Just playing with Android Studio, and trying to add an Preference Activity, to one of the Google UI samples, but not getting very far. For a start the New->Activity->Settings Activity wizard does not appear to know about preference-headers tags, so fails to include an @overide for: isValidFragment(String) and onBuildHeaders(List target) in the code it generates. Anyway after hacking two example app's together and adding a isValidFragment() function e.g.
public class SettingsActivity extends PreferenceActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public void onBuildHeaders(List<Header> target) {
loadHeadersFromResource(R.xml.pref_headers, target);
}
@Override
protected boolean isValidFragment(String fragmentName) {
return SettingsActivity.class.getName().equals(fragmentName)
|| super.isValidFragment(fragmentName);
}
...
public static class DataSyncPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_data_sync);
// 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("prefSyncToGoogle"));
bindPreferenceSummaryToValue(findPreference("prefSyncToApple"));
bindPreferenceSummaryToValue(findPreference("prefSyncToMyFitnessPal"));
}
}
I still get the error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.slidingtabsbasic/com.example.android.slidingtabsbasic.SettingsActivity}: java.lang.RuntimeException: Subclasses of PreferenceActivity must override isValidFragment(String) to verify that the Fragment class is valid! com.example.android.slidingtabsbasic.SettingsActivity has not checked if fragment com.example.android.slidingtabsbasic.SettingsActivity$DataSyncPreferenceFragment is valid.
where the pref_headers.xml file is:
<?xml version="1.0" encoding="utf-8"?>
<preference-headers xmlns:android="http://schemas.android.com/apk/res/android" >
<header
android:fragment="com.example.android.slidingtabsbasic.SettingsHeaders$GeneralPreferenceFragment"
android:title="@string/pref_header_general" />
<header
android:fragment="com.example.android.slidingtabsbasic.SettingsHeaders$NotificationPreferenceFragment"
android:title="@string/pref_header_notifications" />
<header
android:fragment="com.example.android.slidingtabsbasic.SettingsHeaders$DataSyncPreferenceFragment"
android:title="@string/pref_header_data_sync" />
</preference-headers>
A quick debug reveals:
Ok,
SettingsActivity.class.getName() = "com.example.android.slidingtabsbasic.SettingsActivity"
While:
fragmentName = "com.example.android.slidingtabsbasic.SettingsActivity$DataSyncPreferenceFragment"
So the isValidFragment() call above obviously won't work, so is the only option to define a static array of fragment names in the function and do a lookup?
e.g.
private final String[] FRAGMENTS = {
"com.example.android.slidingtabsbasic.SettingsActivity$GeneralPreferenceFragment",
"com.example.android.slidingtabsbasic.SettingsActivity$NotificationPreferenceFragment",
"com.example.android.slidingtabsbasic.SettingsActivity$DataSyncPreferenceFragment"
};
...
@Override
protected boolean isValidFragment(String fragmentName) {
for (String FRAGMENT : FRAGMENTS) {
if (FRAGMENT.equals(fragmentName)) {
return true;
}
}
return super.isValidFragment(fragmentName);
}
