Aquí, todos estos se cortan de la muestra Eclipse SettingsActivity . Tengo que copiar todos estos códigos demasiado para mostrar cómo estos desarrolladores de Android eligen perfectamente para un estilo de codificación más generalizado y estable.
Dejé los códigos para adaptar la PreferenceActivitytableta a una API mayor.
public class SettingsActivity extends PreferenceActivity {
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
setupSummaryUpdatablePreferencesScreen();
}
private void setupSummaryUpdatablePreferencesScreen() {
// 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 preferences to
// their values. When their values change, their summaries are updated
// to reflect the new value, per the Android Design guidelines.
bindPreferenceSummaryToValue(findPreference("example_text"));
bindPreferenceSummaryToValue(findPreference("example_list"));
}
/**
* A preference value change listener that updates the preference's summary
* to reflect its new value.
*/
private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
private String TAG = SettingsActivity.class.getSimpleName();
@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);
}
Log.i(TAG, "pref changed : " + preference.getKey() + " " + value);
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(), ""));
}
}
xml/pref_general.xml
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<!-- NOTE: EditTextPreference accepts EditText attributes. -->
<!-- NOTE: EditTextPreference's summary should be set to its value by the activity code. -->
<EditTextPreference
android:capitalize="words"
android:defaultValue="@string/pref_default_display_name"
android:inputType="textCapWords"
android:key="example_text"
android:maxLines="1"
android:selectAllOnFocus="true"
android:singleLine="true"
android:title="@string/pref_title_display_name" />
<!-- NOTE: Hide buttons to simplify the UI. Users can touch outside the dialog todismiss it.-->
<!-- NOTE: ListPreference's summary should be set to its value by the activity code. -->
<ListPreference
android:defaultValue="-1"
android:entries="@array/pref_example_list_titles"
android:entryValues="@array/pref_example_list_values"
android:key="example_list"
android:negativeButtonText="@null"
android:positiveButtonText="@null"
android:title="@string/pref_title_add_friends_to_messages" />
</PreferenceScreen>
values/strings_activity_settings.xml
<resources>
<!-- Strings related to Settings -->
<!-- Example General settings -->
<string name="pref_title_display_name">Display name</string>
<string name="pref_default_display_name">John Smith</string>
<string name="pref_title_add_friends_to_messages">Add friends to messages</string>
<string-array name="pref_example_list_titles">
<item>Always</item>
<item>When possible</item>
<item>Never</item>
</string-array>
<string-array name="pref_example_list_values">
<item>1</item>
<item>0</item>
<item>-1</item>
</string-array>
</resources>
NOTA: En realidad solo quiero comentar como "La muestra de Google para PreferenceActivity también es interesante". Pero no tengo suficientes puntos de reputación, así que por favor no me culpen.
(Perdón por el mal inglés)
