Java tutorial
/* * Copyright (C) 2014 John Hunt <john.alma.hunt@gmail.com> * * This file is part of Tetravex Android. * * Tetravex Android 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. * * Tetravex Android 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 Tetravex Android. If not, see <http://www.gnu.org/licenses/>. */ package com.github.tetravex_android.activity; import android.annotation.TargetApi; import android.app.AlertDialog; import android.app.Dialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.res.Configuration; import android.os.Build; import android.os.Bundle; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceFragment; import android.preference.PreferenceManager; import android.support.v4.app.NavUtils; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.Window; import android.view.WindowManager; import android.widget.TextView; import android.widget.Toast; import com.github.tetravex_android.R; import com.github.tetravex_android.TetravexApp; import com.github.tetravex_android.domain.five.FiveManager; import com.github.tetravex_android.domain.four.FourManager; import com.github.tetravex_android.domain.three.ThreeManager; import com.github.tetravex_android.domain.two.TwoManager; import java.util.List; import javax.inject.Inject; /** * A {@link PreferenceActivity} that presents a set of application settings. On * handset devices, settings are presented as a single list. On tablets, * settings are split by category, with category headers shown to the left of * the list of settings. * <p> * See <a href="http://developer.android.com/design/patterns/settings.html"> * Android Design: Settings</a> for design guidelines and the <a * href="http://developer.android.com/guide/topics/ui/settings.html">Settings * API Guide</a> for more information on developing a Settings UI. */ public class SettingsActivity extends PreferenceActivity { /** * Determines whether to always show the simplified settings UI, where * settings are presented in a single list. When false, settings are shown * as a master/detail two-pane view on tablets. When true, a single pane is * shown on tablets. */ private static final boolean ALWAYS_SIMPLE_PREFS = false; // Database table managers @Inject TwoManager twoManager; @Inject ThreeManager threeManager; @Inject FourManager fourManager; @Inject FiveManager fiveManager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setupActionBar(); // Full screen this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); TetravexApp.injectActivity(this); } /** * Set up the {@link android.app.ActionBar}, if the API is available. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) private void setupActionBar() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { // Show the Up button in the action bar. getActionBar().setDisplayHomeAsUpEnabled(true); } } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.settings, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: // Navigate up to app's home screen NavUtils.navigateUpFromSameTask(this); return true; case R.id.action_reset_scores: // reset the scores database DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int userChoice) { switch (userChoice) { case DialogInterface.BUTTON_POSITIVE: // reset the scores database deleteAllScores(); break; case DialogInterface.BUTTON_NEGATIVE: break; } } }; AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setMessage(getResources().getString(R.string.dialog_reset_scores_prompt)); builder.setPositiveButton(getResources().getString(R.string.dialog_ok), dialogClickListener); builder.setNegativeButton(getResources().getString(R.string.dialog_cancel), dialogClickListener); builder.show(); return true; case R.id.action_about: Dialog dialog = new Dialog(this); dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); dialog.setContentView(R.layout.dialog_about); TextView linkText = (TextView) dialog.findViewById(R.id.legal_link); linkText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(SettingsActivity.this, LegalActivity.class); startActivity(intent); } }); dialog.setCancelable(true); dialog.show(); return true; default: return super.onOptionsItemSelected(item); } } @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); setupSimplePreferencesScreen(); } /** * Shows the simplified settings UI if the device configuration if the * device configuration dictates that a simplified, single-pane UI should be * shown. */ private void setupSimplePreferencesScreen() { if (!isSimplePreferences(this)) { return; } // 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/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("pref_size_list")); } /** {@inheritDoc} */ @Override public boolean onIsMultiPane() { return isXLargeTablet(this) && !isSimplePreferences(this); } /** * Helper method to determine if the device has an extra-large screen. For * example, 10" tablets are extra-large. */ private static boolean isXLargeTablet(Context context) { return (context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE; } /** * Determines whether the simplified settings UI should be shown. This is * true if this is forced via {@link #ALWAYS_SIMPLE_PREFS}, or the device * doesn't have newer APIs like {@link PreferenceFragment}, or the device * doesn't have an extra-large screen. In these cases, a single-pane * "simplified" settings UI should be shown. */ private static boolean isSimplePreferences(Context context) { return ALWAYS_SIMPLE_PREFS || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB || !isXLargeTablet(context); } /** {@inheritDoc} */ @Override @TargetApi(Build.VERSION_CODES.HONEYCOMB) public void onBuildHeaders(List<Header> target) { if (!isSimplePreferences(this)) { loadHeadersFromResource(R.xml.pref_headers, target); } } /** * A preference value change listener that updates the preference's summary * to reflect its new value. */ private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() { @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); } 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(), "")); } /** * This fragment shows general preferences only. It is used when the * activity is showing a two-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class GeneralPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_general); // 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("pref_size_list")); } } /** * Delete all the high scores from the database. */ private void deleteAllScores() { twoManager.deleteAll(); threeManager.deleteAll(); fourManager.deleteAll(); fiveManager.deleteAll(); Toast.makeText(getApplicationContext(), getResources().getString(R.string.scores_deleted), Toast.LENGTH_SHORT).show(); } }