FakeClock

Artifact: androidx.media3:media3-test-utils

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Kotlin |Java

@UnstableApi
class FakeClock : Clock

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Fake Clock implementation that allows to advance the time manually to trigger pending timed messages.

All timed messages sent by a Handler created from this clock are governed by the clock's time. Messages sent through these handlers are not triggered until previous messages on any thread have been handled to ensure deterministic execution. Note that this includes messages sent from the main Robolectric test thread, meaning that these messages are only triggered if the main test thread is idle, which can be explicitly requested by calling ShadowLooper.idleMainLooper().

The clock also sets the time of the SystemClock to match the clock's time.

Summary

Nested types
protected inner class FakeClock.HandlerMessage : Comparable, HandlerWrapper.Message Message data saved to send messages or execute runnables at a later time on a Handler.

Public constructors
FakeClock(initialTimeMs: Long) Creates a fake clock that doesn't auto-advance and assumes that the system was booted exactly at time 0 (the Unix Epoch) and initialTimeMs milliseconds have passed since system boot.
FakeClock(isAutoAdvancing: Boolean) Creates a fake clock that assumes that the system was booted exactly at time 0 (the Unix Epoch) and an initialTimeMs of 0.
FakeClock(initialTimeMs: Long, isAutoAdvancing: Boolean) Creates a fake clock that assumes that the system was booted exactly at time 0 (the Unix Epoch) and initialTimeMs milliseconds have passed since system boot.
FakeClock(bootTimeMs: Long, initialTimeMs: Long, isAutoAdvancing: Boolean) Creates a fake clock specifying when the system was booted and how much time has passed since then.

Public functions
synchronized Unit	advanceTime(timeDiffMs: Long) Advance timestamp of FakeClock by the specified duration.
HandlerWrapper!	createHandler(looper: Looper!, callback: Handler.Callback?) Creates a HandlerWrapper using a specified looper and a specified callback for handling messages.
synchronized Long	currentTimeMillis() Returns the current time in milliseconds since the Unix Epoch.
synchronized Long	elapsedRealtime()
synchronized Long	nanoTime() See nanoTime
synchronized Unit	onThreadBlocked() Notifies the clock that the current thread is about to be blocked and won't return until a condition on another thread becomes true.
Long	uptimeMillis()

Protected functions
synchronized Unit	addPendingHandlerMessage(message: FakeClock.HandlerMessage!) Adds a message to the list of pending messages.

Inherited Constants
From androidx.media3.common.util.Clock const Clock! DEFAULT Default Clock to use for all non-test cases.

Public constructors

FakeClock

FakeClock(initialTimeMs: Long)

Creates a fake clock that doesn't auto-advance and assumes that the system was booted exactly at time 0 (the Unix Epoch) and initialTimeMs milliseconds have passed since system boot.

Parameters
initialTimeMs: Long	The initial elapsed time since the boot time, in milliseconds.

FakeClock

FakeClock(isAutoAdvancing: Boolean)

Creates a fake clock that assumes that the system was booted exactly at time 0 (the Unix Epoch) and an initialTimeMs of 0.

Parameters
isAutoAdvancing: Boolean	Whether the clock should automatically advance the time to the time of next message that is due to be sent.

FakeClock

FakeClock(initialTimeMs: Long, isAutoAdvancing: Boolean)

Creates a fake clock that assumes that the system was booted exactly at time 0 (the Unix Epoch) and initialTimeMs milliseconds have passed since system boot.

Parameters
initialTimeMs: Long	The initial elapsed time since the boot time, in milliseconds.
isAutoAdvancing: Boolean	Whether the clock should automatically advance the time to the time of next message that is due to be sent.

FakeClock

FakeClock(bootTimeMs: Long, initialTimeMs: Long, isAutoAdvancing: Boolean)

Creates a fake clock specifying when the system was booted and how much time has passed since then.

Parameters
bootTimeMs: Long	The time the system was booted since the Unix Epoch, in milliseconds.
initialTimeMs: Long	The initial elapsed time since the boot time, in milliseconds.
isAutoAdvancing: Boolean	Whether the clock should automatically advance the time to the time of next message that is due to be sent.

Public functions

advanceTime

synchronized fun advanceTime(timeDiffMs: Long): Unit

Advance timestamp of FakeClock by the specified duration.

Parameters
timeDiffMs: Long	The amount of time to add to the timestamp in milliseconds.

createHandler

fun createHandler(looper: Looper!, callback: Handler.Callback?): HandlerWrapper!

Creates a HandlerWrapper using a specified looper and a specified callback for handling messages.

See also
Handler

currentTimeMillis

synchronized fun currentTimeMillis(): Long

Returns the current time in milliseconds since the Unix Epoch.

See also
currentTimeMillis

elapsedRealtime

synchronized fun elapsedRealtime(): Long

See also
elapsedRealtime

nanoTime

synchronized fun nanoTime(): Long

See nanoTime

onThreadBlocked

synchronized fun onThreadBlocked(): Unit

Notifies the clock that the current thread is about to be blocked and won't return until a condition on another thread becomes true.

Should be a no-op for all non-test cases.

uptimeMillis

fun uptimeMillis(): Long

See also
uptimeMillis

Protected functions

addPendingHandlerMessage

synchronized protected fun addPendingHandlerMessage(message: FakeClock.HandlerMessage!): Unit

Adds a message to the list of pending messages.