Android OnPreferenceClickListener

Question

I have an Activity that displays a settings menu using a PreferenceFragment. There is a method that passes a list of Beans to the fragment so it can dynamically generate a list of Preferences that I want to act essentially like buttons. I'm trying to use the OnPreferenceClickListener to react to one of the Preferences being clicked, but I need to let the outermost Activity know about this. My code looks like this:

public class PairActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        fragment = new SettingsFragment();
        getFragmentManager().beginTransaction()
                .replace(android.R.id.content, fragment)
                .commit();
        ...
    }


    public static class SettingsFragment extends PreferenceFragment {
        public void displayBeans(Collection<Bean> beans) {
            ...
            for(Bean bean : beans) {
                Preference pref = new Preference(getActivity());
                pref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
                    @Override
                    public boolean onPreferenceClick(Preference preference) {
                        // want to let the Activity know something happened
                    }
                });
            }
        }
    }

    ...
}

The comment shows where I want to reach the Activity from, but it's inside of an anonymous class inside a static class... What can I do to solve my issue?

It's possible to do `((PairActivity)SettingsFragment.this.getActivity())`, but I'm concerned about the possibility of something breaking somewhere in this line of code... — ttttcrngyblflpp, May 24 '15 at 12:45

Simas · Accepted Answer · 2015-05-24T12:46:59.990

Edit:

~~Make your SettingsFragment an inner class of PairActivity:~~

public class PairActivity extends Activity {

    public class SettingsFragment extends PreferenceFragment {

    }

}

Then you can safely reference the activity with PairActivity.this.

Edit:

That's a nice answer you linked and it's indeed the proper way to use it like that. I didn't think about it.

Nevertheless when the fragment is attached to an activity you can reference it using getActivity. A fragment will definitely be attached to an activity if you call this method from inside of a clickListener so it's fine to do this:

public class PairActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        fragment = new SettingsFragment();
        getFragmentManager().beginTransaction()
                .replace(android.R.id.content, fragment)
                .commit();
        ...
    }


    public static class SettingsFragment extends PreferenceFragment {
        public void displayBeans(Collection<Bean> beans) {
            ...
            for(Bean bean : beans) {
                Preference pref = new Preference(getActivity());
                pref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
                    @Override
                    public boolean onPreferenceClick(Preference preference) {
                        PairActivity pairActivity = (PairActivity) getActivity();
                        // Do something with pairActivity instance
                    }
                });
            }
        }
    }

    ...
}

You just need to make sure that you don't attach your fragment to another activity as the cast (PairActivity) will throw an exception then.

I've tried this, and Android Studio flags this as a potential problem. There is [this question](http://stackoverflow.com/questions/15571010/fragment-inner-class-should-be-static) talking about why it shouldn't be done, but I'm a newbie so I don't understand much of it. — ttttcrngyblflpp, May 24 '15 at 12:39

Android OnPreferenceClickListener

1 Answers1