IMPORTANT: In July 2025, we stopped releasing new versions of KTX modules, and we removed the KTX libraries from the Firebase Android BoM (v34.0.0). If you use KTX APIs from the previously released KTX modules, we recommend that you migrate your app to use KTX APIs from the main modules instead. For details, see the FAQ about this initiative.

CancellableTask

public abstract class CancellableTask<StateT> extends Task

java.lang.Object
↳	com.google.android.gms.tasks.Task
	↳	com.google.firebase.storage.CancellableTask

Known direct subclasses

ControllableTask

ControllableTask

Represents an asynchronous operation that can be paused, resumed and canceled.

Known indirect subclasses

FileDownloadTask, StorageTask, StreamDownloadTask, UploadTask

`FileDownloadTask`	A task that downloads bytes of a GCS blob to a specified File.
`StorageTask`	A controllable Task that has a synchronized state machine.
`StreamDownloadTask`	A task that downloads bytes of a GCS blob.
`UploadTask`	An controllable task that uploads and fires events for success, progress and failure.

Represents an asynchronous operation that can be canceled.

Parameters
`<StateT>`	the type of state this operation returns in events.

Summary

Public constructors
`CancellableTask()`

Public methods
`abstract @NonNull CancellableTask<StateT>`	`addOnProgressListener(@NonNull OnProgressListener<Object> listener)` Adds a listener that is called periodically while the ControllableTask executes.
`abstract @NonNull CancellableTask<StateT>`	`addOnProgressListener( @NonNull Activity activity, @NonNull OnProgressListener<Object> listener )` Adds a listener that is called periodically while the ControllableTask executes.
`abstract @NonNull CancellableTask<StateT>`	`addOnProgressListener( @NonNull Executor executor, @NonNull OnProgressListener<Object> listener )` Adds a listener that is called periodically while the ControllableTask executes.
`abstract boolean`	`cancel()` Attempts to cancel the task.
`abstract boolean`	`isCanceled()`
`abstract boolean`	`isInProgress()`

Inherited methods

From com.google.android.gms.tasks.Task

`Task<TResult>`	`addOnCanceledListener(OnCanceledListener p)`
`Task<TResult>`	`addOnCompleteListener(OnCompleteListener<TResult> p)`
`abstract Task<TResult>`	`addOnFailureListener(OnFailureListener p)`
`abstract Task<TResult>`	`addOnSuccessListener(OnSuccessListener<Object> p)`
`Task<TContinuationResult>`	`<TContinuationResult> continueWith( Continuation<TResult, TContinuationResult> p )`
`Task<TContinuationResult>`	`<TContinuationResult> continueWithTask( Continuation<TResult, Task<TContinuationResult>> p )`
`abstract Exception`	`getException()`
`abstract TResult`	`getResult()`
`abstract boolean`	`isComplete()`
`abstract boolean`	`isSuccessful()`
`Task<TContinuationResult>`	`<TContinuationResult> onSuccessTask( SuccessContinuation<TResult, TContinuationResult> p )`

Public constructors

CancellableTask

public CancellableTask()

Public methods

addOnProgressListener

public abstract @NonNull CancellableTask<StateT> addOnProgressListener(@NonNull OnProgressListener<Object> listener)

Adds a listener that is called periodically while the ControllableTask executes.

Returns
`@NonNull CancellableTask<StateT>`	this Task

addOnProgressListener

public abstract @NonNull CancellableTask<StateT> addOnProgressListener(
    @NonNull Activity activity,
    @NonNull OnProgressListener<Object> listener
)

Adds a listener that is called periodically while the ControllableTask executes.

Parameters
`@NonNull Activity activity`	When the supplied `Activity` stops, this listener will automatically be removed.

Returns
`@NonNull CancellableTask<StateT>`	this Task

addOnProgressListener

public abstract @NonNull CancellableTask<StateT> addOnProgressListener(
    @NonNull Executor executor,
    @NonNull OnProgressListener<Object> listener
)

Adds a listener that is called periodically while the ControllableTask executes.

Parameters
`@NonNull Executor executor`	the executor to use to call the listener

Returns
`@NonNull CancellableTask<StateT>`	this Task

cancel

public abstract boolean cancel()

Attempts to cancel the task. A canceled task cannot be resumed later. A canceled task calls back on listeners subscribed to addOnFailureListener with an exception that indicates the task was canceled.

Returns
`boolean`	true if this task was successfully canceled or is in the process of being canceled. Returns false if the task is already completed or in a state that cannot be canceled.

isCanceled

public abstract boolean isCanceled()

Returns
`boolean`	true if the task has been canceled.

isInProgress

public abstract boolean isInProgress()

Returns
`boolean`	true if the task is currently running.