Gadgetbridge/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/SettingsActivity.java

package nodomain.freeyourgadget.gadgetbridge;

import android.content.Intent;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import android.support.v4.app.NavUtils;
import android.support.v4.content.LocalBroadcastManager;
import android.view.MenuItem;

public class SettingsActivity extends PreferenceActivity {
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        getActionBar().setDisplayHomeAsUpEnabled(true);
        addPreferencesFromResource(R.xml.preferences);

        Preference pref = (Preference) findPreference("notifications_generic");
        pref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
            public boolean onPreferenceClick(Preference preference) {
                Intent enableIntent = new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
                startActivity(enableIntent);
                return true;
            }
        });
        final Preference developmentMiaddr = findPreference(GB.PREF_DEVELOPMENT_MIBAND_ADDRESS);
        bindPreferenceSummaryToValue(developmentMiaddr);

        developmentMiaddr.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
            @Override
            public boolean onPreferenceChange(Preference preference, Object newVal) {
                Intent refreshIntent = new Intent(ControlCenter.ACTION_REFRESH_DEVICELIST);
                LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(refreshIntent);
                preference.setSummary(newVal.toString());
                return true;
            }

        });
    }


    /**
     * A preference value change listener that updates the preference's summary
     * to reflect its new value.
     */
    private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
        @Override
        public boolean onPreferenceChange(Preference preference, Object value) {
            String stringValue = 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 #sBindPreferenceSummaryToValueListener
     */
    private static void bindPreferenceSummaryToValue(Preference preference) {
        // Set the listener to watch for value changes.
        preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);

        // Trigger the listener immediately with the preference's
        // current value.
        sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
                PreferenceManager
                        .getDefaultSharedPreferences(preference.getContext())
                        .getString(preference.getKey(), ""));
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                NavUtils.navigateUpFromSameTask(this);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }
}