Method PlotWidgetBase

pj_plotting/widget/src/PlotWidgetBase.cpp:168–223

};

PlotWidgetBase::PlotWidgetBase(QWidget* parent) : QWidget(parent) {
  auto on_view_resized = [this](const QRectF& rect) { emit viewResized(rect); };
  auto on_event = [this](QEvent* event) {
    if (auto* drag_enter = dynamic_cast<QDragEnterEvent*>(event)) {
      emit dragEnterSignal(drag_enter);
    } else if (auto* drag_leave = dynamic_cast<QDragLeaveEvent*>(event)) {
      emit dragLeaveSignal(drag_leave);
    } else if (auto* drop = dynamic_cast<QDropEvent*>(event)) {
      emit dropSignal(drop);
    }
  };

  const bool use_opengl = !g_opengl_disabled_override && QSettings().value("Preferences::use_opengl", true).toBool();

  // TODO(theme): QwtPlotCanvas uses a backing-store paint path that ignores
  //   QSS background rules, so the canvas needs a solid palette colour here.
  //   Currently baked to the light-theme ${dark_background} value (#F5F5F5);
  //   should be wired to react on themeChanged. See resources/visual_guidelines.md §5.
  const QColor canvas_bg(0xf5, 0xf5, 0xf5);

  QWidget* abs_canvas = nullptr;
  if (use_opengl) {
    auto* canvas = new QwtPlotOpenGLCanvas();
    canvas->setFrameStyle(QFrame::Box | QFrame::Plain);
    canvas->setLineWidth(1);
    canvas->setPalette(canvas_bg);
    abs_canvas = canvas;
  } else {
    auto* canvas = new QwtPlotCanvas();
    canvas->setFrameStyle(QFrame::Box | QFrame::Plain);
    canvas->setLineWidth(1);
    canvas->setPalette(canvas_bg);
    canvas->setPaintAttribute(QwtPlotCanvas::BackingStore, true);
    abs_canvas = canvas;
  }
  abs_canvas->setObjectName("qwtCanvas");

  plot_ = new QwtPlotPimpl(this, abs_canvas, on_view_resized, on_event);

  auto* layout = new QHBoxLayout(this);
  layout->setContentsMargins(0, 0, 0, 0);
  layout->addWidget(plot_);

  plot_->setMinimumSize(100, 100);
  plot_->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  plot_->canvas()->setMouseTracking(true);
  // Opaque background: a transparent canvas forces a per-paint alpha-composite of the whole
  // canvas (slow in software raster) instead of a fast opaque blit. canvas_bg matches the palette set above.
  plot_->setCanvasBackground(canvas_bg);
  plot_->setAxisAutoScale(QwtPlot::yLeft, true);
  plot_->setAxisAutoScale(QwtPlot::xBottom, true);
  plot_->axisScaleEngine(QwtPlot::xBottom)->setAttribute(QwtScaleEngine::Floating, true);
  plot_->plotLayout()->setAlignCanvasToScales(true);
  plot_->setAxisScale(QwtPlot::xBottom, 0.0, 1.0);
  plot_->setAxisScale(QwtPlot::yLeft, 0.0, 1.0);
}

PlotWidgetBase::~PlotWidgetBase() {