How to make the main class know which layout it is using (layout-small, layout-normal, layout-large or layout-xlarge)?

I'm making an application that suits multiple screen sizes so I have 4 types of layout:

• layout-sw360dp
• layout-sw600dp
• layout-sw720dp
• layout-sw800dp

What I want to do is that the MainActivity knows what type of layout it is using when executing the application so that through the result and javacode it can customize the buttons, editText, etc.

Please someone to help me.