Method scrollEvent

dgl/src/EventHandlers.cpp:550–587

    }

    bool scrollEvent(const Widget::ScrollEvent& ev)
    {
        if (! enabledInput)
            return false;

        if (! widget->contains(ev.pos))
            return false;

        const float dir    = (ev.delta.getY() > 0.f) ? 1.f : -1.f;
        const float d      = (ev.mod & kModifierControl) ? accel * 10.f : accel;
        float       value2 = (usingLog ? invlogscale(valueTmp) : valueTmp)
                           + ((maximum - minimum) / d * 10.f * dir);

        if (usingLog)
            value2 = logscale(value2);

        if (value2 < minimum)
        {
            valueTmp = value2 = minimum;
        }
        else if (value2 > maximum)
        {
            valueTmp = value2 = maximum;
        }
        else
        {
            valueTmp = value2;

            if (d_isNotZero(step))
            {
                const float rest = std::fmod(value2, step);
                value2 = value2 - rest + (rest > step/2.0f ? step : 0.0f);
            }
        }

        setValue(value2, true);
        return true;
    }

    float getNormalizedValue() const noexcept
    {