app/src/main/java/uk/me/njae/sunshine/SettingsActivity.java

   1 package uk.me.njae.sunshine;
   2
   3 import android.os.Bundle;
   4 import android.preference.ListPreference;
   5 import android.preference.Preference;
   6 import android.preference.PreferenceActivity;
   7 import android.preference.PreferenceManager;
   8
   9 import uk.me.njae.sunshine.data.WeatherContract;
  10
  11 /**
  12  * A {@link PreferenceActivity} that presents a set of application settings.
  13  * <p>
  14  * See <a href="http://developer.android.com/design/patterns/settings.html">
  15  * Android Design: Settings</a> for design guidelines and the <a
  16  * href="http://developer.android.com/guide/topics/ui/settings.html">Settings
  17  * API Guide</a> for more information on developing a Settings UI.
  18  */
  19 public class SettingsActivity extends PreferenceActivity
  20         implements Preference.OnPreferenceChangeListener {
  21
  22     // since we use the preference change initially to populate the summary
  23     // field, we'll ignore that change at start of the activity
  24     boolean mBindingPreference;
  25
  26     @Override
  27     public void onCreate(Bundle savedInstanceState) {
  28         super.onCreate(savedInstanceState);
  29         // Add 'general' preferences, defined in the XML file
  30         addPreferencesFromResource(R.xml.pref_general);
  31
  32         // For all preferences, attach an OnPreferenceChangeListener so the UI summary can be
  33         // updated when the preference changes.
  34         bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_location_key)));
  35         bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_units_key)));
  36
  37     }
  38
  39     /**
  40      * Attaches a listener so the summary is always updated with the preference value.
  41      * Also fires the listener once, to initialize the summary (so it shows up before the value
  42      * is changed.)
  43      */
  44     private void bindPreferenceSummaryToValue(Preference preference) {
  45         mBindingPreference = true;
  46
  47         // Set the listener to watch for value changes.
  48         preference.setOnPreferenceChangeListener(this);
  49
  50         // Trigger the listener immediately with the preference's
  51         // current value.
  52         onPreferenceChange(preference,
  53                 PreferenceManager
  54                         .getDefaultSharedPreferences(preference.getContext())
  55                         .getString(preference.getKey(), ""));
  56
  57         mBindingPreference = false;
  58     }
  59
  60     @Override
  61     public boolean onPreferenceChange(Preference preference, Object value) {
  62         String stringValue = value.toString().trim();
  63
  64         // are we starting the preference activity?
  65         if ( !mBindingPreference ) {
  66             if (preference.getKey().equals(getString(R.string.pref_location_key))) {
  67                 FetchWeatherTask weatherTask = new FetchWeatherTask(this);
  68                 String location = value.toString();
  69                 weatherTask.execute(location);
  70             } else {
  71                 // notify code that weather may be impacted
  72                 getContentResolver().notifyChange(WeatherContract.WeatherEntry.CONTENT_URI, null);
  73             }
  74         }
  75
  76         if (preference instanceof ListPreference) {
  77             // For list preferences, look up the correct display value in
  78             // the preference's 'entries' list (since they have separate labels/values).
  79             ListPreference listPreference = (ListPreference) preference;
  80             int prefIndex = listPreference.findIndexOfValue(stringValue);
  81             if (prefIndex >= 0) {
  82                 preference.setSummary(listPreference.getEntries()[prefIndex]);
  83             }
  84         } else {
  85             // For other preferences, set the summary to the value's simple string representation.
  86             preference.setSummary(stringValue);
  87         }
  88         return true;
  89     }
  90
  91 }