In our application, we have a tabpanel in which we are adding/removing the panels dynamically.


The panels get added at the click of a menu item by the following code in menu handler:

Code:
    Ext.getCmp('mainTabPanel').add(getPanel());
Here getPanel() method returns the panel after creating it.

In this context, could someone guide at the following:

a. Is it necesarry to call doLayout() on mainTabPanel after the add method?

b. Will a call to doLayout() not slow the rendering?

c. Will a call to doLayout() take care of all the issues related to rendering, like scrollbars esp.?

d. The method getPanel() should return an already created panel (using Ext.create) or should it return a config object (having xtype:'panel')? Which one should be preferred for better performance keeping time in mind?

Thanks for any help in advance.