The Fragment class can be used many ways to achieve a wide variety of * results. In its core, it represents a particular operation or interface * that is running within a larger {@link Activity}. A Fragment is closely * tied to the Activity it is in, and can not be used apart from one. Though * Fragment defines its own lifecycle, that lifecycle is dependent on its * activity: if the activity is stopped, no fragments inside of it can be * started; when the activity is destroyed, all fragments will be destroyed. * *
All subclasses of Fragment must include a public no-argument constructor. * The framework will often re-instantiate a fragment class when needed, * in particular during state restore, and needs to be able to find this * constructor to instantiate it. If the no-argument constructor is not * available, a runtime exception will occur in some cases during state * restore. * *
Topics covered here: *
For more information about using fragments, read the * Fragments developer guide.
*Though a Fragment's lifecycle is tied to its owning activity, it has * its own wrinkle on the standard activity lifecycle. It includes basic * activity lifecycle methods such as {@link #onResume}, but also important * are methods related to interactions with the activity and UI generation. * *
The core series of lifecycle methods that are called to bring a fragment * up to resumed state (interacting with the user) are: * *
As a fragment is no longer being used, it goes through a reverse * series of callbacks: * *
Fragments can be used as part of your application's layout, allowing * you to better modularize your code and more easily adjust your user * interface to the screen it is running on. As an example, we can look * at a simple program consisting of a list of items, and display of the * details of each item.
* *An activity's layout XML can include <fragment> tags
* to embed fragment instances inside of the layout. For example, here is
* a simple layout that embeds one fragment:
The layout is installed in the activity in the normal way:
* * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java * main} * *The titles fragment, showing a list of titles, is fairly simple, relying * on {@link ListFragment} for most of its work. Note the implementation of * clicking an item: depending on the current activity's layout, it can either * create and display a new fragment to show the details in-place (more about * this later), or start a new activity to show the details.
* * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java * titles} * *The details fragment showing the contents of a selected item just * displays a string of text based on an index of a string array built in to * the app:
* * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java * details} * *In this case when the user clicks on a title, there is no details * container in the current activity, so the titles fragment's click code will * launch a new activity to display the details fragment:
* * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentLayout.java * details_activity} * *However the screen may be large enough to show both the list of titles * and details about the currently selected title. To use such a layout on * a landscape screen, this alternative layout can be placed under layout-land:
* * {@sample development/samples/ApiDemos/res/layout-land/fragment_layout.xml layout} * *Note how the prior code will adjust to this alternative UI flow: the titles * fragment will now embed the details fragment inside of this activity, and the * details activity will finish itself if it is running in a configuration * where the details can be shown in-place. * *
When a configuration change causes the activity hosting these fragments * to restart, its new instance may use a different layout that doesn't * include the same fragments as the previous layout. In this case all of * the previous fragments will still be instantiated and running in the new * instance. However, any that are no longer associated with a <fragment> * tag in the view hierarchy will not have their content view created * and will return false from {@link #isInLayout}. (The code here also shows * how you can determine if a fragment placed in a container is no longer * running in a layout with that container and avoid creating its view hierarchy * in that case.) * *
The attributes of the <fragment> tag are used to control the * LayoutParams provided when attaching the fragment's view to the parent * container. They can also be parsed by the fragment in {@link #onInflate} * as parameters. * *
The fragment being instantiated must have some kind of unique identifier * so that it can be re-associated with a previous instance if the parent * activity needs to be destroyed and recreated. This can be provided these * ways: * *
android:tag can be used in <fragment> to provide
* a specific tag name for the fragment.
* android:id can be used in <fragment> to provide
* a specific identifier for the fragment.
* The transaction in which fragments are modified can be placed on an * internal back-stack of the owning activity. When the user presses back * in the activity, any transactions on the back stack are popped off before * the activity itself is finished. * *
For example, consider this simple fragment that is instantiated with * an integer argument and displays that in a TextView in its UI:
* * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java * fragment} * *A function that creates a new instance of the fragment, replacing * whatever current fragment instance is being shown and pushing that change * on to the back stack could be written as: * * {@sample development/samples/ApiDemos/src/com/example/android/apis/app/FragmentStack.java * add_stack} * *
After each call to this function, a new entry is on the stack, and
* pressing back will pop it to return the user to whatever previous state
* the activity UI was in.
*
* @deprecated Use the Support Library
* {@link android.support.v4.app.Fragment} for consistent behavior across all devices
* and access to Lifecycle.
*/
@Deprecated
public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListener {
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
private static final ArrayMap Applications should generally not implement a constructor. Prefer
* {@link #onAttach(Context)} instead. It is the first place application code can run where
* the fragment is ready to be used - the point where the fragment is actually associated with
* its context. Some applications may also want to implement {@link #onInflate} to retrieve
* attributes from a layout resource, although note this happens when the fragment is attached.
*/
public Fragment() {
}
/**
* Like {@link #instantiate(Context, String, Bundle)} but with a null
* argument Bundle.
*/
public static Fragment instantiate(Context context, String fname) {
return instantiate(context, fname, null);
}
/**
* Create a new instance of a Fragment with the given class name. This is
* the same as calling its empty constructor.
*
* @param context The calling context being used to instantiate the fragment.
* This is currently just used to get its ClassLoader.
* @param fname The class name of the fragment to instantiate.
* @param args Bundle of arguments to supply to the fragment, which it
* can retrieve with {@link #getArguments()}. May be null.
* @return Returns a new fragment instance.
* @throws InstantiationException If there is a failure in instantiating
* the given fragment class. This is a runtime exception; it is not
* normally expected to happen.
*/
public static Fragment instantiate(Context context, String fname, @Nullable Bundle args) {
try {
Class clazz = sClassMap.get(fname);
if (clazz == null) {
// Class not found in the cache, see if it's real, and try to add it
clazz = context.getClassLoader().loadClass(fname);
if (!Fragment.class.isAssignableFrom(clazz)) {
throw new InstantiationException("Trying to instantiate a class " + fname
+ " that is not a Fragment", new ClassCastException());
}
sClassMap.put(fname, clazz);
}
Fragment f = (Fragment) clazz.getConstructor().newInstance();
if (args != null) {
args.setClassLoader(f.getClass().getClassLoader());
f.setArguments(args);
}
return f;
} catch (ClassNotFoundException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (java.lang.InstantiationException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (IllegalAccessException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (NoSuchMethodException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": could not find Fragment constructor", e);
} catch (InvocationTargetException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": calling Fragment constructor caused an exception", e);
}
}
final void restoreViewState(Bundle savedInstanceState) {
if (mSavedViewState != null) {
mView.restoreHierarchyState(mSavedViewState);
mSavedViewState = null;
}
mCalled = false;
onViewStateRestored(savedInstanceState);
if (!mCalled) {
throw new SuperNotCalledException("Fragment " + this
+ " did not call through to super.onViewStateRestored()");
}
}
final void setIndex(int index, Fragment parent) {
mIndex = index;
if (parent != null) {
mWho = parent.mWho + ":" + mIndex;
} else {
mWho = "android:fragment:" + mIndex;
}
}
final boolean isInBackStack() {
return mBackStackNesting > 0;
}
/**
* Subclasses can not override equals().
*/
@Override final public boolean equals(Object o) {
return super.equals(o);
}
/**
* Subclasses can not override hashCode().
*/
@Override final public int hashCode() {
return super.hashCode();
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder(128);
DebugUtils.buildShortClassTag(this, sb);
if (mIndex >= 0) {
sb.append(" #");
sb.append(mIndex);
}
if (mFragmentId != 0) {
sb.append(" id=0x");
sb.append(Integer.toHexString(mFragmentId));
}
if (mTag != null) {
sb.append(" ");
sb.append(mTag);
}
sb.append('}');
return sb.toString();
}
/**
* Return the identifier this fragment is known by. This is either
* the android:id value supplied in a layout or the container view ID
* supplied when adding the fragment.
*/
final public int getId() {
return mFragmentId;
}
/**
* Get the tag name of the fragment, if specified.
*/
final public String getTag() {
return mTag;
}
/**
* Supply the construction arguments for this fragment.
* The arguments supplied here will be retained across fragment destroy and
* creation.
*
* This method cannot be called if the fragment is added to a FragmentManager and
* if {@link #isStateSaved()} would return true. Prior to {@link Build.VERSION_CODES#O},
* this method may only be called if the fragment has not yet been added to a FragmentManager.
* If this Fragment is a child of another Fragment, the FragmentManager
* returned here will be the parent's {@link #getChildFragmentManager()}.
*/
final public FragmentManager getFragmentManager() {
return mFragmentManager;
}
/**
* Return a private FragmentManager for placing and managing Fragments
* inside of this Fragment.
*/
final public FragmentManager getChildFragmentManager() {
if (mChildFragmentManager == null) {
instantiateChildFragmentManager();
if (mState >= RESUMED) {
mChildFragmentManager.dispatchResume();
} else if (mState >= STARTED) {
mChildFragmentManager.dispatchStart();
} else if (mState >= ACTIVITY_CREATED) {
mChildFragmentManager.dispatchActivityCreated();
} else if (mState >= CREATED) {
mChildFragmentManager.dispatchCreate();
}
}
return mChildFragmentManager;
}
/**
* Returns the parent Fragment containing this Fragment. If this Fragment
* is attached directly to an Activity, returns null.
*/
final public Fragment getParentFragment() {
return mParentFragment;
}
/**
* Return true if the fragment is currently added to its activity.
*/
final public boolean isAdded() {
return mHost != null && mAdded;
}
/**
* Return true if the fragment has been explicitly detached from the UI.
* That is, {@link FragmentTransaction#detach(Fragment)
* FragmentTransaction.detach(Fragment)} has been used on it.
*/
final public boolean isDetached() {
return mDetached;
}
/**
* Return true if this fragment is currently being removed from its
* activity. This is not whether its activity is finishing, but
* rather whether it is in the process of being removed from its activity.
*/
final public boolean isRemoving() {
return mRemoving;
}
/**
* Return true if the layout is included as part of an activity view
* hierarchy via the <fragment> tag. This will always be true when
* fragments are created through the <fragment> tag, except
* in the case where an old fragment is restored from a previous state and
* it does not appear in the layout of the current state.
*/
final public boolean isInLayout() {
return mInLayout;
}
/**
* Return true if the fragment is in the resumed state. This is true
* for the duration of {@link #onResume()} and {@link #onPause()} as well.
*/
final public boolean isResumed() {
return mState >= RESUMED;
}
/**
* Return true if the fragment is currently visible to the user. This means
* it: (1) has been added, (2) has its view attached to the window, and
* (3) is not hidden.
*/
final public boolean isVisible() {
return isAdded() && !isHidden() && mView != null
&& mView.getWindowToken() != null && mView.getVisibility() == View.VISIBLE;
}
/**
* Return true if the fragment has been hidden. By default fragments
* are shown. You can find out about changes to this state with
* {@link #onHiddenChanged}. Note that the hidden state is orthogonal
* to other states -- that is, to be visible to the user, a fragment
* must be both started and not hidden.
*/
final public boolean isHidden() {
return mHidden;
}
/**
* Called when the hidden state (as returned by {@link #isHidden()} of
* the fragment has changed. Fragments start out not hidden; this will
* be called whenever the fragment changes state from that.
* @param hidden True if the fragment is now hidden, false otherwise.
*/
public void onHiddenChanged(boolean hidden) {
}
/**
* Control whether a fragment instance is retained across Activity
* re-creation (such as from a configuration change). This can only
* be used with fragments not in the back stack. If set, the fragment
* lifecycle will be slightly different when an activity is recreated:
* An app may set this to false to indicate that the fragment's UI is
* scrolled out of visibility or is otherwise not directly visible to the user.
* This may be used by the system to prioritize operations such as fragment lifecycle updates
* or loader ordering behavior. Note: This method may be called outside of the fragment lifecycle
* and thus has no ordering guarantees with regard to fragment lifecycle method calls. Note: Prior to Android N there was a platform bug that could cause
*
* Normal permissions {@link android.content.pm.PermissionInfo#PROTECTION_NORMAL}
* are granted at install time if requested in the manifest. Signature permissions
* {@link android.content.pm.PermissionInfo#PROTECTION_SIGNATURE} are granted at
* install time if requested in the manifest and the signature of your app matches
* the signature of the app declaring the permissions.
*
* If your app does not have the requested permissions the user will be presented
* with UI for accepting them. After the user has accepted or rejected the
* requested permissions you will receive a callback on {@link
* #onRequestPermissionsResult(int, String[], int[])} reporting whether the
* permissions were granted or not.
*
* Note that requesting a permission does not guarantee it will be granted and
* your app should be able to run without having this permission.
*
* This method may start an activity allowing the user to choose which permissions
* to grant and which to reject. Hence, you should be prepared that your activity
* may be paused and resumed. Further, granting some permissions may require
* a restart of you application. In such a case, the system will recreate the
* activity stack before delivering the result to {@link
* #onRequestPermissionsResult(int, String[], int[])}.
*
* When checking whether you have a permission you should use {@link
* android.content.Context#checkSelfPermission(String)}.
*
* Calling this API for permissions already granted to your app would show UI
* to the user to decide whether the app can still hold these permissions. This
* can be useful if the way your app uses data guarded by the permissions
* changes significantly.
*
* You cannot request a permission if your activity sets {@link
* android.R.styleable#AndroidManifestActivity_noHistory noHistory} to
*
* A sample permissions request looks like this:
*
* private void showContacts() {
* if (getActivity().checkSelfPermission(Manifest.permission.READ_CONTACTS)
* != PackageManager.PERMISSION_GRANTED) {
* requestPermissions(new String[]{Manifest.permission.READ_CONTACTS},
* PERMISSIONS_REQUEST_READ_CONTACTS);
* } else {
* doShowContacts();
* }
* }
*
* {@literal @}Override
* public void onRequestPermissionsResult(int requestCode, String[] permissions,
* int[] grantResults) {
* if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS
* && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
* doShowContacts();
* }
* }
* getActivity().getResources().
*/
final public Resources getResources() {
if (mHost == null) {
throw new IllegalStateException("Fragment " + this + " not attached to Activity");
}
return mHost.getContext().getResources();
}
/**
* Return a localized, styled CharSequence from the application's package's
* default string table.
*
* @param resId Resource id for the CharSequence text
*/
public final CharSequence getText(@StringRes int resId) {
return getResources().getText(resId);
}
/**
* Return a localized string from the application's package's
* default string table.
*
* @param resId Resource id for the string
*/
public final String getString(@StringRes int resId) {
return getResources().getString(resId);
}
/**
* Return a localized formatted string from the application's package's
* default string table, substituting the format arguments as defined in
* {@link java.util.Formatter} and {@link java.lang.String#format}.
*
* @param resId Resource id for the format string
* @param formatArgs The format arguments that will be used for substitution.
*/
public final String getString(@StringRes int resId, Object... formatArgs) {
return getResources().getString(resId, formatArgs);
}
/**
* Return the FragmentManager for interacting with fragments associated
* with this fragment's activity. Note that this will be non-null slightly
* before {@link #getActivity()}, during the time from when the fragment is
* placed in a {@link FragmentTransaction} until it is committed and
* attached to its activity.
*
*
*
*/
public void setRetainInstance(boolean retain) {
mRetainInstance = retain;
}
final public boolean getRetainInstance() {
return mRetainInstance;
}
/**
* Report that this fragment would like to participate in populating
* the options menu by receiving a call to {@link #onCreateOptionsMenu}
* and related methods.
*
* @param hasMenu If true, the fragment has menu items to contribute.
*/
public void setHasOptionsMenu(boolean hasMenu) {
if (mHasMenu != hasMenu) {
mHasMenu = hasMenu;
if (isAdded() && !isHidden()) {
mFragmentManager.invalidateOptionsMenu();
}
}
}
/**
* Set a hint for whether this fragment's menu should be visible. This
* is useful if you know that a fragment has been placed in your view
* hierarchy so that the user can not currently seen it, so any menu items
* it has should also not be shown.
*
* @param menuVisible The default is true, meaning the fragment's menu will
* be shown as usual. If false, the user will not see the menu.
*/
public void setMenuVisibility(boolean menuVisible) {
if (mMenuVisible != menuVisible) {
mMenuVisible = menuVisible;
if (mHasMenu && isAdded() && !isHidden()) {
mFragmentManager.invalidateOptionsMenu();
}
}
}
/**
* Set a hint to the system about whether this fragment's UI is currently visible
* to the user. This hint defaults to true and is persistent across fragment instance
* state save and restore.
*
* setUserVisibleHint to bring a fragment up to the started state before its
* FragmentTransaction had been committed. As some apps relied on this behavior,
* it is preserved for apps that declare a targetSdkVersion of 23 or lower.true because in this case the activity would not receive
* result callbacks including {@link #onRequestPermissionsResult(int, String[], int[])}.
*
* Note: It is possible that the permissions request interaction * with the user is interrupted. In this case you will receive empty permissions * and results arrays which should be treated as a cancellation. *
* * @param requestCode The request code passed in {@link #requestPermissions(String[], int)}. * @param permissions The requested permissions. Never null. * @param grantResults The grant results for the corresponding permissions * which is either {@link android.content.pm.PackageManager#PERMISSION_GRANTED} * or {@link android.content.pm.PackageManager#PERMISSION_DENIED}. Never null. * * @see #requestPermissions(String[], int) */ public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { /* callback - do nothing */ } /** * Gets whether you should show UI with rationale for requesting a permission. * You should do this only if you do not have the permission and the context in * which the permission is requested does not clearly communicate to the user * what would be the benefit from granting this permission. ** For example, if you write a camera app, requesting the camera permission * would be expected by the user and no rationale for why it is requested is * needed. If however, the app needs location for tagging photos then a non-tech * savvy user may wonder how location is related to taking photos. In this case * you may choose to show UI with rationale of requesting this permission. *
* * @param permission A permission your app wants to request. * @return Whether you can show permission rationale UI. * * @see Context#checkSelfPermission(String) * @see #requestPermissions(String[], int) * @see #onRequestPermissionsResult(int, String[], int[]) */ public boolean shouldShowRequestPermissionRationale(@NonNull String permission) { if (mHost != null) { return mHost.getContext().getPackageManager() .shouldShowRequestPermissionRationale(permission); } return false; } /** * Returns the LayoutInflater used to inflate Views of this Fragment. The default * implementation will throw an exception if the Fragment is not attached. * * @return The LayoutInflater used to inflate Views of this Fragment. */ public LayoutInflater onGetLayoutInflater(Bundle savedInstanceState) { if (mHost == null) { throw new IllegalStateException("onGetLayoutInflater() cannot be executed until the " + "Fragment is attached to the FragmentManager."); } final LayoutInflater result = mHost.onGetLayoutInflater(); if (mHost.onUseFragmentManagerInflaterFactory()) { getChildFragmentManager(); // Init if needed; use raw implementation below. result.setPrivateFactory(mChildFragmentManager.getLayoutInflaterFactory()); } return result; } /** * Returns the cached LayoutInflater used to inflate Views of this Fragment. If * {@link #onGetLayoutInflater(Bundle)} has not been called {@link #onGetLayoutInflater(Bundle)} * will be called with a {@code null} argument and that value will be cached. *
* The cached LayoutInflater will be replaced immediately prior to
* {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)} and cleared immediately after
* {@link #onDetach()}.
*
* @return The LayoutInflater used to inflate Views of this Fragment.
*/
public final LayoutInflater getLayoutInflater() {
if (mLayoutInflater == null) {
return performGetLayoutInflater(null);
}
return mLayoutInflater;
}
/**
* Calls {@link #onGetLayoutInflater(Bundle)} and caches the result for use by
* {@link #getLayoutInflater()}.
*
* @param savedInstanceState If the fragment is being re-created from
* a previous saved state, this is the state.
* @return The LayoutInflater used to inflate Views of this Fragment.
*/
LayoutInflater performGetLayoutInflater(Bundle savedInstanceState) {
LayoutInflater layoutInflater = onGetLayoutInflater(savedInstanceState);
mLayoutInflater = layoutInflater;
return mLayoutInflater;
}
/**
* @deprecated Use {@link #onInflate(Context, AttributeSet, Bundle)} instead.
*/
@Deprecated
@CallSuper
public void onInflate(AttributeSet attrs, Bundle savedInstanceState) {
mCalled = true;
}
/**
* Called when a fragment is being created as part of a view layout
* inflation, typically from setting the content view of an activity. This
* may be called immediately after the fragment is created from a This is called every time the fragment is inflated, even if it is
* being inflated into a new instance with saved state. It typically makes
* sense to re-parse the parameters each time, to allow them to change with
* different configurations. Here is a typical implementation of a fragment that can take parameters
* both through attributes supplied here as well from {@link #getArguments()}: Note that parsing the XML attributes uses a "styleable" resource. The
* declaration for the styleable used here is: The fragment can then be declared within its activity's content layout
* through a tag like this: This fragment can also be created dynamically from arguments given
* at runtime in the arguments Bundle; here is an example of doing so at
* creation of the containing activity: This is called after the attached fragment's Note that this can be called while the fragment's activity is
* still in the process of being created. As such, you can not rely
* on things like the activity's content view hierarchy being initialized
* at this point. If you want to do work once the activity itself is
* created, see {@link #onActivityCreated(Bundle)}.
*
* If your app's If you return a View from here, you will later be called in
* {@link #onDestroyView} when the view is being released.
*
* @param inflater The LayoutInflater object that can be used to inflate
* any views in the fragment,
* @param container If non-null, this is the parent view that the fragment's
* UI should be attached to. The fragment should not add the view itself,
* but this can be used to generate the LayoutParams of the view.
* @param savedInstanceState If non-null, this fragment is being re-constructed
* from a previous saved state as given here.
*
* @return Return the View for the fragment's UI, or null.
*/
@Nullable
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
Bundle savedInstanceState) {
return null;
}
/**
* Called immediately after {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}
* has returned, but before any saved state has been restored in to the view.
* This gives subclasses a chance to initialize themselves once
* they know their view hierarchy has been completely created. The fragment's
* view hierarchy is not however attached to its parent at this point.
* @param view The View returned by {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}.
* @param savedInstanceState If non-null, this fragment is being re-constructed
* from a previous saved state as given here.
*/
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
}
/**
* Get the root view for the fragment's layout (the one returned by {@link #onCreateView}),
* if provided.
*
* @return The fragment's root view, or null if it has no layout.
*/
@Nullable
public View getView() {
return mView;
}
/**
* Called when the fragment's activity has been created and this
* fragment's view hierarchy instantiated. It can be used to do final
* initialization once these pieces are in place, such as retrieving
* views or restoring state. It is also useful for fragments that use
* {@link #setRetainInstance(boolean)} to retain their instance,
* as this callback tells the fragment when it is fully associated with
* the new activity instance. This is called after {@link #onCreateView}
* and before {@link #onViewStateRestored(Bundle)}.
*
* @param savedInstanceState If the fragment is being re-created from
* a previous saved state, this is the state.
*/
@CallSuper
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
mCalled = true;
}
/**
* Called when all saved state has been restored into the view hierarchy
* of the fragment. This can be used to do initialization based on saved
* state that you are letting the view hierarchy track itself, such as
* whether check box widgets are currently checked. This is called
* after {@link #onActivityCreated(Bundle)} and before
* {@link #onStart()}.
*
* @param savedInstanceState If the fragment is being re-created from
* a previous saved state, this is the state.
*/
@CallSuper
public void onViewStateRestored(Bundle savedInstanceState) {
mCalled = true;
}
/**
* Called when the Fragment is visible to the user. This is generally
* tied to {@link Activity#onStart() Activity.onStart} of the containing
* Activity's lifecycle.
*/
@CallSuper
public void onStart() {
mCalled = true;
if (!mLoadersStarted) {
mLoadersStarted = true;
if (!mCheckedForLoaderManager) {
mCheckedForLoaderManager = true;
mLoaderManager = mHost.getLoaderManager(mWho, mLoadersStarted, false);
} else if (mLoaderManager != null) {
mLoaderManager.doStart();
}
}
}
/**
* Called when the fragment is visible to the user and actively running.
* This is generally
* tied to {@link Activity#onResume() Activity.onResume} of the containing
* Activity's lifecycle.
*/
@CallSuper
public void onResume() {
mCalled = true;
}
/**
* Called to ask the fragment to save its current dynamic state, so it
* can later be reconstructed in a new instance of its process is
* restarted. If a new instance of the fragment later needs to be
* created, the data you place in the Bundle here will be available
* in the Bundle given to {@link #onCreate(Bundle)},
* {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}, and
* {@link #onActivityCreated(Bundle)}.
*
* This corresponds to {@link Activity#onSaveInstanceState(Bundle)
* Activity.onSaveInstanceState(Bundle)} and most of the discussion there
* applies here as well. Note however: this method may be called
* at any time before {@link #onDestroy()}. There are many situations
* where a fragment may be mostly torn down (such as when placed on the
* back stack with no UI showing), but its state will not be saved until
* its owning activity actually needs to save its state.
*
* @param outState Bundle in which to place your saved state.
*/
public void onSaveInstanceState(Bundle outState) {
}
/**
* Called when the Fragment's activity changes from fullscreen mode to multi-window mode and
* visa-versa. This is generally tied to {@link Activity#onMultiWindowModeChanged} of the
* containing Activity. This method provides the same configuration that will be sent in the
* following {@link #onConfigurationChanged(Configuration)} call after the activity enters this
* mode.
*
* @param isInMultiWindowMode True if the activity is in multi-window mode.
* @param newConfig The new configuration of the activity with the state
* {@param isInMultiWindowMode}.
*/
public void onMultiWindowModeChanged(boolean isInMultiWindowMode, Configuration newConfig) {
onMultiWindowModeChanged(isInMultiWindowMode);
}
/**
* Called when the Fragment's activity changes from fullscreen mode to multi-window mode and
* visa-versa. This is generally tied to {@link Activity#onMultiWindowModeChanged} of the
* containing Activity.
*
* @param isInMultiWindowMode True if the activity is in multi-window mode.
*
* @deprecated Use {@link #onMultiWindowModeChanged(boolean, Configuration)} instead.
*/
@Deprecated
public void onMultiWindowModeChanged(boolean isInMultiWindowMode) {
}
/**
* Called by the system when the activity changes to and from picture-in-picture mode. This is
* generally tied to {@link Activity#onPictureInPictureModeChanged} of the containing Activity.
* This method provides the same configuration that will be sent in the following
* {@link #onConfigurationChanged(Configuration)} call after the activity enters this mode.
*
* @param isInPictureInPictureMode True if the activity is in picture-in-picture mode.
* @param newConfig The new configuration of the activity with the state
* {@param isInPictureInPictureMode}.
*/
public void onPictureInPictureModeChanged(boolean isInPictureInPictureMode,
Configuration newConfig) {
onPictureInPictureModeChanged(isInPictureInPictureMode);
}
/**
* Called by the system when the activity changes to and from picture-in-picture mode. This is
* generally tied to {@link Activity#onPictureInPictureModeChanged} of the containing Activity.
*
* @param isInPictureInPictureMode True if the activity is in picture-in-picture mode.
*
* @deprecated Use {@link #onPictureInPictureModeChanged(boolean, Configuration)} instead.
*/
@Deprecated
public void onPictureInPictureModeChanged(boolean isInPictureInPictureMode) {
}
@CallSuper
public void onConfigurationChanged(Configuration newConfig) {
mCalled = true;
}
/**
* Called when the Fragment is no longer resumed. This is generally
* tied to {@link Activity#onPause() Activity.onPause} of the containing
* Activity's lifecycle.
*/
@CallSuper
public void onPause() {
mCalled = true;
}
/**
* Called when the Fragment is no longer started. This is generally
* tied to {@link Activity#onStop() Activity.onStop} of the containing
* Activity's lifecycle.
*/
@CallSuper
public void onStop() {
mCalled = true;
}
@CallSuper
public void onLowMemory() {
mCalled = true;
}
@CallSuper
public void onTrimMemory(int level) {
mCalled = true;
}
/**
* Called when the view previously created by {@link #onCreateView} has
* been detached from the fragment. The next time the fragment needs
* to be displayed, a new view will be created. This is called
* after {@link #onStop()} and before {@link #onDestroy()}. It is called
* regardless of whether {@link #onCreateView} returned a
* non-null view. Internally it is called after the view's state has
* been saved but before it has been removed from its parent.
*/
@CallSuper
public void onDestroyView() {
mCalled = true;
}
/**
* Called when the fragment is no longer in use. This is called
* after {@link #onStop()} and before {@link #onDetach()}.
*/
@CallSuper
public void onDestroy() {
mCalled = true;
//Log.v("foo", "onDestroy: mCheckedForLoaderManager=" + mCheckedForLoaderManager
// + " mLoaderManager=" + mLoaderManager);
if (!mCheckedForLoaderManager) {
mCheckedForLoaderManager = true;
mLoaderManager = mHost.getLoaderManager(mWho, mLoadersStarted, false);
}
if (mLoaderManager != null) {
mLoaderManager.doDestroy();
}
}
/**
* Called by the fragment manager once this fragment has been removed,
* so that we don't have any left-over state if the application decides
* to re-use the instance. This only clears state that the framework
* internally manages, not things the application sets.
*/
void initState() {
mIndex = -1;
mWho = null;
mAdded = false;
mRemoving = false;
mFromLayout = false;
mInLayout = false;
mRestored = false;
mBackStackNesting = 0;
mFragmentManager = null;
mChildFragmentManager = null;
mHost = null;
mFragmentId = 0;
mContainerId = 0;
mTag = null;
mHidden = false;
mDetached = false;
mRetaining = false;
mLoaderManager = null;
mLoadersStarted = false;
mCheckedForLoaderManager = false;
}
/**
* Called when the fragment is no longer attached to its activity. This is called after
* {@link #onDestroy()}, except in the cases where the fragment instance is retained across
* Activity re-creation (see {@link #setRetainInstance(boolean)}), in which case it is called
* after {@link #onStop()}.
*/
@CallSuper
public void onDetach() {
mCalled = true;
}
/**
* Initialize the contents of the Activity's standard options menu. You
* should place your menu items in to menu. For this method
* to be called, you must have first called {@link #setHasOptionsMenu}. See
* {@link Activity#onCreateOptionsMenu(Menu) Activity.onCreateOptionsMenu}
* for more information.
*
* @param menu The options menu in which you place your items.
*
* @see #setHasOptionsMenu
* @see #onPrepareOptionsMenu
* @see #onOptionsItemSelected
*/
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
}
/**
* Prepare the Screen's standard options menu to be displayed. This is
* called right before the menu is shown, every time it is shown. You can
* use this method to efficiently enable/disable items or otherwise
* dynamically modify the contents. See
* {@link Activity#onPrepareOptionsMenu(Menu) Activity.onPrepareOptionsMenu}
* for more information.
*
* @param menu The options menu as last shown or first initialized by
* onCreateOptionsMenu().
*
* @see #setHasOptionsMenu
* @see #onCreateOptionsMenu
*/
public void onPrepareOptionsMenu(Menu menu) {
}
/**
* Called when this fragment's option menu items are no longer being
* included in the overall options menu. Receiving this call means that
* the menu needed to be rebuilt, but this fragment's items were not
* included in the newly built menu (its {@link #onCreateOptionsMenu(Menu, MenuInflater)}
* was not called).
*/
public void onDestroyOptionsMenu() {
}
/**
* This hook is called whenever an item in your options menu is selected.
* The default implementation simply returns false to have the normal
* processing happen (calling the item's Runnable or sending a message to
* its Handler as appropriate). You can use this method for any items
* for which you would like to do processing without those other
* facilities.
*
* Derived classes should call through to the base class for it to
* perform the default menu handling.
*
* @param item The menu item that was selected.
*
* @return boolean Return false to allow normal menu processing to
* proceed, true to consume it here.
*
* @see #onCreateOptionsMenu
*/
public boolean onOptionsItemSelected(MenuItem item) {
return false;
}
/**
* This hook is called whenever the options menu is being closed (either by the user canceling
* the menu with the back/menu button, or when an item is selected).
*
* @param menu The options menu as last shown or first initialized by
* onCreateOptionsMenu().
*/
public void onOptionsMenuClosed(Menu menu) {
}
/**
* Called when a context menu for the {@code view} is about to be shown.
* Unlike {@link #onCreateOptionsMenu}, this will be called every
* time the context menu is about to be shown and should be populated for
* the view (or item inside the view for {@link AdapterView} subclasses,
* this can be found in the {@code menuInfo})).
*
* Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
* item has been selected.
*
* The default implementation calls up to
* {@link Activity#onCreateContextMenu Activity.onCreateContextMenu}, though
* you can not call this implementation if you don't want that behavior.
*
* It is not safe to hold onto the context menu after this method returns.
* {@inheritDoc}
*/
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
getActivity().onCreateContextMenu(menu, v, menuInfo);
}
/**
* Registers a context menu to be shown for the given view (multiple views
* can show the context menu). This method will set the
* {@link OnCreateContextMenuListener} on the view to this fragment, so
* {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
* called when it is time to show the context menu.
*
* @see #unregisterForContextMenu(View)
* @param view The view that should show a context menu.
*/
public void registerForContextMenu(View view) {
view.setOnCreateContextMenuListener(this);
}
/**
* Prevents a context menu to be shown for the given view. This method will
* remove the {@link OnCreateContextMenuListener} on the view.
*
* @see #registerForContextMenu(View)
* @param view The view that should stop showing a context menu.
*/
public void unregisterForContextMenu(View view) {
view.setOnCreateContextMenuListener(null);
}
/**
* This hook is called whenever an item in a context menu is selected. The
* default implementation simply returns false to have the normal processing
* happen (calling the item's Runnable or sending a message to its Handler
* as appropriate). You can use this method for any items for which you
* would like to do processing without those other facilities.
*
* Use {@link MenuItem#getMenuInfo()} to get extra information set by the
* View that added this menu item.
*
* Derived classes should call through to the base class for it to perform
* the default menu handling.
*
* @param item The context menu item that was selected.
* @return boolean Return false to allow normal context menu processing to
* proceed, true to consume it here.
*/
public boolean onContextItemSelected(MenuItem item) {
return false;
}
/**
* When custom transitions are used with Fragments, the enter transition callback
* is called when this Fragment is attached or detached when not popping the back stack.
*
* @param callback Used to manipulate the shared element transitions on this Fragment
* when added not as a pop from the back stack.
*/
public void setEnterSharedElementCallback(SharedElementCallback callback) {
if (callback == null) {
if (mAnimationInfo == null) {
return; // already a null callback
}
callback = SharedElementCallback.NULL_CALLBACK;
}
ensureAnimationInfo().mEnterTransitionCallback = callback;
}
/**
* When custom transitions are used with Fragments, the exit transition callback
* is called when this Fragment is attached or detached when popping the back stack.
*
* @param callback Used to manipulate the shared element transitions on this Fragment
* when added as a pop from the back stack.
*/
public void setExitSharedElementCallback(SharedElementCallback callback) {
if (callback == null) {
if (mAnimationInfo == null) {
return; // already a null callback
}
callback = SharedElementCallback.NULL_CALLBACK;
}
ensureAnimationInfo().mExitTransitionCallback = callback;
}
/**
* Sets the Transition that will be used to move Views into the initial scene. The entering
* Views will be those that are regular Views or ViewGroups that have
* {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as entering is governed by changing visibility from
* {@link View#INVISIBLE} to {@link View#VISIBLE}. If
* This method gives the Fragment the ability to delay Fragment animations
* until all data is loaded. Until then, the added, shown, and
* attached Fragments will be INVISIBLE and removed, hidden, and detached Fragments won't
* be have their Views removed. The transaction runs when all postponed added Fragments in the
* transaction have called {@link #startPostponedEnterTransition()}.
*
* This method should be called before being added to the FragmentTransaction or
* in {@link #onCreate(Bundle)}, {@link #onAttach(Context)}, or
* {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}}.
* {@link #startPostponedEnterTransition()} must be called to allow the Fragment to
* start the transitions.
*
* When a FragmentTransaction is started that may affect a postponed FragmentTransaction,
* based on which containers are in their operations, the postponed FragmentTransaction
* will have its start triggered. The early triggering may result in faulty or nonexistent
* animations in the postponed transaction. FragmentTransactions that operate only on
* independent containers will not interfere with each other's postponement.
*
* Calling postponeEnterTransition on Fragments with a null View will not postpone the
* transition. Likewise, postponement only works if FragmentTransaction optimizations are
* enabled.
*
* @see Activity#postponeEnterTransition()
* @see FragmentTransaction#setReorderingAllowed(boolean)
*/
public void postponeEnterTransition() {
ensureAnimationInfo().mEnterTransitionPostponed = true;
}
/**
* Begin postponed transitions after {@link #postponeEnterTransition()} was called.
* If postponeEnterTransition() was called, you must call startPostponedEnterTransition()
* or {@link FragmentManager#executePendingTransactions()} to complete the FragmentTransaction.
* If postponement was interrupted with {@link FragmentManager#executePendingTransactions()},
* before {@code startPostponedEnterTransition()}, animations may not run or may execute
* improperly.
*
* @see Activity#startPostponedEnterTransition()
*/
public void startPostponedEnterTransition() {
if (mFragmentManager == null || mFragmentManager.mHost == null) {
ensureAnimationInfo().mEnterTransitionPostponed = false;
} else if (Looper.myLooper() != mFragmentManager.mHost.getHandler().getLooper()) {
mFragmentManager.mHost.getHandler().
postAtFrontOfQueue(this::callStartTransitionListener);
} else {
callStartTransitionListener();
}
}
/**
* Calls the start transition listener. This must be called on the UI thread.
*/
private void callStartTransitionListener() {
final OnStartEnterTransitionListener listener;
if (mAnimationInfo == null) {
listener = null;
} else {
mAnimationInfo.mEnterTransitionPostponed = false;
listener = mAnimationInfo.mStartEnterTransitionListener;
mAnimationInfo.mStartEnterTransitionListener = null;
}
if (listener != null) {
listener.onStartEnterTransition();
}
}
/**
* Returns true if mAnimationInfo is not null or the transition differs from the default value.
* This is broken out to ensure mAnimationInfo is properly locked when checking.
*/
private boolean shouldChangeTransition(Transition transition, Transition defaultValue) {
if (transition == defaultValue) {
return mAnimationInfo != null;
}
return true;
}
/**
* Print the Fragments's state into the given stream.
*
* @param prefix Text to print at the front of each line.
* @param fd The raw file descriptor that the dump is being sent to.
* @param writer The PrintWriter to which you should dump your state. This will be
* closed for you after you return.
* @param args additional arguments to the dump request.
*/
public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
writer.print(prefix); writer.print("mFragmentId=#");
writer.print(Integer.toHexString(mFragmentId));
writer.print(" mContainerId=#");
writer.print(Integer.toHexString(mContainerId));
writer.print(" mTag="); writer.println(mTag);
writer.print(prefix); writer.print("mState="); writer.print(mState);
writer.print(" mIndex="); writer.print(mIndex);
writer.print(" mWho="); writer.print(mWho);
writer.print(" mBackStackNesting="); writer.println(mBackStackNesting);
writer.print(prefix); writer.print("mAdded="); writer.print(mAdded);
writer.print(" mRemoving="); writer.print(mRemoving);
writer.print(" mFromLayout="); writer.print(mFromLayout);
writer.print(" mInLayout="); writer.println(mInLayout);
writer.print(prefix); writer.print("mHidden="); writer.print(mHidden);
writer.print(" mDetached="); writer.print(mDetached);
writer.print(" mMenuVisible="); writer.print(mMenuVisible);
writer.print(" mHasMenu="); writer.println(mHasMenu);
writer.print(prefix); writer.print("mRetainInstance="); writer.print(mRetainInstance);
writer.print(" mRetaining="); writer.print(mRetaining);
writer.print(" mUserVisibleHint="); writer.println(mUserVisibleHint);
if (mFragmentManager != null) {
writer.print(prefix); writer.print("mFragmentManager=");
writer.println(mFragmentManager);
}
if (mHost != null) {
writer.print(prefix); writer.print("mHost=");
writer.println(mHost);
}
if (mParentFragment != null) {
writer.print(prefix); writer.print("mParentFragment=");
writer.println(mParentFragment);
}
if (mArguments != null) {
writer.print(prefix); writer.print("mArguments="); writer.println(mArguments);
}
if (mSavedFragmentState != null) {
writer.print(prefix); writer.print("mSavedFragmentState=");
writer.println(mSavedFragmentState);
}
if (mSavedViewState != null) {
writer.print(prefix); writer.print("mSavedViewState=");
writer.println(mSavedViewState);
}
if (mTarget != null) {
writer.print(prefix); writer.print("mTarget="); writer.print(mTarget);
writer.print(" mTargetRequestCode=");
writer.println(mTargetRequestCode);
}
if (getNextAnim() != 0) {
writer.print(prefix); writer.print("mNextAnim="); writer.println(getNextAnim());
}
if (mContainer != null) {
writer.print(prefix); writer.print("mContainer="); writer.println(mContainer);
}
if (mView != null) {
writer.print(prefix); writer.print("mView="); writer.println(mView);
}
if (getAnimatingAway() != null) {
writer.print(prefix); writer.print("mAnimatingAway=");
writer.println(getAnimatingAway());
writer.print(prefix); writer.print("mStateAfterAnimating=");
writer.println(getStateAfterAnimating());
}
if (mLoaderManager != null) {
writer.print(prefix); writer.println("Loader Manager:");
mLoaderManager.dump(prefix + " ", fd, writer, args);
}
if (mChildFragmentManager != null) {
writer.print(prefix); writer.println("Child " + mChildFragmentManager + ":");
mChildFragmentManager.dump(prefix + " ", fd, writer, args);
}
}
Fragment findFragmentByWho(String who) {
if (who.equals(mWho)) {
return this;
}
if (mChildFragmentManager != null) {
return mChildFragmentManager.findFragmentByWho(who);
}
return null;
}
void instantiateChildFragmentManager() {
mChildFragmentManager = new FragmentManagerImpl();
mChildFragmentManager.attachController(mHost, new FragmentContainer() {
@Override
@Nullable
public onAttach and before
* the attached fragment's onCreate if the fragment has not yet had a previous
* call to onCreate.targetSdkVersion is {@link android.os.Build.VERSION_CODES#M}
* or lower, child fragments being restored from the savedInstanceState are restored after
* onCreate returns. When targeting {@link android.os.Build.VERSION_CODES#N} or
* above and running on an N or newer platform version
* they are restored by Fragment.onCreate.transition is null,
* entering Views will remain unaffected.
*
* @param transition The Transition to use to move Views into the initial Scene.
* @attr ref android.R.styleable#Fragment_fragmentEnterTransition
*/
public void setEnterTransition(Transition transition) {
if (shouldChangeTransition(transition, null)) {
ensureAnimationInfo().mEnterTransition = transition;
}
}
/**
* Returns the Transition that will be used to move Views into the initial scene. The entering
* Views will be those that are regular Views or ViewGroups that have
* {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as entering is governed by changing visibility from
* {@link View#INVISIBLE} to {@link View#VISIBLE}.
*
* @return the Transition to use to move Views into the initial Scene.
* @attr ref android.R.styleable#Fragment_fragmentEnterTransition
*/
public Transition getEnterTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mEnterTransition;
}
/**
* Sets the Transition that will be used to move Views out of the scene when the Fragment is
* preparing to be removed, hidden, or detached because of popping the back stack. The exiting
* Views will be those that are regular Views or ViewGroups that have
* {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as entering is governed by changing visibility from
* {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null,
* entering Views will remain unaffected. If nothing is set, the default will be to
* use the same value as set in {@link #setEnterTransition(android.transition.Transition)}.
*
* @param transition The Transition to use to move Views out of the Scene when the Fragment
* is preparing to close.
* @attr ref android.R.styleable#Fragment_fragmentExitTransition
*/
public void setReturnTransition(Transition transition) {
if (shouldChangeTransition(transition, USE_DEFAULT_TRANSITION)) {
ensureAnimationInfo().mReturnTransition = transition;
}
}
/**
* Returns the Transition that will be used to move Views out of the scene when the Fragment is
* preparing to be removed, hidden, or detached because of popping the back stack. The exiting
* Views will be those that are regular Views or ViewGroups that have
* {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as entering is governed by changing visibility from
* {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null,
* entering Views will remain unaffected.
*
* @return the Transition to use to move Views out of the Scene when the Fragment
* is preparing to close.
* @attr ref android.R.styleable#Fragment_fragmentExitTransition
*/
public Transition getReturnTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mReturnTransition == USE_DEFAULT_TRANSITION ? getEnterTransition()
: mAnimationInfo.mReturnTransition;
}
/**
* Sets the Transition that will be used to move Views out of the scene when the
* fragment is removed, hidden, or detached when not popping the back stack.
* The exiting Views will be those that are regular Views or ViewGroups that
* have {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as exiting is governed by changing visibility
* from {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null, the views will
* remain unaffected.
*
* @param transition The Transition to use to move Views out of the Scene when the Fragment
* is being closed not due to popping the back stack.
* @attr ref android.R.styleable#Fragment_fragmentExitTransition
*/
public void setExitTransition(Transition transition) {
if (shouldChangeTransition(transition, null)) {
ensureAnimationInfo().mExitTransition = transition;
}
}
/**
* Returns the Transition that will be used to move Views out of the scene when the
* fragment is removed, hidden, or detached when not popping the back stack.
* The exiting Views will be those that are regular Views or ViewGroups that
* have {@link ViewGroup#isTransitionGroup} return true. Typical Transitions will extend
* {@link android.transition.Visibility} as exiting is governed by changing visibility
* from {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null, the views will
* remain unaffected.
*
* @return the Transition to use to move Views out of the Scene when the Fragment
* is being closed not due to popping the back stack.
* @attr ref android.R.styleable#Fragment_fragmentExitTransition
*/
public Transition getExitTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mExitTransition;
}
/**
* Sets the Transition that will be used to move Views in to the scene when returning due
* to popping a back stack. The entering Views will be those that are regular Views
* or ViewGroups that have {@link ViewGroup#isTransitionGroup} return true. Typical Transitions
* will extend {@link android.transition.Visibility} as exiting is governed by changing
* visibility from {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null,
* the views will remain unaffected. If nothing is set, the default will be to use the same
* transition as {@link #setExitTransition(android.transition.Transition)}.
*
* @param transition The Transition to use to move Views into the scene when reentering from a
* previously-started Activity.
* @attr ref android.R.styleable#Fragment_fragmentReenterTransition
*/
public void setReenterTransition(Transition transition) {
if (shouldChangeTransition(transition, USE_DEFAULT_TRANSITION)) {
ensureAnimationInfo().mReenterTransition = transition;
}
}
/**
* Returns the Transition that will be used to move Views in to the scene when returning due
* to popping a back stack. The entering Views will be those that are regular Views
* or ViewGroups that have {@link ViewGroup#isTransitionGroup} return true. Typical Transitions
* will extend {@link android.transition.Visibility} as exiting is governed by changing
* visibility from {@link View#VISIBLE} to {@link View#INVISIBLE}. If transition is null,
* the views will remain unaffected. If nothing is set, the default will be to use the same
* transition as {@link #setExitTransition(android.transition.Transition)}.
*
* @return the Transition to use to move Views into the scene when reentering from a
* previously-started Activity.
* @attr ref android.R.styleable#Fragment_fragmentReenterTransition
*/
public Transition getReenterTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mReenterTransition == USE_DEFAULT_TRANSITION ? getExitTransition()
: mAnimationInfo.mReenterTransition;
}
/**
* Sets the Transition that will be used for shared elements transferred into the content
* Scene. Typical Transitions will affect size and location, such as
* {@link android.transition.ChangeBounds}. A null
* value will cause transferred shared elements to blink to the final position.
*
* @param transition The Transition to use for shared elements transferred into the content
* Scene.
* @attr ref android.R.styleable#Fragment_fragmentSharedElementEnterTransition
*/
public void setSharedElementEnterTransition(Transition transition) {
if (shouldChangeTransition(transition, null)) {
ensureAnimationInfo().mSharedElementEnterTransition = transition;
}
}
/**
* Returns the Transition that will be used for shared elements transferred into the content
* Scene. Typical Transitions will affect size and location, such as
* {@link android.transition.ChangeBounds}. A null
* value will cause transferred shared elements to blink to the final position.
*
* @return The Transition to use for shared elements transferred into the content
* Scene.
* @attr ref android.R.styleable#Fragment_fragmentSharedElementEnterTransition
*/
public Transition getSharedElementEnterTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mSharedElementEnterTransition;
}
/**
* Sets the Transition that will be used for shared elements transferred back during a
* pop of the back stack. This Transition acts in the leaving Fragment.
* Typical Transitions will affect size and location, such as
* {@link android.transition.ChangeBounds}. A null
* value will cause transferred shared elements to blink to the final position.
* If no value is set, the default will be to use the same value as
* {@link #setSharedElementEnterTransition(android.transition.Transition)}.
*
* @param transition The Transition to use for shared elements transferred out of the content
* Scene.
* @attr ref android.R.styleable#Fragment_fragmentSharedElementReturnTransition
*/
public void setSharedElementReturnTransition(Transition transition) {
if (shouldChangeTransition(transition, USE_DEFAULT_TRANSITION)) {
ensureAnimationInfo().mSharedElementReturnTransition = transition;
}
}
/**
* Return the Transition that will be used for shared elements transferred back during a
* pop of the back stack. This Transition acts in the leaving Fragment.
* Typical Transitions will affect size and location, such as
* {@link android.transition.ChangeBounds}. A null
* value will cause transferred shared elements to blink to the final position.
* If no value is set, the default will be to use the same value as
* {@link #setSharedElementEnterTransition(android.transition.Transition)}.
*
* @return The Transition to use for shared elements transferred out of the content
* Scene.
* @attr ref android.R.styleable#Fragment_fragmentSharedElementReturnTransition
*/
public Transition getSharedElementReturnTransition() {
if (mAnimationInfo == null) {
return null;
}
return mAnimationInfo.mSharedElementReturnTransition == USE_DEFAULT_TRANSITION
? getSharedElementEnterTransition()
: mAnimationInfo.mSharedElementReturnTransition;
}
/**
* Sets whether the exit transition and enter transition overlap or not.
* When true, the enter transition will start as soon as possible. When false, the
* enter transition will wait until the exit transition completes before starting.
*
* @param allow true to start the enter transition when possible or false to
* wait until the exiting transition completes.
* @attr ref android.R.styleable#Fragment_fragmentAllowEnterTransitionOverlap
*/
public void setAllowEnterTransitionOverlap(boolean allow) {
ensureAnimationInfo().mAllowEnterTransitionOverlap = allow;
}
/**
* Returns whether the exit transition and enter transition overlap or not.
* When true, the enter transition will start as soon as possible. When false, the
* enter transition will wait until the exit transition completes before starting.
*
* @return true when the enter transition should start as soon as possible or false to
* when it should wait until the exiting transition completes.
* @attr ref android.R.styleable#Fragment_fragmentAllowEnterTransitionOverlap
*/
public boolean getAllowEnterTransitionOverlap() {
return (mAnimationInfo == null || mAnimationInfo.mAllowEnterTransitionOverlap == null)
? true : mAnimationInfo.mAllowEnterTransitionOverlap;
}
/**
* Sets whether the return transition and reenter transition overlap or not.
* When true, the reenter transition will start as soon as possible. When false, the
* reenter transition will wait until the return transition completes before starting.
*
* @param allow true to start the reenter transition when possible or false to wait until the
* return transition completes.
* @attr ref android.R.styleable#Fragment_fragmentAllowReturnTransitionOverlap
*/
public void setAllowReturnTransitionOverlap(boolean allow) {
ensureAnimationInfo().mAllowReturnTransitionOverlap = allow;
}
/**
* Returns whether the return transition and reenter transition overlap or not.
* When true, the reenter transition will start as soon as possible. When false, the
* reenter transition will wait until the return transition completes before starting.
*
* @return true to start the reenter transition when possible or false to wait until the
* return transition completes.
* @attr ref android.R.styleable#Fragment_fragmentAllowReturnTransitionOverlap
*/
public boolean getAllowReturnTransitionOverlap() {
return (mAnimationInfo == null || mAnimationInfo.mAllowReturnTransitionOverlap == null)
? true : mAnimationInfo.mAllowReturnTransitionOverlap;
}
/**
* Postpone the entering Fragment transition until {@link #startPostponedEnterTransition()}
* or {@link FragmentManager#executePendingTransactions()} has been called.
*