Method updateItems

UnitTests/UnitTest_TreeControl/TreeControl.cpp:234–291

	}

	void TreeControl::updateItems()
	{
		int nPosition = mnTopIndex * mnItemHeight + mnTopOffset;

		int nHeight = (int)mItemWidgets.size() * mnItemHeight - mnTopOffset;
		while ((nHeight <= (getClientWidget()->getHeight() + mnItemHeight)) && mItemWidgets.size() < mnExpandedNodes)
		{
			TreeControlItem* pItem = getClientWidget()->createWidget<TreeControlItem>(
				mstrSkinLine,
				0,
				nHeight,
				getClientWidget()->getWidth(),
				mnItemHeight,
				Align::Top | Align::HStretch);

			pItem->eventMouseButtonPressed += newDelegate(this, &TreeControl::notifyMousePressed);
			pItem->eventMouseButtonDoubleClick += newDelegate(this, &TreeControl::notifyMouseDoubleClick);
			pItem->eventMouseWheel += newDelegate(this, &TreeControl::notifyMouseWheel);
			pItem->eventMouseSetFocus += newDelegate(this, &TreeControl::notifyMouseSetFocus);
			pItem->eventMouseLostFocus += newDelegate(this, &TreeControl::notifyMouseLostFocus);
			pItem->_setInternalData((size_t)mItemWidgets.size());
			pItem->getButtonExpandCollapse()->eventMouseButtonClick +=
				newDelegate(this, &TreeControl::notifyExpandCollapse);

			mItemWidgets.push_back(pItem);

			nHeight += mnItemHeight;
		}

		if (nPosition >= mnScrollRange)
		{
			if (mnScrollRange <= 0)
			{
				if (nPosition || mnTopOffset || mnTopIndex)
				{
					nPosition = 0;
					mnTopIndex = 0;
					mnTopOffset = 0;
				}
			}
			else
			{
				int nCount = getClientWidget()->getHeight() / mnItemHeight;
				mnTopOffset = mnItemHeight - (getClientWidget()->getHeight() % mnItemHeight);

				if (mnTopOffset == mnItemHeight)
				{
					mnTopOffset = 0;
					nCount--;
				}

				mnTopIndex = ((int)mnExpandedNodes) - nCount - 1;
				nPosition = mnTopIndex * mnItemHeight + mnTopOffset;
			}
		}

		mpWidgetScroll->setScrollPosition(nPosition);
	}