I created TabPanel with two tabs. To each tab I also added BorderLayout with toolbar and AccordionLayout inside (generally panels structure is little more complicated, but its not imported here ). All my components are put into viewport to resize with browser. My problem is related to AccordionLayout resizing. It's resizing correctly in first tab, but inside second I must manually resize broswer to change size of contentpanels inside AccordionLayout. AccordionLayout is set to expandMode = "SINGLE_FILL". In first tab contentpanels are full expanded, but in second tab they have min. height. How can I fix that problem ?