qwt_scale_draw.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_scale_draw.h"
#include "qwt_scale_div.h"
#include "qwt_scale_map.h"
#include "qwt_math.h"
#include "qwt_painter.h"
#include <qpen.h>
#include <qpainter.h>
#include <qmath.h>

#if QT_VERSION < 0x040601
#define qFastSin(x) qSin(x)
#define qFastCos(x) qCos(x)
#endif

class QwtScaleDraw::PrivateData
{
public:
    PrivateData():
        len( 0 ),
        alignment( QwtScaleDraw::BottomScale ),
        labelAlignment( 0 ),
        labelRotation( 0.0 )
    {
    }

    QPointF pos;
    double len;

    Alignment alignment;

    Qt::Alignment labelAlignment;
    double labelRotation;
};

/*!
  \brief Constructor

  The range of the scale is initialized to [0, 100],
  The position is at (0, 0) with a length of 100.
  The orientation is QwtAbstractScaleDraw::Bottom.
*/
QwtScaleDraw::QwtScaleDraw()
{
    d_data = new QwtScaleDraw::PrivateData;
    setLength( 100 );
}

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

/*!
   Return alignment of the scale
   \sa setAlignment()
   \return Alignment of the scale
*/
QwtScaleDraw::Alignment QwtScaleDraw::alignment() const
{
    return d_data->alignment;
}

/*!
   Set the alignment of the scale

   \param align Alignment of the scale

   The default alignment is QwtScaleDraw::BottomScale
   \sa alignment()
*/
void QwtScaleDraw::setAlignment( Alignment align )
{
    d_data->alignment = align;
}

/*!
  Return the orientation

  TopScale, BottomScale are horizontal (Qt::Horizontal) scales,
  LeftScale, RightScale are vertical (Qt::Vertical) scales.

  \return Orientation of the scale

  \sa alignment()
*/
Qt::Orientation QwtScaleDraw::orientation() const
{
    switch ( d_data->alignment )
    {
        case TopScale:
        case BottomScale:
            return Qt::Horizontal;
        case LeftScale:
        case RightScale:
        default:
            return Qt::Vertical;
    }
}

/*!
  \brief Determine the minimum border distance

  This member function returns the minimum space
  needed to draw the mark labels at the scale's endpoints.

  \param font Font
  \param start Start border distance
  \param end End border distance
*/
void QwtScaleDraw::getBorderDistHint( 
    const QFont &font, int &start, int &end ) const
{
    start = 0;
    end = 0;

    if ( !hasComponent( QwtAbstractScaleDraw::Labels ) )
        return;

    const QList<double> &ticks = scaleDiv().ticks( QwtScaleDiv::MajorTick );
    if ( ticks.count() == 0 )