Java tutorial
/* * Author: Balch * Created: 9/4/14 12:26 AM * * This file is part of MockTrade. * * MockTrade is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * MockTrade is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with MockTrade. If not, see <http://www.gnu.org/licenses/>. * * Copyright (C) 2014 */ package com.balch.android.app.framework.preference; import android.annotation.SuppressLint; import android.app.Activity; import android.content.Context; 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.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ListView; import java.lang.reflect.Constructor; import java.lang.reflect.Method; /** * A PreferenceFragment for the support library. Based on the platform's code with some removed features and a basic ListView layout. * * @author Christophe Beyls * */ 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 int MSG_REQUEST_FOCUS = 2; private static final String PREFERENCES_TAG = "android:preferences"; private static final float HC_HORIZONTAL_PADDING = 16; @SuppressLint("HandlerLeak") private final Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_BIND_PREFERENCES: bindPreferences(); break; case MSG_REQUEST_FOCUS: mList.focusableViewAvailable(mList); break; } } }; private boolean mHavePrefs; private boolean mInitDone; private ListView mList; private PreferenceManager mPreferenceManager; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { Constructor<PreferenceManager> c = PreferenceManager.class.getDeclaredConstructor(Activity.class, int.class); c.setAccessible(true); mPreferenceManager = c.newInstance(this.getActivity(), FIRST_REQUEST_CODE); } catch (Exception e) { } } @Override public View onCreateView(LayoutInflater layoutInflater, ViewGroup viewGroup, Bundle savedInstanceState) { ListView listView = new ListView(getActivity()); listView.setId(android.R.id.list); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { final int horizontalPadding = (int) (HC_HORIZONTAL_PADDING * getResources().getDisplayMetrics().density); listView.setPadding(horizontalPadding, 0, horizontalPadding, 0); } return listView; } @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); } } } } public void onStop() { super.onStop(); try { Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityStop"); m.setAccessible(true); m.invoke(mPreferenceManager); } catch (Exception e) { } } public void onDestroyView() { mList = null; mHandler.removeCallbacksAndMessages(null); super.onDestroyView(); } public void onDestroy() { super.onDestroy(); try { Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityDestroy"); m.setAccessible(true); m.invoke(mPreferenceManager); } catch (Exception e) { } } public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); PreferenceScreen preferenceScreen = getPreferenceScreen(); if (preferenceScreen != null) { Bundle container = new Bundle(); preferenceScreen.saveHierarchyState(container); outState.putBundle(PREFERENCES_TAG, container); } } public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, 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) { } } public PreferenceManager getPreferenceManager() { return mPreferenceManager; } public void setPreferenceScreen(PreferenceScreen screen) { try { Method m = PreferenceManager.class.getDeclaredMethod("setPreferences", PreferenceScreen.class); m.setAccessible(true); boolean result = (Boolean) m.invoke(mPreferenceManager, screen); if (result && (screen != null)) { mHavePrefs = true; if (mInitDone) { postBindPreferences(); } } } catch (Exception e) { } } public PreferenceScreen getPreferenceScreen() { try { Method m = PreferenceManager.class.getDeclaredMethod("getPreferenceScreen"); m.setAccessible(true); return (PreferenceScreen) m.invoke(mPreferenceManager); } catch (Exception e) { return null; } } public void addPreferencesFromIntent(Intent intent) { requirePreferenceManager(); try { Method m = PreferenceManager.class.getDeclaredMethod("inflateFromIntent", Intent.class, PreferenceScreen.class); m.setAccessible(true); PreferenceScreen screen = (PreferenceScreen) m.invoke(mPreferenceManager, intent, getPreferenceScreen()); setPreferenceScreen(screen); } catch (Exception e) { } } public void addPreferencesFromResource(int resId) { requirePreferenceManager(); try { Method m = PreferenceManager.class.getDeclaredMethod("inflateFromResource", Context.class, int.class, PreferenceScreen.class); m.setAccessible(true); PreferenceScreen screen = (PreferenceScreen) m.invoke(mPreferenceManager, getActivity(), resId, getPreferenceScreen()); setPreferenceScreen(screen); } catch (Exception e) { } } public Preference findPreference(CharSequence key) { if (mPreferenceManager == null) { return null; } return mPreferenceManager.findPreference(key); } private void requirePreferenceManager() { if (this.mPreferenceManager == null) { throw new RuntimeException("This should be called after super.onCreate."); } } private void postBindPreferences() { if (!mHandler.hasMessages(MSG_BIND_PREFERENCES)) { mHandler.sendEmptyMessage(MSG_BIND_PREFERENCES); } } private void bindPreferences() { final PreferenceScreen preferenceScreen = getPreferenceScreen(); if (preferenceScreen != null) { preferenceScreen.bind(getListView()); } } 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'"); } mHandler.sendEmptyMessage(MSG_REQUEST_FOCUS); } }