qwt_compass.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 "qwt_compass.h"
#include "qwt_compass_rose.h"
#include "qwt_math.h"
#include "qwt_scale_draw.h"
#include "qwt_painter.h"
#include "qwt_dial_needle.h"
#include <qpainter.h>
#include <qpixmap.h>
#include <qevent.h>

/*! 
  \brief Constructor

  Initializes a label map for multiples of 45 degrees
 */
QwtCompassScaleDraw::QwtCompassScaleDraw()
{
    enableComponent( QwtAbstractScaleDraw::Backbone, false );
    enableComponent( QwtAbstractScaleDraw::Ticks, false );

    d_labelMap.insert( 0.0, QString::fromLatin1( "N" ) );
    d_labelMap.insert( 45.0, QString::fromLatin1( "NE" ) );
    d_labelMap.insert( 90.0, QString::fromLatin1( "E" ) );
    d_labelMap.insert( 135.0, QString::fromLatin1( "SE" ) );
    d_labelMap.insert( 180.0, QString::fromLatin1( "S" ) );
    d_labelMap.insert( 225.0, QString::fromLatin1( "SW" ) );
    d_labelMap.insert( 270.0, QString::fromLatin1( "W" ) );
    d_labelMap.insert( 315.0, QString::fromLatin1( "NW" ) );

#if 0
    d_labelMap.insert( 22.5, QString::fromLatin1( "NNE" ) );
    d_labelMap.insert( 67.5, QString::fromLatin1( "NEE" ) );
    d_labelMap.insert( 112.5, QString::fromLatin1( "SEE" ) );
    d_labelMap.insert( 157.5, QString::fromLatin1( "SSE" ) );
    d_labelMap.insert( 202.5, QString::fromLatin1( "SSW" ) );
    d_labelMap.insert( 247.5, QString::fromLatin1( "SWW" ) );
    d_labelMap.insert( 292.5, QString::fromLatin1( "NWW" ) );
    d_labelMap.insert( 337.5, QString::fromLatin1( "NNW" ) );
#endif
}

/*! 
  \brief Constructor

  \param map Value to label map
 */
QwtCompassScaleDraw::QwtCompassScaleDraw( const QMap<double, QString> &map ):
    d_labelMap( map )
{
    enableComponent( QwtAbstractScaleDraw::Backbone, false );
    enableComponent( QwtAbstractScaleDraw::Ticks, false );
}

/*!
  \brief Set a map, mapping values to labels
  \param map Value to label map

  The values of the major ticks are found by looking into this
  map. The default map consists of the labels N, NE, E, SE, S, SW, W, NW.

  \warning The map will have no effect for values that are no major
           tick values. Major ticks can be changed by QwtScaleDraw::setScale

  \sa labelMap(), scaleDraw(), setScale()
*/
void QwtCompassScaleDraw::setLabelMap( const QMap<double, QString> &map )
{
    d_labelMap = map;
}


/*!
  \return map, mapping values to labels
  \sa setLabelMap()
*/
QMap<double, QString> QwtCompassScaleDraw::labelMap() const
{
    return d_labelMap;
}

/*!
  Map a value to a corresponding label

  \param value Value that will be mapped

  label() looks in the labelMap() for a corresponding label for value
  or returns an null text.

  \return Label, or QString::null
  \sa labelMap(), setLabelMap()
*/

QwtText QwtCompassScaleDraw::label( double value ) const
{
    if ( qFuzzyCompare( value + 1.0, 1.0 ) )
        value = 0.0;

    if ( value < 0.0 )
        value += 360.0;

    if ( d_labelMap.contains( value ) )
        return d_labelMap[value];

    return QwtText();
}

class QwtCompass::PrivateData
{
public:
    PrivateData():
        rose( NULL )
    {
    }

    ~PrivateData()
    {
        delete rose;
    }

    QwtCompassRose *rose;
};

/*!
  \brief Constructor
  \param parent Parent widget

  Create a compass widget with a scale, no needle and no rose.
  The default origin is 270.0 with no valid value. It accepts
  mouse and keyboard inputs and has no step size. The default mode
  is QwtDial::RotateNeedle.
*/
QwtCompass::QwtCompass( QWidget* parent ):
    QwtDial( parent )
{
    d_data = new PrivateData;

    setScaleDraw( new QwtCompassScaleDraw() );

    setOrigin( 270.0 );
    setWrapping( true );

    setScaleMaxMajor( 36 );
    setScaleMaxMinor( 10 );

    setScale( 0.0, 360.0 ); // degrees as default
    setTotalSteps( 360 );
}

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


/*!
   Draw the contents of the scale

   \param painter Painter
   \param center Center of the content circle
   \param radius Radius of the content circle
*/
void QwtCompass::drawScaleContents( QPainter *painter,
    const QPointF &center, double radius ) const
{
    QPalette::ColorGroup cg;
    if ( isEnabled() )
        cg = hasFocus() ? QPalette::Active : QPalette::Inactive;
    else
        cg = QPalette::Disabled;

    double north = origin();
    if ( isValid() )
    {
        if ( mode() == RotateScale )
            north -= value();
    }

    const int margin = 4;
    drawRose( painter, center, radius - margin, 360.0 - north,  cg );
}

/*!
  Draw the compass rose

  \param painter Painter
  \param center Center of the compass
  \param radius of the circle, where to paint the rose
  \param north Direction pointing north, in degrees counter clockwise
  \param cg Color group
*/
void QwtCompass::drawRose( QPainter *painter, const QPointF &center,
    double radius, double north, QPalette::ColorGroup cg ) const
{
    if ( d_data->rose )
        d_data->rose->draw( painter, center, radius, north,  cg );
}

/*!
  Set a rose for the compass
  \param rose Compass rose
  \warning The rose will be deleted, when a different rose is
    set or in ~QwtCompass
  \sa rose()
*/
void QwtCompass::setRose( QwtCompassRose *rose )
{
    if ( rose != d_data->rose )
    {
        if ( d_data->rose )
            delete d_data->rose;

        d_data->rose = rose;
        update();
    }
}

/*!
  \return rose
  \sa setRose()
*/
const QwtCompassRose *QwtCompass::rose() const
{
    return d_data->rose;
}

/*!
  \return rose
  \sa setRose()
*/
QwtCompassRose *QwtCompass::rose()
{
    return d_data->rose;
}

/*!
  Handles key events

  Beside the keys described in QwtDial::keyPressEvent numbers
  from 1-9 (without 5) set the direction according to their
  position on the num pad.

  \sa isReadOnly()
*/
void QwtCompass::keyPressEvent( QKeyEvent *kev )
{
    if ( isReadOnly() )
        return;

#if 0
    if ( kev->key() == Key_5 )
    {
        invalidate(); // signal ???
        return;
    }
#endif

    double newValue = value();

    if ( kev->key() >= Qt::Key_1 && kev->key() <= Qt::Key_9 )
    {
        if ( mode() != RotateNeedle || kev->key() == Qt::Key_5 )
            return;

        switch ( kev->key() )
        {
            case Qt::Key_6:
                newValue = 180.0 * 0.0;
                break;
            case Qt::Key_3:
                newValue = 180.0 * 0.25;
                break;
            case Qt::Key_2:
                newValue = 180.0 * 0.5;
                break;
            case Qt::Key_1:
                newValue = 180.0 * 0.75;
                break;
            case Qt::Key_4:
                newValue = 180.0 * 1.0;
                break;
            case Qt::Key_7:
                newValue = 180.0 * 1.25;
                break;
            case Qt::Key_8:
                newValue = 180.0 * 1.5;
                break;
            case Qt::Key_9:
                newValue = 180.0 * 1.75;
                break;
        }
        newValue -= origin();
        setValue( newValue );
    }
    else
    {
        QwtDial::keyPressEvent( kev );
    }
}