IssueTracker

Component used: WorkManager/Worker
Version used: alpha01

WorkManager exposes method for cancellation of work. However, I currently don't see how this could be used if the work has already started.

Arguably, being able to cancel an ongoing work is very basic and must have functionality. Not being able to do so will render the entire framework unusable in many scenarios. It can also negatively impact the end users (e.g. by consuming too much battery/bandwidth).

Cancellation mechanism should be given a very good thought. As a starting point for a discussion, I propose adding two methods to Worker:

1) protected final boolean isCancelled() - will return true if the work has been cancelled
2) protected void onCancelled() - will be called after WorkManager determines that a specific Worker needs to be cancelled. Default implementation will be no-op.