Qwt User's Guide: qwt_plot_magnifier.cpp Source File

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# qwt_plot_magnifier.cpp

    00001 /* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
    00002  * Qwt Widget Library
    00003  * Copyright (C) 1997   Josef Wilgen
    00004  * Copyright (C) 2002   Uwe Rathmann
    00005  *
    00006  * This library is free software; you can redistribute it and/or
    00007  * modify it under the terms of the Qwt License, Version 1.0
    00008  *****************************************************************************/
    00009
    00010 // vim: expandtab
    00011
    00012 #include <math.h>
    00013 #include <qevent.h>
    00014 #include "qwt_plot.h"
    00015 #include "qwt_plot_canvas.h"
    00016 #include "qwt_scale_div.h"
    00017 #include "qwt_plot_magnifier.h"
    00018
    00019 class QwtPlotMagnifier::PrivateData
    00020 {
    00021 public:
    00022     PrivateData()
    00023     {
    00024         for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
    00025             isAxisEnabled[axis] = true;
    00026     }
    00027
    00028     bool isAxisEnabled[QwtPlot::axisCnt];
    00029 };
    00030
    00035 QwtPlotMagnifier::QwtPlotMagnifier(QwtPlotCanvas *canvas):
    00036     QwtMagnifier(canvas)
    00037 {
    00038     d_data = new PrivateData();
    00039 }
    00040
    00042 QwtPlotMagnifier::~QwtPlotMagnifier()
    00043 {
    00044     delete d_data;
    00045 }
    00046
    00058 void QwtPlotMagnifier::setAxisEnabled(int axis, bool on)
    00059 {
    00060     if ( axis >= 0 && axis < QwtPlot::axisCnt )
    00061         d_data->isAxisEnabled[axis] = on;
    00062 }
    00063
    00072 bool QwtPlotMagnifier::isAxisEnabled(int axis) const
    00073 {
    00074     if ( axis >= 0 && axis < QwtPlot::axisCnt )
    00075         return d_data->isAxisEnabled[axis];
    00076
    00077     return true;
    00078 }
    00079
    00081 QwtPlotCanvas *QwtPlotMagnifier::canvas()
    00082 {
    00083     QObject *w = parent();
    00084     if ( w && w->inherits("QwtPlotCanvas") )
    00085         return (QwtPlotCanvas *)w;
    00086
    00087     return NULL;
    00088 }
    00089
    00091 const QwtPlotCanvas *QwtPlotMagnifier::canvas() const
    00092 {
    00093     return ((QwtPlotMagnifier *)this)->canvas();
    00094 }
    00095
    00097 QwtPlot *QwtPlotMagnifier::plot()
    00098 {
    00099     QObject *w = canvas();
    00100     if ( w )
    00101     {
    00102         w = w->parent();
    00103         if ( w && w->inherits("QwtPlot") )
    00104             return (QwtPlot *)w;
    00105     }
    00106
    00107     return NULL;
    00108 }
    00109
    00111 const QwtPlot *QwtPlotMagnifier::plot() const
    00112 {
    00113     return ((QwtPlotMagnifier *)this)->plot();
    00114 }
    00115
    00120 void QwtPlotMagnifier::rescale(double factor)
    00121 {
    00122     factor = qwtAbs(factor);
    00123     if ( factor == 1.0 || factor == 0.0 )
    00124         return;
    00125
    00126     bool doReplot = false;
    00127     QwtPlot* plt = plot();
    00128
    00129     const bool autoReplot = plt->autoReplot();
    00130     plt->setAutoReplot(false);
    00131
    00132     for ( int axisId = 0; axisId < QwtPlot::axisCnt; axisId++ )
    00133     {
    00134         const QwtScaleDiv *scaleDiv = plt->axisScaleDiv(axisId);
    00135         if ( isAxisEnabled(axisId) && scaleDiv->isValid() )
    00136         {
    00137             const double center =
    00138                 scaleDiv->lBound() + scaleDiv->range() / 2;
    00139             const double width_2 = scaleDiv->range() / 2 * factor;
    00140
    00141             plt->setAxisScale(axisId, center - width_2, center + width_2);
    00142             doReplot = true;
    00143         }
    00144     }
    00145
    00146     plt->setAutoReplot(autoReplot);
    00147
    00148     if ( doReplot )
    00149         plt->replot();
    00150 }