qwt_text.cpp

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/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2003   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
 *****************************************************************************/

// vim: expandtab

#include <qmap.h>
#include <qfont.h>
#include <qcolor.h>
#include <qpen.h>
#include <qbrush.h>
#include <qpainter.h>
#include "qwt_painter.h"
#include "qwt_text_engine.h"
#include "qwt_text.h"
#if QT_VERSION >= 0x040000
#include <qapplication.h>
#include <qdesktopwidget.h>
#endif

class QwtTextEngineDict
{
public:
    QwtTextEngineDict();
    ~QwtTextEngineDict();

    void setTextEngine(QwtText::TextFormat, QwtTextEngine *);
    const QwtTextEngine *textEngine(QwtText::TextFormat) const;
    const QwtTextEngine *textEngine(const QString &, 
        QwtText::TextFormat) const;

private:
    typedef QMap<int, QwtTextEngine *> EngineMap;

    inline const QwtTextEngine *engine(EngineMap::const_iterator &it) const 
    {
#if QT_VERSION < 0x040000
        return it.data();
#else
        return it.value();
#endif
    }

    EngineMap d_map;
};

QwtTextEngineDict::QwtTextEngineDict()
{
    d_map.insert(QwtText::PlainText, new QwtPlainTextEngine());
#ifndef QT_NO_RICHTEXT
    d_map.insert(QwtText::RichText, new QwtRichTextEngine());
#endif
}

QwtTextEngineDict::~QwtTextEngineDict()
{
    for ( EngineMap::const_iterator it = d_map.begin(); 
        it != d_map.end(); ++it )
    {
        QwtTextEngine *textEngine = (QwtTextEngine *)engine(it);
        delete textEngine;
    }
}

const QwtTextEngine *QwtTextEngineDict::textEngine(const QString& text,
    QwtText::TextFormat format) const
{
    if ( format == QwtText::AutoText )
    {
        for ( EngineMap::const_iterator it = d_map.begin(); 
            it != d_map.end(); ++it )
        {
            if ( it.key() != QwtText::PlainText )
            {
                const QwtTextEngine *e = engine(it);
                if ( e && e->mightRender(text) )
                    return (QwtTextEngine *)e;
            }
        }
    }

    EngineMap::const_iterator it = d_map.find(format);
    if ( it != d_map.end() )
    {
        const QwtTextEngine *e = engine(it);
        if ( e )
            return e;
    }

    it = d_map.find(QwtText::PlainText);
    return engine(it);
}

void QwtTextEngineDict::setTextEngine(QwtText::TextFormat format, 
    QwtTextEngine *engine)
{
    if ( format == QwtText::AutoText )
        return;

    if ( format == QwtText::PlainText && engine == NULL )
        return;

    EngineMap::const_iterator it = d_map.find(format);
    if ( it != d_map.end() )
    {
        const QwtTextEngine *e = this->engine(it);
        if ( e )
            delete e;

        d_map.remove(format);
    }

    if ( engine != NULL )
        d_map.insert(format, engine);
}

const QwtTextEngine *QwtTextEngineDict::textEngine(
    QwtText::TextFormat format) const
{
    const QwtTextEngine *e = NULL;

    EngineMap::const_iterator it = d_map.find(format);
    if ( it != d_map.end() )
        e = engine(it);

    return e;
}

static QwtTextEngineDict *engineDict = NULL;

class QwtText::PrivateData
{
public:
    PrivateData():
        renderFlags(Qt::AlignCenter),
        backgroundPen(Qt::NoPen),
        backgroundBrush(Qt::NoBrush),
        paintAttributes(0),
        layoutAttributes(0),
        textEngine(NULL)
    {
    }

    int renderFlags;
    QString text;
    QFont font;
    QColor color;
    QPen backgroundPen;
    QBrush backgroundBrush;

    int paintAttributes;
    int layoutAttributes;

    const QwtTextEngine *textEngine;
};

class QwtText::LayoutCache
{
public:
    void invalidate()
    {
        textSize = QSize();
    }

    QFont font;
    QSize textSize;
};

QwtText::QwtText(const QString &text, QwtText::TextFormat textFormat)
{
    d_data = new PrivateData;
    d_data->text = text;
    d_data->textEngine = textEngine(text, textFormat);

    d_layoutCache = new LayoutCache;
}

QwtText::QwtText(const QwtText &other)
{
    d_data = new PrivateData;
    *d_data = *other.d_data;

    d_layoutCache = new LayoutCache;
    *d_layoutCache = *other.d_layoutCache;
}

QwtText::~QwtText() 
{
    delete d_data;
    delete d_layoutCache;
}

QwtText &QwtText::operator=(const QwtText &other)
{
    *d_data = *other.d_data;
    *d_layoutCache = *other.d_layoutCache;
    return *this;
}
    
int QwtText::operator==(const QwtText &other) const
{
    return d_data->renderFlags == other.d_data->renderFlags &&
        d_data->text == other.d_data->text &&
        d_data->font == other.d_data->font &&
        d_data->color == other.d_data->color &&
        d_data->backgroundPen == other.d_data->backgroundPen &&
        d_data->backgroundBrush == other.d_data->backgroundBrush &&
        d_data->paintAttributes == other.d_data->paintAttributes &&
        d_data->textEngine == other.d_data->textEngine;
}

int QwtText::operator!=(const QwtText &other) const // invalidate
{
   return !(other == *this);
}

void QwtText::setText(const QString &text, 
    QwtText::TextFormat textFormat) 
{ 
    d_data->text = text; 
    d_data->textEngine = textEngine(text, textFormat);
    d_layoutCache->invalidate();
}

QString QwtText::text() const 
{ 
    return d_data->text; 
}

void QwtText::setRenderFlags(int renderFlags) 
{ 
    if ( renderFlags != d_data->renderFlags )
    {
        d_data->renderFlags = renderFlags; 
        d_layoutCache->invalidate();
    }
}

int QwtText::renderFlags() const 
{ 
    return d_data->renderFlags; 
}

void QwtText::setFont(const QFont &font) 
{
    d_data->font = font; 
    setPaintAttribute(PaintUsingTextFont);
}

QFont QwtText::font() const 
{ 
    return d_data->font; 
}

QFont QwtText::usedFont(const QFont &defaultFont) const
{
    if ( d_data->paintAttributes & PaintUsingTextFont )
        return d_data->font;

    return defaultFont;
}

void QwtText::setColor(const QColor &color) 
{ 
    d_data->color = color; 
    setPaintAttribute(PaintUsingTextColor);
}

QColor QwtText::color() const 
{ 
    return d_data->color; 
}

QColor QwtText::usedColor(const QColor &defaultColor) const
{
    if ( d_data->paintAttributes & PaintUsingTextColor )
        return d_data->color;

    return defaultColor;
}

void QwtText::setBackgroundPen(const QPen &pen) 
{ 
    d_data->backgroundPen = pen; 
    setPaintAttribute(PaintBackground);
}

QPen QwtText::backgroundPen() const 
{ 
    return d_data->backgroundPen; 
}

void QwtText::setBackgroundBrush(const QBrush &brush) 
{ 
    d_data->backgroundBrush = brush; 
    setPaintAttribute(PaintBackground);
}

QBrush QwtText::backgroundBrush() const 
{ 
    return d_data->backgroundBrush; 
}

void QwtText::setPaintAttribute(PaintAttribute attribute, bool on)
{
    if ( on )
        d_data->paintAttributes |= attribute;
    else
        d_data->paintAttributes &= ~attribute;
}

bool QwtText::testPaintAttribute(PaintAttribute attribute) const
{
    return d_data->paintAttributes & attribute;
}

void QwtText::setLayoutAttribute(LayoutAttribute attribute, bool on)
{
    if ( on )
        d_data->layoutAttributes |= attribute;
    else
        d_data->layoutAttributes &= ~attribute;
}

bool QwtText::testLayoutAttribute(LayoutAttribute attribute) const
{
    return d_data->layoutAttributes | attribute;
}

int QwtText::heightForWidth(int width, const QFont &defaultFont) const
{
    const QwtMetricsMap map = QwtPainter::metricsMap();
    width = map.layoutToScreenX(width);

#if QT_VERSION < 0x040000
    const QFont font = usedFont(defaultFont);
#else
    // We want to calculate in screen metrics. So
    // we need a font that uses screen metrics

    const QFont font(usedFont(defaultFont), QApplication::desktop());
#endif

    int h = 0;

    if ( d_data->layoutAttributes & MinimumLayout )
    {
        int left, right, top, bottom;
        d_data->textEngine->textMargins(font, d_data->text,
            left, right, top, bottom);

        h = d_data->textEngine->heightForWidth(
            font, d_data->renderFlags, d_data->text, 
            width + left + right);

        h -= top + bottom;
    }
    else
    {
        h = d_data->textEngine->heightForWidth(
            font, d_data->renderFlags, d_data->text, width);
    }

    h = map.screenToLayoutY(h);
    return h;
}

QSize QwtText::textSize(const QFont &defaultFont) const
{
#if QT_VERSION < 0x040000
    const QFont font(usedFont(defaultFont));
#else
    // We want to calculate in screen metrics. So
    // we need a font that uses screen metrics

    const QFont font(usedFont(defaultFont), QApplication::desktop());
#endif

    if ( !d_layoutCache->textSize.isValid() 
        || d_layoutCache->font != font )
    {
        d_layoutCache->textSize = d_data->textEngine->textSize(
            font, d_data->renderFlags, d_data->text);
        d_layoutCache->font = font;
    }

    QSize sz = d_layoutCache->textSize;

    const QwtMetricsMap map = QwtPainter::metricsMap();

    if ( d_data->layoutAttributes & MinimumLayout )
    {
        int left, right, top, bottom;
        d_data->textEngine->textMargins(font, d_data->text,
            left, right, top, bottom);
        sz -= QSize(left + right, top + bottom);

#if QT_VERSION >= 0x040000
        if ( !map.isIdentity() )
        {
#ifdef __GNUC__
#endif
            /*
                When printing in high resolution, the tick labels
                of are cut of. We need to find out why, but for
                the moment we add a couple of pixels instead.
             */
            sz += QSize(3, 2);
        }
#endif
    }

    sz = map.screenToLayout(sz);
    return sz;
}

void QwtText::draw(QPainter *painter, const QRect &rect) const
{
    if ( d_data->paintAttributes & PaintBackground )
    {
        if ( d_data->backgroundPen != Qt::NoPen || 
            d_data->backgroundBrush != Qt::NoBrush )
        {
            painter->save();
            painter->setPen(QwtPainter::scaledPen(d_data->backgroundPen));
            painter->setBrush(d_data->backgroundBrush);
#if QT_VERSION < 0x040000
            QwtPainter::drawRect(painter, rect);
#else
            const QRect r(rect.x(), rect.y(), 
                rect.width() - 1, rect.height() - 1);
            QwtPainter::drawRect(painter, r);
#endif
            painter->restore();
        }
    }

    painter->save();

    if ( d_data->paintAttributes & PaintUsingTextFont )
    {
        painter->setFont(d_data->font);
    }

    if ( d_data->paintAttributes & PaintUsingTextColor )
    {
        if ( d_data->color.isValid() )
            painter->setPen(d_data->color);
    }

    QRect expandedRect = rect;
    if ( d_data->layoutAttributes & MinimumLayout )
    {
#if QT_VERSION < 0x040000
        const QFont font(painter->font());
#else
        // We want to calculate in screen metrics. So
        // we need a font that uses screen metrics

        const QFont font(painter->font(), QApplication::desktop());
#endif

        int left, right, top, bottom;
        d_data->textEngine->textMargins(
            font, d_data->text,
            left, right, top, bottom);

        const QwtMetricsMap map = QwtPainter::metricsMap();
        left = map.screenToLayoutX(left);
        right = map.screenToLayoutX(right);
        top = map.screenToLayoutY(top);
        bottom = map.screenToLayoutY(bottom);

        expandedRect.setTop(rect.top() - top);
        expandedRect.setBottom(rect.bottom() + bottom);
        expandedRect.setLeft(rect.left() - left);
        expandedRect.setRight(rect.right() + right);
    }

    d_data->textEngine->draw(painter, expandedRect, 
        d_data->renderFlags, d_data->text);

    painter->restore();
}

const QwtTextEngine *QwtText::textEngine(const QString &text,
    QwtText::TextFormat format)
{
    if ( engineDict == NULL )
    {
        /*
          Note: engineDict is allocated, the first time it is used, 
                but never deleted, because there is no known last access time.
                So don't be irritated, if it is reported as a memory leak
                from your memory profiler.
         */
        engineDict = new QwtTextEngineDict();
    }

    return engineDict->textEngine(text, format);
}

void QwtText::setTextEngine(QwtText::TextFormat format, 
    QwtTextEngine *engine)
{
    if ( engineDict == NULL )
        engineDict = new QwtTextEngineDict();

    engineDict->setTextEngine(format, engine);
}

const QwtTextEngine *QwtText::textEngine(QwtText::TextFormat format)
{
    if ( engineDict == NULL )
        engineDict = new QwtTextEngineDict();

    return engineDict->textEngine(format);
}