Lecture 12: Intro to Services Flashcards
A service is launched from the __ as the __ that called it
- same thread
- host
Can services run in parallel?
No
Services have a lifetime that may be controlled by the ___ or __
- service itself
- outside forces
What are the 2 broad categories services can be split into based on their user visibility
- foreground services
- background services
A __ service doesnt require user UI interaction, but does require that a notification be shown to let the user know the serivce is running
foreground
A __ service a a hidden service. Not required to provide a notification or provide any indication that its running
background
__ services are good for silently updating or managing aspects of your app without requiring user interaction
background
What are some of the limitations you may do with background services since they provide no indication that theyre running
- Give them a allowance of time to access sensitive info since the last user noticeable action
- May be restricted from using certain components
When are bound services essential?
When a service must be able to pass data off to other activities or services in real time rather than editing data on disk for others to read
A __ service creates a communication link between itself and one or more binders that allows for data transfer back and forth
bound
What 3 things do you need to create a service?
- An entry in the app manifest file declaring the service with a name and other descriptors
- A java class that extends the standard service class for android and implements the 4 lifecycle functions required
- An intent used to launch the service
Services must be declared within your app manifest within a __ tag and the only required field is the ___
- <service>
</service> - name of the service
Each service is defined it its own __ which ___ from the default Android ___ class
- class
- extends
- service
Within the service class we must __ a set of __ for the service
- override
- lifecycle functions
Describe the service lifecycle
- Begins with onCreate() and ends with onDestroy()
Unbound services are called with a __ and call the __ method
Bound services use __ and call on the __ and __
startService(), onStartCommand()
bindService(), onBind(), onUnbind()
We can think of each lifecycle function as being some block of code we want to execute at a __ of the __
- very specific stage
- services life
When a service terminates depends on the ___
an __ will run ___ if allows
service type
unbound service, indefinitely
Started or unbound services must use ___ to terminate themselves when they have ___
stopSelf()
completed their tasks
Bound services will automatically be __ when all ___ are ___
destroyed
bound components, unbound
What does the constant startMode do?
An int value that tells the system how to handle unexpected termination
What does START_NOT_STICKY tell the system?
Not to restart your service after exiting
What does START_STICKY tell the system?
To restart the service but with a null intent
What does START_REDELIVER_INTENT tell the system?
Restart and resend the original intent when launching the service
What is the safest way to tell the system to handle unexpected termination and why?
START_NOT_STICKY
Ensures service wont be dangling doing nothing
How do you start a service in unbound mode?
Create an intent pointing to the service class and pass it to startService()
