Exam Content

Question 1

What are the Android Emulator limitations?

Answer 1

No USB support
No Bluetooth support
No Headphone support
No SD support
No NFC support

Question 2

What is a task?

Answer 2

A task is a stack of activities

Question 3

How do you get intent data from an intent

Answer 3

Use the getIntent(), getData(), getExtra() methods

Question 4

How do you get a result from another activity?

Answer 4

Create an intent going from one intent to another
Add any required data/extras to intent
Call startActivityForResult(intent)
Do whatever processing is required in Activity B
Call setResult(code, inent) in Activity B
Call finish() in Activity B
Implement onActivityResult() in Activity A

Question 5

What is the Activity lifecycle?

Answer 5

onCreate()
onStart()
onResume()
onPause()
onStop()
onDestroy()

Question 6

What is the task backstack?

Answer 6

The task backstack is the stack containing all active Activities, activities are pushed to it when startActivity() is called and popped when the user goes back - i.e. finish() is called.

Question 7

How do you send and receive an implicit intent?

Answer 7

(Make sure activity has an intent filter)
Create an intent object with an action parameter
Add data/extra info to the intent
Resolve intent activity - otherwise will crash
Send the intent with startActivity()
Use the getIntent(), getData() and getExtras() methods to receieve an intent

Question 8

What are the differences between SavedInstanceState and SharedPreferences?

Answer 8

SavedInstanceState does not persist across user sessions, SharedPreferences does
SharedPreferences stores user preferences, SavedInstanceState recreates the state after a screen rotation
Both save small amounts of private data

Question 9

What are the main features of an SQLite database?

Answer 9

Lightweight, local, no config., no server, easily backedup, store any-type of value

Question 10

What are retreival queries?

Answer 10

Essentially an SQL select statement, can be achieved via a rawQuery() or just a simple query()

Question 11

What are action queries?

Answer 11

Queries that manage the database, eg. table creation, column insertion etc.
Use execSQL() for this task

Question 12

What parameter do simple queries take?

Answer 12

Tablename, Columns, WHERE, WHERE_ARGS, groupBy, Having, Order_by)

Question 13

How do you implement a drag gesture?

Answer 13

Implement view.onDragListener
Implement onDrag(view, event)

Question 14

What are the phases of a drag?

Answer 14

Started, Continuing, Dropped and Ended

Question 15

How do you implement an AsyncTaskLoader?

Answer 15

Initialise loader ID
In onCreate() initialise a loader with (id, null, this)
Create a loader manager and get the loader with specific loaderID
Implement all required methods for interface: onCreateLoader(), onLoadFinished(), onLoaderReset()

Question 16

Why Content Providers?

Answer 16

They provide a standard interface for multiple apps to read, modify and write data without affecting UI code securely

Question 17

Why Content Resolvers?

Answer 17

System needs mechanism to distinguish content providers in order to route the URI to the correct place

Question 18

How do you start a service?

Answer 18

• Register the service in the manifest
• Create an intent which whatever data, extras you want
• Call startService(intent) which will call onCreate and other callbacks
• Passes the intent to the onStartCommand()
• Stops itself with stopSelf() or manually via stopService()
• Handle the service’s lifecycle

Question 19

What are examples of system Broadcast Intents?

Answer 19

• ACTION_POWER_CONNECTED, ACTION_DEVICE_STORAGE_LOW

Question 20

How is a custom Broadcast Intent sent?

Answer 20

• Create an intent
• Set custom action
• sendBroadcast(intent)

Question 21

What are the design principles of a notification?

Answer 21

• Timely
• Concise
• Relevant
• Manageable by the user

Question 22

How do you test a view using Espresso?

Answer 22

• Find the view: onView(withId(R.id.view))
• Perform the action: perform(ViewAction)
• Check it has behaved correctly: check(ViewAssertion)

Question 23

How do you test an AdapterView using Espresso?

Answer 23

• The onView() method doesn’t work, so use the onData() method instead
• onData(Object).DataOptions.perfrom(ViewAction).check(ViewAssertion)

Question 24

What steps should you take when preparing for release?

Answer 24

• Choose a good package name
• Turn off logging and debugging
• Clean up directories
• Check manifest settings
• Update URLs for servers

Question 25

Explain how codesigning works.

Answer 25

• App must be signed by the developer’s private key in order to be released
• Debugging builds are signed with special debug key
• Only release key will suffice for release builds