If you are using a viewport, simple set rtl=true
on the Viewport - this is what the examples show. However your question indicates that you have distributed widgets in your application.
I don't know of any documented way of doing this for distributed widgets. However, if you have a look at the source code, more specifically for the root object Ext and Ext.rtl.AbstractComponent, you will find that there is a private default property for this: Ext.rootHierarchyState.rtl
.
To default your widgets to rtl, set Ext.rootHierarchyState.rtl = true;
in your initalization code.
Disclaimer: this is marked as a private property, thus not intended for modification, so this solution may easily break between versions of ExtJs.