qwt_abstract_scale_draw.cpp

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/* -*- 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_abstract_scale_draw.h"
#include "qwt_math.h"
#include "qwt_text.h"
#include "qwt_painter.h"
#include "qwt_scale_map.h"
#include <qpainter.h>
#include <qpalette.h>
#include <qmap.h>
#include <qlocale.h>

class QwtAbstractScaleDraw::PrivateData
{
public:
    PrivateData():
        spacing( 4.0 ),
        penWidth( 0 ),
        minExtent( 0.0 )
    {
        components = QwtAbstractScaleDraw::Backbone 
            | QwtAbstractScaleDraw::Ticks 
            | QwtAbstractScaleDraw::Labels;

        tickLength[QwtScaleDiv::MinorTick] = 4.0;
        tickLength[QwtScaleDiv::MediumTick] = 6.0;
        tickLength[QwtScaleDiv::MajorTick] = 8.0;
    }

    ScaleComponents components;

    QwtScaleMap map;
    QwtScaleDiv scaleDiv;

    double spacing;
    double tickLength[QwtScaleDiv::NTickTypes];
    int penWidth;

    double minExtent;

    QMap<double, QwtText> labelCache;
};

QwtAbstractScaleDraw::QwtAbstractScaleDraw()
{
    d_data = new QwtAbstractScaleDraw::PrivateData;
}

QwtAbstractScaleDraw::~QwtAbstractScaleDraw()
{
    delete d_data;
}

void QwtAbstractScaleDraw::enableComponent(
    ScaleComponent component, bool enable )
{
    if ( enable )
        d_data->components |= component;
    else
        d_data->components &= ~component;
}

bool QwtAbstractScaleDraw::hasComponent( ScaleComponent component ) const
{
    return ( d_data->components & component );
}

void QwtAbstractScaleDraw::setScaleDiv( const QwtScaleDiv &scaleDiv )
{
    d_data->scaleDiv = scaleDiv;
    d_data->map.setScaleInterval( scaleDiv.lowerBound(), scaleDiv.upperBound() );
    d_data->labelCache.clear();
}

void QwtAbstractScaleDraw::setTransformation(
    QwtTransform *transformation )
{
    d_data->map.setTransformation( transformation );
}

const QwtScaleMap &QwtAbstractScaleDraw::scaleMap() const
{
    return d_data->map;
}

QwtScaleMap &QwtAbstractScaleDraw::scaleMap()
{
    return d_data->map;
}

const QwtScaleDiv& QwtAbstractScaleDraw::scaleDiv() const
{
    return d_data->scaleDiv;
}

void QwtAbstractScaleDraw::setPenWidth( int width )
{
    if ( width < 0 )
        width = 0;

    if ( width != d_data->penWidth )
        d_data->penWidth = width;
}

int QwtAbstractScaleDraw::penWidth() const
{
    return d_data->penWidth;
}

void QwtAbstractScaleDraw::draw( QPainter *painter,
    const QPalette& palette ) const
{
    painter->save();

    QPen pen = painter->pen();
    pen.setWidth( d_data->penWidth );
    pen.setCosmetic( false );
    painter->setPen( pen );

    if ( hasComponent( QwtAbstractScaleDraw::Labels ) )
    {
        painter->save();
        painter->setPen( palette.color( QPalette::Text ) ); // ignore pen style

        const QList<double> &majorTicks =
            d_data->scaleDiv.ticks( QwtScaleDiv::MajorTick );

        for ( int i = 0; i < majorTicks.count(); i++ )
        {
            const double v = majorTicks[i];
            if ( d_data->scaleDiv.contains( v ) )
                drawLabel( painter, v );
        }

        painter->restore();
    }

    if ( hasComponent( QwtAbstractScaleDraw::Ticks ) )
    {
        painter->save();

        QPen pen = painter->pen();
        pen.setColor( palette.color( QPalette::WindowText ) );
        pen.setCapStyle( Qt::FlatCap );

        painter->setPen( pen );

        for ( int tickType = QwtScaleDiv::MinorTick;
            tickType < QwtScaleDiv::NTickTypes; tickType++ )
        {
            const double tickLen = d_data->tickLength[tickType];
            if ( tickLen <= 0.0 )
                continue;

            const QList<double> &ticks = d_data->scaleDiv.ticks( tickType );
            for ( int i = 0; i < ticks.count(); i++ )
            {
                const double v = ticks[i];
                if ( d_data->scaleDiv.contains( v ) )
                    drawTick( painter, v, tickLen );
            }
        }

        painter->restore();
    }

    if ( hasComponent( QwtAbstractScaleDraw::Backbone ) )
    {
        painter->save();

        QPen pen = painter->pen();
        pen.setColor( palette.color( QPalette::WindowText ) );
        pen.setCapStyle( Qt::FlatCap );

        painter->setPen( pen );

        drawBackbone( painter );

        painter->restore();
    }

    painter->restore();
}

void QwtAbstractScaleDraw::setSpacing( double spacing )
{
    if ( spacing < 0 )
        spacing = 0;

    d_data->spacing = spacing;
}

double QwtAbstractScaleDraw::spacing() const
{
    return d_data->spacing;
}

void QwtAbstractScaleDraw::setMinimumExtent( double minExtent )
{
    if ( minExtent < 0.0 )
        minExtent = 0.0;

    d_data->minExtent = minExtent;
}

double QwtAbstractScaleDraw::minimumExtent() const
{
    return d_data->minExtent;
}

void QwtAbstractScaleDraw::setTickLength(
    QwtScaleDiv::TickType tickType, double length )
{
    if ( tickType < QwtScaleDiv::MinorTick ||
        tickType > QwtScaleDiv::MajorTick )
    {
        return;
    }

    if ( length < 0.0 )
        length = 0.0;

    const double maxTickLen = 1000.0;
    if ( length > maxTickLen )
        length = maxTickLen;

    d_data->tickLength[tickType] = length;
}

double QwtAbstractScaleDraw::tickLength( QwtScaleDiv::TickType tickType ) const
{
    if ( tickType < QwtScaleDiv::MinorTick ||
        tickType > QwtScaleDiv::MajorTick )
    {
        return 0;
    }

    return d_data->tickLength[tickType];
}

double QwtAbstractScaleDraw::maxTickLength() const
{
    double length = 0.0;
    for ( int i = 0; i < QwtScaleDiv::NTickTypes; i++ )
        length = qMax( length, d_data->tickLength[i] );

    return length;
}

QwtText QwtAbstractScaleDraw::label( double value ) const
{
    return QLocale().toString( value );
}

const QwtText &QwtAbstractScaleDraw::tickLabel(
    const QFont &font, double value ) const
{
    QMap<double, QwtText>::const_iterator it = d_data->labelCache.constFind( value );
    if ( it == d_data->labelCache.constEnd() )
    {
        QwtText lbl = label( value );
        lbl.setRenderFlags( 0 );
        lbl.setLayoutAttribute( QwtText::MinimumLayout );

        ( void )lbl.textSize( font ); // initialize the internal cache

        it = d_data->labelCache.insert( value, lbl );
    }

    return ( *it );
}

void QwtAbstractScaleDraw::invalidateCache()
{
    d_data->labelCache.clear();
}