Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package android.preference; |
| 18 | |
| 19 | import android.app.Activity; |
| 20 | import android.app.Fragment; |
| 21 | import android.content.Intent; |
| 22 | import android.content.SharedPreferences; |
Dianne Hackborn | e72f237 | 2011-03-16 10:43:18 -0700 | [diff] [blame] | 23 | import android.content.res.Configuration; |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 24 | import android.os.Bundle; |
| 25 | import android.os.Handler; |
| 26 | import android.os.Message; |
| 27 | import android.view.LayoutInflater; |
| 28 | import android.view.View; |
| 29 | import android.view.ViewGroup; |
| 30 | import android.widget.ListView; |
| 31 | |
| 32 | /** |
| 33 | * Shows a hierarchy of {@link Preference} objects as |
| 34 | * lists. These preferences will |
| 35 | * automatically save to {@link SharedPreferences} as the user interacts with |
| 36 | * them. To retrieve an instance of {@link SharedPreferences} that the |
| 37 | * preference hierarchy in this fragment will use, call |
| 38 | * {@link PreferenceManager#getDefaultSharedPreferences(android.content.Context)} |
| 39 | * with a context in the same package as this fragment. |
| 40 | * <p> |
Dianne Hackborn | b1ad597 | 2010-08-02 17:30:33 -0700 | [diff] [blame] | 41 | * Furthermore, the preferences shown will follow the visual style of system |
| 42 | * preferences. It is easy to create a hierarchy of preferences (that can be |
| 43 | * shown on multiple screens) via XML. For these reasons, it is recommended to |
| 44 | * use this fragment (as a superclass) to deal with preferences in applications. |
| 45 | * <p> |
| 46 | * A {@link PreferenceScreen} object should be at the top of the preference |
| 47 | * hierarchy. Furthermore, subsequent {@link PreferenceScreen} in the hierarchy |
| 48 | * denote a screen break--that is the preferences contained within subsequent |
| 49 | * {@link PreferenceScreen} should be shown on another screen. The preference |
| 50 | * framework handles showing these other screens from the preference hierarchy. |
| 51 | * <p> |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 52 | * The preference hierarchy can be formed in multiple ways: |
| 53 | * <li> From an XML file specifying the hierarchy |
| 54 | * <li> From different {@link Activity Activities} that each specify its own |
| 55 | * preferences in an XML file via {@link Activity} meta-data |
| 56 | * <li> From an object hierarchy rooted with {@link PreferenceScreen} |
| 57 | * <p> |
| 58 | * To inflate from XML, use the {@link #addPreferencesFromResource(int)}. The |
| 59 | * root element should be a {@link PreferenceScreen}. Subsequent elements can point |
| 60 | * to actual {@link Preference} subclasses. As mentioned above, subsequent |
| 61 | * {@link PreferenceScreen} in the hierarchy will result in the screen break. |
| 62 | * <p> |
| 63 | * To specify an {@link Intent} to query {@link Activity Activities} that each |
| 64 | * have preferences, use {@link #addPreferencesFromIntent}. Each |
| 65 | * {@link Activity} can specify meta-data in the manifest (via the key |
| 66 | * {@link PreferenceManager#METADATA_KEY_PREFERENCES}) that points to an XML |
| 67 | * resource. These XML resources will be inflated into a single preference |
| 68 | * hierarchy and shown by this fragment. |
| 69 | * <p> |
| 70 | * To specify an object hierarchy rooted with {@link PreferenceScreen}, use |
| 71 | * {@link #setPreferenceScreen(PreferenceScreen)}. |
| 72 | * <p> |
| 73 | * As a convenience, this fragment implements a click listener for any |
| 74 | * preference in the current hierarchy, see |
| 75 | * {@link #onPreferenceTreeClick(PreferenceScreen, Preference)}. |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 76 | * |
| 77 | * <a name="SampleCode"></a> |
| 78 | * <h3>Sample Code</h3> |
| 79 | * |
Dianne Hackborn | b1ad597 | 2010-08-02 17:30:33 -0700 | [diff] [blame] | 80 | * <p>The following sample code shows a simple preference fragment that is |
| 81 | * populated from a resource. The resource it loads is:</p> |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 82 | * |
Dianne Hackborn | b1ad597 | 2010-08-02 17:30:33 -0700 | [diff] [blame] | 83 | * {@sample development/samples/ApiDemos/res/xml/preferences.xml preferences} |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 84 | * |
Dianne Hackborn | b1ad597 | 2010-08-02 17:30:33 -0700 | [diff] [blame] | 85 | * <p>The fragment implementation itself simply populates the preferences |
| 86 | * when created. Note that the preferences framework takes care of loading |
| 87 | * the current values out of the app preferences and writing them when changed:</p> |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 88 | * |
Dianne Hackborn | b1ad597 | 2010-08-02 17:30:33 -0700 | [diff] [blame] | 89 | * {@sample development/samples/ApiDemos/src/com/example/android/apis/preference/FragmentPreferences.java |
| 90 | * fragment} |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 91 | * |
| 92 | * @see Preference |
| 93 | * @see PreferenceScreen |
| 94 | */ |
| 95 | public abstract class PreferenceFragment extends Fragment implements |
| 96 | PreferenceManager.OnPreferenceTreeClickListener { |
| 97 | |
| 98 | private static final String PREFERENCES_TAG = "android:preferences"; |
| 99 | |
| 100 | private PreferenceManager mPreferenceManager; |
| 101 | private ListView mList; |
| 102 | private boolean mHavePrefs; |
| 103 | private boolean mInitDone; |
| 104 | |
| 105 | /** |
| 106 | * The starting request code given out to preference framework. |
| 107 | */ |
| 108 | private static final int FIRST_REQUEST_CODE = 100; |
| 109 | |
Dianne Hackborn | 3e449ce | 2010-09-11 20:52:31 -0700 | [diff] [blame] | 110 | private static final int MSG_BIND_PREFERENCES = 1; |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 111 | private Handler mHandler = new Handler() { |
| 112 | @Override |
| 113 | public void handleMessage(Message msg) { |
| 114 | switch (msg.what) { |
| 115 | |
| 116 | case MSG_BIND_PREFERENCES: |
| 117 | bindPreferences(); |
| 118 | break; |
| 119 | } |
| 120 | } |
| 121 | }; |
| 122 | |
| 123 | final private Runnable mRequestFocus = new Runnable() { |
| 124 | public void run() { |
| 125 | mList.focusableViewAvailable(mList); |
| 126 | } |
| 127 | }; |
| 128 | |
Dianne Hackborn | b3cf10f | 2010-08-03 13:07:11 -0700 | [diff] [blame] | 129 | /** |
| 130 | * Interface that PreferenceFragment's containing activity should |
| 131 | * implement to be able to process preference items that wish to |
| 132 | * switch to a new fragment. |
| 133 | */ |
| 134 | public interface OnPreferenceStartFragmentCallback { |
| 135 | /** |
| 136 | * Called when the user has clicked on a Preference that has |
| 137 | * a fragment class name associated with it. The implementation |
| 138 | * to should instantiate and switch to an instance of the given |
| 139 | * fragment. |
| 140 | */ |
| 141 | boolean onPreferenceStartFragment(PreferenceFragment caller, Preference pref); |
| 142 | } |
| 143 | |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 144 | @Override |
| 145 | public void onCreate(Bundle savedInstanceState) { |
| 146 | super.onCreate(savedInstanceState); |
| 147 | mPreferenceManager = new PreferenceManager(getActivity(), FIRST_REQUEST_CODE); |
Amith Yamasani | 82e7bc1 | 2010-09-23 15:07:58 -0700 | [diff] [blame] | 148 | mPreferenceManager.setFragment(this); |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 149 | mPreferenceManager.setOnPreferenceTreeClickListener(this); |
| 150 | } |
| 151 | |
| 152 | @Override |
| 153 | public View onCreateView(LayoutInflater inflater, ViewGroup container, |
| 154 | Bundle savedInstanceState) { |
Dianne Hackborn | e72f237 | 2011-03-16 10:43:18 -0700 | [diff] [blame] | 155 | if (getResources().getConfiguration().isLayoutSizeAtLeast( |
| 156 | Configuration.SCREENLAYOUT_SIZE_LARGE)) { |
| 157 | return inflater.inflate(com.android.internal.R.layout.preference_list_fragment_large, |
| 158 | container, false); |
| 159 | } else { |
| 160 | return inflater.inflate(com.android.internal.R.layout.preference_list_fragment, |
| 161 | container, false); |
| 162 | } |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | @Override |
| 166 | public void onActivityCreated(Bundle savedInstanceState) { |
| 167 | super.onActivityCreated(savedInstanceState); |
| 168 | getListView().setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY); |
| 169 | |
| 170 | if (mHavePrefs) { |
| 171 | bindPreferences(); |
| 172 | } |
| 173 | |
| 174 | mInitDone = true; |
| 175 | |
| 176 | if (savedInstanceState != null) { |
| 177 | Bundle container = savedInstanceState.getBundle(PREFERENCES_TAG); |
| 178 | if (container != null) { |
| 179 | final PreferenceScreen preferenceScreen = getPreferenceScreen(); |
| 180 | if (preferenceScreen != null) { |
| 181 | preferenceScreen.restoreHierarchyState(container); |
| 182 | } |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | @Override |
| 188 | public void onStop() { |
| 189 | super.onStop(); |
| 190 | mPreferenceManager.dispatchActivityStop(); |
| 191 | } |
| 192 | |
| 193 | @Override |
Dianne Hackborn | b3cf10f | 2010-08-03 13:07:11 -0700 | [diff] [blame] | 194 | public void onDestroyView() { |
| 195 | mList = null; |
| 196 | mHandler.removeCallbacks(mRequestFocus); |
Amith Yamasani | 81d8600 | 2011-03-02 16:11:31 -0800 | [diff] [blame] | 197 | mHandler.removeMessages(MSG_BIND_PREFERENCES); |
Dianne Hackborn | b3cf10f | 2010-08-03 13:07:11 -0700 | [diff] [blame] | 198 | super.onDestroyView(); |
| 199 | } |
| 200 | |
| 201 | @Override |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 202 | public void onDestroy() { |
| 203 | super.onDestroy(); |
| 204 | mPreferenceManager.dispatchActivityDestroy(); |
Amith Yamasani | 74402cf | 2010-12-09 11:22:15 -0800 | [diff] [blame] | 205 | mPreferenceManager.setOnPreferenceTreeClickListener(null); |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 206 | } |
| 207 | |
| 208 | @Override |
| 209 | public void onSaveInstanceState(Bundle outState) { |
| 210 | super.onSaveInstanceState(outState); |
| 211 | |
| 212 | final PreferenceScreen preferenceScreen = getPreferenceScreen(); |
| 213 | if (preferenceScreen != null) { |
| 214 | Bundle container = new Bundle(); |
| 215 | preferenceScreen.saveHierarchyState(container); |
| 216 | outState.putBundle(PREFERENCES_TAG, container); |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | @Override |
| 221 | public void onActivityResult(int requestCode, int resultCode, Intent data) { |
| 222 | super.onActivityResult(requestCode, resultCode, data); |
| 223 | |
| 224 | mPreferenceManager.dispatchActivityResult(requestCode, resultCode, data); |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * Returns the {@link PreferenceManager} used by this fragment. |
| 229 | * @return The {@link PreferenceManager}. |
| 230 | */ |
| 231 | public PreferenceManager getPreferenceManager() { |
| 232 | return mPreferenceManager; |
| 233 | } |
| 234 | |
| 235 | /** |
| 236 | * Sets the root of the preference hierarchy that this fragment is showing. |
| 237 | * |
| 238 | * @param preferenceScreen The root {@link PreferenceScreen} of the preference hierarchy. |
| 239 | */ |
| 240 | public void setPreferenceScreen(PreferenceScreen preferenceScreen) { |
| 241 | if (mPreferenceManager.setPreferences(preferenceScreen) && preferenceScreen != null) { |
| 242 | mHavePrefs = true; |
| 243 | if (mInitDone) { |
| 244 | postBindPreferences(); |
| 245 | } |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * Gets the root of the preference hierarchy that this fragment is showing. |
| 251 | * |
| 252 | * @return The {@link PreferenceScreen} that is the root of the preference |
| 253 | * hierarchy. |
| 254 | */ |
| 255 | public PreferenceScreen getPreferenceScreen() { |
| 256 | return mPreferenceManager.getPreferenceScreen(); |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Adds preferences from activities that match the given {@link Intent}. |
| 261 | * |
| 262 | * @param intent The {@link Intent} to query activities. |
| 263 | */ |
| 264 | public void addPreferencesFromIntent(Intent intent) { |
| 265 | requirePreferenceManager(); |
| 266 | |
| 267 | setPreferenceScreen(mPreferenceManager.inflateFromIntent(intent, getPreferenceScreen())); |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Inflates the given XML resource and adds the preference hierarchy to the current |
| 272 | * preference hierarchy. |
| 273 | * |
| 274 | * @param preferencesResId The XML resource ID to inflate. |
| 275 | */ |
| 276 | public void addPreferencesFromResource(int preferencesResId) { |
| 277 | requirePreferenceManager(); |
| 278 | |
| 279 | setPreferenceScreen(mPreferenceManager.inflateFromResource(getActivity(), |
| 280 | preferencesResId, getPreferenceScreen())); |
| 281 | } |
| 282 | |
| 283 | /** |
| 284 | * {@inheritDoc} |
| 285 | */ |
Dianne Hackborn | b3cf10f | 2010-08-03 13:07:11 -0700 | [diff] [blame] | 286 | public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, |
| 287 | Preference preference) { |
| 288 | if (preference.getFragment() != null && |
| 289 | getActivity() instanceof OnPreferenceStartFragmentCallback) { |
| 290 | return ((OnPreferenceStartFragmentCallback)getActivity()).onPreferenceStartFragment( |
| 291 | this, preference); |
| 292 | } |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 293 | return false; |
| 294 | } |
| 295 | |
| 296 | /** |
| 297 | * Finds a {@link Preference} based on its key. |
| 298 | * |
| 299 | * @param key The key of the preference to retrieve. |
| 300 | * @return The {@link Preference} with the key, or null. |
| 301 | * @see PreferenceGroup#findPreference(CharSequence) |
| 302 | */ |
| 303 | public Preference findPreference(CharSequence key) { |
| 304 | if (mPreferenceManager == null) { |
| 305 | return null; |
| 306 | } |
| 307 | return mPreferenceManager.findPreference(key); |
| 308 | } |
| 309 | |
| 310 | private void requirePreferenceManager() { |
| 311 | if (mPreferenceManager == null) { |
| 312 | throw new RuntimeException("This should be called after super.onCreate."); |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | private void postBindPreferences() { |
| 317 | if (mHandler.hasMessages(MSG_BIND_PREFERENCES)) return; |
| 318 | mHandler.obtainMessage(MSG_BIND_PREFERENCES).sendToTarget(); |
| 319 | } |
| 320 | |
| 321 | private void bindPreferences() { |
| 322 | final PreferenceScreen preferenceScreen = getPreferenceScreen(); |
| 323 | if (preferenceScreen != null) { |
| 324 | preferenceScreen.bind(getListView()); |
| 325 | } |
| 326 | } |
| 327 | |
Amith Yamasani | 9ae5473e | 2010-08-17 16:49:58 -0700 | [diff] [blame] | 328 | /** @hide */ |
| 329 | public ListView getListView() { |
Dianne Hackborn | 42c2936 | 2010-07-28 14:32:15 -0700 | [diff] [blame] | 330 | ensureList(); |
| 331 | return mList; |
| 332 | } |
| 333 | |
| 334 | private void ensureList() { |
| 335 | if (mList != null) { |
| 336 | return; |
| 337 | } |
| 338 | View root = getView(); |
| 339 | if (root == null) { |
| 340 | throw new IllegalStateException("Content view not yet created"); |
| 341 | } |
| 342 | View rawListView = root.findViewById(android.R.id.list); |
| 343 | if (!(rawListView instanceof ListView)) { |
| 344 | throw new RuntimeException( |
| 345 | "Content has view with id attribute 'android.R.id.list' " |
| 346 | + "that is not a ListView class"); |
| 347 | } |
| 348 | mList = (ListView)rawListView; |
| 349 | if (mList == null) { |
| 350 | throw new RuntimeException( |
| 351 | "Your content must have a ListView whose id attribute is " + |
| 352 | "'android.R.id.list'"); |
| 353 | } |
| 354 | mHandler.post(mRequestFocus); |
| 355 | } |
| 356 | } |