private int calculateHeight(TreeRow row) {
		int height = 0;
		int count = mColumns.size();
		for (int i = 0; i < count; i++) {
			TreeColumn column = mColumns.get(i);
			int colWidth = column.getWidth();
			if (mShowDisclosureControls && i == 0) {
				colWidth -= INDENT * row.getDepth();
			}
			int pref = column.calculatePreferredHeight(row, colWidth);
			if (pref > height) {
				height = pref;
			}
		}
		return height;
	}