qwt_plot_picker.cpp

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/* -*- 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_plot.h"
#include "qwt_double_rect.h"
#include "qwt_painter.h"
#include "qwt_array.h"
#include "qwt_plot_picker.h"

/*!
  \brief Create a plot picker

  The picker is set to those x- and y-axis of the plot
  that are enabled. If both or no x-axis are enabled, the picker
  is set to QwtPlot::xBottom. If both or no y-axis are
  enabled, it is set to QwtPlot::yLeft.

  \param canvas Plot canvas to observe, also the parent object
  \param name Object name
*/
  
QwtPlotPicker::QwtPlotPicker(QwtPlotCanvas *canvas, const char *name):
    QwtPicker(canvas, name),
    d_xAxis(-1),
    d_yAxis(-1)
{
    if ( !canvas )
        return;

    // attach axes

    int xAxis = QwtPlot::xBottom;

    const QwtPlot *plot = QwtPlotPicker::plot();
    if ( !plot->axisEnabled(QwtPlot::xBottom) &&
        plot->axisEnabled(QwtPlot::xTop) )
    {
        xAxis = QwtPlot::xTop;
    }

    int yAxis = QwtPlot::yLeft;
    if ( !plot->axisEnabled(QwtPlot::yLeft) &&
        plot->axisEnabled(QwtPlot::yRight) )
    {
        yAxis = QwtPlot::yRight;
    }

    setAxis(xAxis, yAxis);
}

/*!
  Create a plot picker

  \param xAxis Set the x axis of the picker
  \param yAxis Set the y axis of the picker
  \param canvas Plot canvas to observe, also the parent object
  \param name Object name
*/
QwtPlotPicker::QwtPlotPicker(int xAxis, int yAxis, 
        QwtPlotCanvas *canvas, const char *name):
    QwtPicker(canvas, name),
    d_xAxis(xAxis),
    d_yAxis(yAxis)
{
}

/*!
  Create a plot picker

  \param xAxis X axis of the picker
  \param yAxis Y axis of the picker
  \param selectionFlags Or磀 value of SelectionType, RectSelectionType and
                        SelectionMode
  \param rubberBand Rubberband style
  \param cursorLabelMode Cursor label mode
  \param canvas Plot canvas to observe, also the parent object
  \param name Object name

  \sa QwtPicker, QwtPicker::setSelectionFlags(), QwtPicker::setRubberBand(),
      QwtPicker::setCursorLabelMode
*/
QwtPlotPicker::QwtPlotPicker(int xAxis, int yAxis, int selectionFlags,
        RubberBand rubberBand, DisplayMode cursorLabelMode,
        QwtPlotCanvas *canvas, const char *name):
    QwtPicker(selectionFlags, rubberBand, cursorLabelMode, canvas, name),
    d_xAxis(xAxis),
    d_yAxis(yAxis)
{
}

//! Return observed plot canvas
QwtPlotCanvas *QwtPlotPicker::canvas()
{
    QWidget *w = parentWidget();
    if ( w && w->inherits("QwtPlotCanvas") )
        return (QwtPlotCanvas *)w;

    return NULL;
}

//! Return Observed plot canvas
const QwtPlotCanvas *QwtPlotPicker::canvas() const
{
    return ((QwtPlotPicker *)this)->canvas();
}

//! Return plot widget, containing the observed plot canvas
QwtPlot *QwtPlotPicker::plot()
{
    QObject *w = canvas();
    if ( w )
    {
        w = w->parent();
        if ( w && w->inherits("QwtPlot") )
            return (QwtPlot *)w;
    }

    return NULL;
}

//! Return plot widget, containing the observed plot canvas
const QwtPlot *QwtPlotPicker::plot() const
{
    return ((QwtPlotPicker *)this)->plot();
}

//! Return normalized bounding rect of the axes
QwtDoubleRect QwtPlotPicker::scaleRect() const
{
    const QwtPlot *plt = plot();

    const QwtDoubleRect rect(
        plt->axisScale(xAxis())->lBound(),
        plt->axisScale(xAxis())->hBound(),
        plt->axisScale(yAxis())->lBound(),
        plt->axisScale(yAxis())->hBound()
    );

    return rect.normalize();
}

/*!
  Set the x and y axes of the picker

  \param xAxis X axis
  \param yAxis Y axis
*/
void QwtPlotPicker::setAxis(int xAxis, int yAxis)
{
    const QwtPlot *plt = plot();
    if ( !plt )
        return;

    if ( xAxis != d_xAxis || yAxis != d_yAxis )
    {
        d_xAxis = xAxis;
        d_yAxis = yAxis;
    }
}

//! Return x axis
int QwtPlotPicker::xAxis() const
{
    return d_xAxis;
}

//! Return y axis
int QwtPlotPicker::yAxis() const
{
    return d_yAxis;
}

/*!
  Translate a pixel position into a position string

  \param pos Position in pixel coordinates
  \return Position string
*/
QString QwtPlotPicker::cursorLabel(const QPoint &pos) const
{
    return cursorLabel(invTransform(pos));
}

/*!
  \brief Translate a position into a position string

  In case of HLineRubberBand the label is the value of the
  y position, in case of VLineRubberBand the value of the x position.
  Otherwise the label contains x and y position separated by a