Fragment.java revision 5c1637087453de15e31861f073eae5133c4e9f7b
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.support.v4.app;
18
19import android.app.Activity;
20import android.content.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.support.v4.util.DebugUtils;
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.view.animation.Animation;
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 boolean mDetached;
56    final Bundle mArguments;
57
58    Bundle mSavedFragmentState;
59
60    Fragment mInstance;
61
62    public FragmentState(Fragment frag) {
63        mClassName = frag.getClass().getName();
64        mIndex = frag.mIndex;
65        mFromLayout = frag.mFromLayout;
66        mFragmentId = frag.mFragmentId;
67        mContainerId = frag.mContainerId;
68        mTag = frag.mTag;
69        mRetainInstance = frag.mRetainInstance;
70        mDetached = frag.mDetached;
71        mArguments = frag.mArguments;
72    }
73
74    public FragmentState(Parcel in) {
75        mClassName = in.readString();
76        mIndex = in.readInt();
77        mFromLayout = in.readInt() != 0;
78        mFragmentId = in.readInt();
79        mContainerId = in.readInt();
80        mTag = in.readString();
81        mRetainInstance = in.readInt() != 0;
82        mDetached = in.readInt() != 0;
83        mArguments = in.readBundle();
84        mSavedFragmentState = in.readBundle();
85    }
86
87    public Fragment instantiate(FragmentActivity activity) {
88        if (mInstance != null) {
89            return mInstance;
90        }
91
92        if (mArguments != null) {
93            mArguments.setClassLoader(activity.getClassLoader());
94        }
95
96        mInstance = Fragment.instantiate(activity, mClassName, mArguments);
97
98        if (mSavedFragmentState != null) {
99            mSavedFragmentState.setClassLoader(activity.getClassLoader());
100            mInstance.mSavedFragmentState = mSavedFragmentState;
101        }
102        mInstance.setIndex(mIndex);
103        mInstance.mFromLayout = mFromLayout;
104        mInstance.mRestored = true;
105        mInstance.mFragmentId = mFragmentId;
106        mInstance.mContainerId = mContainerId;
107        mInstance.mTag = mTag;
108        mInstance.mRetainInstance = mRetainInstance;
109        mInstance.mDetached = mDetached;
110        mInstance.mFragmentManager = activity.mFragments;
111
112        return mInstance;
113    }
114
115    public int describeContents() {
116        return 0;
117    }
118
119    public void writeToParcel(Parcel dest, int flags) {
120        dest.writeString(mClassName);
121        dest.writeInt(mIndex);
122        dest.writeInt(mFromLayout ? 1 : 0);
123        dest.writeInt(mFragmentId);
124        dest.writeInt(mContainerId);
125        dest.writeString(mTag);
126        dest.writeInt(mRetainInstance ? 1 : 0);
127        dest.writeInt(mDetached ? 1 : 0);
128        dest.writeBundle(mArguments);
129        dest.writeBundle(mSavedFragmentState);
130    }
131
132    public static final Parcelable.Creator<FragmentState> CREATOR
133            = new Parcelable.Creator<FragmentState>() {
134        public FragmentState createFromParcel(Parcel in) {
135            return new FragmentState(in);
136        }
137
138        public FragmentState[] newArray(int size) {
139            return new FragmentState[size];
140        }
141    };
142}
143
144/**
145 * Static library support version of the framework's {@link android.app.Fragment}.
146 * Used to write apps that run on platforms prior to Android 3.0.  When running
147 * on Android 3.0 or above, this implementation is still used; it does not try
148 * to switch to the framework's implementation.  See the framework SDK
149 * documentation for a class overview.
150 */
151public class Fragment implements ComponentCallbacks, OnCreateContextMenuListener {
152    private static final HashMap<String, Class<?>> sClassMap =
153            new HashMap<String, Class<?>>();
154
155    static final int INITIALIZING = 0;     // Not yet created.
156    static final int CREATED = 1;          // Created.
157    static final int ACTIVITY_CREATED = 2; // The activity has finished its creation.
158    static final int STOPPED = 3;          // Fully created, not started.
159    static final int STARTED = 4;          // Created and started, not resumed.
160    static final int RESUMED = 5;          // Created started and resumed.
161
162    int mState = INITIALIZING;
163
164    // Non-null if the fragment's view hierarchy is currently animating away,
165    // meaning we need to wait a bit on completely destroying it.  This is the
166    // view that is animating.
167    View mAnimatingAway;
168
169    // If mAnimatingAway != null, this is the state we should move to once the
170    // animation is done.
171    int mStateAfterAnimating;
172
173    // When instantiated from saved state, this is the saved state.
174    Bundle mSavedFragmentState;
175    SparseArray<Parcelable> mSavedViewState;
176
177    // Index into active fragment array.
178    int mIndex = -1;
179
180    // Internal unique name for this fragment;
181    String mWho;
182
183    // Construction arguments;
184    Bundle mArguments;
185
186    // Target fragment.
187    Fragment mTarget;
188
189    // Target request code.
190    int mTargetRequestCode;
191
192    // True if the fragment is in the list of added fragments.
193    boolean mAdded;
194
195    // If set this fragment is being removed from its activity.
196    boolean mRemoving;
197
198    // True if the fragment is in the resumed state.
199    boolean mResumed;
200
201    // Set to true if this fragment was instantiated from a layout file.
202    boolean mFromLayout;
203
204    // Set to true when the view has actually been inflated in its layout.
205    boolean mInLayout;
206
207    // True if this fragment has been restored from previously saved state.
208    boolean mRestored;
209
210    // Number of active back stack entries this fragment is in.
211    int mBackStackNesting;
212
213    // The fragment manager we are associated with.  Set as soon as the
214    // fragment is used in a transaction; cleared after it has been removed
215    // from all transactions.
216    FragmentManager mFragmentManager;
217
218    // Set as soon as a fragment is added to a transaction (or removed),
219    // to be able to do validation.
220    FragmentActivity mImmediateActivity;
221
222    // Activity this fragment is attached to.
223    FragmentActivity mActivity;
224
225    // The optional identifier for this fragment -- either the container ID if it
226    // was dynamically added to the view hierarchy, or the ID supplied in
227    // layout.
228    int mFragmentId;
229
230    // When a fragment is being dynamically added to the view hierarchy, this
231    // is the identifier of the parent container it is being added to.
232    int mContainerId;
233
234    // The optional named tag for this fragment -- usually used to find
235    // fragments that are not part of the layout.
236    String mTag;
237
238    // Set to true when the app has requested that this fragment be hidden
239    // from the user.
240    boolean mHidden;
241
242    // Set to true when the app has requested that this fragment be deactivated.
243    boolean mDetached;
244
245    // If set this fragment would like its instance retained across
246    // configuration changes.
247    boolean mRetainInstance;
248
249    // If set this fragment is being retained across the current config change.
250    boolean mRetaining;
251
252    // If set this fragment has menu items to contribute.
253    boolean mHasMenu;
254
255    // Used to verify that subclasses call through to super class.
256    boolean mCalled;
257
258    // If app has requested a specific animation, this is the one to use.
259    int mNextAnim;
260
261    // The parent container of the fragment after dynamically added to UI.
262    ViewGroup mContainer;
263
264    // The View generated for this fragment.
265    View mView;
266
267    // The real inner view that will save/restore state.
268    View mInnerView;
269
270    LoaderManagerImpl mLoaderManager;
271    boolean mLoadersStarted;
272    boolean mCheckedForLoaderManager;
273
274    /**
275     * State information that has been retrieved from a fragment instance
276     * through {@link FragmentManager#saveFragmentInstanceState(Fragment)
277     * FragmentManager.saveFragmentInstanceState}.
278     */
279    public static class SavedState implements Parcelable {
280        final Bundle mState;
281
282        SavedState(Bundle state) {
283            mState = state;
284        }
285
286        SavedState(Parcel in, ClassLoader loader) {
287            mState = in.readBundle();
288            if (loader != null && mState != null) {
289                mState.setClassLoader(loader);
290            }
291        }
292
293        @Override
294        public int describeContents() {
295            return 0;
296        }
297
298        @Override
299        public void writeToParcel(Parcel dest, int flags) {
300            dest.writeBundle(mState);
301        }
302
303        public static final Parcelable.Creator<SavedState> CREATOR
304                = new Parcelable.Creator<SavedState>() {
305            public SavedState createFromParcel(Parcel in) {
306                return new SavedState(in, null);
307            }
308
309            public SavedState[] newArray(int size) {
310                return new SavedState[size];
311            }
312        };
313    }
314
315    /**
316     * Thrown by {@link Fragment#instantiate(Context, String, Bundle)} when
317     * there is an instantiation failure.
318     */
319    static public class InstantiationException extends RuntimeException {
320        public InstantiationException(String msg, Exception cause) {
321            super(msg, cause);
322        }
323    }
324
325    /**
326     * Default constructor.  <strong>Every</strong> fragment must have an
327     * empty constructor, so it can be instantiated when restoring its
328     * activity's state.  It is strongly recommended that subclasses do not
329     * have other constructors with parameters, since these constructors
330     * will not be called when the fragment is re-instantiated; instead,
331     * arguments can be supplied by the caller with {@link #setArguments}
332     * and later retrieved by the Fragment with {@link #getArguments}.
333     *
334     * <p>Applications should generally not implement a constructor.  The
335     * first place application code an run where the fragment is ready to
336     * be used is in {@link #onAttach(Activity)}, the point where the fragment
337     * is actually associated with its activity.  Some applications may also
338     * want to implement {@link #onInflate} to retrieve attributes from a
339     * layout resource, though should take care here because this happens for
340     * the fragment is attached to its activity.
341     */
342    public Fragment() {
343    }
344
345    /**
346     * Like {@link #instantiate(Context, String, Bundle)} but with a null
347     * argument Bundle.
348     */
349    public static Fragment instantiate(Context context, String fname) {
350        return instantiate(context, fname, null);
351    }
352
353    /**
354     * Create a new instance of a Fragment with the given class name.  This is
355     * the same as calling its empty constructor.
356     *
357     * @param context The calling context being used to instantiate the fragment.
358     * This is currently just used to get its ClassLoader.
359     * @param fname The class name of the fragment to instantiate.
360     * @param args Bundle of arguments to supply to the fragment, which it
361     * can retrieve with {@link #getArguments()}.  May be null.
362     * @return Returns a new fragment instance.
363     * @throws InstantiationException If there is a failure in instantiating
364     * the given fragment class.  This is a runtime exception; it is not
365     * normally expected to happen.
366     */
367    public static Fragment instantiate(Context context, String fname, Bundle args) {
368        try {
369            Class<?> clazz = sClassMap.get(fname);
370            if (clazz == null) {
371                // Class not found in the cache, see if it's real, and try to add it
372                clazz = context.getClassLoader().loadClass(fname);
373                sClassMap.put(fname, clazz);
374            }
375            Fragment f = (Fragment)clazz.newInstance();
376            if (args != null) {
377                args.setClassLoader(f.getClass().getClassLoader());
378                f.mArguments = args;
379            }
380            return f;
381        } catch (ClassNotFoundException e) {
382            throw new InstantiationException("Unable to instantiate fragment " + fname
383                    + ": make sure class name exists, is public, and has an"
384                    + " empty constructor that is public", e);
385        } catch (java.lang.InstantiationException e) {
386            throw new InstantiationException("Unable to instantiate fragment " + fname
387                    + ": make sure class name exists, is public, and has an"
388                    + " empty constructor that is public", e);
389        } catch (IllegalAccessException e) {
390            throw new InstantiationException("Unable to instantiate fragment " + fname
391                    + ": make sure class name exists, is public, and has an"
392                    + " empty constructor that is public", e);
393        }
394    }
395
396    final void restoreViewState() {
397        if (mSavedViewState != null) {
398            mInnerView.restoreHierarchyState(mSavedViewState);
399            mSavedViewState = null;
400        }
401    }
402
403    final void setIndex(int index) {
404        mIndex = index;
405        mWho = "android:fragment:" + mIndex;
406    }
407
408    final void clearIndex() {
409        mIndex = -1;
410        mWho = null;
411    }
412
413    final boolean isInBackStack() {
414        return mBackStackNesting > 0;
415    }
416
417    /**
418     * Subclasses can not override equals().
419     */
420    @Override final public boolean equals(Object o) {
421        return super.equals(o);
422    }
423
424    /**
425     * Subclasses can not override hashCode().
426     */
427    @Override final public int hashCode() {
428        return super.hashCode();
429    }
430
431    @Override
432    public String toString() {
433        StringBuilder sb = new StringBuilder(128);
434        DebugUtils.buildShortClassTag(this, sb);
435        if (mIndex >= 0) {
436            sb.append(" #");
437            sb.append(mIndex);
438        }
439        if (mFragmentId != 0) {
440            sb.append(" id=0x");
441            sb.append(Integer.toHexString(mFragmentId));
442        }
443        if (mTag != null) {
444            sb.append(" ");
445            sb.append(mTag);
446        }
447        sb.append('}');
448        return sb.toString();
449    }
450
451    /**
452     * Return the identifier this fragment is known by.  This is either
453     * the android:id value supplied in a layout or the container view ID
454     * supplied when adding the fragment.
455     */
456    final public int getId() {
457        return mFragmentId;
458    }
459
460    /**
461     * Get the tag name of the fragment, if specified.
462     */
463    final public String getTag() {
464        return mTag;
465    }
466
467    /**
468     * Supply the construction arguments for this fragment.  This can only
469     * be called before the fragment has been attached to its activity; that
470     * is, you should call it immediately after constructing the fragment.  The
471     * arguments supplied here will be retained across fragment destroy and
472     * creation.
473     */
474    public void setArguments(Bundle args) {
475        if (mIndex >= 0) {
476            throw new IllegalStateException("Fragment already active");
477        }
478        mArguments = args;
479    }
480
481    /**
482     * Return the arguments supplied when the fragment was instantiated,
483     * if any.
484     */
485    final public Bundle getArguments() {
486        return mArguments;
487    }
488
489    /**
490     * Set the initial saved state that this Fragment should restore itself
491     * from when first being constructed, as returned by
492     * {@link FragmentManager#saveFragmentInstanceState(Fragment)
493     * FragmentManager.saveFragmentInstanceState}.
494     *
495     * @param state The state the fragment should be restored from.
496     */
497    public void setInitialSavedState(SavedState state) {
498        if (mIndex >= 0) {
499            throw new IllegalStateException("Fragment already active");
500        }
501        mSavedFragmentState = state != null && state.mState != null
502                ? state.mState : null;
503    }
504
505    /**
506     * Optional target for this fragment.  This may be used, for example,
507     * if this fragment is being started by another, and when done wants to
508     * give a result back to the first.  The target set here is retained
509     * across instances via {@link FragmentManager#putFragment
510     * FragmentManager.putFragment()}.
511     *
512     * @param fragment The fragment that is the target of this one.
513     * @param requestCode Optional request code, for convenience if you
514     * are going to call back with {@link #onActivityResult(int, int, Intent)}.
515     */
516    public void setTargetFragment(Fragment fragment, int requestCode) {
517        mTarget = fragment;
518        mTargetRequestCode = requestCode;
519    }
520
521    /**
522     * Return the target fragment set by {@link #setTargetFragment}.
523     */
524    final public Fragment getTargetFragment() {
525        return mTarget;
526    }
527
528    /**
529     * Return the target request code set by {@link #setTargetFragment}.
530     */
531    final public int getTargetRequestCode() {
532        return mTargetRequestCode;
533    }
534
535    /**
536     * Return the Activity this fragment is currently associated with.
537     */
538    final public FragmentActivity getActivity() {
539        return mActivity;
540    }
541
542    /**
543     * Return <code>getActivity().getResources()</code>.
544     */
545    final public Resources getResources() {
546        if (mActivity == null) {
547            throw new IllegalStateException("Fragment " + this + " not attached to Activity");
548        }
549        return mActivity.getResources();
550    }
551
552    /**
553     * Return a localized, styled CharSequence from the application's package's
554     * default string table.
555     *
556     * @param resId Resource id for the CharSequence text
557     */
558    public final CharSequence getText(int resId) {
559        return getResources().getText(resId);
560    }
561
562    /**
563     * Return a localized string from the application's package's
564     * default string table.
565     *
566     * @param resId Resource id for the string
567     */
568    public final String getString(int resId) {
569        return getResources().getString(resId);
570    }
571
572    /**
573     * Return a localized formatted string from the application's package's
574     * default string table, substituting the format arguments as defined in
575     * {@link java.util.Formatter} and {@link java.lang.String#format}.
576     *
577     * @param resId Resource id for the format string
578     * @param formatArgs The format arguments that will be used for substitution.
579     */
580
581    public final String getString(int resId, Object... formatArgs) {
582        return getResources().getString(resId, formatArgs);
583    }
584
585    /**
586     * Return the FragmentManager for interacting with fragments associated
587     * with this fragment's activity.  Note that this will be non-null slightly
588     * before {@link #getActivity()}, during the time from when the fragment is
589     * placed in a {@link FragmentTransaction} until it is committed and
590     * attached to its activity.
591     */
592    final public FragmentManager getFragmentManager() {
593        return mFragmentManager;
594    }
595
596    /**
597     * Return true if the fragment is currently added to its activity.
598     */
599    final public boolean isAdded() {
600        return mActivity != null && mAdded;
601    }
602
603    /**
604     * Return true if this fragment is currently being removed from its
605     * activity.  This is  <em>not</em> whether its activity is finishing, but
606     * rather whether it is in the process of being removed from its activity.
607     */
608    final public boolean isRemoving() {
609        return mRemoving;
610    }
611
612    /**
613     * Return true if the layout is included as part of an activity view
614     * hierarchy via the &lt;fragment&gt; tag.  This will always be true when
615     * fragments are created through the &lt;fragment&gt; tag, <em>except</em>
616     * in the case where an old fragment is restored from a previous state and
617     * it does not appear in the layout of the current state.
618     */
619    final public boolean isInLayout() {
620        return mInLayout;
621    }
622
623    /**
624     * Return true if the fragment is in the resumed state.  This is true
625     * for the duration of {@link #onResume()} and {@link #onPause()} as well.
626     */
627    final public boolean isResumed() {
628        return mResumed;
629    }
630
631    /**
632     * Return true if the fragment is currently visible to the user.  This means
633     * it: (1) has been added, (2) has its view attached to the window, and
634     * (3) is not hidden.
635     */
636    final public boolean isVisible() {
637        return isAdded() && !isHidden() && mView != null
638                && mView.getWindowToken() != null && mView.getVisibility() == View.VISIBLE;
639    }
640
641    /**
642     * Return true if the fragment has been hidden.  By default fragments
643     * are shown.  You can find out about changes to this state with
644     * {@link #onHiddenChanged}.  Note that the hidden state is orthogonal
645     * to other states -- that is, to be visible to the user, a fragment
646     * must be both started and not hidden.
647     */
648    final public boolean isHidden() {
649        return mHidden;
650    }
651
652    /**
653     * Called when the hidden state (as returned by {@link #isHidden()} of
654     * the fragment has changed.  Fragments start out not hidden; this will
655     * be called whenever the fragment changes state from that.
656     * @param hidden True if the fragment is now hidden, false if it is not
657     * visible.
658     */
659    public void onHiddenChanged(boolean hidden) {
660    }
661
662    /**
663     * Control whether a fragment instance is retained across Activity
664     * re-creation (such as from a configuration change).  This can only
665     * be used with fragments not in the back stack.  If set, the fragment
666     * lifecycle will be slightly different when an activity is recreated:
667     * <ul>
668     * <li> {@link #onDestroy()} will not be called (but {@link #onDetach()} still
669     * will be, because the fragment is being detached from its current activity).
670     * <li> {@link #onCreate(Bundle)} will not be called since the fragment
671     * is not being re-created.
672     * <li> {@link #onAttach(Activity)} and {@link #onActivityCreated(Bundle)} <b>will</b>
673     * still be called.
674     * </ul>
675     */
676    public void setRetainInstance(boolean retain) {
677        mRetainInstance = retain;
678    }
679
680    final public boolean getRetainInstance() {
681        return mRetainInstance;
682    }
683
684    /**
685     * Report that this fragment would like to participate in populating
686     * the options menu by receiving a call to {@link #onCreateOptionsMenu}
687     * and related methods.
688     *
689     * @param hasMenu If true, the fragment has menu items to contribute.
690     */
691    public void setHasOptionsMenu(boolean hasMenu) {
692        if (mHasMenu != hasMenu) {
693            mHasMenu = hasMenu;
694            if (isAdded() && !isHidden()) {
695                mActivity.supportInvalidateOptionsMenu();
696            }
697        }
698    }
699
700    /**
701     * Return the LoaderManager for this fragment, creating it if needed.
702     */
703    public LoaderManager getLoaderManager() {
704        if (mLoaderManager != null) {
705            return mLoaderManager;
706        }
707        if (mActivity == null) {
708            throw new IllegalStateException("Fragment " + this + " not attached to Activity");
709        }
710        mCheckedForLoaderManager = true;
711        mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, true);
712        return mLoaderManager;
713    }
714
715    /**
716     * Call {@link Activity#startActivity(Intent)} on the fragment's
717     * containing Activity.
718     */
719    public void startActivity(Intent intent) {
720        if (mActivity == null) {
721            throw new IllegalStateException("Fragment " + this + " not attached to Activity");
722        }
723        mActivity.startActivityFromFragment(this, intent, -1);
724    }
725
726    /**
727     * Call {@link Activity#startActivityForResult(Intent, int)} on the fragment's
728     * containing Activity.
729     */
730    public void startActivityForResult(Intent intent, int requestCode) {
731        if (mActivity == null) {
732            throw new IllegalStateException("Fragment " + this + " not attached to Activity");
733        }
734        mActivity.startActivityFromFragment(this, intent, requestCode);
735    }
736
737    /**
738     * Receive the result from a previous call to
739     * {@link #startActivityForResult(Intent, int)}.  This follows the
740     * related Activity API as described there in
741     * {@link Activity#onActivityResult(int, int, Intent)}.
742     *
743     * @param requestCode The integer request code originally supplied to
744     *                    startActivityForResult(), allowing you to identify who this
745     *                    result came from.
746     * @param resultCode The integer result code returned by the child activity
747     *                   through its setResult().
748     * @param data An Intent, which can return result data to the caller
749     *               (various data can be attached to Intent "extras").
750     */
751    public void onActivityResult(int requestCode, int resultCode, Intent data) {
752    }
753
754    /**
755     * @hide Hack so that DialogFragment can make its Dialog before creating
756     * its views, and the view construction can use the dialog's context for
757     * inflation.  Maybe this should become a public API. Note sure.
758     */
759    public LayoutInflater getLayoutInflater(Bundle savedInstanceState) {
760        return mActivity.getLayoutInflater();
761    }
762
763    /**
764     * Called when a fragment is being created as part of a view layout
765     * inflation, typically from setting the content view of an activity.  This
766     * may be called immediately after the fragment is created from a <fragment>
767     * tag in a layout file.  Note this is <em>before</em> the fragment's
768     * {@link #onAttach(Activity)} has been called; all you should do here is
769     * parse the attributes and save them away.
770     *
771     * <p>This is called every time the fragment is inflated, even if it is
772     * being inflated into a new instance with saved state.  It typically makes
773     * sense to re-parse the parameters each time, to allow them to change with
774     * different configurations.</p>
775     *
776     * <p>Here is a typical implementation of a fragment that can take parameters
777     * both through attributes supplied here as well from {@link #getArguments()}:</p>
778     *
779     * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentArguments.java
780     *      fragment}
781     *
782     * <p>Note that parsing the XML attributes uses a "styleable" resource.  The
783     * declaration for the styleable used here is:</p>
784     *
785     * {@sample development/samples/ApiDemos/res/values/attrs.xml fragment_arguments}
786     *
787     * <p>The fragment can then be declared within its activity's content layout
788     * through a tag like this:</p>
789     *
790     * {@sample development/samples/ApiDemos/res/layout/fragment_arguments.xml from_attributes}
791     *
792     * <p>This fragment can also be created dynamically from arguments given
793     * at runtime in the arguments Bundle; here is an example of doing so at
794     * creation of the containing activity:</p>
795     *
796     * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentArguments.java
797     *      create}
798     *
799     * @param activity The Activity that is inflating this fragment.
800     * @param attrs The attributes at the tag where the fragment is
801     * being created.
802     * @param savedInstanceState If the fragment is being re-created from
803     * a previous saved state, this is the state.
804     */
805    public void onInflate(Activity activity, AttributeSet attrs, Bundle savedInstanceState) {
806        mCalled = true;
807    }
808
809    /**
810     * Called when a fragment is first attached to its activity.
811     * {@link #onCreate(Bundle)} will be called after this.
812     */
813    public void onAttach(Activity activity) {
814        mCalled = true;
815    }
816
817    /**
818     * Called when a fragment loads an animation.
819     */
820    public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
821        return null;
822    }
823
824    /**
825     * Called to do initial creation of a fragment.  This is called after
826     * {@link #onAttach(Activity)} and before
827     * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}.
828     *
829     * <p>Note that this can be called while the fragment's activity is
830     * still in the process of being created.  As such, you can not rely
831     * on things like the activity's content view hierarchy being initialized
832     * at this point.  If you want to do work once the activity itself is
833     * created, see {@link #onActivityCreated(Bundle)}.
834     *
835     * @param savedInstanceState If the fragment is being re-created from
836     * a previous saved state, this is the state.
837     */
838    public void onCreate(Bundle savedInstanceState) {
839        mCalled = true;
840    }
841
842    /**
843     * Called to have the fragment instantiate its user interface view.
844     * This is optional, and non-graphical fragments can return null (which
845     * is the default implementation).  This will be called between
846     * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}.
847     *
848     * <p>If you return a View from here, you will later be called in
849     * {@link #onDestroyView} when the view is being released.
850     *
851     * @param inflater The LayoutInflater object that can be used to inflate
852     * any views in the fragment,
853     * @param container If non-null, this is the parent view that the fragment's
854     * UI should be attached to.  The fragment should not add the view itself,
855     * but this can be used to generate the LayoutParams of the view.
856     * @param savedInstanceState If non-null, this fragment is being re-constructed
857     * from a previous saved state as given here.
858     *
859     * @return Return the View for the fragment's UI, or null.
860     */
861    public View onCreateView(LayoutInflater inflater, ViewGroup container,
862            Bundle savedInstanceState) {
863        return null;
864    }
865
866    /**
867     * Called immediately after {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}
868     * has returned, but before any saved state has been restored in to the view.
869     * This gives subclasses a chance to initialize themselves once
870     * they know their view hierarchy has been completely created.  The fragment's
871     * view hierarchy is not however attached to its parent at this point.
872     * @param view The View returned by {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}.
873     * @param savedInstanceState If non-null, this fragment is being re-constructed
874     * from a previous saved state as given here.
875     */
876    public void onViewCreated(View view, Bundle savedInstanceState) {
877    }
878
879    /**
880     * Get the root view for the fragment's layout (the one returned by {@link #onCreateView}),
881     * if provided.
882     *
883     * @return The fragment's root view, or null if it has no layout.
884     */
885    public View getView() {
886        return mView;
887    }
888
889    /**
890     * Called when the fragment's activity has been created and this
891     * fragment's view hierarchy instantiated.  It can be used to do final
892     * initialization once these pieces are in place, such as retrieving
893     * views or restoring state.  It is also useful for fragments that use
894     * {@link #setRetainInstance(boolean)} to retain their instance,
895     * as this callback tells the fragment when it is fully associated with
896     * the new activity instance.  This is called after {@link #onCreateView}
897     * and before {@link #onStart()}.
898     *
899     * @param savedInstanceState If the fragment is being re-created from
900     * a previous saved state, this is the state.
901     */
902    public void onActivityCreated(Bundle savedInstanceState) {
903        mCalled = true;
904    }
905
906    /**
907     * Called when the Fragment is visible to the user.  This is generally
908     * tied to {@link Activity#onStart() Activity.onStart} of the containing
909     * Activity's lifecycle.
910     */
911    public void onStart() {
912        mCalled = true;
913
914        if (!mLoadersStarted) {
915            mLoadersStarted = true;
916            if (!mCheckedForLoaderManager) {
917                mCheckedForLoaderManager = true;
918                mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false);
919            }
920            if (mLoaderManager != null) {
921                mLoaderManager.doStart();
922            }
923        }
924    }
925
926    /**
927     * Called when the fragment is visible to the user and actively running.
928     * This is generally
929     * tied to {@link Activity#onResume() Activity.onResume} of the containing
930     * Activity's lifecycle.
931     */
932    public void onResume() {
933        mCalled = true;
934    }
935
936    /**
937     * Called to ask the fragment to save its current dynamic state, so it
938     * can later be reconstructed in a new instance of its process is
939     * restarted.  If a new instance of the fragment later needs to be
940     * created, the data you place in the Bundle here will be available
941     * in the Bundle given to {@link #onCreate(Bundle)},
942     * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}, and
943     * {@link #onActivityCreated(Bundle)}.
944     *
945     * <p>This corresponds to {@link Activity#onSaveInstanceState(Bundle)
946     * Activity.onSaveInstanceState(Bundle)} and most of the discussion there
947     * applies here as well.  Note however: <em>this method may be called
948     * at any time before {@link #onDestroy()}</em>.  There are many situations
949     * where a fragment may be mostly torn down (such as when placed on the
950     * back stack with no UI showing), but its state will not be saved until
951     * its owning activity actually needs to save its state.
952     *
953     * @param outState Bundle in which to place your saved state.
954     */
955    public void onSaveInstanceState(Bundle outState) {
956    }
957
958    public void onConfigurationChanged(Configuration newConfig) {
959        mCalled = true;
960    }
961
962    /**
963     * Called when the Fragment is no longer resumed.  This is generally
964     * tied to {@link Activity#onPause() Activity.onPause} of the containing
965     * Activity's lifecycle.
966     */
967    public void onPause() {
968        mCalled = true;
969    }
970
971    /**
972     * Called when the Fragment is no longer started.  This is generally
973     * tied to {@link Activity#onStop() Activity.onStop} of the containing
974     * Activity's lifecycle.
975     */
976    public void onStop() {
977        mCalled = true;
978    }
979
980    public void onLowMemory() {
981        mCalled = true;
982    }
983
984    /**
985     * Called when the view previously created by {@link #onCreateView} has
986     * been detached from the fragment.  The next time the fragment needs
987     * to be displayed, a new view will be created.  This is called
988     * after {@link #onStop()} and before {@link #onDestroy()}.  It is called
989     * <em>regardless</em> of whether {@link #onCreateView} returned a
990     * non-null view.  Internally it is called after the view's state has
991     * been saved but before it has been removed from its parent.
992     */
993    public void onDestroyView() {
994        mCalled = true;
995    }
996
997    /**
998     * Called when the fragment is no longer in use.  This is called
999     * after {@link #onStop()} and before {@link #onDetach()}.
1000     */
1001    public void onDestroy() {
1002        mCalled = true;
1003        //Log.v("foo", "onDestroy: mCheckedForLoaderManager=" + mCheckedForLoaderManager
1004        //        + " mLoaderManager=" + mLoaderManager);
1005        if (!mCheckedForLoaderManager) {
1006            mCheckedForLoaderManager = true;
1007            mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false);
1008        }
1009        if (mLoaderManager != null) {
1010            mLoaderManager.doDestroy();
1011        }
1012    }
1013
1014    /**
1015     * Called when the fragment is no longer attached to its activity.  This
1016     * is called after {@link #onDestroy()}.
1017     */
1018    public void onDetach() {
1019        mCalled = true;
1020    }
1021
1022    /**
1023     * Initialize the contents of the Activity's standard options menu.  You
1024     * should place your menu items in to <var>menu</var>.  For this method
1025     * to be called, you must have first called {@link #setHasOptionsMenu}.  See
1026     * {@link Activity#onCreateOptionsMenu(Menu) Activity.onCreateOptionsMenu}
1027     * for more information.
1028     *
1029     * @param menu The options menu in which you place your items.
1030     *
1031     * @see #setHasOptionsMenu
1032     * @see #onPrepareOptionsMenu
1033     * @see #onOptionsItemSelected
1034     */
1035    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
1036    }
1037
1038    /**
1039     * Prepare the Screen's standard options menu to be displayed.  This is
1040     * called right before the menu is shown, every time it is shown.  You can
1041     * use this method to efficiently enable/disable items or otherwise
1042     * dynamically modify the contents.  See
1043     * {@link Activity#onPrepareOptionsMenu(Menu) Activity.onPrepareOptionsMenu}
1044     * for more information.
1045     *
1046     * @param menu The options menu as last shown or first initialized by
1047     *             onCreateOptionsMenu().
1048     *
1049     * @see #setHasOptionsMenu
1050     * @see #onCreateOptionsMenu
1051     */
1052    public void onPrepareOptionsMenu(Menu menu) {
1053    }
1054
1055    /**
1056     * Called when this fragment's option menu items are no longer being
1057     * included in the overall options menu.  Receiving this call means that
1058     * the menu needed to be rebuilt, but this fragment's items were not
1059     * included in the newly built menu (its {@link #onCreateOptionsMenu(Menu, MenuInflater)}
1060     * was not called).
1061     */
1062    public void onDestroyOptionsMenu() {
1063    }
1064
1065    /**
1066     * This hook is called whenever an item in your options menu is selected.
1067     * The default implementation simply returns false to have the normal
1068     * processing happen (calling the item's Runnable or sending a message to
1069     * its Handler as appropriate).  You can use this method for any items
1070     * for which you would like to do processing without those other
1071     * facilities.
1072     *
1073     * <p>Derived classes should call through to the base class for it to
1074     * perform the default menu handling.
1075     *
1076     * @param item The menu item that was selected.
1077     *
1078     * @return boolean Return false to allow normal menu processing to
1079     *         proceed, true to consume it here.
1080     *
1081     * @see #onCreateOptionsMenu
1082     */
1083    public boolean onOptionsItemSelected(MenuItem item) {
1084        return false;
1085    }
1086
1087    /**
1088     * This hook is called whenever the options menu is being closed (either by the user canceling
1089     * the menu with the back/menu button, or when an item is selected).
1090     *
1091     * @param menu The options menu as last shown or first initialized by
1092     *             onCreateOptionsMenu().
1093     */
1094    public void onOptionsMenuClosed(Menu menu) {
1095    }
1096
1097    /**
1098     * Called when a context menu for the {@code view} is about to be shown.
1099     * Unlike {@link #onCreateOptionsMenu}, this will be called every
1100     * time the context menu is about to be shown and should be populated for
1101     * the view (or item inside the view for {@link AdapterView} subclasses,
1102     * this can be found in the {@code menuInfo})).
1103     * <p>
1104     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
1105     * item has been selected.
1106     * <p>
1107     * The default implementation calls up to
1108     * {@link Activity#onCreateContextMenu Activity.onCreateContextMenu}, though
1109     * you can not call this implementation if you don't want that behavior.
1110     * <p>
1111     * It is not safe to hold onto the context menu after this method returns.
1112     * {@inheritDoc}
1113     */
1114    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
1115        getActivity().onCreateContextMenu(menu, v, menuInfo);
1116    }
1117
1118    /**
1119     * Registers a context menu to be shown for the given view (multiple views
1120     * can show the context menu). This method will set the
1121     * {@link OnCreateContextMenuListener} on the view to this fragment, so
1122     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
1123     * called when it is time to show the context menu.
1124     *
1125     * @see #unregisterForContextMenu(View)
1126     * @param view The view that should show a context menu.
1127     */
1128    public void registerForContextMenu(View view) {
1129        view.setOnCreateContextMenuListener(this);
1130    }
1131
1132    /**
1133     * Prevents a context menu to be shown for the given view. This method will
1134     * remove the {@link OnCreateContextMenuListener} on the view.
1135     *
1136     * @see #registerForContextMenu(View)
1137     * @param view The view that should stop showing a context menu.
1138     */
1139    public void unregisterForContextMenu(View view) {
1140        view.setOnCreateContextMenuListener(null);
1141    }
1142
1143    /**
1144     * This hook is called whenever an item in a context menu is selected. The
1145     * default implementation simply returns false to have the normal processing
1146     * happen (calling the item's Runnable or sending a message to its Handler
1147     * as appropriate). You can use this method for any items for which you
1148     * would like to do processing without those other facilities.
1149     * <p>
1150     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
1151     * View that added this menu item.
1152     * <p>
1153     * Derived classes should call through to the base class for it to perform
1154     * the default menu handling.
1155     *
1156     * @param item The context menu item that was selected.
1157     * @return boolean Return false to allow normal context menu processing to
1158     *         proceed, true to consume it here.
1159     */
1160    public boolean onContextItemSelected(MenuItem item) {
1161        return false;
1162    }
1163
1164    /**
1165     * Print the Fragments's state into the given stream.
1166     *
1167     * @param prefix Text to print at the front of each line.
1168     * @param fd The raw file descriptor that the dump is being sent to.
1169     * @param writer The PrintWriter to which you should dump your state.  This will be
1170     * closed for you after you return.
1171     * @param args additional arguments to the dump request.
1172     */
1173    public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
1174        writer.print(prefix); writer.print("mFragmentId=#");
1175                writer.print(Integer.toHexString(mFragmentId));
1176                writer.print(" mContainerId#=");
1177                writer.print(Integer.toHexString(mContainerId));
1178                writer.print(" mTag="); writer.println(mTag);
1179        writer.print(prefix); writer.print("mState="); writer.print(mState);
1180                writer.print(" mIndex="); writer.print(mIndex);
1181                writer.print(" mWho="); writer.print(mWho);
1182                writer.print(" mBackStackNesting="); writer.println(mBackStackNesting);
1183        writer.print(prefix); writer.print("mAdded="); writer.print(mAdded);
1184                writer.print(" mRemoving="); writer.print(mRemoving);
1185                writer.print(" mResumed="); writer.print(mResumed);
1186                writer.print(" mFromLayout="); writer.print(mFromLayout);
1187                writer.print(" mInLayout="); writer.println(mInLayout);
1188        writer.print(prefix); writer.print("mHidden="); writer.print(mHidden);
1189                writer.print(" mDetached="); writer.print(mDetached);
1190                writer.print(" mRetainInstance="); writer.print(mRetainInstance);
1191                writer.print(" mRetaining="); writer.print(mRetaining);
1192                writer.print(" mHasMenu="); writer.println(mHasMenu);
1193        if (mFragmentManager != null) {
1194            writer.print(prefix); writer.print("mFragmentManager=");
1195                    writer.println(mFragmentManager);
1196        }
1197        if (mImmediateActivity != null) {
1198            writer.print(prefix); writer.print("mImmediateActivity=");
1199                    writer.println(mImmediateActivity);
1200        }
1201        if (mActivity != null) {
1202            writer.print(prefix); writer.print("mActivity=");
1203                    writer.println(mActivity);
1204        }
1205        if (mArguments != null) {
1206            writer.print(prefix); writer.print("mArguments="); writer.println(mArguments);
1207        }
1208        if (mSavedFragmentState != null) {
1209            writer.print(prefix); writer.print("mSavedFragmentState=");
1210                    writer.println(mSavedFragmentState);
1211        }
1212        if (mSavedViewState != null) {
1213            writer.print(prefix); writer.print("mSavedViewState=");
1214                    writer.println(mSavedViewState);
1215        }
1216        if (mTarget != null) {
1217            writer.print(prefix); writer.print("mTarget="); writer.print(mTarget);
1218                    writer.print(" mTargetRequestCode=");
1219                    writer.println(mTargetRequestCode);
1220        }
1221        if (mNextAnim != 0) {
1222            writer.print(prefix); writer.print("mNextAnim="); writer.println(mNextAnim);
1223        }
1224        if (mContainer != null) {
1225            writer.print(prefix); writer.print("mContainer="); writer.println(mContainer);
1226        }
1227        if (mView != null) {
1228            writer.print(prefix); writer.print("mView="); writer.println(mView);
1229        }
1230        if (mInnerView != null) {
1231            writer.print(prefix); writer.print("mInnerView="); writer.println(mView);
1232        }
1233        if (mAnimatingAway != null) {
1234            writer.print(prefix); writer.print("mAnimatingAway="); writer.println(mAnimatingAway);
1235            writer.print(prefix); writer.print("mStateAfterAnimating=");
1236                    writer.println(mStateAfterAnimating);
1237        }
1238        if (mLoaderManager != null) {
1239            writer.print(prefix); writer.println("Loader Manager:");
1240            mLoaderManager.dump(prefix + "  ", fd, writer, args);
1241        }
1242    }
1243
1244    void performStop() {
1245        onStop();
1246    }
1247
1248    void performReallyStop(boolean retaining) {
1249        if (mLoadersStarted) {
1250            mLoadersStarted = false;
1251            if (!mCheckedForLoaderManager) {
1252                mCheckedForLoaderManager = true;
1253                mLoaderManager = mActivity.getLoaderManager(mIndex, mLoadersStarted, false);
1254            }
1255            if (mLoaderManager != null) {
1256                if (!retaining) {
1257                    mLoaderManager.doStop();
1258                } else {
1259                    mLoaderManager.doRetain();
1260                }
1261            }
1262        }
1263    }
1264}
1265