LuperSettingsActivity.java

package com.teamluper.luper;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.content.res.Configuration;
import android.os.Build;
import android.os.Bundle;
import android.preference.*;
import android.support.v4.app.NavUtils;
import com.actionbarsherlock.app.SherlockPreferenceActivity;
import com.actionbarsherlock.view.MenuItem;
import com.googlecode.androidannotations.annotations.EActivity;
import com.googlecode.androidannotations.annotations.rest.RestService;
import com.teamluper.luper.rest.LuperRestClient;

import java.util.List;

/**
 * A {@link PreferenceActivity} that presents a set of application settings. On
 * handset devices, settings are presented as a single list. On tablets,
 * settings are split by category, with category headers shown to the left of
 * the list of settings.
 * <p>
 * See <a href="http://developer.android.com/design/patterns/settings.html">
 * Android Design: Settings</a> for design guidelines and the <a
 * href="http://developer.android.com/guide/topics/ui/settings.html">Settings
 * API Guide</a> for more information on developing a Settings UI.
 */
@EActivity
public class LuperSettingsActivity extends SherlockPreferenceActivity
                           implements OnSharedPreferenceChangeListener {
  /**
   * Determines whether to always show the simplified settings UI, where
   * settings are presented in a single list. When false, settings are shown as
   * a master/detail two-pane view on tablets. When true, a single pane is shown
   * on tablets.
   */
  private static final boolean ALWAYS_SIMPLE_PREFS = false;

  @RestService
  LuperRestClient rest;

  AccountManager am;

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

  @Override
  protected void onResume() {
    super.onResume();
    if(!testAccounts()) {
      DialogFactory.alert(this,"Warning: since your device is not logged into a google account," +
      		        " your settings will not be saved to the server properly.");
    }
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
    prefs.registerOnSharedPreferenceChangeListener(this);
  }

  @Override
  protected void onPause() {
    super.onPause();
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
    prefs.unregisterOnSharedPreferenceChangeListener(this);
  }

  /**
   * Set up the {@link android.app.ActionBar}, if the API is available.
   */
  @TargetApi(Build.VERSION_CODES.HONEYCOMB)
  private void setupActionBar() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
      // Show the Up button in the action bar.
      getActionBar().setDisplayHomeAsUpEnabled(true);
    }
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
      // This ID represents the Home or Up button. In the case of this
      // activity, the Up button is shown. Use NavUtils to allow users
      // to navigate up one level in the application structure. For
      // more details, see the Navigation pattern on Android Design:
      //
      // http://developer.android.com/design/patterns/navigation.html#up-vs-back
      //
      // TODO: If Settings has multiple levels, Up should navigate up
      // that hierarchy.
      NavUtils.navigateUpFromSameTask(this);
      return true;
    }
    return super.onOptionsItemSelected(item);
  }

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

    setupSimplePreferencesScreen();
  }

  /**
   * Shows the simplified settings UI if the device configuration if the device
   * configuration dictates that a simplified, single-pane UI should be shown.
   */
  private void setupSimplePreferencesScreen() {
    if (!isSimplePreferences(this)) {
      return;
    }

    // In the simplified UI, fragments are not used at all and we instead
    // use the older PreferenceActivity APIs.

    // Add 'general' preferences.
    addPreferencesFromResource(R.xml.pref_general);

    // Bind the summaries of EditText/List/Dialog/Ringtone preferences to
    // their values. When their values change, their summaries are updated
    // to reflect the new value, per the Android Design guidelines.
    bindPreferenceSummaryToValue(findPreference("pref_favColor"));
  }

  /** {@inheritDoc} */
  @Override
  public boolean onIsMultiPane() {
    return isXLargeTablet(this) && !isSimplePreferences(this);
  }

  /**
   * Helper method to determine if the device has an extra-large screen. For
   * example, 10" tablets are extra-large.
   */
  private static boolean isXLargeTablet(Context context) {
    return (context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
  }

  /**
   * Determines whether the simplified settings UI should be shown. This is true
   * if this is forced via {@link #ALWAYS_SIMPLE_PREFS}, or the device doesn't
   * have newer APIs like {@link PreferenceFragment}, or the device doesn't have
   * an extra-large screen. In these cases, a single-pane "simplified" settings
   * UI should be shown.
   */
  private static boolean isSimplePreferences(Context context) {
    return ALWAYS_SIMPLE_PREFS
        || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB
        || !isXLargeTablet(context);
  }

  /** {@inheritDoc} */
  @Override
  @TargetApi(Build.VERSION_CODES.HONEYCOMB)
  public void onBuildHeaders(List<Header> target) {
    if (!isSimplePreferences(this)) {
      loadHeadersFromResource(R.xml.pref_headers, target);
    }
  }

  /**
   * 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(), ""));
  }

  /**
   * This fragment shows general preferences only. It is used when the activity
   * is showing a two-pane settings UI.
   */
  @TargetApi(Build.VERSION_CODES.HONEYCOMB)
  public static class GeneralPreferenceFragment extends PreferenceFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      addPreferencesFromResource(R.xml.pref_general);

      // Bind the summaries of EditText/List/Dialog/Ringtone preferences
      // to their values. When their values change, their summaries are
      // updated to reflect the new value, per the Android Design
      // guidelines.
      bindPreferenceSummaryToValue(findPreference("pref_favColor"));
    }
  }

  boolean testAccounts() {
    if(am == null) am = AccountManager.get(this);
    Account[] accounts = am.getAccountsByType("com.google");
    System.out.println("== LUPER ACCOUNTS TESTING ==  found "+accounts.length+" accounts");
    for(int i=0; i<accounts.length; i++) {
      System.out.println(accounts[i].toString());
    }
    return accounts.length >= 1;
  }

  @Override
  public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
      String key) {
    DialogFactory.toastMessage(this,"TODO: Save new "+key+" preference value to server!");
  }
}