qwt_dial.cpp

/* -*- 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 <math.h>
#include <qpainter.h>
#if QT_VERSION >= 0x040000
#include <qbitmap.h>
#include <qpalette.h>
#endif
#include <qpixmap.h>
#include <qevent.h>
#include "qwt_math.h"
#include "qwt_scale_engine.h"
#include "qwt_scale_map.h"
#include "qwt_paint_buffer.h"
#include "qwt_painter.h"
#include "qwt_dial_needle.h"
#include "qwt_dial.h"

class QwtDial::PrivateData
{
public:
    PrivateData():
        visibleBackground(true),
        frameShadow(Sunken),
        lineWidth(0),
        mode(RotateNeedle),
        origin(90.0),
        minScaleArc(0.0),
        maxScaleArc(0.0),
        scaleDraw(0),
        maxMajIntv(36),
        maxMinIntv(10),
        scaleStep(0.0),
        needle(0)
    {
    }

    ~PrivateData()
    {
        delete scaleDraw;
        delete needle;
    }
    bool visibleBackground;
    Shadow frameShadow;
    int lineWidth;

    QwtDial::Mode mode;

    double origin;
    double minScaleArc;
    double maxScaleArc;

    QwtDialScaleDraw *scaleDraw;
    int maxMajIntv;
    int maxMinIntv;
    double scaleStep;

    QwtDialNeedle *needle;

    static double previousDir;
};

double QwtDial::PrivateData::previousDir = -1.0;

/*!
  Constructor

  \param parent Parent dial widget
*/
QwtDialScaleDraw::QwtDialScaleDraw(QwtDial *parent):
    d_parent(parent),
    d_penWidth(1)
{
}

/*!
  Set the pen width used for painting the scale

  \param penWidth Pen width
  \sa penWidth(), QwtDial::drawScale()
*/
    
void QwtDialScaleDraw::setPenWidth(uint penWidth)
{
    d_penWidth = penWidth;
}

/*!
  \return Pen width used for painting the scale
  \sa setPenWidth, QwtDial::drawScale()
*/
uint QwtDialScaleDraw::penWidth() const
{
    return d_penWidth;
}

/*! 
  Call QwtDial::scaleLabel of the parent dial widget.

  \param value Value to display
    
  \sa QwtDial::scaleLabel
*/  
QwtText QwtDialScaleDraw::label(double value) const
{
    if ( d_parent == NULL )
        return QwtRoundScaleDraw::label(value);

    return d_parent->scaleLabel(value);
}

/*!
  \brief Constructor
  \param parent Parent widget

  Create a dial widget with no scale and no needle. 
  The default origin is 90.0 with no valid value. It accepts
  mouse and keyboard inputs and has no step size. The default mode
  is QwtDial::RotateNeedle.
*/  

QwtDial::QwtDial(QWidget* parent):
    QwtAbstractSlider(Qt::Horizontal, parent)
{
    initDial();
}

#if QT_VERSION < 0x040000
/*!
  \brief Constructor
  \param parent Parent widget
  \param name Object name

  Create a dial widget with no scale and no needle. 
  The default origin is 90.0 with no valid value. It accepts
  mouse and keyboard inputs and has no step size. The default mode
  is QwtDial::RotateNeedle.
*/  
QwtDial::QwtDial(QWidget* parent, const char *name):
    QwtAbstractSlider(Qt::Horizontal, parent)
{
    setName(name);
    initDial();
}
#endif

void QwtDial::initDial()
{
    d_data = new PrivateData;

#if QT_VERSION < 0x040000
    setWFlags(Qt::WNoAutoErase);
#endif 

#if QT_VERSION >= 0x040000
    using namespace Qt;
#endif
    setFocusPolicy(TabFocus);

    QPalette p = palette();
    for ( int i = 0; i < QPalette::NColorGroups; i++ )
    {
        const QPalette::ColorGroup cg = (QPalette::ColorGroup)i;

        // Base: background color of the circle inside the frame.
        // Foreground: background color of the circle inside the scale

#if QT_VERSION < 0x040000
        p.setColor(cg, QColorGroup::Foreground, 
            p.color(cg, QColorGroup::Base));
#else
        p.setColor(cg, QPalette::Foreground, 
            p.color(cg, QPalette::Base));
#endif
    }
    setPalette(p);

    d_data->scaleDraw = new QwtDialScaleDraw(this);
    d_data->scaleDraw->setRadius(0);

    setScaleArc(0.0, 360.0); // scale as a full circle
    setRange(0.0, 360.0, 1.0, 10); // degrees as deafult
}

//!  Destructor
QwtDial::~QwtDial() 
{
    delete d_data;
}

/*!
  Show/Hide the area outside of the frame
  \param show Show if true, hide if false