connect(scrollarea_.horizontalScrollBar(), SIGNAL(valueChanged(int)),
this, SLOT(h_scroll_value_changed(int)));
connect(scrollarea_.verticalScrollBar(), SIGNAL(valueChanged(int)),
connect(scrollarea_.horizontalScrollBar(), SIGNAL(valueChanged(int)),
this, SLOT(h_scroll_value_changed(int)));
connect(scrollarea_.verticalScrollBar(), SIGNAL(valueChanged(int)),