Making Simple Bluetooth Transfer App

I'm currently developing a simple app with the following functions:

So far I've managed to make the View Files work by viewing files and folders in the memory card, but I haven't added any function other than being able to view them.

Here is the code for the FileManager.java class, I just copied it from a site because I just wanted to test out if the code could really view files. I have yet to be able to make my own file manager code:

Code:
package com.android.bluetoothfiletransfer;
import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import android.app.Activity;

[Code] ......

All other buttons are nonfunctional. Can I ask for preferably codes for the functions I'm looking for? I'm just planning to use this as a stepping stone for future apps.