Fragment.java revision bdd19bc338286e1042f59808545665a061e73ffc
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 17package android.app; 18 19import android.animation.Animator; 20import android.content.ComponentCallbacks; 21import android.content.Context; 22import android.content.Intent; 23import android.content.res.Configuration; 24import android.content.res.Resources; 25import android.os.Bundle; 26import android.os.Parcel; 27import android.os.Parcelable; 28import android.util.AndroidRuntimeException; 29import android.util.AttributeSet; 30import android.util.SparseArray; 31import android.view.ContextMenu; 32import android.view.LayoutInflater; 33import android.view.Menu; 34import android.view.MenuInflater; 35import android.view.MenuItem; 36import android.view.View; 37import android.view.ViewGroup; 38import android.view.ContextMenu.ContextMenuInfo; 39import android.view.View.OnCreateContextMenuListener; 40import android.widget.AdapterView; 41 42import java.io.FileDescriptor; 43import java.io.PrintWriter; 44import java.util.HashMap; 45 46final class FragmentState implements Parcelable { 47 final String mClassName; 48 final int mIndex; 49 final boolean mFromLayout; 50 final int mFragmentId; 51 final int mContainerId; 52 final String mTag; 53 final boolean mRetainInstance; 54 final Bundle mArguments; 55 56 Bundle mSavedFragmentState; 57 58 Fragment mInstance; 59 60 public FragmentState(Fragment frag) { 61 mClassName = frag.getClass().getName(); 62 mIndex = frag.mIndex; 63 mFromLayout = frag.mFromLayout; 64 mFragmentId = frag.mFragmentId; 65 mContainerId = frag.mContainerId; 66 mTag = frag.mTag; 67 mRetainInstance = frag.mRetainInstance; 68 mArguments = frag.mArguments; 69 } 70 71 public FragmentState(Parcel in) { 72 mClassName = in.readString(); 73 mIndex = in.readInt(); 74 mFromLayout = in.readInt() != 0; 75 mFragmentId = in.readInt(); 76 mContainerId = in.readInt(); 77 mTag = in.readString(); 78 mRetainInstance = in.readInt() != 0; 79 mArguments = in.readBundle(); 80 mSavedFragmentState = in.readBundle(); 81 } 82 83 public Fragment instantiate(Activity activity) { 84 if (mInstance != null) { 85 return mInstance; 86 } 87 88 if (mArguments != null) { 89 mArguments.setClassLoader(activity.getClassLoader()); 90 } 91 92 mInstance = Fragment.instantiate(activity, mClassName, mArguments); 93 94 if (mSavedFragmentState != null) { 95 mSavedFragmentState.setClassLoader(activity.getClassLoader()); 96 mInstance.mSavedFragmentState = mSavedFragmentState; 97 } 98 mInstance.setIndex(mIndex); 99 mInstance.mFromLayout = mFromLayout; 100 mInstance.mFragmentId = mFragmentId; 101 mInstance.mContainerId = mContainerId; 102 mInstance.mTag = mTag; 103 mInstance.mRetainInstance = mRetainInstance; 104 mInstance.mFragmentManager = activity.mFragments; 105 106 return mInstance; 107 } 108 109 public int describeContents() { 110 return 0; 111 } 112 113 public void writeToParcel(Parcel dest, int flags) { 114 dest.writeString(mClassName); 115 dest.writeInt(mIndex); 116 dest.writeInt(mFromLayout ? 1 : 0); 117 dest.writeInt(mFragmentId); 118 dest.writeInt(mContainerId); 119 dest.writeString(mTag); 120 dest.writeInt(mRetainInstance ? 1 : 0); 121 dest.writeBundle(mArguments); 122 dest.writeBundle(mSavedFragmentState); 123 } 124 125 public static final Parcelable.Creator<FragmentState> CREATOR 126 = new Parcelable.Creator<FragmentState>() { 127 public FragmentState createFromParcel(Parcel in) { 128 return new FragmentState(in); 129 } 130 131 public FragmentState[] newArray(int size) { 132 return new FragmentState[size]; 133 } 134 }; 135} 136 137/** 138 * A Fragment is a piece of an application's user interface or behavior 139 * that can be placed in an {@link Activity}. Interaction with fragments 140 * is done through {@link FragmentManager}, which can be obtained via 141 * {@link Activity#getFragmentManager() Activity.getFragmentManager()} and 142 * {@link Fragment#getFragmentManager() Fragment.getFragmentManager()}. 143 * 144 * <p>The Fragment class can be used many ways to achieve a wide variety of 145 * results. It is core, it represents a particular operation or interface 146 * that is running within a larger {@link Activity}. A Fragment is closely 147 * tied to the Activity it is in, and can not be used apart from one. Though 148 * Fragment defines its own lifecycle, that lifecycle is dependent on its 149 * activity: if the activity is stopped, no fragments inside of it can be 150 * started; when the activity is destroyed, all fragments will be destroyed. 151 * 152 * <p>All subclasses of Fragment must include a public empty constructor. 153 * The framework will often re-instantiate a fragment class when needed, 154 * in particular during state restore, and needs to be able to find this 155 * constructor to instantiate it. If the empty constructor is not available, 156 * a runtime exception will occur in some cases during state restore. 157 * 158 * <p>Topics covered here: 159 * <ol> 160 * <li><a href="#Lifecycle">Lifecycle</a> 161 * <li><a href="#Layout">Layout</a> 162 * <li><a href="#BackStack">Back Stack</a> 163 * </ol> 164 * 165 * <a name="Lifecycle"></a> 166 * <h3>Lifecycle</h3> 167 * 168 * <p>Though a Fragment's lifecycle is tied to its owning activity, it has 169 * its own wrinkle on the standard activity lifecycle. It includes basic 170 * activity lifecycle methods such as {@link #onResume}, but also important 171 * are methods related to interactions with the activity and UI generation. 172 * 173 * <p>The core series of lifecycle methods that are called to bring a fragment 174 * up to resumed state (interacting with the user) are: 175 * 176 * <ol> 177 * <li> {@link #onAttach} called once the fragment is associated with its activity. 178 * <li> {@link #onCreate} called to do initial creation of the fragment. 179 * <li> {@link #onCreateView} creates and returns the view hierarchy associated 180 * with the fragment. 181 * <li> {@link #onActivityCreated} tells the fragment that its activity has 182 * completed its own {@link Activity#onCreate Activity.onCreaate}. 183 * <li> {@link #onStart} makes the fragment visible to the user (based on its 184 * containing activity being started). 185 * <li> {@link #onResume} makes the fragment interacting with the user (based on its 186 * containing activity being resumed). 187 * </ol> 188 * 189 * <p>As a fragment is no longer being used, it goes through a reverse 190 * series of callbacks: 191 * 192 * <ol> 193 * <li> {@link #onPause} fragment is no longer interacting with the user either 194 * because its activity is being paused or a fragment operation is modifying it 195 * in the activity. 196 * <li> {@link #onStop} fragment is no longer visible to the user either 197 * because its activity is being stopped or a fragment operation is modifying it 198 * in the activity. 199 * <li> {@link #onDestroyView} allows the fragment to clean up resources 200 * associated with its View. 201 * <li> {@link #onDestroy} called to do final cleanup of the fragment's state. 202 * <li> {@link #onDetach} called immediately prior to the fragment no longer 203 * being associated with its activity. 204 * </ol> 205 * 206 * <a name="Layout"></a> 207 * <h3>Layout</h3> 208 * 209 * <p>Fragments can be used as part of your application's layout, allowing 210 * you to better modularize your code and more easily adjust your user 211 * interface to the screen it is running on. As an example, we can look 212 * at a simple program consisting of a list of items, and display of the 213 * details of each item.</p> 214 * 215 * <p>An activity's layout XML can include <code><fragment></code> tags 216 * to embed fragment instances inside of the layout. For example, here is 217 * a simple layout that embeds one fragment:</p> 218 * 219 * {@sample development/samples/ApiDemos/res/layout/fragment_layout.xml layout} 220 * 221 * <p>The layout is installed in the activity in the normal way:</p> 222 * 223 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 224 * main} 225 * 226 * <p>The titles fragment, showing a list of titles, is very simple, relying 227 * on {@link ListFragment} for most of its work. Note the implementation of 228 * clicking an item, which can either update 229 * the content of the details fragment or start a new activity show the 230 * details depending on whether the current activity's layout can show the 231 * details.</p> 232 * 233 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 234 * titles} 235 * 236 * <p>The details fragment showing the contents of selected item here just 237 * displays a string of text based on an index of a string array built in to 238 * the app:</p> 239 * 240 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 241 * details} 242 * 243 * <p>In this case when the user clicks on a title, there is no details 244 * fragment in the current activity, so the title title fragment's click code will 245 * launch a new activity to display the details fragment:</p> 246 * 247 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 248 * details_activity} 249 * 250 * <p>However the screen may be large enough to show both the list of titles 251 * and details about the currently selected title. To use such a layout on 252 * a landscape screen, this alternative layout can be placed under layout-land:</p> 253 * 254 * {@sample development/samples/ApiDemos/res/layout-land/fragment_layout.xml layout} 255 * 256 * <p>Note how the prior code will adjust to this alternative UI flow: the 257 * titles fragment will now show its text inside of its activity, and the 258 * details activity will finish of it finds itself running in a configuration 259 * where the details can be shown inline. 260 * 261 * <p>When a configuration change causes the activity hosting these fragments 262 * to restart, its new instance may use a different layout that doesn't 263 * include the same fragments as the previous layout. In this case all of 264 * the previous fragments will still be instantiated and running in the new 265 * instance; however, any that are no longer associated with a <fragment> 266 * tag in the view hierarchy will not have their content view created and will 267 * return false from {@link #isInLayout}. 268 * 269 * <p>The attributes of the <fragment> tag are used to control the 270 * LayoutParams provider when attaching the fragment's view to the parent 271 * container. They can alse be parsed by the fragment in {@link #onInflate} 272 * as parameters. 273 * 274 * <p>The fragment being instantiated must have some kind of unique identifier 275 * so that it can be re-associated with a previous instance if the parent 276 * activity needs to be destroyed and recreated. This can be provided these 277 * ways: 278 * 279 * <ul> 280 * <li>If nothing is explicitly supplied, the view ID of the container will 281 * be used. 282 * <li><code>android:tag</code> can be used in <fragment> to provide 283 * a specific tag name for the fragment. 284 * <li><code>android:id</code> can be used in <fragment> to provide 285 * a specific identifier for the fragment. 286 * </ul> 287 * 288 * <a name="BackStack"></a> 289 * <h3>Back Stack</h3> 290 * 291 * <p>The transaction in which fragments are modified can be placed on an 292 * internal back-stack of the owning activity. When the user presses back 293 * in the activity, any transactions on the back stack are popped off before 294 * the activity itself is finished. 295 * 296 * <p>For example, consider this simple fragment that is instantiated with 297 * an integer argument and displays that in a TextView in its UI:</p> 298 * 299 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java 300 * fragment} 301 * 302 * <p>A function that creates a new instance of the fragment, replacing 303 * whatever current fragment instance is being shown and pushing that change 304 * on to the back stack could be written as: 305 * 306 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java 307 * add_stack} 308 * 309 * <p>After each call to this function, a new entry is on the stack, and 310 * pressing back will pop it to return the user to whatever previous state 311 * the activity UI was in. 312 */ 313public class Fragment implements ComponentCallbacks, OnCreateContextMenuListener { 314 private static final HashMap<String, Class<?>> sClassMap = 315 new HashMap<String, Class<?>>(); 316 317 static final int INITIALIZING = 0; // Not yet created. 318 static final int CREATED = 1; // Created. 319 static final int ACTIVITY_CREATED = 2; // The activity has finished its creation. 320 static final int STARTED = 3; // Created and started, not resumed. 321 static final int RESUMED = 4; // Created started and resumed. 322 323 int mState = INITIALIZING; 324 325 // When instantiated from saved state, this is the saved state. 326 Bundle mSavedFragmentState; 327 SparseArray<Parcelable> mSavedViewState; 328 329 // Index into active fragment array. 330 int mIndex = -1; 331 332 // Internal unique name for this fragment; 333 String mWho; 334 335 // Construction arguments; 336 Bundle mArguments; 337 338 // Target fragment. 339 Fragment mTarget; 340 341 // Target request code. 342 int mTargetRequestCode; 343 344 // True if the fragment is in the list of added fragments. 345 boolean mAdded; 346 347 // True if the fragment is in the resumed state. 348 boolean mResumed; 349 350 // Set to true if this fragment was instantiated from a layout file. 351 boolean mFromLayout; 352 353 // Set to true when the view has actually been inflated in its layout. 354 boolean mInLayout; 355 356 // Number of active back stack entries this fragment is in. 357 int mBackStackNesting; 358 359 // The fragment manager we are associated with. Set as soon as the 360 // fragment is used in a transaction; cleared after it has been removed 361 // from all transactions. 362 FragmentManager mFragmentManager; 363 364 // Set as soon as a fragment is added to a transaction (or removed), 365 // to be able to do validation. 366 Activity mImmediateActivity; 367 368 // Activity this fragment is attached to. 369 Activity mActivity; 370 371 // The optional identifier for this fragment -- either the container ID if it 372 // was dynamically added to the view hierarchy, or the ID supplied in 373 // layout. 374 int mFragmentId; 375 376 // When a fragment is being dynamically added to the view hierarchy, this 377 // is the identifier of the parent container it is being added to. 378 int mContainerId; 379 380 // The optional named tag for this fragment -- usually used to find 381 // fragments that are not part of the layout. 382 String mTag; 383 384 // Set to true when the app has requested that this fragment be hidden 385 // from the user. 386 boolean mHidden; 387 388 // If set this fragment would like its instance retained across 389 // configuration changes. 390 boolean mRetainInstance; 391 392 // If set this fragment is being retained across the current config change. 393 boolean mRetaining; 394 395 // If set this fragment has menu items to contribute. 396 boolean mHasMenu; 397 398 // Used to verify that subclasses call through to super class. 399 boolean mCalled; 400 401 // If app has requested a specific animation, this is the one to use. 402 int mNextAnim; 403 404 // The parent container of the fragment after dynamically added to UI. 405 ViewGroup mContainer; 406 407 // The View generated for this fragment. 408 View mView; 409 410 LoaderManagerImpl mLoaderManager; 411 boolean mLoadersStarted; 412 boolean mCheckedForLoaderManager; 413 414 /** 415 * Thrown by {@link Fragment#instantiate(Context, String, Bundle)} when 416 * there is an instantiation failure. 417 */ 418 static public class InstantiationException extends AndroidRuntimeException { 419 public InstantiationException(String msg, Exception cause) { 420 super(msg, cause); 421 } 422 } 423 424 /** 425 * Default constructor. <strong>Every</strong> fragment must have an 426 * empty constructor, so it can be instantiated when restoring its 427 * activity's state. It is strongly recommended that subclasses do not 428 * have other constructors with parameters, since these constructors 429 * will not be called when the fragment is re-instantiated; instead, 430 * arguments can be supplied by the caller with {@link #setArguments} 431 * and later retrieved by the Fragment with {@link #getArguments}. 432 * 433 * <p>Applications should generally not implement a constructor. The 434 * first place application code an run where the fragment is ready to 435 * be used is in {@link #onAttach(Activity)}, the point where the fragment 436 * is actually associated with its activity. Some applications may also 437 * want to implement {@link #onInflate} to retrieve attributes from a 438 * layout resource, though should take care here because this happens for 439 * the fragment is attached to its activity. 440 */ 441 public Fragment() { 442 } 443 444 /** 445 * Like {@link #instantiate(Context, String, Bundle)} but with a null 446 * argument Bundle. 447 */ 448 public static Fragment instantiate(Context context, String fname) { 449 return instantiate(context, fname, null); 450 } 451 452 /** 453 * Create a new instance of a Fragment with the given class name. This is 454 * the same as calling its empty constructor. 455 * 456 * @param context The calling context being used to instantiate the fragment. 457 * This is currently just used to get its ClassLoader. 458 * @param fname The class name of the fragment to instantiate. 459 * @param args Bundle of arguments to supply to the fragment, which it 460 * can retrieve with {@link #getArguments()}. May be null. 461 * @return Returns a new fragment instance. 462 * @throws InstantiationException If there is a failure in instantiating 463 * the given fragment class. This is a runtime exception; it is not 464 * normally expected to happen. 465 */ 466 public static Fragment instantiate(Context context, String fname, Bundle args) { 467 try { 468 Class<?> clazz = sClassMap.get(fname); 469 if (clazz == null) { 470 // Class not found in the cache, see if it's real, and try to add it 471 clazz = context.getClassLoader().loadClass(fname); 472 sClassMap.put(fname, clazz); 473 } 474 Fragment f = (Fragment)clazz.newInstance(); 475 if (args != null) { 476 args.setClassLoader(f.getClass().getClassLoader()); 477 f.mArguments = args; 478 } 479 return f; 480 } catch (ClassNotFoundException e) { 481 throw new InstantiationException("Unable to instantiate fragment " + fname 482 + ": make sure class name exists, is public, and has an" 483 + " empty constructor that is public", e); 484 } catch (java.lang.InstantiationException e) { 485 throw new InstantiationException("Unable to instantiate fragment " + fname 486 + ": make sure class name exists, is public, and has an" 487 + " empty constructor that is public", e); 488 } catch (IllegalAccessException e) { 489 throw new InstantiationException("Unable to instantiate fragment " + fname 490 + ": make sure class name exists, is public, and has an" 491 + " empty constructor that is public", e); 492 } 493 } 494 495 void restoreViewState() { 496 if (mSavedViewState != null) { 497 mView.restoreHierarchyState(mSavedViewState); 498 mSavedViewState = null; 499 } 500 } 501 502 void setIndex(int index) { 503 mIndex = index; 504 mWho = "android:fragment:" + mIndex; 505 } 506 507 void clearIndex() { 508 mIndex = -1; 509 mWho = null; 510 } 511 512 /** 513 * Subclasses can not override equals(). 514 */ 515 @Override final public boolean equals(Object o) { 516 return super.equals(o); 517 } 518 519 /** 520 * Subclasses can not override hashCode(). 521 */ 522 @Override final public int hashCode() { 523 return super.hashCode(); 524 } 525 526 @Override 527 public String toString() { 528 StringBuilder sb = new StringBuilder(128); 529 sb.append("Fragment{"); 530 sb.append(Integer.toHexString(System.identityHashCode(this))); 531 if (mIndex >= 0) { 532 sb.append(" #"); 533 sb.append(mIndex); 534 } 535 if (mFragmentId != 0) { 536 sb.append(" id=0x"); 537 sb.append(Integer.toHexString(mFragmentId)); 538 } 539 if (mTag != null) { 540 sb.append(" "); 541 sb.append(mTag); 542 } 543 sb.append('}'); 544 return sb.toString(); 545 } 546 547 /** 548 * Return the identifier this fragment is known by. This is either 549 * the android:id value supplied in a layout or the container view ID 550 * supplied when adding the fragment. 551 */ 552 final public int getId() { 553 return mFragmentId; 554 } 555 556 /** 557 * Get the tag name of the fragment, if specified. 558 */ 559 final public String getTag() { 560 return mTag; 561 } 562 563 /** 564 * Supply the construction arguments for this fragment. This can only 565 * be called before the fragment has been attached to its activity; that 566 * is, you should call it immediately after constructing the fragment. The 567 * arguments supplied here will be retained across fragment destroy and 568 * creation. 569 */ 570 public void setArguments(Bundle args) { 571 if (mIndex >= 0) { 572 throw new IllegalStateException("Fragment already active"); 573 } 574 mArguments = args; 575 } 576 577 /** 578 * Return the arguments supplied when the fragment was instantiated, 579 * if any. 580 */ 581 final public Bundle getArguments() { 582 return mArguments; 583 } 584 585 /** 586 * Optional target for this fragment. This may be used, for example, 587 * if this fragment is being started by another, and when done wants to 588 * give a result back to the first. The target set here is retained 589 * across instances via {@link FragmentManager#putFragment 590 * FragmentManager.putFragment()}. 591 * 592 * @param fragment The fragment that is the target of this one. 593 * @param requestCode Optional request code, for convenience if you 594 * are going to call back with {@link #onActivityResult(int, int, Intent)}. 595 */ 596 public void setTargetFragment(Fragment fragment, int requestCode) { 597 mTarget = fragment; 598 mTargetRequestCode = requestCode; 599 } 600 601 /** 602 * Return the target fragment set by {@link #setTargetFragment}. 603 */ 604 final public Fragment getTargetFragment() { 605 return mTarget; 606 } 607 608 /** 609 * Return the target request code set by {@link #setTargetFragment}. 610 */ 611 final public int getTargetRequestCode() { 612 return mTargetRequestCode; 613 } 614 615 /** 616 * Return the Activity this fragment is currently associated with. 617 */ 618 final public Activity getActivity() { 619 return mActivity; 620 } 621 622 /** 623 * Return <code>getActivity().getResources()</code>. 624 */ 625 final public Resources getResources() { 626 return mActivity.getResources(); 627 } 628 629 /** 630 * Return a localized, styled CharSequence from the application's package's 631 * default string table. 632 * 633 * @param resId Resource id for the CharSequence text 634 */ 635 public final CharSequence getText(int resId) { 636 return getResources().getText(resId); 637 } 638 639 /** 640 * Return a localized string from the application's package's 641 * default string table. 642 * 643 * @param resId Resource id for the string 644 */ 645 public final String getString(int resId) { 646 return getResources().getString(resId); 647 } 648 649 /** 650 * Return a localized formatted string from the application's package's 651 * default string table, substituting the format arguments as defined in 652 * {@link java.util.Formatter} and {@link java.lang.String#format}. 653 * 654 * @param resId Resource id for the format string 655 * @param formatArgs The format arguments that will be used for substitution. 656 */ 657 658 public final String getString(int resId, Object... formatArgs) { 659 return getResources().getString(resId, formatArgs); 660 } 661 662 /** 663 * Return the FragmentManager for interacting with fragments associated 664 * with this fragment's activity. Note that this will be non-null slightly 665 * before {@link #getActivity()}, during the time from when the fragment is 666 * placed in a {@link FragmentTransaction} until it is committed and 667 * attached to its activity. 668 */ 669 final public FragmentManager getFragmentManager() { 670 return mFragmentManager; 671 } 672 673 /** 674 * Return true if the fragment is currently added to its activity. 675 */ 676 final public boolean isAdded() { 677 return mActivity != null && mActivity.mFragments.mAdded.contains(this); 678 } 679 680 /** 681 * Return true if the layout is included as part of an activity view 682 * hierarchy via the <fragment> tag. This will always be true when 683 * fragments are created through the <fragment> tag, <em>except</em> 684 * in the case where an old fragment is restored from a previous state and 685 * it does not appear in the layout of the current state. 686 */ 687 final public boolean isInLayout() { 688 return mInLayout; 689 } 690 691 /** 692 * Return true if the fragment is in the resumed state. This is true 693 * for the duration of {@link #onResume()} and {@link #onPause()} as well. 694 */ 695 final public boolean isResumed() { 696 return mResumed; 697 } 698 699 /** 700 * Return true if the fragment is currently visible to the user. This means 701 * it: (1) has been added, (2) has its view attached to the window, and 702 * (3) is not hidden. 703 */ 704 final public boolean isVisible() { 705 return isAdded() && !isHidden() && mView != null 706 && mView.getWindowToken() != null && mView.getVisibility() == View.VISIBLE; 707 } 708 709 /** 710 * Return true if the fragment has been hidden. By default fragments 711 * are shown. You can find out about changes to this state with 712 * {@link #onHiddenChanged}. Note that the hidden state is orthogonal 713 * to other states -- that is, to be visible to the user, a fragment 714 * must be both started and not hidden. 715 */ 716 final public boolean isHidden() { 717 return mHidden; 718 } 719 720 /** 721 * Called when the hidden state (as returned by {@link #isHidden()} of 722 * the fragment has changed. Fragments start out not hidden; this will 723 * be called whenever the fragment changes state from that. 724 * @param hidden True if the fragment is now hidden, false if it is not 725 * visible. 726 */ 727 public void onHiddenChanged(boolean hidden) { 728 } 729 730 /** 731 * Control whether a fragment instance is retained across Activity 732 * re-creation (such as from a configuration change). This can only 733 * be used with fragments not in the back stack. If set, the fragment 734 * lifecycle will be slightly different when an activity is recreated: 735 * <ul> 736 * <li> {@link #onDestroy()} will not be called (but {@link #onDetach()} still 737 * will be, because the fragment is being detached from its current activity). 738 * <li> {@link #onCreate(Bundle)} will not be called since the fragment 739 * is not being re-created. 740 * <li> {@link #onAttach(Activity)} and {@link #onActivityCreated(Bundle)} <b>will</b> 741 * still be called. 742 * </ul> 743 */ 744 public void setRetainInstance(boolean retain) { 745 mRetainInstance = retain; 746 } 747 748 final public boolean getRetainInstance() { 749 return mRetainInstance; 750 } 751 752 /** 753 * Report that this fragment would like to participate in populating 754 * the options menu by receiving a call to {@link #onCreateOptionsMenu} 755 * and related methods. 756 * 757 * @param hasMenu If true, the fragment has menu items to contribute. 758 */ 759 public void setHasOptionsMenu(boolean hasMenu) { 760 if (mHasMenu != hasMenu) { 761 mHasMenu = hasMenu; 762 if (isAdded() && !isHidden()) { 763 mActivity.invalidateOptionsMenu(); 764 } 765 } 766 } 767 768 /** 769 * Return the LoaderManager for this fragment, creating it if needed. 770 */ 771 public LoaderManager getLoaderManager() { 772 if (mLoaderManager != null) { 773 return mLoaderManager; 774 } 775 mCheckedForLoaderManager = true; 776 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, true); 777 return mLoaderManager; 778 } 779 780 /** 781 * Call {@link Activity#startActivity(Intent)} on the fragment's 782 * containing Activity. 783 */ 784 public void startActivity(Intent intent) { 785 mActivity.startActivityFromFragment(this, intent, -1); 786 } 787 788 /** 789 * Call {@link Activity#startActivityForResult(Intent, int)} on the fragment's 790 * containing Activity. 791 */ 792 public void startActivityForResult(Intent intent, int requestCode) { 793 mActivity.startActivityFromFragment(this, intent, requestCode); 794 } 795 796 /** 797 * Receive the result from a previous call to 798 * {@link #startActivityForResult(Intent, int)}. This follows the 799 * related Activity API as described there in 800 * {@link Activity#onActivityResult(int, int, Intent)}. 801 * 802 * @param requestCode The integer request code originally supplied to 803 * startActivityForResult(), allowing you to identify who this 804 * result came from. 805 * @param resultCode The integer result code returned by the child activity 806 * through its setResult(). 807 * @param data An Intent, which can return result data to the caller 808 * (various data can be attached to Intent "extras"). 809 */ 810 public void onActivityResult(int requestCode, int resultCode, Intent data) { 811 } 812 813 /** 814 * Called when a fragment is being created as part of a view layout 815 * inflation, typically from setting the content view of an activity. This 816 * will be called immediately after the fragment is created from a <fragment> 817 * tag in a layout file. Note this is <em>before</em> the fragment's 818 * {@link #onAttach(Activity)} has been called; all you should do here is 819 * parse the attributes and save them away. A convenient thing to do is 820 * simply copy them into a Bundle that is given to {@link #setArguments(Bundle)}. 821 * 822 * <p>This is called every time the fragment is inflated, even if it is 823 * being inflated into a new instance with saved state. Because a fragment's 824 * arguments are retained across instances, it may make no sense to re-parse 825 * the attributes into new arguments. You may want to first check 826 * {@link #getArguments()} and only parse the attributes if it returns null, 827 * the assumption being that if it is non-null those are the same arguments 828 * from the first time the fragment was inflated. (That said, you may want 829 * to have layouts change for different configurations such as landscape 830 * and portrait, which can have different attributes. If so, you will need 831 * to re-parse the attributes each time this is called to generate new 832 * arguments.)</p> 833 * 834 * @param attrs The attributes at the tag where the fragment is 835 * being created. 836 * @param savedInstanceState If the fragment is being re-created from 837 * a previous saved state, this is the state. 838 */ 839 public void onInflate(AttributeSet attrs, Bundle savedInstanceState) { 840 mCalled = true; 841 } 842 843 /** 844 * Called when a fragment is first attached to its activity. 845 * {@link #onCreate(Bundle)} will be called after this. 846 */ 847 public void onAttach(Activity activity) { 848 mCalled = true; 849 } 850 851 /** 852 * Called when a fragment loads an animation. 853 */ 854 public Animator onCreateAnimator(int transit, boolean enter, int nextAnim) { 855 return null; 856 } 857 858 /** 859 * Called to do initial creation of a fragment. This is called after 860 * {@link #onAttach(Activity)} and before 861 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}. 862 * 863 * <p>Note that this can be called while the fragment's activity is 864 * still in the process of being created. As such, you can not rely 865 * on things like the activity's content view hierarchy being initialized 866 * at this point. If you want to do work once the activity itself is 867 * created, see {@link #onActivityCreated(Bundle)}. 868 * 869 * @param savedInstanceState If the fragment is being re-created from 870 * a previous saved state, this is the state. 871 */ 872 public void onCreate(Bundle savedInstanceState) { 873 mCalled = true; 874 } 875 876 /** 877 * Called to have the fragment instantiate its user interface view. 878 * This is optional, and non-graphical fragments can return null (which 879 * is the default implementation). This will be called between 880 * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}. 881 * 882 * <p>If you return a View from here, you will later be called in 883 * {@link #onDestroyView} when the view is being released. 884 * 885 * @param inflater The LayoutInflater object that can be used to inflate 886 * any views in the fragment, 887 * @param container If non-null, this is the parent view that the fragment's 888 * UI should be attached to. The fragment should not add the view itself, 889 * but this can be used to generate the LayoutParams of the view. 890 * @param savedInstanceState If non-null, this fragment is being re-constructed 891 * from a previous saved state as given here. 892 * 893 * @return Return the View for the fragment's UI, or null. 894 */ 895 public View onCreateView(LayoutInflater inflater, ViewGroup container, 896 Bundle savedInstanceState) { 897 return null; 898 } 899 900 public View getView() { 901 return mView; 902 } 903 904 /** 905 * Called when the fragment's activity has been created and this 906 * fragment's view hierarchy instantiated. It can be used to do final 907 * initialization once these pieces are in place, such as retrieving 908 * views or restoring state. It is also useful for fragments that use 909 * {@link #setRetainInstance(boolean)} to retain their instance, 910 * as this callback tells the fragment when it is fully associated with 911 * the new activity instance. This is called after {@link #onCreateView} 912 * and before {@link #onStart()}. 913 * 914 * @param savedInstanceState If the fragment is being re-created from 915 * a previous saved state, this is the state. 916 */ 917 public void onActivityCreated(Bundle savedInstanceState) { 918 mCalled = true; 919 } 920 921 /** 922 * Called when the Fragment is visible to the user. This is generally 923 * tied to {@link Activity#onStart() Activity.onStart} of the containing 924 * Activity's lifecycle. 925 */ 926 public void onStart() { 927 mCalled = true; 928 929 if (!mLoadersStarted) { 930 mLoadersStarted = true; 931 if (!mCheckedForLoaderManager) { 932 mCheckedForLoaderManager = true; 933 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 934 } 935 if (mLoaderManager != null) { 936 mLoaderManager.doStart(); 937 } 938 } 939 } 940 941 /** 942 * Called when the fragment is visible to the user and actively running. 943 * This is generally 944 * tied to {@link Activity#onResume() Activity.onResume} of the containing 945 * Activity's lifecycle. 946 */ 947 public void onResume() { 948 mCalled = true; 949 } 950 951 /** 952 * Called to ask the fragment to save its current dynamic state, so it 953 * can later be reconstructed in a new instance of its process is 954 * restarted. If a new instance of the fragment later needs to be 955 * created, the data you place in the Bundle here will be available 956 * in the Bundle given to {@link #onCreate(Bundle)}, 957 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}, and 958 * {@link #onActivityCreated(Bundle)}. 959 * 960 * <p>This corresponds to {@link Activity#onSaveInstanceState(Bundle) 961 * Activity.onSaveInstanceState(Bundle)} and most of the discussion there 962 * applies here as well. Note however: <em>this method may be called 963 * at any time before {@link #onDestroy()}</em>. There are many situations 964 * where a fragment may be mostly torn down (such as when placed on the 965 * back stack with no UI showing), but its state will not be saved until 966 * its owning activity actually needs to save its state. 967 * 968 * @param outState Bundle in which to place your saved state. 969 */ 970 public void onSaveInstanceState(Bundle outState) { 971 } 972 973 public void onConfigurationChanged(Configuration newConfig) { 974 mCalled = true; 975 } 976 977 /** 978 * Called when the Fragment is no longer resumed. This is generally 979 * tied to {@link Activity#onPause() Activity.onPause} of the containing 980 * Activity's lifecycle. 981 */ 982 public void onPause() { 983 mCalled = true; 984 } 985 986 /** 987 * Called when the Fragment is no longer started. This is generally 988 * tied to {@link Activity#onStop() Activity.onStop} of the containing 989 * Activity's lifecycle. 990 */ 991 public void onStop() { 992 mCalled = true; 993 } 994 995 public void onLowMemory() { 996 mCalled = true; 997 } 998 999 /** 1000 * Called when the view previously created by {@link #onCreateView} has 1001 * been detached from the fragment. The next time the fragment needs 1002 * to be displayed, a new view will be created. This is called 1003 * after {@link #onStop()} and before {@link #onDestroy()}. It is called 1004 * <em>regardless</em> of whether {@link #onCreateView} returned a 1005 * non-null view. Internally it is called after the view's state has 1006 * been saved but before it has been removed from its parent. 1007 */ 1008 public void onDestroyView() { 1009 mCalled = true; 1010 } 1011 1012 /** 1013 * Called when the fragment is no longer in use. This is called 1014 * after {@link #onStop()} and before {@link #onDetach()}. 1015 */ 1016 public void onDestroy() { 1017 mCalled = true; 1018 //Log.v("foo", "onDestroy: mCheckedForLoaderManager=" + mCheckedForLoaderManager 1019 // + " mLoaderManager=" + mLoaderManager); 1020 if (!mCheckedForLoaderManager) { 1021 mCheckedForLoaderManager = true; 1022 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1023 } 1024 if (mLoaderManager != null) { 1025 mLoaderManager.doDestroy(); 1026 } 1027 } 1028 1029 /** 1030 * Called when the fragment is no longer attached to its activity. This 1031 * is called after {@link #onDestroy()}. 1032 */ 1033 public void onDetach() { 1034 mCalled = true; 1035 } 1036 1037 /** 1038 * Initialize the contents of the Activity's standard options menu. You 1039 * should place your menu items in to <var>menu</var>. For this method 1040 * to be called, you must have first called {@link #setHasOptionsMenu}. See 1041 * {@link Activity#onCreateOptionsMenu(Menu) Activity.onCreateOptionsMenu} 1042 * for more information. 1043 * 1044 * @param menu The options menu in which you place your items. 1045 * 1046 * @see #setHasOptionsMenu 1047 * @see #onPrepareOptionsMenu 1048 * @see #onOptionsItemSelected 1049 */ 1050 public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 1051 } 1052 1053 /** 1054 * Prepare the Screen's standard options menu to be displayed. This is 1055 * called right before the menu is shown, every time it is shown. You can 1056 * use this method to efficiently enable/disable items or otherwise 1057 * dynamically modify the contents. See 1058 * {@link Activity#onPrepareOptionsMenu(Menu) Activity.onPrepareOptionsMenu} 1059 * for more information. 1060 * 1061 * @param menu The options menu as last shown or first initialized by 1062 * onCreateOptionsMenu(). 1063 * 1064 * @see #setHasOptionsMenu 1065 * @see #onCreateOptionsMenu 1066 */ 1067 public void onPrepareOptionsMenu(Menu menu) { 1068 } 1069 1070 /** 1071 * Called when this fragment's option menu items are no longer being 1072 * included in the overall options menu. Receiving this call means that 1073 * the menu needed to be rebuilt, but this fragment's items were not 1074 * included in the newly built menu (its {@link #onCreateOptionsMenu(Menu, MenuInflater)} 1075 * was not called). 1076 */ 1077 public void onDestroyOptionsMenu() { 1078 } 1079 1080 /** 1081 * This hook is called whenever an item in your options menu is selected. 1082 * The default implementation simply returns false to have the normal 1083 * processing happen (calling the item's Runnable or sending a message to 1084 * its Handler as appropriate). You can use this method for any items 1085 * for which you would like to do processing without those other 1086 * facilities. 1087 * 1088 * <p>Derived classes should call through to the base class for it to 1089 * perform the default menu handling. 1090 * 1091 * @param item The menu item that was selected. 1092 * 1093 * @return boolean Return false to allow normal menu processing to 1094 * proceed, true to consume it here. 1095 * 1096 * @see #onCreateOptionsMenu 1097 */ 1098 public boolean onOptionsItemSelected(MenuItem item) { 1099 return false; 1100 } 1101 1102 /** 1103 * This hook is called whenever the options menu is being closed (either by the user canceling 1104 * the menu with the back/menu button, or when an item is selected). 1105 * 1106 * @param menu The options menu as last shown or first initialized by 1107 * onCreateOptionsMenu(). 1108 */ 1109 public void onOptionsMenuClosed(Menu menu) { 1110 } 1111 1112 /** 1113 * Called when a context menu for the {@code view} is about to be shown. 1114 * Unlike {@link #onCreateOptionsMenu}, this will be called every 1115 * time the context menu is about to be shown and should be populated for 1116 * the view (or item inside the view for {@link AdapterView} subclasses, 1117 * this can be found in the {@code menuInfo})). 1118 * <p> 1119 * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an 1120 * item has been selected. 1121 * <p> 1122 * The default implementation calls up to 1123 * {@link Activity#onCreateContextMenu Activity.onCreateContextMenu}, though 1124 * you can not call this implementation if you don't want that behavior. 1125 * <p> 1126 * It is not safe to hold onto the context menu after this method returns. 1127 * {@inheritDoc} 1128 */ 1129 public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { 1130 getActivity().onCreateContextMenu(menu, v, menuInfo); 1131 } 1132 1133 /** 1134 * Registers a context menu to be shown for the given view (multiple views 1135 * can show the context menu). This method will set the 1136 * {@link OnCreateContextMenuListener} on the view to this fragment, so 1137 * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be 1138 * called when it is time to show the context menu. 1139 * 1140 * @see #unregisterForContextMenu(View) 1141 * @param view The view that should show a context menu. 1142 */ 1143 public void registerForContextMenu(View view) { 1144 view.setOnCreateContextMenuListener(this); 1145 } 1146 1147 /** 1148 * Prevents a context menu to be shown for the given view. This method will 1149 * remove the {@link OnCreateContextMenuListener} on the view. 1150 * 1151 * @see #registerForContextMenu(View) 1152 * @param view The view that should stop showing a context menu. 1153 */ 1154 public void unregisterForContextMenu(View view) { 1155 view.setOnCreateContextMenuListener(null); 1156 } 1157 1158 /** 1159 * This hook is called whenever an item in a context menu is selected. The 1160 * default implementation simply returns false to have the normal processing 1161 * happen (calling the item's Runnable or sending a message to its Handler 1162 * as appropriate). You can use this method for any items for which you 1163 * would like to do processing without those other facilities. 1164 * <p> 1165 * Use {@link MenuItem#getMenuInfo()} to get extra information set by the 1166 * View that added this menu item. 1167 * <p> 1168 * Derived classes should call through to the base class for it to perform 1169 * the default menu handling. 1170 * 1171 * @param item The context menu item that was selected. 1172 * @return boolean Return false to allow normal context menu processing to 1173 * proceed, true to consume it here. 1174 */ 1175 public boolean onContextItemSelected(MenuItem item) { 1176 return false; 1177 } 1178 1179 /** 1180 * Print the Fragments's state into the given stream. 1181 * 1182 * @param prefix Text to print at the front of each line. 1183 * @param fd The raw file descriptor that the dump is being sent to. 1184 * @param writer The PrintWriter to which you should dump your state. This will be 1185 * closed for you after you return. 1186 * @param args additional arguments to the dump request. 1187 */ 1188 public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { 1189 writer.print(prefix); writer.print("mFragmentId="); writer.print(mFragmentId); 1190 writer.print(" mContainerId="); writer.print(mContainerId); 1191 writer.print(" mTag="); writer.println(mTag); 1192 writer.print(prefix); writer.print("mState="); writer.print(mState); 1193 writer.print(" mIndex="); writer.print(mIndex); 1194 writer.print(" mWho="); writer.print(mWho); 1195 writer.print(" mBackStackNesting="); writer.println(mBackStackNesting); 1196 writer.print(prefix); writer.print("mAdded="); writer.print(mAdded); 1197 writer.print(" mResumed="); writer.print(mResumed); 1198 writer.print(" mFromLayout="); writer.print(mFromLayout); 1199 writer.print(" mInLayout="); writer.println(mInLayout); 1200 writer.print(prefix); writer.print("mHidden="); writer.print(mHidden); 1201 writer.print(" mRetainInstance="); writer.print(mRetainInstance); 1202 writer.print(" mRetaining="); writer.print(mRetaining); 1203 writer.print(" mHasMenu="); writer.println(mHasMenu); 1204 if (mFragmentManager != null) { 1205 writer.print(prefix); writer.print("mFragmentManager="); 1206 writer.println(mFragmentManager); 1207 } 1208 if (mImmediateActivity != null) { 1209 writer.print(prefix); writer.print("mImmediateActivity="); 1210 writer.println(mImmediateActivity); 1211 } 1212 if (mActivity != null) { 1213 writer.print(prefix); writer.print("mActivity="); 1214 writer.println(mActivity); 1215 } 1216 if (mArguments != null) { 1217 writer.print(prefix); writer.print("mArguments="); writer.println(mArguments); 1218 } 1219 if (mSavedFragmentState != null) { 1220 writer.print(prefix); writer.print("mSavedFragmentState="); 1221 writer.println(mSavedFragmentState); 1222 } 1223 if (mSavedViewState != null) { 1224 writer.print(prefix); writer.print("mSavedViewState="); 1225 writer.println(mSavedViewState); 1226 } 1227 if (mTarget != null) { 1228 writer.print(prefix); writer.print("mTarget="); writer.print(mTarget); 1229 writer.print(" mTargetRequestCode="); 1230 writer.println(mTargetRequestCode); 1231 } 1232 if (mNextAnim != 0) { 1233 writer.print(prefix); writer.print("mNextAnim="); writer.println(mNextAnim); 1234 } 1235 if (mContainer != null) { 1236 writer.print(prefix); writer.print("mContainer="); writer.println(mContainer); 1237 } 1238 if (mView != null) { 1239 writer.print(prefix); writer.print("mView="); writer.println(mView); 1240 } 1241 if (mLoaderManager != null) { 1242 writer.print(prefix); writer.print("mLoaderManager="); writer.print(mLoaderManager); 1243 writer.print(" mLoadersStarted="); writer.print(mLoadersStarted); 1244 writer.print(" mCheckedForLoaderManager="); 1245 writer.println(mCheckedForLoaderManager); 1246 } 1247 } 1248 1249 void performStop() { 1250 onStop(); 1251 1252 if (mLoadersStarted) { 1253 mLoadersStarted = false; 1254 if (!mCheckedForLoaderManager) { 1255 mCheckedForLoaderManager = true; 1256 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1257 } 1258 if (mLoaderManager != null) { 1259 if (mActivity == null || !mActivity.mChangingConfigurations) { 1260 mLoaderManager.doStop(); 1261 } else { 1262 mLoaderManager.doRetain(); 1263 } 1264 } 1265 } 1266 } 1267} 1268