Method invalidate

src/ui/widget.cpp:1078–1089

}

void Widget::invalidate()
{
  if (isVisible()) {
    m_updateRegion.clear();
    getDrawableRegion(m_updateRegion, kCutTopWindows);

    mark_dirty_flag(this);

    for (auto child : m_children)
      child->invalidate();
  }
}

void Widget::invalidateRect(const gfx::Rect& rect)
{