Professional Android 4 Application Development

Creating a Standard Preference Activity for the Earthquake Viewer x 239
This example describes two ways of creating a Preference Activity — first, using the legacy
PreferencesActivity, and then a backward-compatible alternative using the newer
PreferenceFragment techniques.
1. Start by creating a new XML resource folder at res/xml. Within it create a new
userpreferences.xml file. This file will define the settings UI for your earthquake
application settings. Use the same controls and data sources as in the previous Activity, but
this time create them using the standard application settings framework. Note that in this
example difference key names are selected. This is because where you were previously recording
integers, you’re now recording strings. To avoid type mismatches when the application
attempts to read the saved preferences, use a different key name.
2. Open the PreferencesActivity Activity and modify its inheritance to extend
PreferenceActivity:
public class PreferencesActivity extends PreferenceActivity {
3. The Preference Activity will handle the controls used in the UI, so you can remove the
variables used to store the check box and spinner objects. You can also remove the populateSpinners,
updateUIFromPreferences, and savePreferences methods. Update the
preference name strings to match those used in the user preferences definition in step 1.
public static final String PREF_MIN_MAG = “PREF_MIN_MAG”;
public static final String PREF_UPDATE_FREQ = “PREF_UPDATE_FREQ”;