1/* 2 * Copyright (C) 2015 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 17package android.support.v4.app; 18 19import android.app.Activity; 20import android.content.Context; 21import android.content.Intent; 22import android.content.IntentSender; 23import android.os.Bundle; 24import android.os.Handler; 25import android.support.annotation.NonNull; 26import android.support.annotation.Nullable; 27import android.support.v4.util.SimpleArrayMap; 28import android.view.LayoutInflater; 29import android.view.View; 30 31import java.io.FileDescriptor; 32import java.io.PrintWriter; 33 34/** 35 * Integration points with the Fragment host. 36 * <p> 37 * Fragments may be hosted by any object; such as an {@link Activity}. In order to 38 * host fragments, implement {@link FragmentHostCallback}, overriding the methods 39 * applicable to the host. 40 */ 41public abstract class FragmentHostCallback<E> extends FragmentContainer { 42 private final Activity mActivity; 43 final Context mContext; 44 private final Handler mHandler; 45 final int mWindowAnimations; 46 final FragmentManagerImpl mFragmentManager = new FragmentManagerImpl(); 47 /** The loader managers for individual fragments [i.e. Fragment#getLoaderManager()] */ 48 private SimpleArrayMap<String, LoaderManager> mAllLoaderManagers; 49 /** Whether or not fragment loaders should retain their state */ 50 private boolean mRetainLoaders; 51 /** The loader manger for the fragment host [i.e. Activity#getLoaderManager()] */ 52 private LoaderManagerImpl mLoaderManager; 53 private boolean mCheckedForLoaderManager; 54 /** Whether or not the fragment host loader manager was started */ 55 private boolean mLoadersStarted; 56 57 public FragmentHostCallback(Context context, Handler handler, int windowAnimations) { 58 this(context instanceof Activity ? (Activity) context : null, context, handler, 59 windowAnimations); 60 } 61 62 FragmentHostCallback(FragmentActivity activity) { 63 this(activity, activity /*context*/, activity.mHandler, 0 /*windowAnimations*/); 64 } 65 66 FragmentHostCallback(Activity activity, Context context, Handler handler, 67 int windowAnimations) { 68 mActivity = activity; 69 mContext = context; 70 mHandler = handler; 71 mWindowAnimations = windowAnimations; 72 } 73 74 /** 75 * Print internal state into the given stream. 76 * 77 * @param prefix Desired prefix to prepend at each line of output. 78 * @param fd The raw file descriptor that the dump is being sent to. 79 * @param writer The PrintWriter to which you should dump your state. This will be closed 80 * for you after you return. 81 * @param args additional arguments to the dump request. 82 */ 83 public void onDump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { 84 } 85 86 /** 87 * Return {@code true} if the fragment's state needs to be saved. 88 */ 89 public boolean onShouldSaveFragmentState(Fragment fragment) { 90 return true; 91 } 92 93 /** 94 * Return a {@link LayoutInflater}. 95 * See {@link Activity#getLayoutInflater()}. 96 */ 97 public LayoutInflater onGetLayoutInflater() { 98 return (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 99 } 100 101 /** 102 * Return the object that's currently hosting the fragment. If a {@link Fragment} 103 * is hosted by a {@link FragmentActivity}, the object returned here should be 104 * the same object returned from {@link Fragment#getActivity()}. 105 */ 106 @Nullable 107 public abstract E onGetHost(); 108 109 /** 110 * Invalidates the activity's options menu. 111 * See {@link FragmentActivity#supportInvalidateOptionsMenu()} 112 */ 113 public void onSupportInvalidateOptionsMenu() { 114 } 115 116 /** 117 * Starts a new {@link Activity} from the given fragment. 118 * See {@link FragmentActivity#startActivityForResult(Intent, int)}. 119 */ 120 public void onStartActivityFromFragment(Fragment fragment, Intent intent, int requestCode) { 121 onStartActivityFromFragment(fragment, intent, requestCode, null); 122 } 123 124 /** 125 * Starts a new {@link Activity} from the given fragment. 126 * See {@link FragmentActivity#startActivityForResult(Intent, int, Bundle)}. 127 */ 128 public void onStartActivityFromFragment( 129 Fragment fragment, Intent intent, int requestCode, @Nullable Bundle options) { 130 if (requestCode != -1) { 131 throw new IllegalStateException( 132 "Starting activity with a requestCode requires a FragmentActivity host"); 133 } 134 mContext.startActivity(intent); 135 } 136 137 /** 138 * Starts a new {@link IntentSender} from the given fragment. 139 * See {@link Activity#startIntentSender(IntentSender, Intent, int, int, int, Bundle)}. 140 */ 141 public void onStartIntentSenderFromFragment(Fragment fragment, IntentSender intent, 142 int requestCode, @Nullable Intent fillInIntent, int flagsMask, int flagsValues, 143 int extraFlags, Bundle options) throws IntentSender.SendIntentException { 144 if (requestCode != -1) { 145 throw new IllegalStateException( 146 "Starting intent sender with a requestCode requires a FragmentActivity host"); 147 } 148 ActivityCompat.startIntentSenderForResult(mActivity, intent, requestCode, fillInIntent, 149 flagsMask, flagsValues, extraFlags, options); 150 } 151 152 /** 153 * Requests permissions from the given fragment. 154 * See {@link FragmentActivity#requestPermissions(String[], int)} 155 */ 156 public void onRequestPermissionsFromFragment(@NonNull Fragment fragment, 157 @NonNull String[] permissions, int requestCode) { 158 } 159 160 /** 161 * Checks whether to show permission rationale UI from a fragment. 162 * See {@link FragmentActivity#shouldShowRequestPermissionRationale(String)} 163 */ 164 public boolean onShouldShowRequestPermissionRationale(@NonNull String permission) { 165 return false; 166 } 167 168 /** 169 * Return {@code true} if there are window animations. 170 */ 171 public boolean onHasWindowAnimations() { 172 return true; 173 } 174 175 /** 176 * Return the window animations. 177 */ 178 public int onGetWindowAnimations() { 179 return mWindowAnimations; 180 } 181 182 @Nullable 183 @Override 184 public View onFindViewById(int id) { 185 return null; 186 } 187 188 @Override 189 public boolean onHasView() { 190 return true; 191 } 192 193 Activity getActivity() { 194 return mActivity; 195 } 196 197 Context getContext() { 198 return mContext; 199 } 200 201 Handler getHandler() { 202 return mHandler; 203 } 204 205 FragmentManagerImpl getFragmentManagerImpl() { 206 return mFragmentManager; 207 } 208 209 LoaderManagerImpl getLoaderManagerImpl() { 210 if (mLoaderManager != null) { 211 return mLoaderManager; 212 } 213 mCheckedForLoaderManager = true; 214 mLoaderManager = getLoaderManager("(root)", mLoadersStarted, true /*create*/); 215 return mLoaderManager; 216 } 217 218 void inactivateFragment(String who) { 219 //Log.v(TAG, "invalidateSupportFragment: who=" + who); 220 if (mAllLoaderManagers != null) { 221 LoaderManagerImpl lm = (LoaderManagerImpl) mAllLoaderManagers.get(who); 222 if (lm != null && !lm.mRetaining) { 223 lm.doDestroy(); 224 mAllLoaderManagers.remove(who); 225 } 226 } 227 } 228 229 void onAttachFragment(Fragment fragment) { 230 } 231 232 boolean getRetainLoaders() { 233 return mRetainLoaders; 234 } 235 236 void doLoaderStart() { 237 if (mLoadersStarted) { 238 return; 239 } 240 mLoadersStarted = true; 241 242 if (mLoaderManager != null) { 243 mLoaderManager.doStart(); 244 } else if (!mCheckedForLoaderManager) { 245 mLoaderManager = getLoaderManager("(root)", mLoadersStarted, false); 246 // the returned loader manager may be a new one, so we have to start it 247 if ((mLoaderManager != null) && (!mLoaderManager.mStarted)) { 248 mLoaderManager.doStart(); 249 } 250 } 251 mCheckedForLoaderManager = true; 252 } 253 254 // retain -- whether to stop the loader or retain it 255 void doLoaderStop(boolean retain) { 256 mRetainLoaders = retain; 257 258 if (mLoaderManager == null) { 259 return; 260 } 261 262 if (!mLoadersStarted) { 263 return; 264 } 265 mLoadersStarted = false; 266 267 if (retain) { 268 mLoaderManager.doRetain(); 269 } else { 270 mLoaderManager.doStop(); 271 } 272 } 273 274 void doLoaderRetain() { 275 if (mLoaderManager == null) { 276 return; 277 } 278 mLoaderManager.doRetain(); 279 } 280 281 void doLoaderDestroy() { 282 if (mLoaderManager == null) { 283 return; 284 } 285 mLoaderManager.doDestroy(); 286 } 287 288 void reportLoaderStart() { 289 if (mAllLoaderManagers != null) { 290 final int N = mAllLoaderManagers.size(); 291 LoaderManagerImpl loaders[] = new LoaderManagerImpl[N]; 292 for (int i=N-1; i>=0; i--) { 293 loaders[i] = (LoaderManagerImpl) mAllLoaderManagers.valueAt(i); 294 } 295 for (int i=0; i<N; i++) { 296 LoaderManagerImpl lm = loaders[i]; 297 lm.finishRetain(); 298 lm.doReportStart(); 299 } 300 } 301 } 302 303 LoaderManagerImpl getLoaderManager(String who, boolean started, boolean create) { 304 if (mAllLoaderManagers == null) { 305 mAllLoaderManagers = new SimpleArrayMap<String, LoaderManager>(); 306 } 307 LoaderManagerImpl lm = (LoaderManagerImpl) mAllLoaderManagers.get(who); 308 if (lm == null && create) { 309 lm = new LoaderManagerImpl(who, this, started); 310 mAllLoaderManagers.put(who, lm); 311 } else if (started && lm != null && !lm.mStarted) { 312 lm.doStart(); 313 } 314 return lm; 315 } 316 317 SimpleArrayMap<String, LoaderManager> retainLoaderNonConfig() { 318 boolean retainLoaders = false; 319 if (mAllLoaderManagers != null) { 320 // Restart any loader managers that were already stopped so that they 321 // will be ready to retain 322 final int N = mAllLoaderManagers.size(); 323 LoaderManagerImpl loaders[] = new LoaderManagerImpl[N]; 324 for (int i=N-1; i>=0; i--) { 325 loaders[i] = (LoaderManagerImpl) mAllLoaderManagers.valueAt(i); 326 } 327 final boolean doRetainLoaders = getRetainLoaders(); 328 for (int i=0; i<N; i++) { 329 LoaderManagerImpl lm = loaders[i]; 330 if (!lm.mRetaining && doRetainLoaders) { 331 if (!lm.mStarted) { 332 lm.doStart(); 333 } 334 lm.doRetain(); 335 } 336 if (lm.mRetaining) { 337 retainLoaders = true; 338 } else { 339 lm.doDestroy(); 340 mAllLoaderManagers.remove(lm.mWho); 341 } 342 } 343 } 344 345 if (retainLoaders) { 346 return mAllLoaderManagers; 347 } 348 return null; 349 } 350 351 void restoreLoaderNonConfig(SimpleArrayMap<String, LoaderManager> loaderManagers) { 352 if (loaderManagers != null) { 353 for (int i = 0, N = loaderManagers.size(); i < N; i++) { 354 ((LoaderManagerImpl) loaderManagers.valueAt(i)).updateHostController(this); 355 } 356 } 357 mAllLoaderManagers = loaderManagers; 358 } 359 360 void dumpLoaders(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { 361 writer.print(prefix); writer.print("mLoadersStarted="); 362 writer.println(mLoadersStarted); 363 if (mLoaderManager != null) { 364 writer.print(prefix); writer.print("Loader Manager "); 365 writer.print(Integer.toHexString(System.identityHashCode(mLoaderManager))); 366 writer.println(":"); 367 mLoaderManager.dump(prefix + " ", fd, writer, args); 368 } 369 } 370} 371