Question

I’m using common code in my Activity like this:

abstract class CommonCode extends Activity {
    //Common Code here...
}

then in my “Activity” I extend CommonCode instead of Activity and it all works fine.

My problem arise when I try to use commoncode in a PreferenceActivity, I tried:

abstract class CommonCode extends Activity {

    class CommonCodePreferences extends PreferenceActivity {

    }
    //Common Code here...
}

but it isn’t right.

How can I do it?

Answer 1

I usually have one each since you can’t mess with the existing hierarchy of the base classes.

For example, I have an ActivityBase, ServiceBase, ListActivityBase, etc. If you want to have common code that they all use, I would suggest using composition – each of your base classes has a single instance of your CommonCode class or something to that effect. Another possibility is to use static methods and/or use a custom Application class (requires declaring the custom Application class in the manifest in the name attribute of the application element)