BackgroundMatchingService

class BackgroundMatchingService : Service

A Service running in the background, which detects when new photos are taken on the smartphone. A ContentObserver monitors changes in the phone gallery directory and sends match requests once new photos are detected.

Constructors

fun BackgroundMatchingService()

Types

Companion

object Companion

Companion object for starting/stopping the service.

Functions

calculateInSampleSize

private fun calculateInSampleSize(options: BitmapFactory.Options, reqWidth: Int, reqHeight: Int): Int

Calculates the inSampleSize for the bitmap decoding.

createForegroundNotification

private fun createForegroundNotification()

Creates a notification channel for the foreground notification as well as the notification itself.

createForegroundNotificationChannel

private fun createForegroundNotificationChannel()

Creates the notification channel for the foreground notification.

createMatchNotification

private fun createMatchNotification(matchResult: Bitmap)

Creates a notification channel for the match notification as well as the notification itself.

createMatchNotificationChannel

private fun createMatchNotificationChannel()

Creates the notification channel for the match notification.

decodeSampledBitmapFromResource

fun decodeSampledBitmapFromResource(file: File, reqWidth: Int, reqHeight: Int): Bitmap

Decode a sampled bitmap from a file to a Bitmap.

getConnectedStatusIcon

private fun getConnectedStatusIcon(): Int

Returns the icon representing the corresponding connected status.

getConnectedStatusString

private fun getConnectedStatusString(): String

Returns the string representing the corresponding connected status.

getMatchingOptionsFromPref

private fun getMatchingOptionsFromPref(): HashMap<Any?, Any?>

Returns the matching options for the match request.

getPathFromObserverUri

fun getPathFromObserverUri(uri: Uri): String?

Returns the file path of a given uri.

isNewCameraPhoto

private fun isNewCameraPhoto(file: File): Boolean

Checks whether a given file is a new camera photo.

isValidFilePath

private fun isValidFilePath(path: String?): Boolean

Checks whether a given path is a valid file path.

onBind

open override fun onBind(intent: Intent?): IBinder?

onCreate

open override fun onCreate()

Called when the service is created, initializes the service.

onDestroy

open override fun onDestroy()

On destroy, calls stopService.

onMatch

private fun onMatch(matchId: String, ba: ByteArray?)

Called when CaptureCallback.onMatchResult of captureCallback is called. Sends a notification to the user with the result of the matching by calling sendMatchNotification.

onStartCommand

open override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int

queryAbsoluteDataColumn

private fun queryAbsoluteDataColumn(uri: Uri): String?

queryRelativeDataColumn

@RequiresApi(value = 29)

fun queryRelativeDataColumn(uri: Uri): String?

rescaleAndSendToServer

private fun rescaleAndSendToServer(image: Bitmap)

Rescales an image to 512x512 and calls sendCaptureRequest with the scaled image.

sendMatchNotification

private fun sendMatchNotification(bmp: Bitmap)

Send a match notification to the user with the result of the matching process.

sleepService

private fun sleepService()

Sleeps the service. Called when the screen is turned off.

startContentObserver

private fun startContentObserver()

Initializes contentObserver and registers it.

startService

private fun startService()

Starts the service.

stopService

private fun stopService()

Stops the service. Called when the service is destroyed.

updateForegroundNotification

private fun updateForegroundNotification()

Updates the foreground notification with the new connected status.

updateMatchNotification

private fun updateMatchNotification(matchResult: Bitmap)

Updates the match notification with the new image of the match.

Properties

broadcastReceiver

private var broadcastReceiver: BroadcastReceiver? = null

BroadcastReceiver instance, which receives broadcasts from the system (screen on/off).

captureCallback

private val captureCallback: BackgroundMatchingService.<no name provided>

CaptureCallback object that is used to handle the response from the server. Used in rescaleAndSendToServer.

contentObserver

private var contentObserver: ContentObserver? = null

Instance of ContentObserver which monitors changes in the phone gallery directory and sends match requests once new photos are detected.

foregroundNotificationBuilder

private lateinit var foregroundNotificationBuilder: NotificationCompat.Builder

The notification builder for the foreground notification.

foregroundNotificationChannelId

private val foregroundNotificationChannelId: String

The id of the foreground notification channel.

isActive

private var isActive: Boolean = false

Whether or not the service is active.

isConnected

var isConnected: Boolean = false

Whether or not the service is connected to the server.

isConnectedObserver

private val isConnectedObserver: Observer<Boolean>

Observer instance, which observes ServerConnectionModel.isConnected and updates isConnected accordingly.

isWaitingForMatchingResponse

private var isWaitingForMatchingResponse: Boolean = false

Whether or not the service is waiting for a match response from the server.

MATCHING_MODE_PREF_KEY

private lateinit var MATCHING_MODE_PREF_KEY: String

The key for the preference that determines the matching mode.

matchNotificationBuilder

private lateinit var matchNotificationBuilder: NotificationCompat.Builder

The notification builder for the match notification.

matchNotificationChannelId

private val matchNotificationChannelId: String

The id of the match notification channel.

recentContentObserverPaths

private var recentContentObserverPaths: LinkedList<String>

Stores the last 10 files dispatched by contentObserver. This is done to avoid double processing, because contentObserver sometimes fires multiple identical events per file.

private lateinit var sp: SharedPreferences

SharedPreferences instance, stores the preferences.