canvaspicker.cpp

来自「This a framework to test new ideas in tr」· C++ 代码 · 共 30 行

#include <qevent.h>
#include <qwhatsthis.h>
#include <qpainter.h>
#include <qwt_plot.h>
#include <qwt_plot_canvas.h>
#include "canvaspicker.h"

CanvasPicker::CanvasPicker(QwtPlot *plot):
    QObject(plot),
    d_selectedCurve(-1),
    d_selectedPoint(-1)
{
    QwtPlotCanvas *canvas = plot->canvas();

    canvas->installEventFilter(this);

    // We want the focus, but no focus rect. The
    // selected point will be highlighted instead.

    canvas->setFocusPolicy(QWidget::StrongFocus);
    canvas->setFocusIndicator(QwtPlotCanvas::ItemFocusIndicator);
    canvas->setFocus();
    canvas->setCursor(Qt::pointingHandCursor);

    QWhatsThis::add(canvas,
        "All points can be moved using the left mouse button "
        "or with these keys:\n\n"
        "- Up:\t\tSelect next curve\n"
        "- Down:\t\tSelect previous curve\n"
        "- Left,