Method paintEvent

src/openms_gui/source/VISUAL/MultiGradientSelector.cpp:56–100

  }

  void MultiGradientSelector::paintEvent(QPaintEvent * /* e */)
  {
    static QPixmap pixmap = QPixmap(size());
    pixmap.fill(palette().window().color());

    //calculate gradient area width
    if (gradient_area_width_ == 0)
    {
      gradient_area_width_ = width() - 2 * margin_ - 2;
    }

    QPainter painter(&pixmap);

    //gradient field outline
    painter.setPen(QColor(0, 0, 0));
    painter.drawRect(margin_, margin_, width() - 2 * margin_, height() - 2 * margin_ - lever_area_height_);

    //draw gradient
    for (Int i = 0; i <= gradient_area_width_; ++i)
    {
      painter.setPen(gradient_.interpolatedColorAt(i, 0, gradient_area_width_));
      painter.drawLine(margin_ + 1 + i, margin_ + 1, margin_ + 1 + i, height() - margin_ - lever_area_height_ - 1);
    }

    //levers
    painter.setPen(QColor(0, 0, 0));
    for (UInt i = 0; i < (UInt)gradient_.size(); ++i)
    {
      Int pos = Int(float(gradient_.position(i)) / 100.0 * gradient_area_width_ + margin_ + 1);
      painter.drawRect(pos - 4, height() - margin_ - lever_area_height_ + 5, 9, 9);
      painter.drawLine(pos - 4, height() - margin_ - lever_area_height_ + 5, pos, height() - margin_ - lever_area_height_);
      painter.drawLine(pos, height() - margin_ - lever_area_height_, pos + 4, height() - margin_ - lever_area_height_ + 5);
      painter.fillRect(pos - 3, height() - margin_ - lever_area_height_ + 6, 8, 8, gradient_.color(i));

      //selected lever
      if (Int(gradient_.position(i)) == selected_)
      {
        painter.fillRect(pos - 2, height() - margin_ - lever_area_height_ + 3, 6, 3, QColor(0, 0, 0));
        painter.fillRect(pos - 1, height() - margin_ - lever_area_height_ + 1, 4, 3, QColor(0, 0, 0));
      }
    }

    QPainter painter2(this);
    painter2.drawPixmap(0, 0, pixmap);
  }

  void MultiGradientSelector::mousePressEvent(QMouseEvent * e)
  {