Fragment.java revision d2835935d2df8be70d1b37d3ef3b2fe0155b3422
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 String simpleName = getClass().getSimpleName(); 530 if (simpleName == null || simpleName.isEmpty()) { 531 simpleName = getClass().getName(); 532 int end = simpleName.lastIndexOf('.'); 533 if (end > 0) { 534 simpleName = simpleName.substring(end+1); 535 } 536 } 537 sb.append(simpleName); 538 sb.append("{"); 539 sb.append(Integer.toHexString(System.identityHashCode(this))); 540 if (mIndex >= 0) { 541 sb.append(" #"); 542 sb.append(mIndex); 543 } 544 if (mFragmentId != 0) { 545 sb.append(" id=0x"); 546 sb.append(Integer.toHexString(mFragmentId)); 547 } 548 if (mTag != null) { 549 sb.append(" "); 550 sb.append(mTag); 551 } 552 sb.append('}'); 553 return sb.toString(); 554 } 555 556 /** 557 * Return the identifier this fragment is known by. This is either 558 * the android:id value supplied in a layout or the container view ID 559 * supplied when adding the fragment. 560 */ 561 final public int getId() { 562 return mFragmentId; 563 } 564 565 /** 566 * Get the tag name of the fragment, if specified. 567 */ 568 final public String getTag() { 569 return mTag; 570 } 571 572 /** 573 * Supply the construction arguments for this fragment. This can only 574 * be called before the fragment has been attached to its activity; that 575 * is, you should call it immediately after constructing the fragment. The 576 * arguments supplied here will be retained across fragment destroy and 577 * creation. 578 */ 579 public void setArguments(Bundle args) { 580 if (mIndex >= 0) { 581 throw new IllegalStateException("Fragment already active"); 582 } 583 mArguments = args; 584 } 585 586 /** 587 * Return the arguments supplied when the fragment was instantiated, 588 * if any. 589 */ 590 final public Bundle getArguments() { 591 return mArguments; 592 } 593 594 /** 595 * Optional target for this fragment. This may be used, for example, 596 * if this fragment is being started by another, and when done wants to 597 * give a result back to the first. The target set here is retained 598 * across instances via {@link FragmentManager#putFragment 599 * FragmentManager.putFragment()}. 600 * 601 * @param fragment The fragment that is the target of this one. 602 * @param requestCode Optional request code, for convenience if you 603 * are going to call back with {@link #onActivityResult(int, int, Intent)}. 604 */ 605 public void setTargetFragment(Fragment fragment, int requestCode) { 606 mTarget = fragment; 607 mTargetRequestCode = requestCode; 608 } 609 610 /** 611 * Return the target fragment set by {@link #setTargetFragment}. 612 */ 613 final public Fragment getTargetFragment() { 614 return mTarget; 615 } 616 617 /** 618 * Return the target request code set by {@link #setTargetFragment}. 619 */ 620 final public int getTargetRequestCode() { 621 return mTargetRequestCode; 622 } 623 624 /** 625 * Return the Activity this fragment is currently associated with. 626 */ 627 final public Activity getActivity() { 628 return mActivity; 629 } 630 631 /** 632 * Return <code>getActivity().getResources()</code>. 633 */ 634 final public Resources getResources() { 635 return mActivity.getResources(); 636 } 637 638 /** 639 * Return a localized, styled CharSequence from the application's package's 640 * default string table. 641 * 642 * @param resId Resource id for the CharSequence text 643 */ 644 public final CharSequence getText(int resId) { 645 return getResources().getText(resId); 646 } 647 648 /** 649 * Return a localized string from the application's package's 650 * default string table. 651 * 652 * @param resId Resource id for the string 653 */ 654 public final String getString(int resId) { 655 return getResources().getString(resId); 656 } 657 658 /** 659 * Return a localized formatted string from the application's package's 660 * default string table, substituting the format arguments as defined in 661 * {@link java.util.Formatter} and {@link java.lang.String#format}. 662 * 663 * @param resId Resource id for the format string 664 * @param formatArgs The format arguments that will be used for substitution. 665 */ 666 667 public final String getString(int resId, Object... formatArgs) { 668 return getResources().getString(resId, formatArgs); 669 } 670 671 /** 672 * Return the FragmentManager for interacting with fragments associated 673 * with this fragment's activity. Note that this will be non-null slightly 674 * before {@link #getActivity()}, during the time from when the fragment is 675 * placed in a {@link FragmentTransaction} until it is committed and 676 * attached to its activity. 677 */ 678 final public FragmentManager getFragmentManager() { 679 return mFragmentManager; 680 } 681 682 /** 683 * Return true if the fragment is currently added to its activity. 684 */ 685 final public boolean isAdded() { 686 return mActivity != null && mActivity.mFragments.mAdded.contains(this); 687 } 688 689 /** 690 * Return true if the layout is included as part of an activity view 691 * hierarchy via the <fragment> tag. This will always be true when 692 * fragments are created through the <fragment> tag, <em>except</em> 693 * in the case where an old fragment is restored from a previous state and 694 * it does not appear in the layout of the current state. 695 */ 696 final public boolean isInLayout() { 697 return mInLayout; 698 } 699 700 /** 701 * Return true if the fragment is in the resumed state. This is true 702 * for the duration of {@link #onResume()} and {@link #onPause()} as well. 703 */ 704 final public boolean isResumed() { 705 return mResumed; 706 } 707 708 /** 709 * Return true if the fragment is currently visible to the user. This means 710 * it: (1) has been added, (2) has its view attached to the window, and 711 * (3) is not hidden. 712 */ 713 final public boolean isVisible() { 714 return isAdded() && !isHidden() && mView != null 715 && mView.getWindowToken() != null && mView.getVisibility() == View.VISIBLE; 716 } 717 718 /** 719 * Return true if the fragment has been hidden. By default fragments 720 * are shown. You can find out about changes to this state with 721 * {@link #onHiddenChanged}. Note that the hidden state is orthogonal 722 * to other states -- that is, to be visible to the user, a fragment 723 * must be both started and not hidden. 724 */ 725 final public boolean isHidden() { 726 return mHidden; 727 } 728 729 /** 730 * Called when the hidden state (as returned by {@link #isHidden()} of 731 * the fragment has changed. Fragments start out not hidden; this will 732 * be called whenever the fragment changes state from that. 733 * @param hidden True if the fragment is now hidden, false if it is not 734 * visible. 735 */ 736 public void onHiddenChanged(boolean hidden) { 737 } 738 739 /** 740 * Control whether a fragment instance is retained across Activity 741 * re-creation (such as from a configuration change). This can only 742 * be used with fragments not in the back stack. If set, the fragment 743 * lifecycle will be slightly different when an activity is recreated: 744 * <ul> 745 * <li> {@link #onDestroy()} will not be called (but {@link #onDetach()} still 746 * will be, because the fragment is being detached from its current activity). 747 * <li> {@link #onCreate(Bundle)} will not be called since the fragment 748 * is not being re-created. 749 * <li> {@link #onAttach(Activity)} and {@link #onActivityCreated(Bundle)} <b>will</b> 750 * still be called. 751 * </ul> 752 */ 753 public void setRetainInstance(boolean retain) { 754 mRetainInstance = retain; 755 } 756 757 final public boolean getRetainInstance() { 758 return mRetainInstance; 759 } 760 761 /** 762 * Report that this fragment would like to participate in populating 763 * the options menu by receiving a call to {@link #onCreateOptionsMenu} 764 * and related methods. 765 * 766 * @param hasMenu If true, the fragment has menu items to contribute. 767 */ 768 public void setHasOptionsMenu(boolean hasMenu) { 769 if (mHasMenu != hasMenu) { 770 mHasMenu = hasMenu; 771 if (isAdded() && !isHidden()) { 772 mActivity.invalidateOptionsMenu(); 773 } 774 } 775 } 776 777 /** 778 * Return the LoaderManager for this fragment, creating it if needed. 779 */ 780 public LoaderManager getLoaderManager() { 781 if (mLoaderManager != null) { 782 return mLoaderManager; 783 } 784 mCheckedForLoaderManager = true; 785 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, true); 786 return mLoaderManager; 787 } 788 789 /** 790 * Call {@link Activity#startActivity(Intent)} on the fragment's 791 * containing Activity. 792 */ 793 public void startActivity(Intent intent) { 794 mActivity.startActivityFromFragment(this, intent, -1); 795 } 796 797 /** 798 * Call {@link Activity#startActivityForResult(Intent, int)} on the fragment's 799 * containing Activity. 800 */ 801 public void startActivityForResult(Intent intent, int requestCode) { 802 mActivity.startActivityFromFragment(this, intent, requestCode); 803 } 804 805 /** 806 * Receive the result from a previous call to 807 * {@link #startActivityForResult(Intent, int)}. This follows the 808 * related Activity API as described there in 809 * {@link Activity#onActivityResult(int, int, Intent)}. 810 * 811 * @param requestCode The integer request code originally supplied to 812 * startActivityForResult(), allowing you to identify who this 813 * result came from. 814 * @param resultCode The integer result code returned by the child activity 815 * through its setResult(). 816 * @param data An Intent, which can return result data to the caller 817 * (various data can be attached to Intent "extras"). 818 */ 819 public void onActivityResult(int requestCode, int resultCode, Intent data) { 820 } 821 822 /** 823 * Called when a fragment is being created as part of a view layout 824 * inflation, typically from setting the content view of an activity. This 825 * will be called immediately after the fragment is created from a <fragment> 826 * tag in a layout file. Note this is <em>before</em> the fragment's 827 * {@link #onAttach(Activity)} has been called; all you should do here is 828 * parse the attributes and save them away. A convenient thing to do is 829 * simply copy them into a Bundle that is given to {@link #setArguments(Bundle)}. 830 * 831 * <p>This is called every time the fragment is inflated, even if it is 832 * being inflated into a new instance with saved state. Because a fragment's 833 * arguments are retained across instances, it may make no sense to re-parse 834 * the attributes into new arguments. You may want to first check 835 * {@link #getArguments()} and only parse the attributes if it returns null, 836 * the assumption being that if it is non-null those are the same arguments 837 * from the first time the fragment was inflated. (That said, you may want 838 * to have layouts change for different configurations such as landscape 839 * and portrait, which can have different attributes. If so, you will need 840 * to re-parse the attributes each time this is called to generate new 841 * arguments.)</p> 842 * 843 * @param attrs The attributes at the tag where the fragment is 844 * being created. 845 * @param savedInstanceState If the fragment is being re-created from 846 * a previous saved state, this is the state. 847 */ 848 public void onInflate(AttributeSet attrs, Bundle savedInstanceState) { 849 mCalled = true; 850 } 851 852 /** 853 * Called when a fragment is first attached to its activity. 854 * {@link #onCreate(Bundle)} will be called after this. 855 */ 856 public void onAttach(Activity activity) { 857 mCalled = true; 858 } 859 860 /** 861 * Called when a fragment loads an animation. 862 */ 863 public Animator onCreateAnimator(int transit, boolean enter, int nextAnim) { 864 return null; 865 } 866 867 /** 868 * Called to do initial creation of a fragment. This is called after 869 * {@link #onAttach(Activity)} and before 870 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}. 871 * 872 * <p>Note that this can be called while the fragment's activity is 873 * still in the process of being created. As such, you can not rely 874 * on things like the activity's content view hierarchy being initialized 875 * at this point. If you want to do work once the activity itself is 876 * created, see {@link #onActivityCreated(Bundle)}. 877 * 878 * @param savedInstanceState If the fragment is being re-created from 879 * a previous saved state, this is the state. 880 */ 881 public void onCreate(Bundle savedInstanceState) { 882 mCalled = true; 883 } 884 885 /** 886 * Called to have the fragment instantiate its user interface view. 887 * This is optional, and non-graphical fragments can return null (which 888 * is the default implementation). This will be called between 889 * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}. 890 * 891 * <p>If you return a View from here, you will later be called in 892 * {@link #onDestroyView} when the view is being released. 893 * 894 * @param inflater The LayoutInflater object that can be used to inflate 895 * any views in the fragment, 896 * @param container If non-null, this is the parent view that the fragment's 897 * UI should be attached to. The fragment should not add the view itself, 898 * but this can be used to generate the LayoutParams of the view. 899 * @param savedInstanceState If non-null, this fragment is being re-constructed 900 * from a previous saved state as given here. 901 * 902 * @return Return the View for the fragment's UI, or null. 903 */ 904 public View onCreateView(LayoutInflater inflater, ViewGroup container, 905 Bundle savedInstanceState) { 906 return null; 907 } 908 909 public View getView() { 910 return mView; 911 } 912 913 /** 914 * Called when the fragment's activity has been created and this 915 * fragment's view hierarchy instantiated. It can be used to do final 916 * initialization once these pieces are in place, such as retrieving 917 * views or restoring state. It is also useful for fragments that use 918 * {@link #setRetainInstance(boolean)} to retain their instance, 919 * as this callback tells the fragment when it is fully associated with 920 * the new activity instance. This is called after {@link #onCreateView} 921 * and before {@link #onStart()}. 922 * 923 * @param savedInstanceState If the fragment is being re-created from 924 * a previous saved state, this is the state. 925 */ 926 public void onActivityCreated(Bundle savedInstanceState) { 927 mCalled = true; 928 } 929 930 /** 931 * Called when the Fragment is visible to the user. This is generally 932 * tied to {@link Activity#onStart() Activity.onStart} of the containing 933 * Activity's lifecycle. 934 */ 935 public void onStart() { 936 mCalled = true; 937 938 if (!mLoadersStarted) { 939 mLoadersStarted = true; 940 if (!mCheckedForLoaderManager) { 941 mCheckedForLoaderManager = true; 942 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 943 } 944 if (mLoaderManager != null) { 945 mLoaderManager.doStart(); 946 } 947 } 948 } 949 950 /** 951 * Called when the fragment is visible to the user and actively running. 952 * This is generally 953 * tied to {@link Activity#onResume() Activity.onResume} of the containing 954 * Activity's lifecycle. 955 */ 956 public void onResume() { 957 mCalled = true; 958 } 959 960 /** 961 * Called to ask the fragment to save its current dynamic state, so it 962 * can later be reconstructed in a new instance of its process is 963 * restarted. If a new instance of the fragment later needs to be 964 * created, the data you place in the Bundle here will be available 965 * in the Bundle given to {@link #onCreate(Bundle)}, 966 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}, and 967 * {@link #onActivityCreated(Bundle)}. 968 * 969 * <p>This corresponds to {@link Activity#onSaveInstanceState(Bundle) 970 * Activity.onSaveInstanceState(Bundle)} and most of the discussion there 971 * applies here as well. Note however: <em>this method may be called 972 * at any time before {@link #onDestroy()}</em>. There are many situations 973 * where a fragment may be mostly torn down (such as when placed on the 974 * back stack with no UI showing), but its state will not be saved until 975 * its owning activity actually needs to save its state. 976 * 977 * @param outState Bundle in which to place your saved state. 978 */ 979 public void onSaveInstanceState(Bundle outState) { 980 } 981 982 public void onConfigurationChanged(Configuration newConfig) { 983 mCalled = true; 984 } 985 986 /** 987 * Called when the Fragment is no longer resumed. This is generally 988 * tied to {@link Activity#onPause() Activity.onPause} of the containing 989 * Activity's lifecycle. 990 */ 991 public void onPause() { 992 mCalled = true; 993 } 994 995 /** 996 * Called when the Fragment is no longer started. This is generally 997 * tied to {@link Activity#onStop() Activity.onStop} of the containing 998 * Activity's lifecycle. 999 */ 1000 public void onStop() { 1001 mCalled = true; 1002 } 1003 1004 public void onLowMemory() { 1005 mCalled = true; 1006 } 1007 1008 /** 1009 * Called when the view previously created by {@link #onCreateView} has 1010 * been detached from the fragment. The next time the fragment needs 1011 * to be displayed, a new view will be created. This is called 1012 * after {@link #onStop()} and before {@link #onDestroy()}. It is called 1013 * <em>regardless</em> of whether {@link #onCreateView} returned a 1014 * non-null view. Internally it is called after the view's state has 1015 * been saved but before it has been removed from its parent. 1016 */ 1017 public void onDestroyView() { 1018 mCalled = true; 1019 } 1020 1021 /** 1022 * Called when the fragment is no longer in use. This is called 1023 * after {@link #onStop()} and before {@link #onDetach()}. 1024 */ 1025 public void onDestroy() { 1026 mCalled = true; 1027 //Log.v("foo", "onDestroy: mCheckedForLoaderManager=" + mCheckedForLoaderManager 1028 // + " mLoaderManager=" + mLoaderManager); 1029 if (!mCheckedForLoaderManager) { 1030 mCheckedForLoaderManager = true; 1031 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1032 } 1033 if (mLoaderManager != null) { 1034 mLoaderManager.doDestroy(); 1035 } 1036 } 1037 1038 /** 1039 * Called when the fragment is no longer attached to its activity. This 1040 * is called after {@link #onDestroy()}. 1041 */ 1042 public void onDetach() { 1043 mCalled = true; 1044 } 1045 1046 /** 1047 * Initialize the contents of the Activity's standard options menu. You 1048 * should place your menu items in to <var>menu</var>. For this method 1049 * to be called, you must have first called {@link #setHasOptionsMenu}. See 1050 * {@link Activity#onCreateOptionsMenu(Menu) Activity.onCreateOptionsMenu} 1051 * for more information. 1052 * 1053 * @param menu The options menu in which you place your items. 1054 * 1055 * @see #setHasOptionsMenu 1056 * @see #onPrepareOptionsMenu 1057 * @see #onOptionsItemSelected 1058 */ 1059 public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 1060 } 1061 1062 /** 1063 * Prepare the Screen's standard options menu to be displayed. This is 1064 * called right before the menu is shown, every time it is shown. You can 1065 * use this method to efficiently enable/disable items or otherwise 1066 * dynamically modify the contents. See 1067 * {@link Activity#onPrepareOptionsMenu(Menu) Activity.onPrepareOptionsMenu} 1068 * for more information. 1069 * 1070 * @param menu The options menu as last shown or first initialized by 1071 * onCreateOptionsMenu(). 1072 * 1073 * @see #setHasOptionsMenu 1074 * @see #onCreateOptionsMenu 1075 */ 1076 public void onPrepareOptionsMenu(Menu menu) { 1077 } 1078 1079 /** 1080 * Called when this fragment's option menu items are no longer being 1081 * included in the overall options menu. Receiving this call means that 1082 * the menu needed to be rebuilt, but this fragment's items were not 1083 * included in the newly built menu (its {@link #onCreateOptionsMenu(Menu, MenuInflater)} 1084 * was not called). 1085 */ 1086 public void onDestroyOptionsMenu() { 1087 } 1088 1089 /** 1090 * This hook is called whenever an item in your options menu is selected. 1091 * The default implementation simply returns false to have the normal 1092 * processing happen (calling the item's Runnable or sending a message to 1093 * its Handler as appropriate). You can use this method for any items 1094 * for which you would like to do processing without those other 1095 * facilities. 1096 * 1097 * <p>Derived classes should call through to the base class for it to 1098 * perform the default menu handling. 1099 * 1100 * @param item The menu item that was selected. 1101 * 1102 * @return boolean Return false to allow normal menu processing to 1103 * proceed, true to consume it here. 1104 * 1105 * @see #onCreateOptionsMenu 1106 */ 1107 public boolean onOptionsItemSelected(MenuItem item) { 1108 return false; 1109 } 1110 1111 /** 1112 * This hook is called whenever the options menu is being closed (either by the user canceling 1113 * the menu with the back/menu button, or when an item is selected). 1114 * 1115 * @param menu The options menu as last shown or first initialized by 1116 * onCreateOptionsMenu(). 1117 */ 1118 public void onOptionsMenuClosed(Menu menu) { 1119 } 1120 1121 /** 1122 * Called when a context menu for the {@code view} is about to be shown. 1123 * Unlike {@link #onCreateOptionsMenu}, this will be called every 1124 * time the context menu is about to be shown and should be populated for 1125 * the view (or item inside the view for {@link AdapterView} subclasses, 1126 * this can be found in the {@code menuInfo})). 1127 * <p> 1128 * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an 1129 * item has been selected. 1130 * <p> 1131 * The default implementation calls up to 1132 * {@link Activity#onCreateContextMenu Activity.onCreateContextMenu}, though 1133 * you can not call this implementation if you don't want that behavior. 1134 * <p> 1135 * It is not safe to hold onto the context menu after this method returns. 1136 * {@inheritDoc} 1137 */ 1138 public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { 1139 getActivity().onCreateContextMenu(menu, v, menuInfo); 1140 } 1141 1142 /** 1143 * Registers a context menu to be shown for the given view (multiple views 1144 * can show the context menu). This method will set the 1145 * {@link OnCreateContextMenuListener} on the view to this fragment, so 1146 * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be 1147 * called when it is time to show the context menu. 1148 * 1149 * @see #unregisterForContextMenu(View) 1150 * @param view The view that should show a context menu. 1151 */ 1152 public void registerForContextMenu(View view) { 1153 view.setOnCreateContextMenuListener(this); 1154 } 1155 1156 /** 1157 * Prevents a context menu to be shown for the given view. This method will 1158 * remove the {@link OnCreateContextMenuListener} on the view. 1159 * 1160 * @see #registerForContextMenu(View) 1161 * @param view The view that should stop showing a context menu. 1162 */ 1163 public void unregisterForContextMenu(View view) { 1164 view.setOnCreateContextMenuListener(null); 1165 } 1166 1167 /** 1168 * This hook is called whenever an item in a context menu is selected. The 1169 * default implementation simply returns false to have the normal processing 1170 * happen (calling the item's Runnable or sending a message to its Handler 1171 * as appropriate). You can use this method for any items for which you 1172 * would like to do processing without those other facilities. 1173 * <p> 1174 * Use {@link MenuItem#getMenuInfo()} to get extra information set by the 1175 * View that added this menu item. 1176 * <p> 1177 * Derived classes should call through to the base class for it to perform 1178 * the default menu handling. 1179 * 1180 * @param item The context menu item that was selected. 1181 * @return boolean Return false to allow normal context menu processing to 1182 * proceed, true to consume it here. 1183 */ 1184 public boolean onContextItemSelected(MenuItem item) { 1185 return false; 1186 } 1187 1188 /** 1189 * Print the Fragments's state into the given stream. 1190 * 1191 * @param prefix Text to print at the front of each line. 1192 * @param fd The raw file descriptor that the dump is being sent to. 1193 * @param writer The PrintWriter to which you should dump your state. This will be 1194 * closed for you after you return. 1195 * @param args additional arguments to the dump request. 1196 */ 1197 public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) { 1198 writer.print(prefix); writer.print("mFragmentId=#"); 1199 writer.print(Integer.toHexString(mFragmentId)); 1200 writer.print(" mContainerId#="); 1201 writer.print(Integer.toHexString(mContainerId)); 1202 writer.print(" mTag="); writer.println(mTag); 1203 writer.print(prefix); writer.print("mState="); writer.print(mState); 1204 writer.print(" mIndex="); writer.print(mIndex); 1205 writer.print(" mWho="); writer.print(mWho); 1206 writer.print(" mBackStackNesting="); writer.println(mBackStackNesting); 1207 writer.print(prefix); writer.print("mAdded="); writer.print(mAdded); 1208 writer.print(" mResumed="); writer.print(mResumed); 1209 writer.print(" mFromLayout="); writer.print(mFromLayout); 1210 writer.print(" mInLayout="); writer.println(mInLayout); 1211 writer.print(prefix); writer.print("mHidden="); writer.print(mHidden); 1212 writer.print(" mRetainInstance="); writer.print(mRetainInstance); 1213 writer.print(" mRetaining="); writer.print(mRetaining); 1214 writer.print(" mHasMenu="); writer.println(mHasMenu); 1215 if (mFragmentManager != null) { 1216 writer.print(prefix); writer.print("mFragmentManager="); 1217 writer.println(mFragmentManager); 1218 } 1219 if (mImmediateActivity != null) { 1220 writer.print(prefix); writer.print("mImmediateActivity="); 1221 writer.println(mImmediateActivity); 1222 } 1223 if (mActivity != null) { 1224 writer.print(prefix); writer.print("mActivity="); 1225 writer.println(mActivity); 1226 } 1227 if (mArguments != null) { 1228 writer.print(prefix); writer.print("mArguments="); writer.println(mArguments); 1229 } 1230 if (mSavedFragmentState != null) { 1231 writer.print(prefix); writer.print("mSavedFragmentState="); 1232 writer.println(mSavedFragmentState); 1233 } 1234 if (mSavedViewState != null) { 1235 writer.print(prefix); writer.print("mSavedViewState="); 1236 writer.println(mSavedViewState); 1237 } 1238 if (mTarget != null) { 1239 writer.print(prefix); writer.print("mTarget="); writer.print(mTarget); 1240 writer.print(" mTargetRequestCode="); 1241 writer.println(mTargetRequestCode); 1242 } 1243 if (mNextAnim != 0) { 1244 writer.print(prefix); writer.print("mNextAnim="); writer.println(mNextAnim); 1245 } 1246 if (mContainer != null) { 1247 writer.print(prefix); writer.print("mContainer="); writer.println(mContainer); 1248 } 1249 if (mView != null) { 1250 writer.print(prefix); writer.print("mView="); writer.println(mView); 1251 } 1252 if (mLoaderManager != null) { 1253 writer.print(prefix); writer.println("Loader Manager:"); 1254 mLoaderManager.dump(prefix + " ", fd, writer, args); 1255 } 1256 } 1257 1258 void performStop() { 1259 onStop(); 1260 1261 if (mLoadersStarted) { 1262 mLoadersStarted = false; 1263 if (!mCheckedForLoaderManager) { 1264 mCheckedForLoaderManager = true; 1265 mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false); 1266 } 1267 if (mLoaderManager != null) { 1268 if (mActivity == null || !mActivity.mChangingConfigurations) { 1269 mLoaderManager.doStop(); 1270 } else { 1271 mLoaderManager.doRetain(); 1272 } 1273 } 1274 } 1275 } 1276} 1277