Java tutorial
package org.segin.ttleditor; /* * Copyright 2014 Kirn Gill II <segin2005@gmail.com> * * 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.annotation.TargetApi; import android.app.ActionBar; import android.content.Context; import android.content.Intent; import android.content.res.Configuration; import android.os.Build; import android.os.Bundle; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceCategory; import android.preference.PreferenceFragment; import android.preference.PreferenceManager; import android.view.MenuItem; import android.support.v4.app.NavUtils; import java.util.List; /** * 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; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setupActionBar(); } /** * 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); } } @TargetApi(Build.VERSION_CODES.KITKAT) @Override protected boolean isValidFragment(String fragmentName) { if (SettingsActivity.class.getName().equals(fragmentName)) return true; return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == android.R.id.home) { NavUtils.navigateUpFromSameTask(this); return true; } 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; } ActionBar actionBar = getActionBar(); try { actionBar.setIcon(getResources().getDrawable(R.drawable.ic_settings)); } catch (Exception e) { e.printStackTrace(); } // 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); // Add 'notifications' preferences, and a corresponding header. PreferenceCategory fakeHeader = new PreferenceCategory(this); fakeHeader.setTitle(R.string.pref_header_debug); getPreferenceScreen().addPreference(fakeHeader); addPreferencesFromResource(R.xml.pref_debug); // 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("iface")); bindPreferenceSummaryToValue(findPreference("ttl")); Preference sharePref = (Preference) findPreference("share"); sharePref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() { public boolean onPreferenceClick(Preference preference) { Intent sendIntent = new Intent(); sendIntent.setAction(Intent.ACTION_SEND); sendIntent.putExtra(Intent.EXTRA_TEXT, getString(R.string.share_text)); sendIntent.putExtra(Intent.EXTRA_SUBJECT, getString(R.string.share_subject)); sendIntent.setType("text/plain"); startActivity(sendIntent); return true; } }); } /** {@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(); 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 thelistener 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); bindPreferenceSummaryToValue(findPreference("iface")); bindPreferenceSummaryToValue(findPreference("ttl")); Preference sharePref = (Preference) findPreference("share"); sharePref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() { public boolean onPreferenceClick(Preference preference) { Intent sendIntent = new Intent(); sendIntent.setAction(Intent.ACTION_SEND); sendIntent.putExtra(Intent.EXTRA_TEXT, getString(R.string.share_text)); sendIntent.putExtra(Intent.EXTRA_SUBJECT, getString(R.string.share_subject)); sendIntent.setType("text/plain"); startActivity(sendIntent); return true; } }); } } /** * This fragment shows notification preferences only. It is used when the * activity is showing a two-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class DebuggingPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_debug); } } }