qwt_plot_axis.cpp

QWT5.01用于Qt开发的二维图形库程序

/* -*- 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_plot.h"
#include "qwt_math.h"
#include "qwt_scale_widget.h"
#include "qwt_scale_div.h"
#include "qwt_scale_engine.h"

class QwtPlot::AxisData
{
public:
    bool isEnabled;
    bool doAutoScale;

    double minValue;
    double maxValue;
    double stepSize;

    int maxMajor;
    int maxMinor;

    QwtScaleDiv scaleDiv;
    QwtScaleEngine *scaleEngine;
    QwtScaleWidget *scaleWidget;
};

//! Initialize axes
void QwtPlot::initAxesData()
{
    int axisId;

    for( axisId = 0; axisId < axisCnt; axisId++)
        d_axisData[axisId] = new AxisData;

    d_axisData[yLeft]->scaleWidget = 
        new QwtScaleWidget(QwtScaleDraw::LeftScale, this);
    d_axisData[yRight]->scaleWidget = 
        new QwtScaleWidget(QwtScaleDraw::RightScale, this);
    d_axisData[xTop]->scaleWidget = 
        new QwtScaleWidget(QwtScaleDraw::TopScale, this);
    d_axisData[xBottom]->scaleWidget = 
        new QwtScaleWidget(QwtScaleDraw::BottomScale, this);


    QFont fscl(fontInfo().family(), 10);
    QFont fttl(fontInfo().family(), 12, QFont::Bold);

    for(axisId = 0; axisId < axisCnt; axisId++)
    {
        AxisData &d = *d_axisData[axisId];

        d.scaleWidget->setFont(fscl);
        d.scaleWidget->setMargin(2);

        QwtText text;
        text.setFont(fttl);
        d.scaleWidget->setTitle(text);

        d.doAutoScale = true;

        d.minValue = 0.0;
        d.maxValue = 1000.0;
        d.stepSize = 0.0;

        d.maxMinor = 5;
        d.maxMajor = 8;

        d.scaleEngine = new QwtLinearScaleEngine;

        d.scaleDiv.invalidate();
    }

    d_axisData[yLeft]->isEnabled = true;
    d_axisData[yRight]->isEnabled = false;
    d_axisData[xBottom]->isEnabled = true;
    d_axisData[xTop]->isEnabled = false;
}

void QwtPlot::deleteAxesData()
{
    for( int axisId = 0; axisId < axisCnt; axisId++)
    {
        delete d_axisData[axisId]->scaleEngine;
        delete d_axisData[axisId];
        d_axisData[axisId] = NULL;
    }
}

/*!
  \return specified axis, or NULL if axisId is invalid.
  \param axisId axis index
*/
const QwtScaleWidget *QwtPlot::axisWidget(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->scaleWidget;

    return NULL;
}

/*!
  \return specified axis, or NULL if axisId is invalid.
  \param axisId axis index
*/
QwtScaleWidget *QwtPlot::axisWidget(int axisId)
{
    if (axisValid(axisId))
        return d_axisData[axisId]->scaleWidget;

    return NULL;
}

void QwtPlot::setAxisScaleEngine(int axisId, QwtScaleEngine *scaleEngine)
{
    if (axisValid(axisId) && scaleEngine != NULL )
    {
        AxisData &d = *d_axisData[axisId];

        delete d.scaleEngine;
        d.scaleEngine = scaleEngine;

        d.scaleDiv.invalidate();

        autoRefresh();
    }
}

QwtScaleEngine *QwtPlot::axisScaleEngine(int axisId)
{
    if (axisValid(axisId))
        return d_axisData[axisId]->scaleEngine;
    else
        return NULL;
}

const QwtScaleEngine *QwtPlot::axisScaleEngine(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->scaleEngine;
    else
        return NULL;
}
/*!
  \return \c true if autoscaling is enabled
  \param axisId axis index
*/
bool QwtPlot::axisAutoScale(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->doAutoScale;
    else
        return false;
    
}

/*!
  \return \c true if a specified axis is enabled
  \param axisId axis index
*/
bool QwtPlot::axisEnabled(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->isEnabled;
    else
        return false;
}

/*!
  \return the font of the scale labels for a specified axis
  \param axisId axis index
*/
QFont QwtPlot::axisFont(int axisId) const
{
    if (axisValid(axisId))
        return axisWidget(axisId)->font();
    else
        return QFont();
    
}

/*!
  \return the maximum number of major ticks for a specified axis
  \param axisId axis index
*/
int QwtPlot::axisMaxMajor(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->maxMajor;
    else
        return 0;
}

/*!
  \return the maximum number of minor ticks for a specified axis
  \param axisId axis index
*/
int QwtPlot::axisMaxMinor(int axisId) const
{
    if (axisValid(axisId))
        return d_axisData[axisId]->maxMinor;
    else
        return 0;
}

/*!
  \brief Return the scale division of a specified axis

  axisScaleDiv(axisId)->lBound(), axisScaleDiv(axisId)->hBound()
  are the current limits of the axis scale.

  \param axisId axis index
  \return Scale division 

  \sa QwtScaleDiv, setAxisScaleDiv
*/
const QwtScaleDiv *QwtPlot::axisScaleDiv(int axisId) const
{
    if (!axisValid(axisId))
        return NULL;

    return &d_axisData[axisId]->scaleDiv;
}

/*!
  \brief Return the scale division of a specified axis

  axisScaleDiv(axisId)->lBound(), axisScaleDiv(axisId)->hBound()
  are the current limits of the axis scale.

  \param axisId axis index
  \return Scale division 

  \sa QwtScaleDiv, setAxisScaleDiv
*/
QwtScaleDiv *QwtPlot::axisScaleDiv(int axisId) 
{
    if (!axisValid(axisId))
        return NULL;

    return &d_axisData[axisId]->scaleDiv;
}

/*!
  \returns the scale draw of a specified axis
  \param axisId axis index
  \return specified scaleDraw for axis, or NULL if axis is invalid.
  \sa QwtScaleDraw
*/
const QwtScaleDraw *QwtPlot::axisScaleDraw(int axisId) const
{
    if (!axisValid(axisId))
        return NULL;

    return axisWidget(axisId)->scaleDraw();
}

/*!
  \returns the scale draw of a specified axis
  \param axisId axis index
  \return specified scaleDraw for axis, or NULL if axis is invalid.
  \sa QwtScaleDraw
*/
QwtScaleDraw *QwtPlot::axisScaleDraw(int axisId) 
{
    if (!axisValid(axisId))
        return NULL;

    return axisWidget(axisId)->scaleDraw();
}

/*!
  \return the title of a specified axis
  \param axisId axis index
*/
QwtText QwtPlot::axisTitle(int axisId) const
{
    if (axisValid(axisId))
        return axisWidget(axisId)->title();
    else
        return QwtText();
}

/*!
  \brief Enable or disable a specified axis

  When an axis is disabled, this only means that it is not
  visible on the screen. Curves, markers and can be attached
  to disabled axes, and transformation of screen coordinates
  into values works as normal.

  Only xBottom and yLeft are enabled by default.
  \param axisId axis index
  \param tf \c true (enabled) or \c false (disabled)
*/
void QwtPlot::enableAxis(int axisId, bool tf)
{
    if (axisValid(axisId) && tf != d_axisData[axisId]->isEnabled)
    {
        d_axisData[axisId]->isEnabled = tf;
        updateLayout();
    }