextEngine()
Destructor.
Definition: qwt_text_engine.cpp:146