BaseSettingsFragment.java

package de.devland.masterpassword.ui.preferences;

import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;

/**
 * Created by David Kunzler on 26.11.2014.
 */
public abstract class BaseSettingsFragment extends PreferenceFragment {

    /**
     * A preference value change listener that updates the preference's summary
     * to reflect its new value.
     */
    protected Preference.OnPreferenceChangeListener bindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
        @Override
        public boolean onPreferenceChange(Preference preference, Object value) {
            String stringValue = value != null ? value.toString() : "";

            if (preference instanceof ListPreference) {
                // For list preferences, look up the correct display value in
                // the preference's 'entries' list.
                ListPreference listPreference = (ListPreference) preference;
                int index = listPreference.findIndexOfValue(stringValue);

                // Set the summary to reflect the new value.
                preference.setSummary(
                        index >= 0
                                ? listPreference.getEntries()[index]
                                : null);
            } else {
                // For all other preferences, set the summary to the value's
                // simple string representation.
                preference.setSummary(stringValue);
            }
            return true;
        }
    };


    /**
     * Binds a preference's summary to its value. More specifically, when the
     * preference's value is changed, its summary (line of text below the
     * preference title) is updated to reflect the value. The summary is also
     * immediately updated upon calling this method. The exact display format is
     * dependent on the type of preference.
     *
     * @see #bindPreferenceSummaryToValueListener
     */
    protected void bindPreferenceSummaryToValue(Preference preference) {
        if (preference != null) {
            // Set the listener to watch for value changes.
            preference.setOnPreferenceChangeListener(bindPreferenceSummaryToValueListener);

            // Trigger the listener immediately with the preference's
            // current value.
            bindPreferenceSummaryToValueListener.onPreferenceChange(preference,
                    PreferenceManager
                            .getDefaultSharedPreferences(preference.getContext())
                            .getAll().get(preference.getKey()));
        }
    }

    public AppCompatActivity getAppCompatActivity() {
        return (AppCompatActivity) getActivity();
    }
}