Confirm and discard button in the android preferences activity

I'm working on the preference activity. The matter is about the possibility of add a button that allow to confirm, and eventually (that would be nice) a discard button in order to discard the changes applied at the preferences.

Let me explain better.

As far as I've seen it is possible using the com开发者_JS百科mon techniques that i've found in the tutorial to set different preferences using checkboxes and so on. The normal use case that involve preferences require that the user performs selections and after that click the BACK button in order to return to the old view.

However in the usability test i've done, it seems that this step is not always straightforward for all the users, and moreover a lot of them are not sure about the fact that the changes on the preferences are comfirmed.

Now we arrive at the question. is it possible somehow to have in the preference view selections (in particular one just composed by a group of checkboxes) to have an OK and eventually CANCEL button?

You have 4 options:

1) Design a layout and use a normal activity similar to the preferences screen where you give the user 2 buttons: Save and Discard.

2) Add a menu to the preferences activity with save/discard (and of course you will have to save the previous state and revert back to it if the user decided to discard).

3) Handle back button press on the preference activity where you popup a dialog asking if they want to save the changes

4) Add 2 "actions" to the preferences where 1 is save and 1 is discard and each goes to its own activity... Complicated and ugly in my opinion...

On a side note, I really believe users are familiar with Android's UI as 99% of the apps using preferences don't have this save button so it should be straightforward to the users that when they click on a checkbox - it is saved.