Method updateScroll

UnitTests/UnitTest_TreeControl/TreeControl.cpp:205–232

	}

	void TreeControl::updateScroll()
	{
		mnScrollRange = (mnItemHeight * (int)mnExpandedNodes) - getClientWidget()->getHeight();

		if (!mbScrollAlwaysVisible || mnScrollRange <= 0 || mpWidgetScroll->getLeft() <= getClientWidget()->getLeft())
		{
			if (mpWidgetScroll->getVisible())
			{
				mpWidgetScroll->setVisible(false);
				getClientWidget()->setSize(
					getClientWidget()->getWidth() + mpWidgetScroll->getWidth(),
					getClientWidget()->getHeight());
			}
		}
		else if (!mpWidgetScroll->getVisible())
		{
			getClientWidget()->setSize(
				getClientWidget()->getWidth() - mpWidgetScroll->getWidth(),
				getClientWidget()->getHeight());
			mpWidgetScroll->setVisible(true);
		}

		mpWidgetScroll->setScrollRange(mnScrollRange + 1);

		if (mnExpandedNodes)
			mpWidgetScroll->setTrackSize(
				mpWidgetScroll->getLineSize() * getClientWidget()->getHeight() / mnItemHeight / mnExpandedNodes);
	}

	void TreeControl::updateItems()
	{