qwt_layout_metrics.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 <qapplication.h>
#include <qpainter.h>
#if QT_VERSION < 0x040000
#include <qpaintdevicemetrics.h>
#include <qwmatrix.h>
#define QwtMatrix QWMatrix
#else
#include <qmatrix.h>
#define QwtMatrix QMatrix
#endif
#include <qpaintdevice.h>
#include <qdesktopwidget.h>
#include "qwt_math.h"
#include "qwt_polygon.h"
#include "qwt_layout_metrics.h"

static QSize deviceDpi(const QPaintDevice *device)
{
    QSize dpi;
#if QT_VERSION < 0x040000
    const QPaintDeviceMetrics metrics(device);
    dpi.setWidth(metrics.logicalDpiX());
    dpi.setHeight(metrics.logicalDpiY());
#else
    dpi.setWidth(device->logicalDpiX());
    dpi.setHeight(device->logicalDpiY());
#endif

    return dpi;
}

#if QT_VERSION < 0x040000

inline static const QWMatrix &matrix(const QPainter *painter)
{
    return painter->worldMatrix();
}
inline static QWMatrix invMatrix(const QPainter *painter)
{
    return painter->worldMatrix().invert();
}

#else // QT_VERSION >= 0x040000

inline static const QMatrix &matrix(const QPainter *painter)
{
    return painter->matrix();
}
inline static QMatrix invMatrix(const QPainter *painter)
{
    return painter->matrix().inverted();
}

#endif

QwtMetricsMap::QwtMetricsMap()
{
    d_screenToLayoutX = d_screenToLayoutY =
                            d_deviceToLayoutX = d_deviceToLayoutY = 1.0;
}

void QwtMetricsMap::setMetrics(const QPaintDevice *layoutDevice,
                               const QPaintDevice *paintDevice)
{
    const QSize screenDpi = deviceDpi(QApplication::desktop());
    const QSize layoutDpi = deviceDpi(layoutDevice);
    const QSize paintDpi = deviceDpi(paintDevice);

    d_screenToLayoutX = double(layoutDpi.width()) /
                        double(screenDpi.width());
    d_screenToLayoutY = double(layoutDpi.height()) /
                        double(screenDpi.height());

    d_deviceToLayoutX = double(layoutDpi.width()) /
                        double(paintDpi.width());
    d_deviceToLayoutY = double(layoutDpi.height()) /
                        double(paintDpi.height());
}

#ifndef QT_NO_TRANSFORMATIONS
QPoint QwtMetricsMap::layoutToDevice(const QPoint &point,
                                     const QPainter *painter) const
#else
QPoint QwtMetricsMap::layoutToDevice(const QPoint &point,
                                     const QPainter *) const
#endif
{
    if ( isIdentity() )
        return point;

    QPoint mappedPoint(point);

#ifndef QT_NO_TRANSFORMATIONS
    if ( painter )
        mappedPoint = matrix(painter).map(mappedPoint);
#endif

    mappedPoint.setX(layoutToDeviceX(mappedPoint.x()));
    mappedPoint.setY(layoutToDeviceY(mappedPoint.y()));

#ifndef QT_NO_TRANSFORMATIONS
    if ( painter )
        mappedPoint = invMatrix(painter).map(mappedPoint);
#endif

    return mappedPoint;
}

#ifndef QT_NO_TRANSFORMATIONS
QPoint QwtMetricsMap::deviceToLayout(const QPoint &point,
                                     const QPainter *painter) const
#else
QPoint QwtMetricsMap::deviceToLayout(const QPoint &point,
                                     const QPainter *) const
#endif
{
    if ( isIdentity() )
        return point;

    QPoint mappedPoint(point);

#ifndef QT_NO_TRANSFORMATIONS
    if ( painter )
        mappedPoint = matrix(painter).map(mappedPoint);
#endif

    mappedPoint.setX(deviceToLayoutX(mappedPoint.x()));
    mappedPoint.setY(deviceToLayoutY(mappedPoint.y()));

#ifndef QT_NO_TRANSFORMATIONS
    if ( painter )
        mappedPoint = invMatrix(painter).map(mappedPoint);
#endif

    return mappedPoint;
}

QPoint QwtMetricsMap::screenToLayout(const QPoint &point) const
{
    if ( d_screenToLayoutX == 1.0 && d_screenToLayoutY == 1.0 )
        return point;

    return QPoint(screenToLayoutX(point.x()), screenToLayoutY(point.y()));
}

QPoint QwtMetricsMap::layoutToScreen(const QPoint &point) const
{
    if ( d_screenToLayoutX == 1.0 && d_screenToLayoutY == 1.0 )
        return point;