ClientState.showHighlighting = !ClientState.showHighlighting;
if(ClientState.showHighlighting)
tabPanel.addStyleName("showHighlighting");
else
tabPanel.removeStyleName("showHighlighting");
// switch state
if(ClientState.showHighlighting){
toggleHighlighting.setText("Deactivate Highlighting");
toggleHighlighting.setIconStyle("icon-menu-highlightingActivated");