Unfold the Potential of Galaxy Fold Gadgets with WindowManager’s Rear Show Mode

Step 1: Add the WindowManager library into the undertaking

WindowManager, a Jetpack library launched by Google, helps rear show mode ranging from model 1.2.0-beta03. So as to add the WindowManager library, go to Gradle Scripts > construct.gradle (Module: app) and enter the next to the dependencies block:

implementation "androidx.window:window:1.3.0"

Step 2: Implement the WindowAreaSessionCallback interface in MainActivity.kt

The WindowAreaSessionCallback interface updates an Exercise about when the WindowAreaSession is began and ended. Utilizing the onSessionStarted methodology, this interface offers the present WindowAreaSession as quickly as a brand new window session is began.

class MainActivity : AppCompatActivity() , WindowAreaSessionCallback {

…

   override enjoyable onSessionEnded(t: Throwable?) {
      if(t != null) {
      println("One thing was damaged: ${t.message}")
      }
   }
   override enjoyable onSessionStarted(session: WindowAreaSession) {
   }

}

Step 3: Declare variables

The WindowAreaController offers details about the transferring home windows between the quilt show and the principle show of the Galaxy Fold gadget.

The WindowAreaSession interface offers an energetic window session within the onSessionStarted methodology.

WindowAreaInfo represents the present state of a window space. It offers a token which is used later to activate rear show mode.

WindowAreaCapability.Standing represents the provision and functionality standing of the window space outlined by the WindowAreaInfo object. We make the most of this standing to alter the UI of our software. The standing of the Galaxy Fold gadget will be one of many following:

1. WINDOW_AREA_STATUS_ACTIVE: if the quilt show is presently energetic.

2. WINDOW_AREA_STATUS_AVAILABLE: if the quilt show is obtainable to be enabled.

3. WINDOW_AREA_STATUS_UNAVAILABLE: if the quilt show is presently not obtainable to be enabled.

4. WINDOW_AREA_STATUS_UNSUPPORTED: if the Galaxy Fold gadget is working on Android 13 or decrease.

personal lateinit var windowAreaController: WindowAreaController
personal var windowAreaSession: WindowAreaSession? = null
personal var windowAreaInfo: WindowAreaInfo? = null
personal var capabilityStatus: WindowAreaCapability.Standing = WindowAreaCapability.Standing.WINDOW_AREA_STATUS_UNSUPPORTED
personal val operation = WindowAreaCapability.Operation.OPERATION_TRANSFER_ACTIVITY_TO_AREA

Step 4: Create an occasion of WindowAreaController within the onCreate methodology

windowAreaController = WindowAreaController.getOrCreate()

Step 5: Arrange a movement to get data from WindowAreaController

Within the onCreate() methodology, add a lifecycle-aware coroutine to question the record of obtainable WindowAreaInfo objects and their standing. The coroutine executes every time the lifecycle begins.

lifecycleScope.launch(Dispatchers.Predominant) {
   lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
      windowAreaController.windowAreaInfos
         .map { information -> information.firstOrNull { it.sort == WindowAreaInfo.Kind.TYPE_REAR_FACING } }
         .onEach { information -> windowAreaInfo = information }
         .map { it?.getCapability(operation)?.standing ?: WindowAreaCapability.Standing.WINDOW_AREA_STATUS_UNSUPPORTED }
         .distinctUntilChanged()
         .gather {
            capabilityStatus = it
            updateUI()
         }
   }
}

Step 6: Replace the UI in line with the gadget’s WindowAreaCapability.Standing

personal enjoyable updateUI() {
   if(windowAreaSession != null) {
      viewBinding.switchScreenButton.isEnabled = true
   } else {
      when(capabilityStatus) {
         WindowAreaCapability.Standing.WINDOW_AREA_STATUS_UNSUPPORTED -> {
            viewBinding.switchScreenButton.isEnabled = false
            Toast.makeText(baseContext, "RearDisplay just isn't supported on this gadget", Toast.LENGTH_SHORT).present()
         }
         WindowAreaCapability.Standing.WINDOW_AREA_STATUS_UNAVAILABLE -> {
            viewBinding.switchScreenButton.isEnabled = false
            Toast.makeText(baseContext, "RearDisplay just isn't presently obtainable", Toast.LENGTH_SHORT).present()
         }
         WindowAreaCapability.Standing.WINDOW_AREA_STATUS_AVAILABLE -> {
            viewBinding.switchScreenButton.isEnabled = true
         }
         WindowAreaCapability.Standing.WINDOW_AREA_STATUS_ACTIVE -> {
            viewBinding.switchScreenButton.isEnabled = true
            Toast.makeText(baseContext, "RearDisplay is presently energetic", Toast.LENGTH_SHORT).present()
         }
         else -> {
            viewBinding.switchScreenButton.isEnabled = false
            Toast.makeText(baseContext, "RearDisplay standing is unknown", Toast.LENGTH_SHORT).present()
         }
      }
   }
}

Step 7: Toggle to rear show mode with WindowAreaController

Shut the session whether it is already energetic, in any other case begin a switch session to maneuver the MainActivity to the window space recognized by the token.

Whereas activating rear show mode, the system creates a dialog to request the person’s permission to permit the appliance to change screens. This dialog just isn’t customizable.

personal enjoyable toggleRearDisplayMode() {
   if(capabilityStatus == WindowAreaCapability.Standing.WINDOW_AREA_STATUS_ACTIVE) {
      if(windowAreaSession == null) {
         windowAreaSession = windowAreaInfo?.getActiveSession(
            operation
         )
      }
      windowAreaSession?.shut()
   } else {
      windowAreaInfo?.token?.let { token ->
         windowAreaController.transferActivityToWindowArea(
            token = token,
            exercise = this,
            executor = displayExecutor,
            windowAreaSessionCallback = this
         )
      }
   }
}

Step 8: Begin the digicam preview

Name startCamera() when onSessionStarted is triggered by the WindowAreaSessionCallback interface.

override enjoyable onSessionStarted(session: WindowAreaSession) {
   startCamera()
}

Step 9: Add a button and set a listener to it for activating rear show mode

<Button
   android:id="@+id/switch_screen_button"
   android:layout_width="110dp"
   android:layout_height="110dp"
   android:layout_marginStart="50dp"
   android:elevation="2dp"
   android:textual content="@string/switch_screen"
   app:layout_constraintBottom_toBottomOf="mother or father"
   app:layout_constraintBottom_toTopOf="@+id/horizontal_baseline"
   app:layout_constraintStart_toEndOf="@id/vertical_centerline" />

viewBinding.switchScreenButton.setOnClickListener{
   updateUI()
   toggleRearDisplayMode()
}