I want to add in the tabsheet of my portlet some component like timeline, Calendar…
how can i do this??

I am not sure if this is what you ask but you can add a new tab to your tabsheet by saying for example:

Label myComponent = new Label("Hello World");
tabsheet.addTab(myComponent, "Tab caption");

I have a vaadin portlet MyEventTimeline and i want to add the window returned by this class to the tab of the tabsheet in my new portlet!!!