Java tutorial
package com.anprosit.android.dagger.ui.v4; /* * Copyright (C) 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import android.content.Intent; import android.os.Build; 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.KeyEvent; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnKeyListener; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ListView; import com.anprosit.android.dagger.R; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public abstract class PreferenceFragment extends Fragment implements PreferenceManagerCompat.OnPreferenceTreeClickListener { private static final String PREFERENCES_TAG = "android:preferences"; private PreferenceManager mPreferenceManager; private ListView mList; private boolean mHavePrefs; private boolean mInitDone; /** * The starting request code given out to preference framework. */ private static final int FIRST_REQUEST_CODE = 100; private static final int MSG_BIND_PREFERENCES = 1; 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); } }; /** * Interface that PreferenceFragment's containing activity should * implement to be able to process preference items that wish to * switch to a new fragment. */ public interface OnPreferenceStartFragmentCallback { /** * Called when the user has clicked on a Preference that has * a fragment class name associated with it. The implementation * to should instantiate and switch to an instance of the given * fragment. */ boolean onPreferenceStartFragment(PreferenceFragment caller, Preference pref); } @Override public void onCreate(Bundle paramBundle) { super.onCreate(paramBundle); mPreferenceManager = PreferenceManagerCompat.newInstance(getActivity(), FIRST_REQUEST_CODE); PreferenceManagerCompat.setFragment(mPreferenceManager, this); } @Override public View onCreateView(LayoutInflater paramLayoutInflater, ViewGroup paramViewGroup, Bundle paramBundle) { return paramLayoutInflater.inflate(R.layout.preference_list_fragment, paramViewGroup, false); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); if (mHavePrefs) { bindPreferences(); } mInitDone = true; if (savedInstanceState != null) { Bundle container = savedInstanceState.getBundle(PREFERENCES_TAG); if (container != null) { final PreferenceScreen preferenceScreen = getPreferenceScreen(); if (preferenceScreen != null) { preferenceScreen.restoreHierarchyState(container); } } } } @Override public void onStart() { super.onStart(); PreferenceManagerCompat.setOnPreferenceTreeClickListener(mPreferenceManager, this); } @Override public void onStop() { super.onStop(); PreferenceManagerCompat.dispatchActivityStop(mPreferenceManager); PreferenceManagerCompat.setOnPreferenceTreeClickListener(mPreferenceManager, null); } @Override public void onDestroyView() { mList = null; mHandler.removeCallbacks(mRequestFocus); mHandler.removeMessages(MSG_BIND_PREFERENCES); super.onDestroyView(); } @Override public void onDestroy() { super.onDestroy(); PreferenceManagerCompat.dispatchActivityDestroy(mPreferenceManager); } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); final PreferenceScreen preferenceScreen = getPreferenceScreen(); if (preferenceScreen != null) { Bundle container = new Bundle(); preferenceScreen.saveHierarchyState(container); outState.putBundle(PREFERENCES_TAG, container); } } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); PreferenceManagerCompat.dispatchActivityResult(mPreferenceManager, requestCode, resultCode, data); } /** * Returns the {@link android.preference.PreferenceManager} used by this fragment. * * @return The {@link android.preference.PreferenceManager}. */ public PreferenceManager getPreferenceManager() { return mPreferenceManager; } /** * Sets the root of the preference hierarchy that this fragment is showing. * * @param preferenceScreen The root {@link android.preference.PreferenceScreen} of the preference hierarchy. */ public void setPreferenceScreen(PreferenceScreen preferenceScreen) { if (PreferenceManagerCompat.setPreferences(mPreferenceManager, preferenceScreen) && preferenceScreen != null) { mHavePrefs = true; if (mInitDone) { postBindPreferences(); } } } /** * Gets the root of the preference hierarchy that this fragment is showing. * * @return The {@link android.preference.PreferenceScreen} that is the root of the preference * hierarchy. */ public PreferenceScreen getPreferenceScreen() { return PreferenceManagerCompat.getPreferenceScreen(mPreferenceManager); } /** * Adds preferences from activities that match the given {@link android.content.Intent}. * * @param intent The {@link android.content.Intent} to query activities. */ public void addPreferencesFromIntent(Intent intent) { requirePreferenceManager(); setPreferenceScreen( PreferenceManagerCompat.inflateFromIntent(mPreferenceManager, intent, getPreferenceScreen())); } /** * Inflates the given XML resource and adds the preference hierarchy to the current * preference hierarchy. * * @param preferencesResId The XML resource ID to inflate. */ public void addPreferencesFromResource(int preferencesResId) { requirePreferenceManager(); setPreferenceScreen(PreferenceManagerCompat.inflateFromResource(mPreferenceManager, getActivity(), preferencesResId, getPreferenceScreen())); } /** * {@inheritDoc} */ public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) { //if (preference.getFragment() != null && if (getActivity() instanceof OnPreferenceStartFragmentCallback) { return ((OnPreferenceStartFragmentCallback) getActivity()).onPreferenceStartFragment(this, preference); } return false; } /** * Finds a {@link android.preference.Preference} based on its key. * * @param key The key of the preference to retrieve. * @return The {@link android.preference.Preference} with the key, or null. * @see android.preference.PreferenceGroup#findPreference(CharSequence) */ public Preference findPreference(CharSequence key) { if (mPreferenceManager == null) { return null; } return mPreferenceManager.findPreference(key); } private void requirePreferenceManager() { if (mPreferenceManager == null) { throw new RuntimeException("This should be called after super.onCreate."); } } private void postBindPreferences() { if (mHandler.hasMessages(MSG_BIND_PREFERENCES)) return; mHandler.obtainMessage(MSG_BIND_PREFERENCES).sendToTarget(); } private void bindPreferences() { final PreferenceScreen preferenceScreen = getPreferenceScreen(); if (preferenceScreen != null) { preferenceScreen.bind(getListView()); } if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.GINGERBREAD_MR1) { // Workaround android bug for SDK 10 and below - see // https://github.com/android/platform_frameworks_base/commit/2d43d283fc0f22b08f43c6db4da71031168e7f59 getListView().setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { // If the list has headers, subtract them from the index. if (parent instanceof ListView) { position -= ((ListView) parent).getHeaderViewsCount(); } Object item = preferenceScreen.getRootAdapter().getItem(position); if (!(item instanceof Preference)) return; final Preference preference = (Preference) item; try { Method performClick = Preference.class.getDeclaredMethod("performClick", PreferenceScreen.class); performClick.setAccessible(true); performClick.invoke(preference, preferenceScreen); } catch (InvocationTargetException e) { } catch (IllegalAccessException e) { } catch (NoSuchMethodException e) { } } }); } } public ListView getListView() { ensureList(); return mList; } private void ensureList() { if (mList != null) { return; } View root = getView(); if (root == null) { throw new IllegalStateException("Content view not yet created"); } View rawListView = root.findViewById(android.R.id.list); if (!(rawListView instanceof ListView)) { throw new RuntimeException( "Content has view with id attribute 'android.R.id.list' " + "that is not a ListView class"); } mList = (ListView) rawListView; if (mList == null) { throw new RuntimeException( "Your content must have a ListView whose id attribute is " + "'android.R.id.list'"); } mList.setOnKeyListener(mListOnKeyListener); mHandler.post(mRequestFocus); } private OnKeyListener mListOnKeyListener = new OnKeyListener() { @Override public boolean onKey(View v, int keyCode, KeyEvent event) { Object selectedItem = mList.getSelectedItem(); if (selectedItem instanceof Preference) { @SuppressWarnings("unused") View selectedView = mList.getSelectedView(); //return ((Preference)selectedItem).onKey( // selectedView, keyCode, event); return false; } return false; } }; }