FragmentTransaction

public abstract class FragmentTransaction


Static library support version of the framework's android.app.FragmentTransaction. Used to write apps that run on platforms prior to Android 3.0. When running on Android 3.0 or above, this implementation is still used; it does not try to switch to the framework's implementation. See the framework SDK documentation for a class overview.

Summary

Constants

static final int

Bit mask that is set for all enter transitions.

static final int

Bit mask that is set for all exit transitions.

static final int

Fragment is being removed from the stack

static final int

Fragment should simply fade in or out; that is, no strong navigation associated with it except that it is appearing or disappearing for some reason.

static final int

Fragment is being removed from the stack with Activity close transition.

static final int

Fragment is being added onto the stack with Activity open transition.

static final int

Fragment is being added onto the stack

static final int

No animation for transition.

static final int

Not set up for a transition.

Public constructors

This method is deprecated.

You should not instantiate a FragmentTransaction except via beginTransaction.

Public methods

@NonNull FragmentTransaction
add(@IdRes int containerViewId, @NonNull Fragment fragment)

Calls add with a null tag.

@NonNull FragmentTransaction
add(@NonNull Fragment fragment, @Nullable String tag)

Calls add with a 0 containerViewId.

final @NonNull FragmentTransaction
add(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args
)

Calls add with a null tag.

@NonNull FragmentTransaction
add(
    @IdRes int containerViewId,
    @NonNull Fragment fragment,
    @Nullable String tag
)

Add a fragment to the activity state.

final @NonNull FragmentTransaction
add(
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Calls add with a 0 containerViewId.

final @NonNull FragmentTransaction
add(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Add a fragment to the activity state.

@NonNull FragmentTransaction
addSharedElement(@NonNull View sharedElement, @NonNull String name)

Used with custom Transitions to map a View from a removed or hidden Fragment to a View from a shown or added Fragment.

@NonNull FragmentTransaction

Add this transaction to the back stack.

@NonNull FragmentTransaction
attach(@NonNull Fragment fragment)

Re-attach a fragment after it had previously been detached from the UI with detach.

abstract int

Schedules a commit of this transaction.

abstract int

Like commit but allows the commit to be executed after an activity's state is saved.

abstract void

Commits this transaction synchronously.

abstract void

Like commitNow but allows the commit to be executed after an activity's state is saved.

@NonNull FragmentTransaction
detach(@NonNull Fragment fragment)

Detach the given fragment from the UI.

@NonNull FragmentTransaction

Disallow calls to addToBackStack.

@NonNull FragmentTransaction
hide(@NonNull Fragment fragment)

Hides an existing fragment.

boolean

Returns true if this FragmentTransaction is allowed to be added to the back stack.

boolean
@NonNull FragmentTransaction
remove(@NonNull Fragment fragment)

Remove an existing fragment.

@NonNull FragmentTransaction
replace(@IdRes int containerViewId, @NonNull Fragment fragment)

Calls replace with a null tag.

final @NonNull FragmentTransaction
replace(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args
)

Calls replace with a null tag.

@NonNull FragmentTransaction
replace(
    @IdRes int containerViewId,
    @NonNull Fragment fragment,
    @Nullable String tag
)

Replace an existing fragment that was added to a container.

final @NonNull FragmentTransaction
replace(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Replace an existing fragment that was added to a container.

@NonNull FragmentTransaction

Add a Runnable to this transaction that will be run after this transaction has been committed.

@NonNull FragmentTransaction
setAllowOptimization(boolean allowOptimization)

This method is deprecated.

This has been renamed setReorderingAllowed.

@NonNull FragmentTransaction

This method is deprecated.

Store breadcrumb short titles separately from fragment transactions.

@NonNull FragmentTransaction

This method is deprecated.

Store breadcrumb short titles separately from fragment transactions.

@NonNull FragmentTransaction

This method is deprecated.

Store breadcrumb titles separately from fragment transactions.

@NonNull FragmentTransaction

This method is deprecated.

Store breadcrumb titles separately from fragment transactions.

@NonNull FragmentTransaction
setCustomAnimations(
    @AnimatorRes @AnimRes int enter,
    @AnimatorRes @AnimRes int exit
)

Set specific animation resources to run for the fragments that are entering and exiting in this transaction.

@NonNull FragmentTransaction
setCustomAnimations(
    @AnimatorRes @AnimRes int enter,
    @AnimatorRes @AnimRes int exit,
    @AnimatorRes @AnimRes int popEnter,
    @AnimatorRes @AnimRes int popExit
)

Set specific animation resources to run for the fragments that are entering and exiting in this transaction.

@NonNull FragmentTransaction

Set a ceiling for the state of an active fragment in this FragmentManager.

@NonNull FragmentTransaction

Set a currently active fragment in this FragmentManager as the primary navigation fragment.

@NonNull FragmentTransaction
setReorderingAllowed(boolean reorderingAllowed)

Sets whether or not to allow optimizing operations within and across transactions.

@NonNull FragmentTransaction
setTransition(int transition)

Select a standard transition animation for this transaction.

@NonNull FragmentTransaction

This method is deprecated.

The desired functionality never worked correctly.

@NonNull FragmentTransaction
show(@NonNull Fragment fragment)

Shows a previously hidden fragment.

Extension functions

final @NonNull FragmentTransaction
<F extends Fragment> FragmentTransactionKt.add(
    @NonNull FragmentTransaction receiver,
    @NonNull String tag,
    Bundle args
)

Add a fragment to the associated FragmentManager without adding the Fragment to any container view.

final @NonNull FragmentTransaction
<F extends Fragment> FragmentTransactionKt.add(
    @NonNull FragmentTransaction receiver,
    @IdRes int containerViewId,
    String tag,
    Bundle args
)

Add a fragment to the associated FragmentManager, inflating the Fragment's view into the container view specified by containerViewId, to later retrieve via FragmentManager.findFragmentById.

final @NonNull FragmentTransaction
<F extends Fragment> FragmentTransactionKt.replace(
    @NonNull FragmentTransaction receiver,
    @IdRes int containerViewId,
    String tag,
    Bundle args
)

Replace an existing fragment that was added to a container.

Constants

TRANSIT_ENTER_MASK

Added in 1.1.0
public static final int TRANSIT_ENTER_MASK = 4096

Bit mask that is set for all enter transitions.

TRANSIT_EXIT_MASK

Added in 1.1.0
public static final int TRANSIT_EXIT_MASK = 8192

Bit mask that is set for all exit transitions.

TRANSIT_FRAGMENT_CLOSE

Added in 1.1.0
public static final int TRANSIT_FRAGMENT_CLOSE = 8194

Fragment is being removed from the stack

TRANSIT_FRAGMENT_FADE

Added in 1.1.0
public static final int TRANSIT_FRAGMENT_FADE = 4099

Fragment should simply fade in or out; that is, no strong navigation associated with it except that it is appearing or disappearing for some reason.

TRANSIT_FRAGMENT_MATCH_ACTIVITY_CLOSE

Added in 1.4.0
public static final int TRANSIT_FRAGMENT_MATCH_ACTIVITY_CLOSE = 8197

Fragment is being removed from the stack with Activity close transition.

TRANSIT_FRAGMENT_MATCH_ACTIVITY_OPEN

Added in 1.4.0
public static final int TRANSIT_FRAGMENT_MATCH_ACTIVITY_OPEN = 4100

Fragment is being added onto the stack with Activity open transition.

TRANSIT_FRAGMENT_OPEN

Added in 1.1.0
public static final int TRANSIT_FRAGMENT_OPEN = 4097

Fragment is being added onto the stack

TRANSIT_NONE

Added in 1.1.0
public static final int TRANSIT_NONE = 0

No animation for transition.

TRANSIT_UNSET

Added in 1.1.0
public static final int TRANSIT_UNSET = -1

Not set up for a transition.

Public constructors

FragmentTransaction

Added in 1.1.0
Deprecated in 1.2.0
public FragmentTransaction()

Public methods

add

Added in 1.1.0
public @NonNull FragmentTransaction add(@IdRes int containerViewId, @NonNull Fragment fragment)

Calls add with a null tag.

add

Added in 1.1.0
public @NonNull FragmentTransaction add(@NonNull Fragment fragment, @Nullable String tag)

Calls add with a 0 containerViewId.

add

Added in 1.2.0
public final @NonNull FragmentTransaction add(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args
)

Calls add with a null tag.

add

Added in 1.1.0
public @NonNull FragmentTransaction add(
    @IdRes int containerViewId,
    @NonNull Fragment fragment,
    @Nullable String tag
)

Add a fragment to the activity state. This fragment may optionally also have its view (if Fragment.onCreateView returns non-null) into a container view of the activity.

Parameters
@IdRes int containerViewId

Optional identifier of the container this fragment is to be placed in. If 0, it will not be placed in a container.

@NonNull Fragment fragment

The fragment to be added. This fragment must not already be added to the activity.

@Nullable String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag(String).

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

add

Added in 1.2.0
public final @NonNull FragmentTransaction add(
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Calls add with a 0 containerViewId.

add

Added in 1.2.0
public final @NonNull FragmentTransaction add(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Add a fragment to the activity state. This fragment may optionally also have its view (if Fragment.onCreateView returns non-null) into a container view of the activity.

Parameters
@IdRes int containerViewId

Optional identifier of the container this fragment is to be placed in. If 0, it will not be placed in a container.

@NonNull Class<Fragment> fragmentClass

The fragment to be added, created via the FragmentManager's FragmentFactory.

@Nullable Bundle args

Optional arguments to be set on the fragment.

@Nullable String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag(String).

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

addSharedElement

Added in 1.1.0
public @NonNull FragmentTransaction addSharedElement(@NonNull View sharedElement, @NonNull String name)

Used with custom Transitions to map a View from a removed or hidden Fragment to a View from a shown or added Fragment. sharedElement must have a unique transitionName in the View hierarchy.

Parameters
@NonNull View sharedElement

A View in a disappearing Fragment to match with a View in an appearing Fragment.

@NonNull String name

The transitionName for a View in an appearing Fragment to match to the shared element.

addToBackStack

Added in 1.1.0
public @NonNull FragmentTransaction addToBackStack(@Nullable String name)

Add this transaction to the back stack. This means that the transaction will be remembered after it is committed, and will reverse its operation when later popped off the stack.

setReorderingAllowed must be set to true in the same transaction as addToBackStack() to allow the pop of that transaction to be reordered.

Parameters
@Nullable String name

An optional name for this back stack state, or null.

attach

Added in 1.1.0
public @NonNull FragmentTransaction attach(@NonNull Fragment fragment)

Re-attach a fragment after it had previously been detached from the UI with detach. This causes its view hierarchy to be re-created, attached to the UI, and displayed.

Parameters
@NonNull Fragment fragment

The fragment to be attached.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

commit

Added in 1.1.0
public abstract int commit()

Schedules a commit of this transaction. The commit does not happen immediately; it will be scheduled as work on the main thread to be done the next time that thread is ready.

A transaction can only be committed with this method prior to its containing activity saving its state. If the commit is attempted after that point, an exception will be thrown. This is because the state after the commit can be lost if the activity needs to be restored from its state. See commitAllowingStateLoss for situations where it may be okay to lose the commit.

Returns
int

Returns the identifier of this transaction's back stack entry, if addToBackStack had been called. Otherwise, returns a negative number.

commitAllowingStateLoss

Added in 1.1.0
public abstract int commitAllowingStateLoss()

Like commit but allows the commit to be executed after an activity's state is saved. This is dangerous because the commit can be lost if the activity needs to later be restored from its state, so this should only be used for cases where it is okay for the UI state to change unexpectedly on the user.

commitNow

Added in 1.1.0
@MainThread
public abstract void commitNow()

Commits this transaction synchronously. Any added fragments will be initialized and brought completely to the lifecycle state of their host and any removed fragments will be torn down accordingly before this call returns. Committing a transaction in this way allows fragments to be added as dedicated, encapsulated components that monitor the lifecycle state of their host while providing firmer ordering guarantees around when those fragments are fully initialized and ready. Fragments that manage views will have those views created and attached.

Calling commitNow is preferable to calling commit followed by executePendingTransactions as the latter will have the side effect of attempting to commit all currently pending transactions whether that is the desired behavior or not.

Transactions committed in this way may not be added to the FragmentManager's back stack, as doing so would break other expected ordering guarantees for other asynchronously committed transactions. This method will throw IllegalStateException if the transaction previously requested to be added to the back stack with addToBackStack.

A transaction can only be committed with this method prior to its containing activity saving its state. If the commit is attempted after that point, an exception will be thrown. This is because the state after the commit can be lost if the activity needs to be restored from its state. See commitAllowingStateLoss for situations where it may be okay to lose the commit.

commitNowAllowingStateLoss

Added in 1.1.0
@MainThread
public abstract void commitNowAllowingStateLoss()

Like commitNow but allows the commit to be executed after an activity's state is saved. This is dangerous because the commit can be lost if the activity needs to later be restored from its state, so this should only be used for cases where it is okay for the UI state to change unexpectedly on the user.

detach

Added in 1.1.0
public @NonNull FragmentTransaction detach(@NonNull Fragment fragment)

Detach the given fragment from the UI. This is the same state as when it is put on the back stack: the fragment is removed from the UI, however its state is still being actively managed by the fragment manager. When going into this state its view hierarchy is destroyed.

Parameters
@NonNull Fragment fragment

The fragment to be detached.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

disallowAddToBackStack

Added in 1.1.0
public @NonNull FragmentTransaction disallowAddToBackStack()

Disallow calls to addToBackStack. Any future calls to addToBackStack will throw IllegalStateException. If addToBackStack has already been called, this method will throw IllegalStateException.

hide

Added in 1.1.0
public @NonNull FragmentTransaction hide(@NonNull Fragment fragment)

Hides an existing fragment. This is only relevant for fragments whose views have been added to a container, as this will cause the view to be hidden.

Parameters
@NonNull Fragment fragment

The fragment to be hidden.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

isAddToBackStackAllowed

Added in 1.1.0
public boolean isAddToBackStackAllowed()

Returns true if this FragmentTransaction is allowed to be added to the back stack. If this method would return false, addToBackStack will throw IllegalStateException.

Returns
boolean

True if addToBackStack is permitted on this transaction.

isEmpty

Added in 1.1.0
public boolean isEmpty()
Returns
boolean

true if this transaction contains no operations, false otherwise.

remove

Added in 1.1.0
public @NonNull FragmentTransaction remove(@NonNull Fragment fragment)

Remove an existing fragment. If it was added to a container, its view is also removed from that container.

Parameters
@NonNull Fragment fragment

The fragment to be removed.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

replace

Added in 1.1.0
public @NonNull FragmentTransaction replace(@IdRes int containerViewId, @NonNull Fragment fragment)

Calls replace with a null tag.

replace

Added in 1.2.0
public final @NonNull FragmentTransaction replace(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args
)

Calls replace with a null tag.

replace

Added in 1.1.0
public @NonNull FragmentTransaction replace(
    @IdRes int containerViewId,
    @NonNull Fragment fragment,
    @Nullable String tag
)

Replace an existing fragment that was added to a container. This is essentially the same as calling remove for all currently added fragments that were added with the same containerViewId and then add with the same arguments given here.

Parameters
@IdRes int containerViewId

Identifier of the container whose fragment(s) are to be replaced.

@NonNull Fragment fragment

The new fragment to place in the container.

@Nullable String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag(String).

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

replace

Added in 1.2.0
public final @NonNull FragmentTransaction replace(
    @IdRes int containerViewId,
    @NonNull Class<Fragment> fragmentClass,
    @Nullable Bundle args,
    @Nullable String tag
)

Replace an existing fragment that was added to a container. This is essentially the same as calling remove for all currently added fragments that were added with the same containerViewId and then add with the same arguments given here.

Parameters
@IdRes int containerViewId

Identifier of the container whose fragment(s) are to be replaced.

@NonNull Class<Fragment> fragmentClass

The new fragment to place in the container, created via the FragmentManager's FragmentFactory.

@Nullable Bundle args

Optional arguments to be set on the fragment.

@Nullable String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag(String).

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

runOnCommit

Added in 1.1.0
public @NonNull FragmentTransaction runOnCommit(@NonNull Runnable runnable)

Add a Runnable to this transaction that will be run after this transaction has been committed. If fragment transactions are optimized this may be after other subsequent fragment operations have also taken place, or operations in this transaction may have been optimized out due to the presence of a subsequent fragment transaction in the batch.

If a transaction is committed using commitAllowingStateLoss this runnable may be executed when the FragmentManager is in a state where new transactions may not be committed without allowing state loss.

runOnCommit may not be used with transactions added to the back stack as Runnables cannot be persisted with back stack state. IllegalStateException will be thrown if addToBackStack has been previously called for this transaction or if it is called after a call to runOnCommit.

Parameters
@NonNull Runnable runnable

Runnable to add

Returns
@NonNull FragmentTransaction

this FragmentTransaction

setAllowOptimization

Added in 1.1.0
Deprecated in 1.1.0
public @NonNull FragmentTransaction setAllowOptimization(boolean allowOptimization)

setBreadCrumbShortTitle

Added in 1.1.0
Deprecated in 1.2.0
public @NonNull FragmentTransaction setBreadCrumbShortTitle(@StringRes int res)

Set the short title to show as a bread crumb when this transaction is on the back stack.

Parameters
@StringRes int res

A string resource containing the title.

setBreadCrumbShortTitle

Added in 1.1.0
Deprecated in 1.2.0
public @NonNull FragmentTransaction setBreadCrumbShortTitle(@Nullable CharSequence text)

Like setBreadCrumbShortTitle but taking a raw string; this method is not recommended, as the string can not be changed later if the locale changes.

setBreadCrumbTitle

Added in 1.1.0
Deprecated in 1.2.0
public @NonNull FragmentTransaction setBreadCrumbTitle(@StringRes int res)

Set the full title to show as a bread crumb when this transaction is on the back stack.

Parameters
@StringRes int res

A string resource containing the title.

setBreadCrumbTitle

Added in 1.1.0
Deprecated in 1.2.0
public @NonNull FragmentTransaction setBreadCrumbTitle(@Nullable CharSequence text)

Like setBreadCrumbTitle but taking a raw string; this method is not recommended, as the string can not be changed later if the locale changes.

setCustomAnimations

Added in 1.1.0
public @NonNull FragmentTransaction setCustomAnimations(
    @AnimatorRes @AnimRes int enter,
    @AnimatorRes @AnimRes int exit
)

Set specific animation resources to run for the fragments that are entering and exiting in this transaction. These animations will not be played when popping the back stack.

This method applies the custom animations to all future fragment operations; previous operations are unaffected. Fragment operations in the same FragmentTransaction can set different animations by calling this method prior to each operation, e.g:

 fragmentManager.beginTransaction()
     .setCustomAnimations(enter1, exit1)
     .add(MyFragmentClass, args, tag1) // this fragment gets the first animations
     .setCustomAnimations(enter2, exit2)
     .add(MyFragmentClass, args, tag2) // this fragment gets the second animations
     .commit()
Parameters
@AnimatorRes @AnimRes int enter

An animation or animator resource ID used for the enter animation on the view of the fragment being added or attached.

@AnimatorRes @AnimRes int exit

An animation or animator resource ID used for the exit animation on the view of the fragment being removed or detached.

setCustomAnimations

Added in 1.1.0
public @NonNull FragmentTransaction setCustomAnimations(
    @AnimatorRes @AnimRes int enter,
    @AnimatorRes @AnimRes int exit,
    @AnimatorRes @AnimRes int popEnter,
    @AnimatorRes @AnimRes int popExit
)

Set specific animation resources to run for the fragments that are entering and exiting in this transaction. The popEnter and popExit animations will be played for enter/exit operations specifically when popping the back stack.

This method applies the custom animations to all future fragment operations; previous operations are unaffected. Fragment operations in the same FragmentTransaction can set different animations by calling this method prior to each operation, e.g:

 fragmentManager.beginTransaction()
     .setCustomAnimations(enter1, exit1, popEnter1, popExit1)
     .add(MyFragmentClass, args, tag1) // this fragment gets the first animations
     .setCustomAnimations(enter2, exit2, popEnter2, popExit2)
     .add(MyFragmentClass, args, tag2) // this fragment gets the second animations
     .commit()
Parameters
@AnimatorRes @AnimRes int enter

An animation or animator resource ID used for the enter animation on the view of the fragment being added or attached.

@AnimatorRes @AnimRes int exit

An animation or animator resource ID used for the exit animation on the view of the fragment being removed or detached.

@AnimatorRes @AnimRes int popEnter

An animation or animator resource ID used for the enter animation on the view of the fragment being readded or reattached caused by popBackStack or similar methods.

@AnimatorRes @AnimRes int popExit

An animation or animator resource ID used for the enter animation on the view of the fragment being removed or detached caused by popBackStack or similar methods.

setMaxLifecycle

Added in 1.1.0
public @NonNull FragmentTransaction setMaxLifecycle(@NonNull Fragment fragment, @NonNull Lifecycle.State state)

Set a ceiling for the state of an active fragment in this FragmentManager. If fragment is already above the received state, it will be forced down to the correct state.

The fragment provided must currently be added to the FragmentManager to have it's Lifecycle state capped, or previously added as part of this transaction. If the INITIALIZED is passed in as the Lifecycle.State and the provided fragment has already moved beyond INITIALIZED, an IllegalArgumentException will be thrown.

If the DESTROYED is passed in as the Lifecycle.State an IllegalArgumentException will be thrown.

Parameters
@NonNull Fragment fragment

the fragment to have it's state capped.

@NonNull Lifecycle.State state

the ceiling state for the fragment.

Returns
@NonNull FragmentTransaction

the same FragmentTransaction instance

setPrimaryNavigationFragment

Added in 1.1.0
public @NonNull FragmentTransaction setPrimaryNavigationFragment(@Nullable Fragment fragment)

Set a currently active fragment in this FragmentManager as the primary navigation fragment.

The primary navigation fragment's child FragmentManager will be called first to process delegated navigation actions such as popBackStack if no ID or transaction name is provided to pop to. Navigation operations outside of the fragment system may choose to delegate those actions to the primary navigation fragment as returned by getPrimaryNavigationFragment.

The fragment provided must currently be added to the FragmentManager to be set as a primary navigation fragment, or previously added as part of this transaction.

Parameters
@Nullable Fragment fragment

the fragment to set as the primary navigation fragment

Returns
@NonNull FragmentTransaction

the same FragmentTransaction instance

setReorderingAllowed

Added in 1.1.0
public @NonNull FragmentTransaction setReorderingAllowed(boolean reorderingAllowed)

Sets whether or not to allow optimizing operations within and across transactions. This will remove redundant operations, eliminating operations that cancel. For example, if two transactions are executed together, one that adds a fragment A and the next replaces it with fragment B, the operations will cancel and only fragment B will be added. That means that fragment A may not go through the creation/destruction lifecycle.

The side effect of removing redundant operations is that fragments may have state changes out of the expected order. For example, one transaction adds fragment A, a second adds fragment B, then a third removes fragment A. Without removing the redundant operations, fragment B could expect that while it is being created, fragment A will also exist because fragment A will be removed after fragment B was added. With removing redundant operations, fragment B cannot expect fragment A to exist when it has been created because fragment A's add/remove will be optimized out.

It can also reorder the state changes of Fragments to allow for better Transitions. Added Fragments may have onCreate called before replaced Fragments have onDestroy called.

postponeEnterTransition requires setReorderingAllowed(true).

The default is false.

Parameters
boolean reorderingAllowed

true to enable optimizing out redundant operations or false to disable optimizing out redundant operations on this transaction.

setTransition

Added in 1.1.0
public @NonNull FragmentTransaction setTransition(int transition)

Select a standard transition animation for this transaction. May be one of TRANSIT_NONE, TRANSIT_FRAGMENT_OPEN, TRANSIT_FRAGMENT_CLOSE, or TRANSIT_FRAGMENT_FADE.

setTransitionStyle

Added in 1.1.0
Deprecated in 1.2.0
public @NonNull FragmentTransaction setTransitionStyle(@StyleRes int styleRes)

Set a custom style resource that will be used for resolving transit animations.

show

Added in 1.1.0
public @NonNull FragmentTransaction show(@NonNull Fragment fragment)

Shows a previously hidden fragment. This is only relevant for fragments whose views have been added to a container, as this will cause the view to be shown.

Parameters
@NonNull Fragment fragment

The fragment to be shown.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

Extension functions

FragmentTransactionKt.add

public final @NonNull FragmentTransaction <F extends Fragment> FragmentTransactionKt.add(
    @NonNull FragmentTransaction receiver,
    @NonNull String tag,
    Bundle args
)

Add a fragment to the associated FragmentManager without adding the Fragment to any container view.

The new fragment to be added will be created via the FragmentFactory of the FragmentManager.

Parameters
@NonNull String tag

Tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.

Bundle args

Optional arguments to be set on the fragment.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

FragmentTransactionKt.add

public final @NonNull FragmentTransaction <F extends Fragment> FragmentTransactionKt.add(
    @NonNull FragmentTransaction receiver,
    @IdRes int containerViewId,
    String tag,
    Bundle args
)

Add a fragment to the associated FragmentManager, inflating the Fragment's view into the container view specified by containerViewId, to later retrieve via FragmentManager.findFragmentById.

The new fragment to be added will be created via the FragmentFactory of the FragmentManager.

Parameters
@IdRes int containerViewId

Identifier of the container this fragment is to be placed in.

String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.

Bundle args

Optional arguments to be set on the fragment.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.

FragmentTransactionKt.replace

public final @NonNull FragmentTransaction <F extends Fragment> FragmentTransactionKt.replace(
    @NonNull FragmentTransaction receiver,
    @IdRes int containerViewId,
    String tag,
    Bundle args
)

Replace an existing fragment that was added to a container. This is essentially the same as calling remove for all currently added fragments that were added with the same containerViewId and then add with the same arguments given here.

The new fragment to place in the container will be created via the FragmentFactory of the FragmentManager.

Parameters
@IdRes int containerViewId

Identifier of the container whose fragment(s) are to be replaced.

String tag

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.

Bundle args

Optional arguments to be set on the fragment.

Returns
@NonNull FragmentTransaction

Returns the same FragmentTransaction instance.