FragmentTransaction

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
const Int

Bit mask that is set for all enter transitions.
const Int

Bit mask that is set for all exit transitions.
const Int

Fragment is being removed from the stack
const 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.
const Int

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

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

Fragment is being added onto the stack
const Int

No animation for transition.
const Int

Not set up for a transition.

Public constructors

This function is deprecated.

You should not instantiate a FragmentTransaction except via beginTransaction.

Public functions
FragmentTransaction
add(containerViewId: @IdRes Int, fragment: Fragment)

Calls add with a null tag.
FragmentTransaction
add(fragment: Fragment, tag: String?)

Calls add with a 0 containerViewId.
FragmentTransaction
add(container: ViewGroup, fragment: Fragment, tag: String?)

Add a fragment to the activity state.
FragmentTransaction
add(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?
)

Calls add with a null tag.
FragmentTransaction
add(containerViewId: @IdRes Int, fragment: Fragment, tag: String?)

Add a fragment to the activity state.
FragmentTransaction
add(fragmentClass: Class<Fragment!>, args: Bundle?, tag: String?)

Calls add with a 0 containerViewId.
FragmentTransaction
add(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?,
    tag: String?
)

Add a fragment to the activity state.
FragmentTransaction
addSharedElement(sharedElement: View, name: String)

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

Add this transaction to the back stack.
FragmentTransaction
attach(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 Unit

Commits this transaction synchronously.
abstract Unit

Like commitNow but allows the commit to be executed after an activity's state is saved.
FragmentTransaction
detach(fragment: Fragment)

Detach the given fragment from the UI.
FragmentTransaction

Disallow calls to addToBackStack.
FragmentTransaction
hide(fragment: Fragment)

Hides an existing fragment.
Boolean

Returns true if this FragmentTransaction is allowed to be added to the back stack.
Boolean
FragmentTransaction
remove(fragment: Fragment)

Remove an existing fragment.
FragmentTransaction
replace(containerViewId: @IdRes Int, fragment: Fragment)

Calls replace with a null tag.
FragmentTransaction
replace(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?
)

Calls replace with a null tag.
FragmentTransaction
replace(containerViewId: @IdRes Int, fragment: Fragment, tag: String?)

Replace an existing fragment that was added to a container.
FragmentTransaction
replace(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?,
    tag: String?
)

Replace an existing fragment that was added to a container.
FragmentTransaction
runOnCommit(runnable: Runnable)

Add a Runnable to this transaction that will be run after this transaction has been committed.
FragmentTransaction
setAllowOptimization(allowOptimization: Boolean)

This function is deprecated.

This has been renamed setReorderingAllowed.
FragmentTransaction

This function is deprecated.

Store breadcrumb short titles separately from fragment transactions.
FragmentTransaction

This function is deprecated.

Store breadcrumb short titles separately from fragment transactions.
FragmentTransaction

This function is deprecated.

Store breadcrumb titles separately from fragment transactions.
FragmentTransaction

This function is deprecated.

Store breadcrumb titles separately from fragment transactions.
FragmentTransaction
setCustomAnimations(
    enter: @AnimatorRes @AnimRes Int,
    exit: @AnimatorRes @AnimRes Int
)

Set specific animation resources to run for the fragments that are entering and exiting in this transaction.
FragmentTransaction
setCustomAnimations(
    enter: @AnimatorRes @AnimRes Int,
    exit: @AnimatorRes @AnimRes Int,
    popEnter: @AnimatorRes @AnimRes Int,
    popExit: @AnimatorRes @AnimRes Int
)

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

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

Set a currently active fragment in this FragmentManager as the primary navigation fragment.
FragmentTransaction
setReorderingAllowed(reorderingAllowed: Boolean)

Sets whether or not to allow optimizing operations within and across transactions.
FragmentTransaction
setTransition(transition: Int)

Select a standard transition animation for this transaction.
FragmentTransaction

This function is deprecated.

The desired functionality never worked correctly.
FragmentTransaction
show(fragment: Fragment)

Shows a previously hidden fragment.

Extension functions
inline FragmentTransaction
<F : Fragment> FragmentTransaction.add(tag: String, args: Bundle?)

Add a fragment to the associated FragmentManager without adding the Fragment to any container view.
inline FragmentTransaction
<F : Fragment> FragmentTransaction.add(
    containerViewId: @IdRes Int,
    tag: String?,
    args: Bundle?
)

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.
inline FragmentTransaction
<F : Fragment> FragmentTransaction.replace(
    containerViewId: @IdRes Int,
    tag: String?,
    args: Bundle?
)

Replace an existing fragment that was added to a container.

Constants

TRANSIT_ENTER_MASK

Added in 1.1.0
const val TRANSIT_ENTER_MASK = 4096: Int

Bit mask that is set for all enter transitions.

TRANSIT_EXIT_MASK

Added in 1.1.0
const val TRANSIT_EXIT_MASK = 8192: Int

Bit mask that is set for all exit transitions.

TRANSIT_FRAGMENT_CLOSE

Added in 1.1.0
const val TRANSIT_FRAGMENT_CLOSE = 8194: Int

Fragment is being removed from the stack

TRANSIT_FRAGMENT_FADE

Added in 1.1.0
const val TRANSIT_FRAGMENT_FADE = 4099: 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.

TRANSIT_FRAGMENT_MATCH_ACTIVITY_CLOSE

Added in 1.4.0
const val TRANSIT_FRAGMENT_MATCH_ACTIVITY_CLOSE = 8197: Int

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

See also
activityCloseEnterAnimation
activityCloseExitAnimation

TRANSIT_FRAGMENT_MATCH_ACTIVITY_OPEN

Added in 1.4.0
const val TRANSIT_FRAGMENT_MATCH_ACTIVITY_OPEN = 4100: Int

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

See also
activityOpenEnterAnimation
activityOpenExitAnimation

TRANSIT_FRAGMENT_OPEN

Added in 1.1.0
const val TRANSIT_FRAGMENT_OPEN = 4097: Int

Fragment is being added onto the stack

TRANSIT_NONE

Added in 1.1.0
const val TRANSIT_NONE = 0: Int

No animation for transition.

TRANSIT_UNSET

Added in 1.1.0
const val TRANSIT_UNSET = -1: Int

Not set up for a transition.

Public constructors

FragmentTransaction

Added in 1.1.0
Deprecated in 1.2.0
FragmentTransaction()

Public functions

add

Added in 1.1.0
fun add(containerViewId: @IdRes Int, fragment: Fragment): FragmentTransaction

Calls add with a null tag.

add

Added in 1.1.0
fun add(fragment: Fragment, tag: String?): FragmentTransaction

Calls add with a 0 containerViewId.

add

Added in 1.8.8
fun add(container: ViewGroup, fragment: Fragment, tag: String?): FragmentTransaction

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
container: ViewGroup

The container this fragment is to be placed in. The id of the container should be non-zero and unique.
fragment: Fragment

The fragment to be added. This fragment must not already be added to the activity.
tag: String?

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

Returns the same FragmentTransaction instance.

add

Added in 1.2.0
fun add(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?
): FragmentTransaction

Calls add with a null tag.

add

Added in 1.1.0
fun add(containerViewId: @IdRes Int, fragment: Fragment, tag: String?): FragmentTransaction

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
containerViewId: @IdRes Int

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

The fragment to be added. This fragment must not already be added to the activity.
tag: String?

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

Returns the same FragmentTransaction instance.

add

Added in 1.2.0
fun add(fragmentClass: Class<Fragment!>, args: Bundle?, tag: String?): FragmentTransaction

Calls add with a 0 containerViewId.

add

Added in 1.2.0
fun add(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?,
    tag: String?
): FragmentTransaction

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
containerViewId: @IdRes Int

Optional identifier of the container this fragment is to be placed in. If 0, it will not be placed in a container.
fragmentClass: Class<Fragment!>

The fragment to be added, created via the FragmentManager's FragmentFactory.
args: Bundle?

Optional arguments to be set on the fragment.
tag: String?

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

Returns the same FragmentTransaction instance.

addSharedElement

Added in 1.1.0
fun addSharedElement(sharedElement: View, name: String): FragmentTransaction

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
sharedElement: View

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

The transitionName for a View in an appearing Fragment to match to the shared element.
See also
setSharedElementReturnTransition
setSharedElementEnterTransition

addToBackStack

Added in 1.1.0
fun addToBackStack(name: String?): FragmentTransaction

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
name: String?

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

attach

Added in 1.1.0
fun attach(fragment: Fragment): FragmentTransaction

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
fragment: Fragment

The fragment to be attached.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

commit

Added in 1.1.0
abstract fun commit(): Int

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
abstract fun commitAllowingStateLoss(): Int

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
abstract fun commitNow(): Unit

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
abstract fun commitNowAllowingStateLoss(): Unit

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
fun detach(fragment: Fragment): FragmentTransaction

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
fragment: Fragment

The fragment to be detached.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

disallowAddToBackStack

Added in 1.1.0
fun disallowAddToBackStack(): FragmentTransaction

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
fun hide(fragment: Fragment): FragmentTransaction

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
fragment: Fragment

The fragment to be hidden.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

isAddToBackStackAllowed

Added in 1.1.0
fun isAddToBackStackAllowed(): Boolean

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
fun isEmpty(): Boolean
Returns
Boolean

true if this transaction contains no operations, false otherwise.

remove

Added in 1.1.0
fun remove(fragment: Fragment): FragmentTransaction

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

Parameters
fragment: Fragment

The fragment to be removed.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

replace

Added in 1.1.0
fun replace(containerViewId: @IdRes Int, fragment: Fragment): FragmentTransaction

Calls replace with a null tag.

replace

Added in 1.2.0
fun replace(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?
): FragmentTransaction

Calls replace with a null tag.

replace

Added in 1.1.0
fun replace(containerViewId: @IdRes Int, fragment: Fragment, tag: String?): FragmentTransaction

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
containerViewId: @IdRes Int

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

The new fragment to place in the container.
tag: String?

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

Returns the same FragmentTransaction instance.

replace

Added in 1.2.0
fun replace(
    containerViewId: @IdRes Int,
    fragmentClass: Class<Fragment!>,
    args: Bundle?,
    tag: String?
): FragmentTransaction

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
containerViewId: @IdRes Int

Identifier of the container whose fragment(s) are to be replaced.
fragmentClass: Class<Fragment!>

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

Optional arguments to be set on the fragment.
tag: String?

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

Returns the same FragmentTransaction instance.

runOnCommit

Added in 1.1.0
fun runOnCommit(runnable: Runnable): FragmentTransaction

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
runnable: Runnable

Runnable to add
Returns
FragmentTransaction

this FragmentTransaction
Throws
java.lang.IllegalStateException

if addToBackStack has been called

setAllowOptimization

Added in 1.1.0
Deprecated in 1.1.0
fun setAllowOptimization(allowOptimization: Boolean): FragmentTransaction

setBreadCrumbShortTitle

Added in 1.1.0
Deprecated in 1.2.0
fun setBreadCrumbShortTitle(res: @StringRes Int): FragmentTransaction

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

Parameters
res: @StringRes Int

A string resource containing the title.

setBreadCrumbShortTitle

Added in 1.1.0
Deprecated in 1.2.0
fun setBreadCrumbShortTitle(text: CharSequence?): FragmentTransaction

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
fun setBreadCrumbTitle(res: @StringRes Int): FragmentTransaction

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

Parameters
res: @StringRes Int

A string resource containing the title.

setBreadCrumbTitle

Added in 1.1.0
Deprecated in 1.2.0
fun setBreadCrumbTitle(text: CharSequence?): FragmentTransaction

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
fun setCustomAnimations(
    enter: @AnimatorRes @AnimRes Int,
    exit: @AnimatorRes @AnimRes Int
): FragmentTransaction

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
enter: @AnimatorRes @AnimRes Int

An animation or animator resource ID used for the enter animation on the view of the fragment being added or attached.
exit: @AnimatorRes @AnimRes Int

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
fun setCustomAnimations(
    enter: @AnimatorRes @AnimRes Int,
    exit: @AnimatorRes @AnimRes Int,
    popEnter: @AnimatorRes @AnimRes Int,
    popExit: @AnimatorRes @AnimRes Int
): FragmentTransaction

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
enter: @AnimatorRes @AnimRes Int

An animation or animator resource ID used for the enter animation on the view of the fragment being added or attached.
exit: @AnimatorRes @AnimRes Int

An animation or animator resource ID used for the exit animation on the view of the fragment being removed or detached.
popEnter: @AnimatorRes @AnimRes Int

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.
popExit: @AnimatorRes @AnimRes Int

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
fun setMaxLifecycle(fragment: Fragment, state: Lifecycle.State): FragmentTransaction

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
fragment: Fragment

the fragment to have it's state capped.
state: Lifecycle.State

the ceiling state for the fragment.
Returns
FragmentTransaction

the same FragmentTransaction instance

setPrimaryNavigationFragment

Added in 1.1.0
fun setPrimaryNavigationFragment(fragment: Fragment?): FragmentTransaction

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
fragment: Fragment?

the fragment to set as the primary navigation fragment
Returns
FragmentTransaction

the same FragmentTransaction instance

setReorderingAllowed

Added in 1.1.0
fun setReorderingAllowed(reorderingAllowed: Boolean): FragmentTransaction

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
reorderingAllowed: Boolean

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

setTransition

Added in 1.1.0
fun setTransition(transition: Int): FragmentTransaction

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
fun setTransitionStyle(styleRes: @StyleRes Int): FragmentTransaction

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

show

Added in 1.1.0
fun show(fragment: Fragment): FragmentTransaction

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
fragment: Fragment

The fragment to be shown.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

Extension functions

add

inline fun <F : Fragment> FragmentTransaction.add(tag: String, args: Bundle? = null): FragmentTransaction

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
tag: String

Tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.
args: Bundle? = null

Optional arguments to be set on the fragment.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

add

inline fun <F : Fragment> FragmentTransaction.add(
    containerViewId: @IdRes Int,
    tag: String? = null,
    args: Bundle? = null
): FragmentTransaction

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
containerViewId: @IdRes Int

Identifier of the container this fragment is to be placed in.
tag: String? = null

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.
args: Bundle? = null

Optional arguments to be set on the fragment.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.

replace

inline fun <F : Fragment> FragmentTransaction.replace(
    containerViewId: @IdRes Int,
    tag: String? = null,
    args: Bundle? = null
): FragmentTransaction

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
containerViewId: @IdRes Int

Identifier of the container whose fragment(s) are to be replaced.
tag: String? = null

Optional tag name for the fragment, to later retrieve the fragment with FragmentManager.findFragmentByTag.
args: Bundle? = null

Optional arguments to be set on the fragment.
Returns
FragmentTransaction

Returns the same FragmentTransaction instance.