Fragment.java revision 5d9d03a0234faa3cffd11502f973057045cafe82
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.DebugUtils; 31import android.util.SparseArray; 32import android.view.ContextMenu; 33import android.view.LayoutInflater; 34import android.view.Menu; 35import android.view.MenuInflater; 36import android.view.MenuItem; 37import android.view.View; 38import android.view.ViewGroup; 39import android.view.ContextMenu.ContextMenuInfo; 40import android.view.View.OnCreateContextMenuListener; 41import android.widget.AdapterView; 42 43import java.io.FileDescriptor; 44import java.io.PrintWriter; 45import java.util.HashMap; 46 47final class FragmentState implements Parcelable { 48 final String mClassName; 49 final int mIndex; 50 final boolean mFromLayout; 51 final int mFragmentId; 52 final int mContainerId; 53 final String mTag; 54 final boolean mRetainInstance; 55 final Bundle mArguments; 56 57 Bundle mSavedFragmentState; 58 59 Fragment mInstance; 60 61 public FragmentState(Fragment frag) { 62 mClassName = frag.getClass().getName(); 63 mIndex = frag.mIndex; 64 mFromLayout = frag.mFromLayout; 65 mFragmentId = frag.mFragmentId; 66 mContainerId = frag.mContainerId; 67 mTag = frag.mTag; 68 mRetainInstance = frag.mRetainInstance; 69 mArguments = frag.mArguments; 70 } 71 72 public FragmentState(Parcel in) { 73 mClassName = in.readString(); 74 mIndex = in.readInt(); 75 mFromLayout = in.readInt() != 0; 76 mFragmentId = in.readInt(); 77 mContainerId = in.readInt(); 78 mTag = in.readString(); 79 mRetainInstance = in.readInt() != 0; 80 mArguments = in.readBundle(); 81 mSavedFragmentState = in.readBundle(); 82 } 83 84 public Fragment instantiate(Activity activity) { 85 if (mInstance != null) { 86 return mInstance; 87 } 88 89 if (mArguments != null) { 90 mArguments.setClassLoader(activity.getClassLoader()); 91 } 92 93 mInstance = Fragment.instantiate(activity, mClassName, mArguments); 94 95 if (mSavedFragmentState != null) { 96 mSavedFragmentState.setClassLoader(activity.getClassLoader()); 97 mInstance.mSavedFragmentState = mSavedFragmentState; 98 } 99 mInstance.setIndex(mIndex); 100 mInstance.mFromLayout = mFromLayout; 101 mInstance.mRestored = true; 102 mInstance.mFragmentId = mFragmentId; 103 mInstance.mContainerId = mContainerId; 104 mInstance.mTag = mTag; 105 mInstance.mRetainInstance = mRetainInstance; 106 mInstance.mFragmentManager = activity.mFragments; 107 108 return mInstance; 109 } 110 111 public int describeContents() { 112 return 0; 113 } 114 115 public void writeToParcel(Parcel dest, int flags) { 116 dest.writeString(mClassName); 117 dest.writeInt(mIndex); 118 dest.writeInt(mFromLayout ? 1 : 0); 119 dest.writeInt(mFragmentId); 120 dest.writeInt(mContainerId); 121 dest.writeString(mTag); 122 dest.writeInt(mRetainInstance ? 1 : 0); 123 dest.writeBundle(mArguments); 124 dest.writeBundle(mSavedFragmentState); 125 } 126 127 public static final Parcelable.Creator<FragmentState> CREATOR 128 = new Parcelable.Creator<FragmentState>() { 129 public FragmentState createFromParcel(Parcel in) { 130 return new FragmentState(in); 131 } 132 133 public FragmentState[] newArray(int size) { 134 return new FragmentState[size]; 135 } 136 }; 137} 138 139/** 140 * A Fragment is a piece of an application's user interface or behavior 141 * that can be placed in an {@link Activity}. Interaction with fragments 142 * is done through {@link FragmentManager}, which can be obtained via 143 * {@link Activity#getFragmentManager() Activity.getFragmentManager()} and 144 * {@link Fragment#getFragmentManager() Fragment.getFragmentManager()}. 145 * 146 * <p>The Fragment class can be used many ways to achieve a wide variety of 147 * results. It is core, it represents a particular operation or interface 148 * that is running within a larger {@link Activity}. A Fragment is closely 149 * tied to the Activity it is in, and can not be used apart from one. Though 150 * Fragment defines its own lifecycle, that lifecycle is dependent on its 151 * activity: if the activity is stopped, no fragments inside of it can be 152 * started; when the activity is destroyed, all fragments will be destroyed. 153 * 154 * <p>All subclasses of Fragment must include a public empty constructor. 155 * The framework will often re-instantiate a fragment class when needed, 156 * in particular during state restore, and needs to be able to find this 157 * constructor to instantiate it. If the empty constructor is not available, 158 * a runtime exception will occur in some cases during state restore. 159 * 160 * <p>Topics covered here: 161 * <ol> 162 * <li><a href="#Lifecycle">Lifecycle</a> 163 * <li><a href="#Layout">Layout</a> 164 * <li><a href="#BackStack">Back Stack</a> 165 * </ol> 166 * 167 * <a name="Lifecycle"></a> 168 * <h3>Lifecycle</h3> 169 * 170 * <p>Though a Fragment's lifecycle is tied to its owning activity, it has 171 * its own wrinkle on the standard activity lifecycle. It includes basic 172 * activity lifecycle methods such as {@link #onResume}, but also important 173 * are methods related to interactions with the activity and UI generation. 174 * 175 * <p>The core series of lifecycle methods that are called to bring a fragment 176 * up to resumed state (interacting with the user) are: 177 * 178 * <ol> 179 * <li> {@link #onAttach} called once the fragment is associated with its activity. 180 * <li> {@link #onCreate} called to do initial creation of the fragment. 181 * <li> {@link #onCreateView} creates and returns the view hierarchy associated 182 * with the fragment. 183 * <li> {@link #onActivityCreated} tells the fragment that its activity has 184 * completed its own {@link Activity#onCreate Activity.onCreaate}. 185 * <li> {@link #onStart} makes the fragment visible to the user (based on its 186 * containing activity being started). 187 * <li> {@link #onResume} makes the fragment interacting with the user (based on its 188 * containing activity being resumed). 189 * </ol> 190 * 191 * <p>As a fragment is no longer being used, it goes through a reverse 192 * series of callbacks: 193 * 194 * <ol> 195 * <li> {@link #onPause} fragment is no longer interacting with the user either 196 * because its activity is being paused or a fragment operation is modifying it 197 * in the activity. 198 * <li> {@link #onStop} fragment is no longer visible to the user either 199 * because its activity is being stopped or a fragment operation is modifying it 200 * in the activity. 201 * <li> {@link #onDestroyView} allows the fragment to clean up resources 202 * associated with its View. 203 * <li> {@link #onDestroy} called to do final cleanup of the fragment's state. 204 * <li> {@link #onDetach} called immediately prior to the fragment no longer 205 * being associated with its activity. 206 * </ol> 207 * 208 * <a name="Layout"></a> 209 * <h3>Layout</h3> 210 * 211 * <p>Fragments can be used as part of your application's layout, allowing 212 * you to better modularize your code and more easily adjust your user 213 * interface to the screen it is running on. As an example, we can look 214 * at a simple program consisting of a list of items, and display of the 215 * details of each item.</p> 216 * 217 * <p>An activity's layout XML can include <code><fragment></code> tags 218 * to embed fragment instances inside of the layout. For example, here is 219 * a simple layout that embeds one fragment:</p> 220 * 221 * {@sample development/samples/ApiDemos/res/layout/fragment_layout.xml layout} 222 * 223 * <p>The layout is installed in the activity in the normal way:</p> 224 * 225 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 226 * main} 227 * 228 * <p>The titles fragment, showing a list of titles, is fairly simple, relying 229 * on {@link ListFragment} for most of its work. Note the implementation of 230 * clicking an item: depending on the current activity's layout, it can either 231 * create and display a new fragment to show the details in-place (more about 232 * this later), or start a new activity show the details.</p> 233 * 234 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 235 * titles} 236 * 237 * <p>The details fragment showing the contents of selected item here just 238 * displays a string of text based on an index of a string array built in to 239 * the app:</p> 240 * 241 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 242 * details} 243 * 244 * <p>In this case when the user clicks on a title, there is no details 245 * container in the current activity, so the title title fragment's click code will 246 * launch a new activity to display the details fragment:</p> 247 * 248 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java 249 * details_activity} 250 * 251 * <p>However the screen may be large enough to show both the list of titles 252 * and details about the currently selected title. To use such a layout on 253 * a landscape screen, this alternative layout can be placed under layout-land:</p> 254 * 255 * {@sample development/samples/ApiDemos/res/layout-land/fragment_layout.xml layout} 256 * 257 * <p>Note how the prior code will adjust to this alternative UI flow: the titles 258 * fragment will now embed the details fragment inside of this activity, and the 259 * details activity will finish itself if it is running in a configuration 260 * where the details can be shown in-place. 261 * 262 * <p>When a configuration change causes the activity hosting these fragments 263 * to restart, its new instance may use a different layout that doesn't 264 * include the same fragments as the previous layout. In this case all of 265 * the previous fragments will still be instantiated and running in the new 266 * instance. However, any that are no longer associated with a <fragment> 267 * tag in the view hierarchy will not have their content view created 268 * and will return false from {@link #isInLayout}. (The code here also shows 269 * how you can determine if a fragment placed in a container is no longer 270 * running in a layout with that container and avoid creating its view hierarchy 271 * in that case.) 272 * 273 * <p>The attributes of the <fragment> tag are used to control the 274 * LayoutParams provided when attaching the fragment's view to the parent 275 * container. They can also be parsed by the fragment in {@link #onInflate} 276 * as parameters. 277 * 278 * <p>The fragment being instantiated must have some kind of unique identifier 279 * so that it can be re-associated with a previous instance if the parent 280 * activity needs to be destroyed and recreated. This can be provided these 281 * ways: 282 * 283 * <ul> 284 * <li>If nothing is explicitly supplied, the view ID of the container will 285 * be used. 286 * <li><code>android:tag</code> can be used in <fragment> to provide 287 * a specific tag name for the fragment. 288 * <li><code>android:id</code> can be used in <fragment> to provide 289 * a specific identifier for the fragment. 290 * </ul> 291 * 292 * <a name="BackStack"></a> 293 * <h3>Back Stack</h3> 294 * 295 * <p>The transaction in which fragments are modified can be placed on an 296 * internal back-stack of the owning activity. When the user presses back 297 * in the activity, any transactions on the back stack are popped off before 298 * the activity itself is finished. 299 * 300 * <p>For example, consider this simple fragment that is instantiated with 301 * an integer argument and displays that in a TextView in its UI:</p> 302 * 303 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java 304 * fragment} 305 * 306 * <p>A function that creates a new instance of the fragment, replacing 307 * whatever current fragment instance is being shown and pushing that change 308 * on to the back stack could be written as: 309 * 310 * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java 311 * add_stack} 312 * 313 * <p>After each call to this function, a new entry is on the stack, and 314 * pressing back will pop it to return the user to whatever previous state 315 * the activity UI was in. 316 */ 317public class Fragment implements ComponentCallbacks, OnCreateContextMenuListener { 318 private static final HashMap<String, Class<?>> sClassMap = 319 new HashMap<String, Class<?>>(); 320 321 static final int INITIALIZING = 0; // Not yet created. 322 static final int CREATED = 1; // Created. 323 static final int ACTIVITY_CREATED = 2; // The activity has finished its creation. 324 static final int STARTED = 3; // Created and started, not resumed. 325 static final int RESUMED = 4; // Created started and resumed. 326 327 int mState = INITIALIZING; 328 329 // Non-null if the fragment's view hierarchy is currently animating away, 330 // meaning we need to wait a bit on completely destroying it. This is the 331 // animation that is running. 332 Animator mAnimatingAway; 333 334 // If mAnimatingAway != null, this is the state we should move to once the 335 // animation is done. 336 int mStateAfterAnimating; 337 338 // When instantiated from saved state, this is the saved state. 339 Bundle mSavedFragmentState; 340 SparseArray<Parcelable> mSavedViewState; 341 342 // Index into active fragment array. 343 int mIndex = -1; 344 345 // Internal unique name for this fragment; 346 String mWho; 347 348 // Construction arguments; 349 Bundle mArguments; 350 351 // Target fragment. 352 Fragment mTarget; 353 354 // Target request code. 355 int mTargetRequestCode; 356 357 // True if the fragment is in the list of added fragments. 358 boolean mAdded; 359 360 // If set this fragment is being removed from its activity. 361 boolean mRemoving; 362 363 // True if the fragment is in the resumed state. 364 boolean mResumed; 365 366 // Set to true if this fragment was instantiated from a layout file. 367 boolean mFromLayout; 368 369 // Set to true when the view has actually been inflated in its layout. 370 boolean mInLayout; 371 372 // True if this fragment has been restored from previously saved state. 373 boolean mRestored; 374 375 // Number of active back stack entries this fragment is in. 376 int mBackStackNesting; 377 378 // The fragment manager we are associated with. Set as soon as the 379 // fragment is used in a transaction; cleared after it has been removed 380 // from all transactions. 381 FragmentManager mFragmentManager; 382 383 // Set as soon as a fragment is added to a transaction (or removed), 384 // to be able to do validation. 385 Activity mImmediateActivity; 386 387 // Activity this fragment is attached to. 388 Activity mActivity; 389 390 // The optional identifier for this fragment -- either the container ID if it 391 // was dynamically added to the view hierarchy, or the ID supplied in 392 // layout. 393 int mFragmentId; 394 395 // When a fragment is being dynamically added to the view hierarchy, this 396 // is the identifier of the parent container it is being added to. 397 int mContainerId; 398 399 // The optional named tag for this fragment -- usually used to find 400 // fragments that are not part of the layout. 401 String mTag; 402 403 // Set to true when the app has requested that this fragment be hidden 404 // from the user. 405 boolean mHidden; 406 407 // If set this fragment would like its instance retained across 408 // configuration changes. 409 boolean mRetainInstance; 410 411 // If set this fragment is being retained across the current config change. 412 boolean mRetaining; 413 414 // If set this fragment has menu items to contribute. 415 boolean mHasMenu; 416 417 // Used to verify that subclasses call through to super class. 418 boolean mCalled; 419 420 // If app has requested a specific animation, this is the one to use. 421 int mNextAnim; 422 423 // The parent container of the fragment after dynamically added to UI. 424 ViewGroup mContainer; 425 426 // The View generated for this fragment. 427 View mView; 428 429 LoaderManagerImpl mLoaderManager; 430 boolean mLoadersStarted; 431 boolean mCheckedForLoaderManager; 432 433 /** 434 * Thrown by {@link Fragment#instantiate(Context, String, Bundle)} when 435 * there is an instantiation failure. 436 */ 437 static public class InstantiationException extends AndroidRuntimeException { 438 public InstantiationException(String msg, Exception cause) { 439 super(msg, cause); 440 } 441 } 442 443 /** 444 * Default constructor. <strong>Every</strong> fragment must have an 445 * empty constructor, so it can be instantiated when restoring its 446 * activity's state. It is strongly recommended that subclasses do not 447 * have other constructors with parameters, since these constructors 448 * will not be called when the fragment is re-instantiated; instead, 449 * arguments can be supplied by the caller with {@link #setArguments} 450 * and later retrieved by the Fragment with {@link #getArguments}. 451 * 452 * <p>Applications should generally not implement a constructor. The 453 * first place application code an run where the fragment is ready to 454 * be used is in {@link #onAttach(Activity)}, the point where the fragment 455 * is actually associated with its activity. Some applications may also 456 * want to implement {@link #onInflate} to retrieve attributes from a 457 * layout resource, though should take care here because this happens for 458 * the fragment is attached to its activity. 459 */ 460 public Fragment() { 461 } 462 463 /** 464 * Like {@link #instantiate(Context, String, Bundle)} but with a null 465 * argument Bundle. 466 */ 467 public static Fragment instantiate(Context context, String fname) { 468 return instantiate(context, fname, null); 469 } 470 471 /** 472 * Create a new instance of a Fragment with the given class name. This is 473 * the same as calling its empty constructor. 474 * 475 * @param context The calling context being used to instantiate the fragment. 476 * This is currently just used to get its ClassLoader. 477 * @param fname The class name of the fragment to instantiate. 478 * @param args Bundle of arguments to supply to the fragment, which it 479 * can retrieve with {@link #getArguments()}. May be null. 480 * @return Returns a new fragment instance. 481 * @throws InstantiationException If there is a failure in instantiating 482 * the given fragment class. This is a runtime exception; it is not 483 * normally expected to happen. 484 */ 485 public static Fragment instantiate(Context context, String fname, Bundle args) { 486 try { 487 Class<?> clazz = sClassMap.get(fname); 488 if (clazz == null) { 489 // Class not found in the cache, see if it's real, and try to add it 490 clazz = context.getClassLoader().loadClass(fname); 491 sClassMap.put(fname, clazz); 492 } 493 Fragment f = (Fragment)clazz.newInstance(); 494 if (args != null) { 495 args.setClassLoader(f.getClass().getClassLoader()); 496 f.mArguments = args; 497 } 498 return f; 499 } catch (ClassNotFoundException e) { 500 throw new InstantiationException("Unable to instantiate fragment " + fname 501 + ": make sure class name exists, is public, and has an" 502 + " empty constructor that is public", e); 503 } catch (java.lang.InstantiationException e) { 504 throw new InstantiationException("Unable to instantiate fragment " + fname 505 + ": make sure class name exists, is public, and has an" 506 + " empty constructor that is public", e); 507 } catch (IllegalAccessException e) { 508 throw new InstantiationException("Unable to instantiate fragment " + fname 509 + ": make sure class name exists, is public, and has an" 510 + " empty constructor that is public", e); 511 } 512 } 513 514 void restoreViewState() { 515 if (mSavedViewState != null) { 516 mView.restoreHierarchyState(mSavedViewState); 517 mSavedViewState = null; 518 } 519 } 520 521 void setIndex(int index) { 522 mIndex = index; 523 mWho = "android:fragment:" + mIndex; 524 } 525 526 void clearIndex() { 527 mIndex = -1; 528 mWho = null; 529 } 530 531 /** 532 * Subclasses can not override equals(). 533 */ 534 @Override final public boolean equals(Object o) { 535 return super.equals(o); 536 } 537 538 /** 539 * Subclasses can not override hashCode(). 540 */ 541 @Override final public int hashCode() { 542 return super.hashCode(); 543 } 544 545 @Override 546 public String toString() { 547 StringBuilder sb = new StringBuilder(128); 548 DebugUtils.buildShortClassTag(this, sb); 549 if (mIndex >= 0) { 550 sb.append(" #"); 551 sb.append(mIndex); 552 } 553 if (mFragmentId != 0) { 554 sb.append(" id=0x"); 555 sb.append(Integer.toHexString(mFragmentId)); 556 } 557 if (mTag != null) { 558 sb.append(" "); 559 sb.append(mTag); 560 } 561 sb.append('}'); 562 return sb.toString(); 563 } 564 565 /** 566 * Return the identifier this fragment is known by. This is either 567 * the android:id value supplied in a layout or the container view ID 568 * supplied when adding the fragment. 569 */ 570 final public int getId() { 571 return mFragmentId; 572 } 573 574 /** 575 * Get the tag name of the fragment, if specified. 576 */ 577 final public String getTag() { 578 return mTag; 579 } 580 581 /** 582 * Supply the construction arguments for this fragment. This can only 583 * be called before the fragment has been attached to its activity; that 584 * is, you should call it immediately after constructing the fragment. The 585 * arguments supplied here will be retained across fragment destroy and 586 * creation. 587 */ 588 public void setArguments(Bundle args) { 589 if (mIndex >= 0) { 590 throw new IllegalStateException("Fragment already active"); 591 } 592 mArguments = args; 593 } 594 595 /** 596 * Return the arguments supplied when the fragment was instantiated, 597 * if any. 598 */ 599 final public Bundle getArguments() { 600 return mArguments; 601 } 602 603 /** 604 * Optional target for this fragment. This may be used, for example, 605 * if this fragment is being started by another, and when done wants to 606 * give a result back to the first. The target set here is retained 607 * across instances via {@link FragmentManager#putFragment 608 * FragmentManager.putFragment()}. 609 * 610 * @param fragment The fragment that is the target of this one. 611 * @param requestCode Optional request code, for convenience if you 612 * are going to call back with {@link #onActivityResult(int, int, Intent)}. 613 */ 614 public void setTargetFragment(Fragment fragment, int requestCode) { 615 mTarget = fragment; 616 mTargetRequestCode = requestCode; 617 } 618 619 /** 620 * Return the target fragment set by {@link #setTargetFragment}. 621 */ 622 final public Fragment getTargetFragment() { 623 return mTarget; 624 } 625 626 /** 627 * Return the target request code set by {@link #setTargetFragment}. 628 */ 629 final public int getTargetRequestCode() { 630 return mTargetRequestCode; 631 } 632 633 /** 634 * Return the Activity this fragment is currently associated with. 635 */ 636 final public Activity getActivity() { 637 return mActivity; 638 } 639 640 /** 641 * Return <code>getActivity().getResources()</code>. 642 */ 643 final public Resources getResources() { 644 if (mActivity == null) { 645 throw new IllegalStateException("Fragment " + this + " not attached to Activity"); 646 } 647 return mActivity.getResources(); 648 } 649 650 /** 651 * Return a localized, styled CharSequence from the application's package's 652 * default string table. 653 * 654 * @param resId Resource id for the CharSequence text 655 */ 656 public final CharSequence getText(int resId) { 657 return getResources().getText(resId); 658 } 659 660 /** 661 * Return a localized string from the application's package's 662 * default string table. 663 * 664 * @param resId Resource id for the string 665 */ 666 public final String getString(int resId) { 667 return getResources().getString(resId); 668 } 669 670 /** 671 * Return a localized formatted string from the application's package's 672 * default string table, substituting the format arguments as defined in 673 * {@link java.util.Formatter} and {@link java.lang.String#format}. 674 * 675 * @param resId Resource id for the format string 676 * @param formatArgs The format arguments that will be used for substitution. 677 */ 678 679 public final String getString(int resId, Object... formatArgs) { 680 return getResources().getString(resId, formatArgs); 681 } 682 683 /** 684 * Return the FragmentManager for interacting with fragments associated 685 * with this fragment's activity. Note that this will be non-null slightly 686 * before {@link #getActivity()}, during the time from when the fragment is 687 * placed in a {@link FragmentTransaction} until it is committed and 688 * attached to its activity. 689 */ 690 final public FragmentManager getFragmentManager() { 691 return mFragmentManager; 692 } 693 694 /** 695 * Return true if the fragment is currently added to its activity. 696 */ 697 final public boolean isAdded() { 698 return mActivity != null && mAdded; 699 } 700 701 /** 702 * Return true if this fragment is currently being removed from its 703 * activity. This is <em>not</em> whether its activity is finishing, but 704 * rather whether it is in the process of being removed from its activity. 705 */ 706 final public boolean isRemoving() { 707 return mRemoving; 708 } 709 710 /** 711 * Return true if the layout is included as part of an activity view 712 * hierarchy via the <fragment> tag. This will always be true when 713 * fragments are created through the <fragment> tag, <em>except</em> 714 * in the case where an old fragment is restored from a previous state and 715 * it does not appear in the layout of the current state. 716 */ 717 final public boolean isInLayout() { 718 return mInLayout; 719 } 720 721 /** 722 * Return true if the fragment is in the resumed state. This is true 723 * for the duration of {@link #onResume()} and {@link #onPause()} as well. 724 */ 725 final public boolean isResumed() { 726 return mResumed; 727 } 728 729 /** 730 * Return true if the fragment is currently visible to the user. This means 731 * it: (1) has been added, (2) has its view attached to the window, and 732 * (3) is not hidden. 733 */ 734 final public boolean isVisible() { 735 return isAdded() && !isHidden() && mView != null 736 && mView.getWindowToken() != null && mView.getVisibility() == View.VISIBLE; 737 } 738 739 /** 740 * Return true if the fragment has been hidden. By default fragments 741 * are shown. You can find out about changes to this state with 742 * {@link #onHiddenChanged}. Note that the hidden state is orthogonal 743 * to other states -- that is, to be visible to the user, a fragment 744 * must be both started and not hidden. 745 */ 746 final public boolean isHidden() { 747 return mHidden; 748 } 749 750 /** 751 * Called when the hidden state (as returned by {@link #isHidden()} of 752 * the fragment has changed. Fragments start out not hidden; this will 753 * be called whenever the fragment changes state from that. 754 * @param hidden True if the fragment is now hidden, false if it is not 755 * visible. 756 */ 757 public void onHiddenChanged(boolean hidden) { 758 } 759 760 /** 761 * Control whether a fragment instance is retained across Activity 762 * re-creation (such as from a configuration change). This can only 763 * be used with fragments not in the back stack. If set, the fragment 764 * lifecycle will be slightly different when an activity is recreated: 765 * <ul> 766 * <li> {@link #onDestroy()} will not be called (but {@link #onDetach()} still 767 * will be, because the fragment is being detached from its current activity). 768 * <li> {@link #onCreate(Bundle)} will not be called since the fragment 769 * is not being re-created. 770 * <li> {@link #onAttach(Activity)} and {@link #onActivityCreated(Bundle)} <b>will</b> 771 * still be called. 772 * </ul> 773 */ 774 public void setRetainInstance(boolean retain) { 775 mRetainInstance = retain; 776 } 777 778 final public boolean getRetainInstance() { 779 return mRetainInstance; 780 } 781 782 /** 783 * Report that this fragment would like to participate in populating 784 * the options menu by receiving a call to {@link #onCreateOptionsMenu} 785 * and related methods. 786 * 787 * @param hasMenu If true, the fragment has menu items to contribute. 788 */ 789 public void setHasOptionsMenu(boolean hasMenu) { 790 if (mHasMenu != hasMenu) { 791 mHasMenu = hasMenu; 792 if (isAdded() && !isHidden()) { 793 mActivity.invalidateOptionsMenu(); 794 } 795 } 796 } 797 798 /** 799 * Return the LoaderManager for this fragment, creating it if needed. 800 */ 801 public LoaderManager getLoaderManager() { 802 if (mLoaderManager != null) { 803 return mLoaderManager; 804 } 805 if (mActivity == null) { 806 throw new IllegalStateException("Fragment " + this + " not attached to Activity"); 807 } 808 mCheckedForLoaderManager = true; 809 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, true); 810 return mLoaderManager; 811 } 812 813 /** 814 * Call {@link Activity#startActivity(Intent)} on the fragment's 815 * containing Activity. 816 */ 817 public void startActivity(Intent intent) { 818 if (mActivity == null) { 819 throw new IllegalStateException("Fragment " + this + " not attached to Activity"); 820 } 821 mActivity.startActivityFromFragment(this, intent, -1); 822 } 823 824 /** 825 * Call {@link Activity#startActivityForResult(Intent, int)} on the fragment's 826 * containing Activity. 827 */ 828 public void startActivityForResult(Intent intent, int requestCode) { 829 if (mActivity == null) { 830 throw new IllegalStateException("Fragment " + this + " not attached to Activity"); 831 } 832 mActivity.startActivityFromFragment(this, intent, requestCode); 833 } 834 835 /** 836 * Receive the result from a previous call to 837 * {@link #startActivityForResult(Intent, int)}. This follows the 838 * related Activity API as described there in 839 * {@link Activity#onActivityResult(int, int, Intent)}. 840 * 841 * @param requestCode The integer request code originally supplied to 842 * startActivityForResult(), allowing you to identify who this 843 * result came from. 844 * @param resultCode The integer result code returned by the child activity 845 * through its setResult(). 846 * @param data An Intent, which can return result data to the caller 847 * (various data can be attached to Intent "extras"). 848 */ 849 public void onActivityResult(int requestCode, int resultCode, Intent data) { 850 } 851 852 /** 853 * Called when a fragment is being created as part of a view layout 854 * inflation, typically from setting the content view of an activity. This 855 * will be called immediately after the fragment is created from a <fragment> 856 * tag in a layout file. Note this is <em>before</em> the fragment's 857 * {@link #onAttach(Activity)} has been called; all you should do here is 858 * parse the attributes and save them away. A convenient thing to do is 859 * simply copy them into a Bundle that is given to {@link #setArguments(Bundle)}. 860 * 861 * <p>This is called every time the fragment is inflated, even if it is 862 * being inflated into a new instance with saved state. Because a fragment's 863 * arguments are retained across instances, it may make no sense to re-parse 864 * the attributes into new arguments. You may want to first check 865 * {@link #getArguments()} and only parse the attributes if it returns null, 866 * the assumption being that if it is non-null those are the same arguments 867 * from the first time the fragment was inflated. (That said, you may want 868 * to have layouts change for different configurations such as landscape 869 * and portrait, which can have different attributes. If so, you will need 870 * to re-parse the attributes each time this is called to generate new 871 * arguments.)</p> 872 * 873 * @param attrs The attributes at the tag where the fragment is 874 * being created. 875 * @param savedInstanceState If the fragment is being re-created from 876 * a previous saved state, this is the state. 877 */ 878 public void onInflate(AttributeSet attrs, Bundle savedInstanceState) { 879 mCalled = true; 880 } 881 882 /** 883 * Called when a fragment is first attached to its activity. 884 * {@link #onCreate(Bundle)} will be called after this. 885 */ 886 public void onAttach(Activity activity) { 887 mCalled = true; 888 } 889 890 /** 891 * Called when a fragment loads an animation. 892 */ 893 public Animator onCreateAnimator(int transit, boolean enter, int nextAnim) { 894 return null; 895 } 896 897 /** 898 * Called to do initial creation of a fragment. This is called after 899 * {@link #onAttach(Activity)} and before 900 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}. 901 * 902 * <p>Note that this can be called while the fragment's activity is 903 * still in the process of being created. As such, you can not rely 904 * on things like the activity's content view hierarchy being initialized 905 * at this point. If you want to do work once the activity itself is 906 * created, see {@link #onActivityCreated(Bundle)}. 907 * 908 * @param savedInstanceState If the fragment is being re-created from 909 * a previous saved state, this is the state. 910 */ 911 public void onCreate(Bundle savedInstanceState) { 912 mCalled = true; 913 } 914 915 /** 916 * Called to have the fragment instantiate its user interface view. 917 * This is optional, and non-graphical fragments can return null (which 918 * is the default implementation). This will be called between 919 * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}. 920 * 921 * <p>If you return a View from here, you will later be called in 922 * {@link #onDestroyView} when the view is being released. 923 * 924 * @param inflater The LayoutInflater object that can be used to inflate 925 * any views in the fragment, 926 * @param container If non-null, this is the parent view that the fragment's 927 * UI should be attached to. The fragment should not add the view itself, 928 * but this can be used to generate the LayoutParams of the view. 929 * @param savedInstanceState If non-null, this fragment is being re-constructed 930 * from a previous saved state as given here. 931 * 932 * @return Return the View for the fragment's UI, or null. 933 */ 934 public View onCreateView(LayoutInflater inflater, ViewGroup container, 935 Bundle savedInstanceState) { 936 return null; 937 } 938 939 /** 940 * Get the root view for the fragment's layout (the one returned by {@link #onCreateView}), 941 * if provided. 942 * 943 * @return The fragment's root view, or null if it has no layout. 944 */ 945 public View getView() { 946 return mView; 947 } 948 949 /** 950 * Called when the fragment's activity has been created and this 951 * fragment's view hierarchy instantiated. It can be used to do final 952 * initialization once these pieces are in place, such as retrieving 953 * views or restoring state. It is also useful for fragments that use 954 * {@link #setRetainInstance(boolean)} to retain their instance, 955 * as this callback tells the fragment when it is fully associated with 956 * the new activity instance. This is called after {@link #onCreateView} 957 * and before {@link #onStart()}. 958 * 959 * @param savedInstanceState If the fragment is being re-created from 960 * a previous saved state, this is the state. 961 */ 962 public void onActivityCreated(Bundle savedInstanceState) { 963 mCalled = true; 964 } 965 966 /** 967 * Called when the Fragment is visible to the user. This is generally 968 * tied to {@link Activity#onStart() Activity.onStart} of the containing 969 * Activity's lifecycle. 970 */ 971 public void onStart() { 972 mCalled = true; 973 974 if (!mLoadersStarted) { 975 mLoadersStarted = true; 976 if (!mCheckedForLoaderManager) { 977 mCheckedForLoaderManager = true; 978 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 979 } 980 if (mLoaderManager != null) { 981 mLoaderManager.doStart(); 982 } 983 } 984 } 985 986 /** 987 * Called when the fragment is visible to the user and actively running. 988 * This is generally 989 * tied to {@link Activity#onResume() Activity.onResume} of the containing 990 * Activity's lifecycle. 991 */ 992 public void onResume() { 993 mCalled = true; 994 } 995 996 /** 997 * Called to ask the fragment to save its current dynamic state, so it 998 * can later be reconstructed in a new instance of its process is 999 * restarted. If a new instance of the fragment later needs to be 1000 * created, the data you place in the Bundle here will be available 1001 * in the Bundle given to {@link #onCreate(Bundle)}, 1002 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}, and 1003 * {@link #onActivityCreated(Bundle)}. 1004 * 1005 * <p>This corresponds to {@link Activity#onSaveInstanceState(Bundle) 1006 * Activity.onSaveInstanceState(Bundle)} and most of the discussion there 1007 * applies here as well. Note however: <em>this method may be called 1008 * at any time before {@link #onDestroy()}</em>. There are many situations 1009 * where a fragment may be mostly torn down (such as when placed on the 1010 * back stack with no UI showing), but its state will not be saved until 1011 * its owning activity actually needs to save its state. 1012 * 1013 * @param outState Bundle in which to place your saved state. 1014 */ 1015 public void onSaveInstanceState(Bundle outState) { 1016 } 1017 1018 public void onConfigurationChanged(Configuration newConfig) { 1019 mCalled = true; 1020 } 1021 1022 /** 1023 * Called when the Fragment is no longer resumed. This is generally 1024 * tied to {@link Activity#onPause() Activity.onPause} of the containing 1025 * Activity's lifecycle. 1026 */ 1027 public void onPause() { 1028 mCalled = true; 1029 } 1030 1031 /** 1032 * Called when the Fragment is no longer started. This is generally 1033 * tied to {@link Activity#onStop() Activity.onStop} of the containing 1034 * Activity's lifecycle. 1035 */ 1036 public void onStop() { 1037 mCalled = true; 1038 } 1039 1040 public void onLowMemory() { 1041 mCalled = true; 1042 } 1043 1044 /** 1045 * Called when the view previously created by {@link #onCreateView} has 1046 * been detached from the fragment. The next time the fragment needs 1047 * to be displayed, a new view will be created. This is called 1048 * after {@link #onStop()} and before {@link #onDestroy()}. It is called 1049 * <em>regardless</em> of whether {@link #onCreateView} returned a 1050 * non-null view. Internally it is called after the view's state has 1051 * been saved but before it has been removed from its parent. 1052 */ 1053 public void onDestroyView() { 1054 mCalled = true; 1055 } 1056 1057 /** 1058 * Called when the fragment is no longer in use. This is called 1059 * after {@link #onStop()} and before {@link #onDetach()}. 1060 */ 1061 public void onDestroy() { 1062 mCalled = true; 1063 //Log.v("foo", "onDestroy: mCheckedForLoaderManager=" + mCheckedForLoaderManager 1064 // + " mLoaderManager=" + mLoaderManager); 1065 if (!mCheckedForLoaderManager) { 1066 mCheckedForLoaderManager = true; 1067 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1068 } 1069 if (mLoaderManager != null) { 1070 mLoaderManager.doDestroy(); 1071 } 1072 } 1073 1074 /** 1075 * Called when the fragment is no longer attached to its activity. This 1076 * is called after {@link #onDestroy()}. 1077 */ 1078 public void onDetach() { 1079 mCalled = true; 1080 } 1081 1082 /** 1083 * Initialize the contents of the Activity's standard options menu. You 1084 * should place your menu items in to <var>menu</var>. For this method 1085 * to be called, you must have first called {@link #setHasOptionsMenu}. See 1086 * {@link Activity#onCreateOptionsMenu(Menu) Activity.onCreateOptionsMenu} 1087 * for more information. 1088 * 1089 * @param menu The options menu in which you place your items. 1090 * 1091 * @see #setHasOptionsMenu 1092 * @see #onPrepareOptionsMenu 1093 * @see #onOptionsItemSelected 1094 */ 1095 public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 1096 } 1097 1098 /** 1099 * Prepare the Screen's standard options menu to be displayed. This is 1100 * called right before the menu is shown, every time it is shown. You can 1101 * use this method to efficiently enable/disable items or otherwise 1102 * dynamically modify the contents. See 1103 * {@link Activity#onPrepareOptionsMenu(Menu) Activity.onPrepareOptionsMenu} 1104 * for more information. 1105 * 1106 * @param menu The options menu as last shown or first initialized by 1107 * onCreateOptionsMenu(). 1108 * 1109 * @see #setHasOptionsMenu 1110 * @see #onCreateOptionsMenu 1111 */ 1112 public void onPrepareOptionsMenu(Menu menu) { 1113 } 1114 1115 /** 1116 * Called when this fragment's option menu items are no longer being 1117 * included in the overall options menu. Receiving this call means that 1118 * the menu needed to be rebuilt, but this fragment's items were not 1119 * included in the newly built menu (its {@link #onCreateOptionsMenu(Menu, MenuInflater)} 1120 * was not called). 1121 */ 1122 public void onDestroyOptionsMenu() { 1123 } 1124 1125 /** 1126 * This hook is called whenever an item in your options menu is selected. 1127 * The default implementation simply returns false to have the normal 1128 * processing happen (calling the item's Runnable or sending a message to 1129 * its Handler as appropriate). You can use this method for any items 1130 * for which you would like to do processing without those other 1131 * facilities. 1132 * 1133 * <p>Derived classes should call through to the base class for it to 1134 * perform the default menu handling. 1135 * 1136 * @param item The menu item that was selected. 1137 * 1138 * @return boolean Return false to allow normal menu processing to 1139 * proceed, true to consume it here. 1140 * 1141 * @see #onCreateOptionsMenu 1142 */ 1143 public boolean onOptionsItemSelected(MenuItem item) { 1144 return false; 1145 } 1146 1147 /** 1148 * This hook is called whenever the options menu is being closed (either by the user canceling 1149 * the menu with the back/menu button, or when an item is selected). 1150 * 1151 * @param menu The options menu as last shown or first initialized by 1152 * onCreateOptionsMenu(). 1153 */ 1154 public void onOptionsMenuClosed(Menu menu) { 1155 } 1156 1157 /** 1158 * Called when a context menu for the {@code view} is about to be shown. 1159 * Unlike {@link #onCreateOptionsMenu}, this will be called every 1160 * time the context menu is about to be shown and should be populated for 1161 * the view (or item inside the view for {@link AdapterView} subclasses, 1162 * this can be found in the {@code menuInfo})). 1163 * <p> 1164 * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an 1165 * item has been selected. 1166 * <p> 1167 * The default implementation calls up to 1168 * {@link Activity#onCreateContextMenu Activity.onCreateContextMenu}, though 1169 * you can not call this implementation if you don't want that behavior. 1170 * <p> 1171 * It is not safe to hold onto the context menu after this method returns. 1172 * {@inheritDoc} 1173 */ 1174 public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { 1175 getActivity().onCreateContextMenu(menu, v, menuInfo); 1176 } 1177 1178 /** 1179 * Registers a context menu to be shown for the given view (multiple views 1180 * can show the context menu). This method will set the 1181 * {@link OnCreateContextMenuListener} on the view to this fragment, so 1182 * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be 1183 * called when it is time to show the context menu. 1184 * 1185 * @see #unregisterForContextMenu(View) 1186 * @param view The view that should show a context menu. 1187 */ 1188 public void registerForContextMenu(View view) { 1189 view.setOnCreateContextMenuListener(this); 1190 } 1191 1192 /** 1193 * Prevents a context menu to be shown for the given view. This method will 1194 * remove the {@link OnCreateContextMenuListener} on the view. 1195 * 1196 * @see #registerForContextMenu(View) 1197 * @param view The view that should stop showing a context menu. 1198 */ 1199 public void unregisterForContextMenu(View view) { 1200 view.setOnCreateContextMenuListener(null); 1201 } 1202 1203 /** 1204 * This hook is called whenever an item in a context menu is selected. The 1205 * default implementation simply returns false to have the normal processing 1206 * happen (calling the item's Runnable or sending a message to its Handler 1207 * as appropriate). You can use this method for any items for which you 1208 * would like to do processing without those other facilities. 1209 * <p> 1210 * Use {@link MenuItem#getMenuInfo()} to get extra information set by the 1211 * View that added this menu item. 1212 * <p> 1213 * Derived classes should call through to the base class for it to perform 1214 * the default menu handling. 1215 * 1216 * @param item The context menu item that was selected. 1217 * @return boolean Return false to allow normal context menu processing to 1218 * proceed, true to consume it here. 1219 */ 1220 public boolean onContextItemSelected(MenuItem item) { 1221 return false; 1222 } 1223 1224 /** 1225 * Print the Fragments's state into the given stream. 1226 * 1227 * @param prefix Text to print at the front of each line. 1228 * @param fd The raw file descriptor that the dump is being sent to. 1229 * @param writer The PrintWriter to which you should dump your state. This will be 1230 * closed for you after you return. 1231 * @param args additional arguments to the dump request. 1232 */ 1233 public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { 1234 writer.print(prefix); writer.print("mFragmentId=#"); 1235 writer.print(Integer.toHexString(mFragmentId)); 1236 writer.print(" mContainerId#="); 1237 writer.print(Integer.toHexString(mContainerId)); 1238 writer.print(" mTag="); writer.println(mTag); 1239 writer.print(prefix); writer.print("mState="); writer.print(mState); 1240 writer.print(" mIndex="); writer.print(mIndex); 1241 writer.print(" mWho="); writer.print(mWho); 1242 writer.print(" mBackStackNesting="); writer.println(mBackStackNesting); 1243 writer.print(prefix); writer.print("mAdded="); writer.print(mAdded); 1244 writer.print(" mRemoving="); writer.print(mRemoving); 1245 writer.print(" mResumed="); writer.print(mResumed); 1246 writer.print(" mFromLayout="); writer.print(mFromLayout); 1247 writer.print(" mInLayout="); writer.println(mInLayout); 1248 writer.print(prefix); writer.print("mHidden="); writer.print(mHidden); 1249 writer.print(" mRetainInstance="); writer.print(mRetainInstance); 1250 writer.print(" mRetaining="); writer.print(mRetaining); 1251 writer.print(" mHasMenu="); writer.println(mHasMenu); 1252 if (mFragmentManager != null) { 1253 writer.print(prefix); writer.print("mFragmentManager="); 1254 writer.println(mFragmentManager); 1255 } 1256 if (mImmediateActivity != null) { 1257 writer.print(prefix); writer.print("mImmediateActivity="); 1258 writer.println(mImmediateActivity); 1259 } 1260 if (mActivity != null) { 1261 writer.print(prefix); writer.print("mActivity="); 1262 writer.println(mActivity); 1263 } 1264 if (mArguments != null) { 1265 writer.print(prefix); writer.print("mArguments="); writer.println(mArguments); 1266 } 1267 if (mSavedFragmentState != null) { 1268 writer.print(prefix); writer.print("mSavedFragmentState="); 1269 writer.println(mSavedFragmentState); 1270 } 1271 if (mSavedViewState != null) { 1272 writer.print(prefix); writer.print("mSavedViewState="); 1273 writer.println(mSavedViewState); 1274 } 1275 if (mTarget != null) { 1276 writer.print(prefix); writer.print("mTarget="); writer.print(mTarget); 1277 writer.print(" mTargetRequestCode="); 1278 writer.println(mTargetRequestCode); 1279 } 1280 if (mNextAnim != 0) { 1281 writer.print(prefix); writer.print("mNextAnim="); writer.println(mNextAnim); 1282 } 1283 if (mContainer != null) { 1284 writer.print(prefix); writer.print("mContainer="); writer.println(mContainer); 1285 } 1286 if (mView != null) { 1287 writer.print(prefix); writer.print("mView="); writer.println(mView); 1288 } 1289 if (mAnimatingAway != null) { 1290 writer.print(prefix); writer.print("mAnimatingAway="); writer.println(mAnimatingAway); 1291 writer.print(prefix); writer.print("mStateAfterAnimating="); 1292 writer.println(mStateAfterAnimating); 1293 } 1294 if (mLoaderManager != null) { 1295 writer.print(prefix); writer.println("Loader Manager:"); 1296 mLoaderManager.dump(prefix + " ", fd, writer, args); 1297 } 1298 } 1299 1300 void performStop() { 1301 onStop(); 1302 1303 if (mLoadersStarted) { 1304 mLoadersStarted = false; 1305 if (!mCheckedForLoaderManager) { 1306 mCheckedForLoaderManager = true; 1307 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1308 } 1309 if (mLoaderManager != null) { 1310 if (mActivity == null || !mActivity.mChangingConfigurations) { 1311 mLoaderManager.doStop(); 1312 } else { 1313 mLoaderManager.doRetain(); 1314 } 1315 } 1316 } 1317 } 1318} 1319