Java tutorial
package android.support.v4.preference; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.preference.Preference; import android.preference.PreferenceManager; import android.preference.PreferenceScreen; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ListView; import java.lang.reflect.Constructor; import java.lang.reflect.Method; public abstract class PreferenceFragment extends Fragment { private static final int FIRST_REQUEST_CODE = 100; private static final int MSG_BIND_PREFERENCES = 1; private static final String PREFERENCES_TAG = "android:preferences"; private boolean mHavePrefs; private boolean mInitDone; private ListView mList; private PreferenceManager mPreferenceManager; private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_BIND_PREFERENCES: bindPreferences(); break; } } }; final private Runnable mRequestFocus = new Runnable() { public void run() { mList.focusableViewAvailable(mList); } }; private void bindPreferences() { PreferenceScreen localPreferenceScreen = getPreferenceScreen(); if (localPreferenceScreen != null) { ListView localListView = getListView(); localPreferenceScreen.bind(localListView); } } private void ensureList() { if (mList == null) { View view = getView(); if (view == null) { throw new IllegalStateException("Content view not yet created"); } View listView = view.findViewById(android.R.id.list); if (!(listView instanceof ListView)) { throw new RuntimeException( "Content has view with id attribute 'android.R.id.list' that is not a ListView class"); } mList = (ListView) listView; if (mList == null) { throw new RuntimeException( "Your content must have a ListView whose id attribute is 'android.R.id.list'"); } mHandler.post(mRequestFocus); } } private void postBindPreferences() { if (mHandler.hasMessages(MSG_BIND_PREFERENCES)) { mHandler.obtainMessage(MSG_BIND_PREFERENCES).sendToTarget(); } } private void requirePreferenceManager() { if (this.mPreferenceManager == null) { throw new RuntimeException("This should be called after super.onCreate."); } } public void addPreferencesFromIntent(Intent intent) { requirePreferenceManager(); PreferenceScreen screen = inflateFromIntent(intent, getPreferenceScreen()); setPreferenceScreen(screen); } public void addPreferencesFromResource(int resId) { requirePreferenceManager(); PreferenceScreen screen = inflateFromResource(getActivity(), resId, getPreferenceScreen()); setPreferenceScreen(screen); } public Preference findPreference(CharSequence key) { if (mPreferenceManager == null) { return null; } return mPreferenceManager.findPreference(key); } public ListView getListView() { ensureList(); return mList; } public PreferenceManager getPreferenceManager() { return mPreferenceManager; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); getListView().setScrollBarStyle(0); if (mHavePrefs) { bindPreferences(); } mInitDone = true; if (savedInstanceState != null) { Bundle localBundle = savedInstanceState.getBundle(PREFERENCES_TAG); if (localBundle != null) { PreferenceScreen screen = getPreferenceScreen(); if (screen != null) { screen.restoreHierarchyState(localBundle); } } } } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); dispatchActivityResult(requestCode, resultCode, data); } @Override public void onCreate(Bundle paramBundle) { super.onCreate(paramBundle); mPreferenceManager = createPreferenceManager(); } @Override public View onCreateView(LayoutInflater paramLayoutInflater, ViewGroup paramViewGroup, Bundle paramBundle) { ListView listView = new ListView(paramLayoutInflater.getContext()); listView.setId(android.R.id.list); listView.setDrawSelectorOnTop(false); listView.setPadding(12, 6, 12, 0); //listView.setSelector(null); return listView; } @Override public void onDestroy() { super.onDestroy(); dispatchActivityDestroy(); } @Override public void onDestroyView() { mList = null; mHandler.removeCallbacks(mRequestFocus); mHandler.removeMessages(MSG_BIND_PREFERENCES); super.onDestroyView(); } @Override public void onSaveInstanceState(Bundle bundle) { super.onSaveInstanceState(bundle); PreferenceScreen screen = getPreferenceScreen(); if (screen != null) { Bundle localBundle = new Bundle(); screen.saveHierarchyState(localBundle); bundle.putBundle(PREFERENCES_TAG, localBundle); } } @Override public void onStop() { super.onStop(); dispatchActivityStop(); } /** * Access methods with visibility private * */ private PreferenceManager createPreferenceManager() { try { Constructor<PreferenceManager> c = PreferenceManager.class.getDeclaredConstructor(Activity.class, int.class); c.setAccessible(true); return c.newInstance(this.getActivity(), FIRST_REQUEST_CODE); } catch (Exception e) { throw new RuntimeException(e); } } private PreferenceScreen getPreferenceScreen() { try { Method m = PreferenceManager.class.getDeclaredMethod("getPreferenceScreen"); m.setAccessible(true); return (PreferenceScreen) m.invoke(mPreferenceManager); } catch (Exception e) { throw new RuntimeException(e); } } private void setPreferenceScreen(PreferenceScreen preferenceScreen) { try { Method m = PreferenceManager.class.getDeclaredMethod("setPreferences", PreferenceScreen.class); m.setAccessible(true); boolean result = (Boolean) m.invoke(mPreferenceManager, preferenceScreen); if (result && preferenceScreen != null) { mHavePrefs = true; if (mInitDone) { postBindPreferences(); } } } catch (Exception e) { throw new RuntimeException(e); } } private void dispatchActivityResult(int requestCode, int resultCode, Intent data) { try { Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityResult", int.class, int.class, Intent.class); m.setAccessible(true); m.invoke(mPreferenceManager, requestCode, resultCode, data); } catch (Exception e) { throw new RuntimeException(e); } } private void dispatchActivityDestroy() { try { Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityDestroy"); m.setAccessible(true); m.invoke(mPreferenceManager); } catch (Exception e) { throw new RuntimeException(e); } } private void dispatchActivityStop() { try { Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityStop"); m.setAccessible(true); m.invoke(mPreferenceManager); } catch (Exception e) { throw new RuntimeException(e); } } public PreferenceScreen inflateFromResource(Context context, int resId, PreferenceScreen rootPreferences) { PreferenceScreen preferenceScreen; try { Method m = PreferenceManager.class.getDeclaredMethod("inflateFromResource", Context.class, int.class, PreferenceScreen.class); m.setAccessible(true); preferenceScreen = (PreferenceScreen) m.invoke(mPreferenceManager, context, resId, rootPreferences); } catch (Exception e) { throw new RuntimeException(e); } return preferenceScreen; } public PreferenceScreen inflateFromIntent(Intent queryIntent, PreferenceScreen rootPreferences) { PreferenceScreen preferenceScreen; try { Method m = PreferenceManager.class.getDeclaredMethod("inflateFromIntent", Intent.class, PreferenceScreen.class); m.setAccessible(true); preferenceScreen = (PreferenceScreen) m.invoke(mPreferenceManager, queryIntent, rootPreferences); } catch (Exception e) { throw new RuntimeException(e); } return preferenceScreen; } }