Preferences.java

package com.movisens.gattsensorexample.activities;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceCategory;
import android.preference.PreferenceFragment;
import android.preference.PreferenceScreen;
import android.view.MenuItem;

import com.movisens.gattsensorexample.R;
import com.movisens.gattsensorexample.application.App;

public class Preferences extends Activity {

	public static final String SAMPLING_RUNNING = "sampling_running";
	public static final String SENSOR_ADDRESS = "sensor_address";
	public static final String SENSOR_NAME = "sensor_name";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		getActionBar().setDisplayHomeAsUpEnabled(true);

		// Display the fragment as the main content.
		getFragmentManager().beginTransaction()
				.replace(android.R.id.content, new PrefsFragment()).commit();
	}

	@Override
	public boolean onMenuItemSelected(int featureId, MenuItem item) {
		switch (item.getItemId()) {
		case android.R.id.home:
			startActivity(new Intent(this, StartActivity.class));
			finish();
			return true;
		default:
			return super.onOptionsItemSelected(item);
		}
	}

	public static class PrefsFragment extends PreferenceFragment implements
			OnSharedPreferenceChangeListener {

		@Override
		public void onCreate(Bundle savedInstanceState) {
			super.onCreate(savedInstanceState);

			// Load the preferences from an XML resource
			addPreferencesFromResource(R.xml.preferences);

			for (int i = 0; i < getPreferenceScreen().getPreferenceCount(); i++) {
				initSummary(getPreferenceScreen().getPreference(i));
			}
		}

		@Override
		public void onResume() {
			super.onResume();
			// Set up a listener whenever a key changes
			getPreferenceScreen().getSharedPreferences()
					.registerOnSharedPreferenceChangeListener(this);
			updatePrefSummary(findPreference("select_sensor"));
		}

		@Override
		public void onPause() {
			super.onPause();
			// Unregister the listener whenever a key changes
			getPreferenceScreen().getSharedPreferences()
					.unregisterOnSharedPreferenceChangeListener(this);
		}

		public void onSharedPreferenceChanged(
				SharedPreferences sharedPreferences, String key) {
			updatePrefSummary(findPreference(key));
		}

		private void initSummary(Preference p) {
			if (p instanceof PreferenceCategory) {
				PreferenceCategory pCat = (PreferenceCategory) p;
				for (int i = 0; i < pCat.getPreferenceCount(); i++) {
					initSummary(pCat.getPreference(i));
				}
			} else {
				updatePrefSummary(p);
			}
		}

		private void updatePrefSummary(Preference p) {
			if (p instanceof ListPreference) {
				ListPreference listPref = (ListPreference) p;
				p.setSummary(listPref.getEntry());
			} else if (p instanceof EditTextPreference) {
				EditTextPreference editTextPref = (EditTextPreference) p;
				p.setSummary(editTextPref.getText());
			} else if (p instanceof PreferenceScreen) {
				p.setSummary(App.app().getSensor());
			}
		}
	}
}