MIDTERM | Activities and Intents | MST

Activity

represents a single screen in the app where the user can perform a single focused task such as sending an e-mail. It is usually presented to the user as a full-screen window.

Activity

To implement an activity: 1. Create an __________ Java class.

XML layout

To implement an activity: 2. Implement a basic UI for the Activity in an associated ____ _________ file.

AndroidManifest

To implement an activity: 3. Declare the new Activity in ______________.xml

Main activity (MainActivity.java)

It is presented to the user when the app is launched.

Activities

Main activity (MainActivity.java) can then start other ___________ to perform different actions.

Activity life cycle

It is the set of states an activity can be in during its entire lifetime.

onCreate()

It is invoked when the app is launched for the first time. It happens only once for the entire life of the activity.

onStart()

It is invoked before the activity becomes visible to the user.

onResume() or onStop()

onStart() is followed by either: _____________ or ____________

onResume()

onStart() is followed by either: • ___________ – if the activity comes to the foreground

onStop()

onStart() is followed by either: • ___________ – if the activity becomes hidden

onResume()

It is invoked before the activity starts interacting with the user.

onPause()

It is invoked when the system is about to start resuming another activity.

onResume() or onStop()

onPause() is followed by either: ___________ or ___________

onResume()

onPause() is followed by either: • ____________ – if the activity returns to the background

onStop()

onPause() is followed by either: • __________ – if the activity becomes invisible to the user

onStop()

It is invoked when the activity is no longer visible to the user.

onRestart()

onStop() is followed by either: • __________ – if the activity is coming back to interact with the user

onDestroy()

onStop() is followed by either: • ___________ – if the activity is about to end

onDestroy()

It is invoked when: • the activity is finishing (due to the user completely dismissing the activity or due to finish() being called on the activity)

configuration change

onDestroy() is invoked when: • the system is temporarily destroying the activity due to a ___________ ________ (such as device rotation or multi-window mode)

onRestart()

It is invoked if the activity comes back after being stopped.

onStart()

onRestart() is always followed by ______________.

back stack

Each time a new activity starts, the previous activity is stopped, but the system preserves the activity in a stack called the __________ __________.

Intent

An activity is started or activated with an ________.

Intent

It is an asynchronous message that is used in an activity to request an action from another activity, or from some other app component.

Start

An intent can be used to ________ one activity from another activity, and to pass data between activities.

Target activity

the activity that will receive the intent.

Intent data/object

contains a reference to the data you want the receiving activity to operate on.

Intent extras

carry information the receiving activity requires to accomplish the requested action (optional).

Intent flags

may instruct the Android system how to launch an Activity or how to treat it after it's launched (optional).

Target Activity, Intent Data/Object, Intent Extras, Intent Flags

Parts of an Intent: HINT: TA ID/O IE IF

Explicit intent

The target of the intent (the class name of the activity) is already identified.

Implicit intent

The target of the intent is not yet identified but there is a general action to perform.

action, category, and data type

Implicit intent also includes an ________, ____________, and _______ ______.

parentActivityName

This attribute indicates that the main activity is the parent of the second activity. Arrow

onClick

To add an intent after creating a new activity: 2. Add the android:________ attribute to the Button element that will be used to start another activity.

Method

To add an intent after creating a new activity: 3. Define the _________ that will be used to start another activity.

Explicit

The intent added is an _________ intent because the receiving activity is specified (Main2Activity).

Current

The this keyword represents the _______ activity

Toast

To verify if the intent works, add a _______ to Main2Activity.