FMX.Android Notification Service Sample

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This demo shows an Android application using an Android Service to present a scheduled notification. The Android Service works as a background task, and presents the notification after the service is started. The notification launches even if the main application is not running. The service stops itself after performing the task.

Location

You can find the Android Notification Service sample project at:

Description

This sample demonstrates how to create and use a local Android service to present a scheduled notification.

  • The Notification Service project consists of a Data Module. A TNotificationCenter component creates and presents a notification after the service is started from the Notification application.
  • The Notification Application project starts the Android Service to present a notification on the Android device. Once the notification is handled by the user, a message is sent to the TMemo. To handle notifications, the application uses a TNotificationCenter component.

How to Use the Sample

To open the projects:

  1. Navigate to the location given above.
  2. Open the sample application group project file: NotificationServiceDemo.groupproj.

To create the Android Service:

  1. Select libNotificationService.so on the Projects Window.
  2. Right-click to select Compile.
    Note: Compiling the project generates the files that you need to add to the main application.

To add the Android Service to the main application:

  1. Select NotificationApp on the Projects Window.
  2. Expand the Target Platforms node.
  3. Select the Android device.
  4. Right-click on the Android device, and select Add Android Service.
  5. Select the location to C:\Users\Public\Documents\Embarcadero\Studio\\Samples\Object Pascal\Multi-Device Samples\Device Sensors and Services\AndroidNotificationServiceDemo\NotificationService.
  6. Click Next.
    Note: Check that the location to these files is added: libNotificationService.so, NotificationService.jar, and NotificationServiceUnit.pas.
  7. Press F9 or choose Run > Run to deploy the application to an Android device.

Starting the Android Service

  1. To start the service, on the Notification application click Start Service.
  2. On the Android device wait the scheduled time to see the notification in the screen.
  3. Click the notification to trigger the OnReceiveLocalNotification event of the TNotificationCenter from the main application.
  4. See the message Notification received: RAD Studio 10 Seattle in the TMemo.

Implementation

Notification Service

The Notification Service is an Android Service project. The type of the service is local.

The Data Module has a TNotificationCenter component.

The OnStartCommand event from the Data Module triggers when the service starts. After starting, the OnStartCommand event calls the LaunchNotification procedure that creates and presents the notification after eight seconds.

function TNotificationServiceDM.AndroidServiceStartCommand(const Sender: TObject; const Intent: JIntent; Flags,
  StartId: Integer): Integer;
begin
  LaunchNotification; //Calls the procedure that defines and presents the notification.
  JavaService.stopSelf; // The service stops itselfs after presenting the notification.
  Result := TJService.JavaClass.START_STICKY; //The '''OnStartCommand''' event is defined by default as START_NOT_STICKY, this line of code sets it to START_STICKY.
end;
Note: When defined as START_STICKY, the system tries to re-create the service when killed.

Notification App

The Notification Service is a Multi-Device application project.

The OnClick event-handler of the Start Service button calls the StartService method of the TLocalServiceConnection class.

Note: TLocalServiceConnection is the helper class that manages the connection to an Android Local Service.
procedure TForm1.Button1Click(Sender: TObject);
begin
  TLocalServiceConnection.StartService('NotificationService'); //Initialize the TLocalServiceConnection variable to a specific service, and starts it.
end;
Note: After starting a service, you do not need to refer to the service name for the rest of methods.

The OnReceiveLocalNotification event of the TNotification component triggers once the user handles the notification on the Android device, that means clicking on the notification, not dismissing it.

procedure TForm1.NotificationCenter1ReceiveLocalNotification(Sender: TObject; ANotification: TNotification);
begin
  Memo1.Lines.Add('Notification received:'); //It shows on the memo a message when the user handles the notification.
  Memo1.Lines.Add(ANotification.AlertBody); //It shows the alert body of the notification defined on the Android Service project.
end;

Uses

The sample uses Built-in Java libraries for Android.

  • Androidapi.JNI.App
  • AndroidApi.JNI.GraphicsContentViewText
  • Androidapi.JNI.Os

See Also