Lesson 4: Using Intent in Services and Notification

Intent

is a request from an app to the Android system to perform an operation.

Explicit Intents

A type of Intent that Specify component to start by name. It is used to start in your own app.

Implicit Intents

This is a type of intent. Specify component by declaring general action to perform.

Intent Filter

is a description of what intents an activity (or intent receiver) is capable of handling

<intent-filter>

It defines what activity can do and cannot do.

• Core components (i.e. activities, services, broadcast receivers) can use intent filters to tell the system which implicit intents they can handle or are willing to receive.

• filters unwanted intents (i.e. those that don’t name a target class)

MAIN

The intent-filter declares the main entry point of the app.

• [blank] action = entry point (requires no other info in the intent)

• LAUNCHER category = lists the entry point in the app launcher

LAUNCHER

The intent-filter declares the main entry point of the app.

• MAIN action = entry point (requires no other info in the intent)

• [blank] category = lists the entry point in the app launcher

Intent.ACTION_CALL tel:phone_number

Opens phone application and calls phone_number.

Intent.ACTION_DIAL tel:phone_number

Opens phone application and dials (but doesn’t call) phone_number.

Intent.ACTION_DIAL voicemail:

Opens phone application and dials (but doesn’t call) the voice mail number.

Intent.ACTION_VIEW geo:lat,long

Opens the maps application centered on (lat, long).

Intent.ACTION_VIEW geo:0,0?q=address

Opens the maps application centered on the specified address.

Intent.ACTION_VIEW http://url | name

Opens the browser application to the specified address (https://url).

Intent.ACTION_WEB_SEARCH plain_text

• Opens the browser application and uses Google search for a given string (plain text).

• Use outExtra(SearchManager.Query, value)

Android Services

• Are the application components that run in the background.

• They have no user

  interface as they perform long-running processes without user intervention.

Foreground Services

Are type of services that perform operation that are visible to the users.

Background Services

Are type of services that run in the background, such that the user can’t see or access them.

Bound Services

A type of service that runs as long as some other application component is bound to it.

Started Services

A type of service lifecycle that calls startService(). Once this service starts, it runs in the background even if the component created it destroys. This service can be stopped only using stopService or stopself() methods.

Bounded Services

A type of service lifecycle where an application components binds it using bindService() method. The bounded components can send requests to services and get results. When all clients unbind from bound service by calling unBindService() method, service ends with onUnBind and onDestroy methods.

onStart() (onStartCommand())

The system uses this callback method when another component like an activity makes a request for the service to be started. Once started, it will run in the background indefinitely.

onBind()

A Lifecycle Callback Method when some other components want to bind with the service, the system callback this method by giving the command bindService().

onUnbind()

A lifecycle callback method when all clients disconnect from a specific interface published on the service, the systems calls for this method.

onRebind()

Once the system receives the notice that clients have disconnected, it callback this method for connecting with the new clients.

onCreate()

A Lifecycle Callback Method where the system invokes this method when the service initially created using onStart() or onBind().

onDestroy()

The system invokes this method when the client/Android destroy the service.

IntentService

It is a Started Service class that executes long-running programs without affecting any user’s interface interaction.

Notification

Are the messages that are visible to the users outside the app UI.

Application Icons

A form of notification of the application from which notification has come are shown on the left of the Status bar

Notification Drawer

A form of notification where a list of all the android notifications that have come are found in the notification drawer.

Text Notification

A form of notification that contains message or information

Expandable Notification

A form of notification that look just like a normal notification, but they can be expanded for further details

Notification Action

A form of notification that is the one where actions can be directly performed in the notification itself.

Lock Screen Notification

A form of notification that can also be visible on the lock screen.

Wear OS

A form of notification If the user has a paired Wear OS device

Small icon

Part of the Notification Anatomy. This is required and set with setSmallIcon().

App name

Part of the Notification Anatomy. This is provided by the system.

TimeStamp

Part of the Notification Anatomy. This is provided by the system but you can override with setWhen() or hide it with setShowWhen(false).

Large icon

Part of the Notification Anatomy. This is optional and set with setLargeIcon()

Title

Part of the Notification Anatomy. This is optional and set with setContentTitle()

Text

Part of the Notification Anatomy. This is optional and set with setCiontentText()

Notification Channel

is an Android feature that groups an app's notifications into categories

Pending Intent

is a type of intent used to grant other application the right to perform the operation you have specified as if the other application was yourself.

NotificationCompat.Builder

A [blank] class allows easier control, as well as helps to design different design layouts for notifications.

WorkManager

is an Android Jetpack library used to run deferrable, guaranteed background tasks.