/* -*- 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
 *****************************************************************************/

#ifndef QWT_LAYOUT_METRICS_H
#define QWT_LAYOUT_METRICS_H

#include <qsize.h>
#include <qrect.h>
#include "qwt_polygon.h"
#include "qwt_global.h"

class QPainter;
class QString;
class QFontMetrics;
#if QT_VERSION < 0x040000
class QWMatrix;
#else
class QMatrix;
#endif
class QPaintDevice;

/*!
  \brief A Map to translate between layout, screen and paint device metrics

  Qt3 supports painting in integer coordinates only. Therefore it is not
  possible to scale the layout in screen coordinates to layouts in higher
  resolutions ( f.e printing ) without losing the higher precision.
  QwtMetricsMap is used to incorporate the various widget attributes
  ( always in screen resolution ) into the layout/printing code of QwtPlot.

  Qt4 is able to paint floating point based coordinates, what makes it
  possible always to render in screen coordinates 
  ( with a common scale factor ).
  QwtMetricsMap will be obsolete as soon as Qt3 support has been
  dropped ( Qwt 6.x ).
*/
class QWT_EXPORT QwtMetricsMap
{
public:
    QwtMetricsMap();

    bool isIdentity() const;

    void setMetrics(const QPaintDevice *layoutMetrics,
        const QPaintDevice *deviceMetrics);

    int layoutToDeviceX(int x) const;
    int deviceToLayoutX(int x) const;
    int screenToLayoutX(int x) const;
    int layoutToScreenX(int x) const;

    int layoutToDeviceY(int y) const;
    int deviceToLayoutY(int y) const;
    int screenToLayoutY(int y) const;
    int layoutToScreenY(int y) const;

    QPoint layoutToDevice(const QPoint &, const QPainter * = NULL) const;
    QPoint deviceToLayout(const QPoint &, const QPainter * = NULL) const;
    QPoint screenToLayout(const QPoint &) const;
    QPoint layoutToScreen(const QPoint &point) const;


    QSize layoutToDevice(const QSize &) const;
    QSize deviceToLayout(const QSize &) const;
    QSize screenToLayout(const QSize &) const;
    QSize layoutToScreen(const QSize &) const;

    QRect layoutToDevice(const QRect &, const QPainter * = NULL) const;
    QRect deviceToLayout(const QRect &, const QPainter * = NULL) const;
    QRect screenToLayout(const QRect &) const;
    QRect layoutToScreen(const QRect &) const;

    QwtPolygon layoutToDevice(const QwtPolygon &, 
        const QPainter * = NULL) const;
    QwtPolygon deviceToLayout(const QwtPolygon &, 
        const QPainter * = NULL) const;

#if QT_VERSION < 0x040000
    static QwtPolygon translate(const QWMatrix &, const QwtPolygon &);
    static QRect translate(const QWMatrix &, const QRect &);
#else
    static QwtPolygon translate(const QMatrix &, const QwtPolygon &);
    static QRect translate(const QMatrix &, const QRect &);
#endif

private:
    double d_screenToLayoutX;
    double d_screenToLayoutY;

    double d_deviceToLayoutX;
    double d_deviceToLayoutY;
};

inline bool QwtMetricsMap::isIdentity() const
{
    return d_deviceToLayoutX == 1.0 && d_deviceToLayoutY == 1.0;
}

inline int QwtMetricsMap::layoutToDeviceX(int x) const
{
    return qRound(x / d_deviceToLayoutX);
}

inline int QwtMetricsMap::deviceToLayoutX(int x) const
{
    return qRound(x * d_deviceToLayoutX);
}

inline int QwtMetricsMap::screenToLayoutX(int x) const
{
    return qRound(x * d_screenToLayoutX);
}

inline int QwtMetricsMap::layoutToScreenX(int x) const
{
    return qRound(x / d_screenToLayoutX);
}

inline int QwtMetricsMap::layoutToDeviceY(int y) const
{
    return qRound(y / d_deviceToLayoutY);
}

inline int QwtMetricsMap::deviceToLayoutY(int y) const
{
    return qRound(y * d_deviceToLayoutY);
}

inline int QwtMetricsMap::screenToLayoutY(int y) const
{
    return qRound(y * d_screenToLayoutY);
}

inline int QwtMetricsMap::layoutToScreenY(int y) const
{
    return qRound(y / d_screenToLayoutY);
}

inline QSize QwtMetricsMap::layoutToDevice(const QSize &size) const
{
    return QSize(layoutToDeviceX(size.width()), 
        layoutToDeviceY(size.height()));
}

inline QSize QwtMetricsMap::deviceToLayout(const QSize &size) const
{
    return QSize(deviceToLayoutX(size.width()), 
        deviceToLayoutY(size.height()));
}

inline QSize QwtMetricsMap::screenToLayout(const QSize &size) const
{
    return QSize(screenToLayoutX(size.width()), 
        screenToLayoutY(size.height()));
}

inline QSize QwtMetricsMap::layoutToScreen(const QSize &size) const
{
    return QSize(layoutToScreenX(size.width()), 
        layoutToScreenY(size.height()));
}

#endif
