arraylist - Can't Get Multiple Charts (Google Visualization) on Multiple Tabs (GWT TabPanel) -

i need display unknown quantity of tabs each unknown quantity of graphs (google visualizations). have created "tab" , "graph" classes , tab contains arraylist.

tabwrappers extends flextable , empty. it's place holder @ moment, behavior not change if use flextable rather tabwrapper.

the code below, minus section adds tab2 works creating 1 tab populated graphs. when adding 2nd tab both tabs displayed , named correctly neither have graphs.

    public class someclass {  ...          datatable data = response.getdatatable();         dataview result;         options options = createoptions();          arraylist<tab> displaytab = new arraylist<tab>();         tab t;         arraylist<graph> graphlist = new arraylist<graph>();         graph g;          t = new tab();              g = new graph();             result = dataview.create(data);             result.setrows(new int[]{0, 2, 4, 6});             g.setgraphtype(new piechart(result, options));             graphlist.add(g);              g = new graph();             result = dataview.create(data);             result.setrows(new int[]{1, 3, 5, 7});             g.setgraphtype(new piechart(result, options));             graphlist.add(g);              g = new graph();             result = dataview.create(data);             g.setgraphtype(new piechart(result, options));             graphlist.add(g);          t.settabname("tab1");         t.setgraphs(graphlist);         displaytab.add(t);         // add 2nd tab         t = new tab();         t.settabname("tab2");         t.setgraphs(graphlist);         displaytab.add(t);          tabwrapper tabwrapper;         (tab tx : displaytab){             int row = 0, col = 0, maxcol = 2;             tabwrapper = new tabwrapper();             (graph gx : tx.getgraphs()) {                 col = tx.getgraphs().indexof(gx) - (row * maxcol);                 tabwrapper.setwidget(row, col, gx.getgraphtype().aswidget());                 if (++col == maxcol) {                     row++;                 }             }         tabpanel.add(tabwrapper, tx.gettabname());         }  ...      } 

when use tabs in gwt, panels held in each tab seem lazy loaded , aren't set until user clicks on each tab.

in particular, tab containers have 0 widths , heights (the error logs giving error containers having 0 width) graph drawing fail , leave empty space.

what need (and practice anyway) lazy load contents of tabs graph loaded when tab set up. can done removing call t.setgraphs(...) , adding selection handler instead:

tabpanel.addselectionhandler(new selectionhandler<integer> () {     public void onselection(selectionevent<integer> event) {         // pseudocode:         // n = event.getselecteditem()         // t = displaytab[n]         // g = graphlist[n]         // t.setgraphs(g)     } }); 

so graphs added , drawn when tab selected.

you'll want call

tabpanel.selecttab(0); 

to force selection of first tab after selection handler in place.

i had same issues describe , resolved it.