Create and use a low light boost client

To use Google Low Light Boost, you'll need a low light boost client. You can use the client to check if the low light boost module is installed, and to check whether Google Low Light Boost is supported by the device and camera your app is running on. You'll also use the client to create a LowLightBoostSession. (You'll use the session to turn low light boost on and off.) You can also set up a listener to receive callbacks when low light boost is active.

LowLightBoostClient methods don't signal success or failure directly. Instead, they return a Task object. You use a Task to set up success and failure listeners. This lets the methods signal success or failure asynchronously, which is necessary since the methods need to communicate with Google Play services.

Dependencies

Kotlin

dependencies {
  val low_light_boost_version = "16.0.0-beta01"
  implementation("org.jetbrains.kotlinx:kotlinx-coroutines-play-services:1.10.2")
  implementation("com.google.android.gms:play-services-base:18.7.0")
  implementation("com.google.android.gms:play-services-camera-low-light-boost:${low_light_boost_version}")
  implementation("com.google.android.gms:play-services-tasks:18.3.0")
}

Groovy

dependencies {
  def low_light_boost_version = "16.0.0-beta01"
  implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-play-services:1.10.2'
  implementation 'com.google.android.gms:play-services-base:18.7.0'
  implementation 'com.google.android.gms:play-services-camera-low-light-boost:${low_light_boost_version}'
  implementation 'com.google.android.gms:play-services-tasks:18.3.0'
}

LowLightBoostClient is provided by the Google Play services com.google.android.gms.cameralowlight package. See the Google Play services documentation for information on accessing Google Play services APIs.

Create a client

You need a low light boost client to do anything else. The following code creates a client:

Kotlin

val lowLightBoostClient = LowLightBoost.getClient(context)

Java

LowLightBoostClient lowLightBoostClient = LowLightBoost.getClient(context);

Key points about this code

  • The LowLightBoost class provides the static method getClient, which returns an instance of LowLightBoostClient.

Check if the low light boost module is installed

Once you have a client, you can confirm whether the low light boost module is installed on your device. The following code checks if the module is installed:

Kotlin

// Handle the Google Play services Task API with Kotlin coroutines
// (kotlinx-coroutines-play-services)
launch {
  try {
    val isInstalled: Boolean = lowLightBoostClient
      .isModuleInstalled(context).await()

    if (isInstalled) {
      Log.d(TAG, "Module is installed")
      try {
        openCamera(cameraId)
      } catch (e: CameraAccessException) {
        Log.e(TAG, "Failed to open camera", e)
      }
    } else {
      Log.d(TAG, "Module is not installed")
      launchInstallRequest()
    }
  } catch (e: Exception) {
    Log.e(TAG, "Failed to check module availability", e)
  }
}

Java

lowLightBoostClient
  .isModuleInstalled(context)
  .addOnSuccessListener(
    (isInstalled) -> {
      if (isInstalled) {
        Log.d(TAG, "Module is installed");
        try {
          openCamera(cameraId);
        } catch (CameraAccessException e) {
          Log.e(TAG, "Failed to open camera", e);
        }
      } else {
        Log.d(TAG, "Module is not installed");
        launchInstallRequest();
      }
    })
  .addOnFailureListener(
    (e) -> {
      Log.e(TAG, "Failed to check module availability", e);
    });

Key points about this code

  • This code opens a camera session connecting to the camera identified by cameraId. For more information, see the Camera2 documentation.
  • The method LowLightBoostClient.isModuleInstalled() returns a Task object. You use this object to set up success and failure listeners.
  • Use Task.addOnSuccessListener() to set up a listener that's called if the call to isModuleInstalled() succeeds. Importantly, if the success listener is called, that just tells you that the client succeeded in finding out whether the module is installed on the device. In the body of your listener, you need to check whether the module is actually installed or not.
  • If the module isn't already installed, this snippet installs it by calling the method launchInstallRequest(). That method is defined in the snippet in Install the low light boost module.

Install the low light boost module

If the low light boost module isn't already installed on the device, you'll need to download and install it from Google Play services. This code shows how to do that:

Kotlin

private suspend fun launchInstallRequest() {
  Log.v(TAG, "Launching install request")

  try {
    // Check if this device can support Google LLB.
    val isDeviceSupported: Boolean = lowLightBoostClient
      .isDeviceSupported(context).await()

    if (isDeviceSupported) {
      Log.d(TAG, "Device is supported")
      // Show download indicator, if needed.

      try {
        val isInstallSuccessful: Boolean = lowLightBoostClient
          .installModule(context,
                        createInstallStatusCallback()
          ).await()

        if (isInstallSuccessful) {
          Log.d(TAG, "Module installed")
          // Hide download indicator, if needed.
          try {
            openCamera()
          } catch (e: CameraAccessException) {
            Log.e(TAG, "Failed to open camera", e)
          }
        } else {
          Log.d(TAG, "Module install failed")
        }
      } catch (e: Exception) {
        Log.e(TAG, "An error occurred installing the module:", e)
      }
    } else {
      Log.d(TAG, "Device is not supported")
    }
  } catch (e: Exception) {
    Log.e(TAG, "An error occurred checking device support:", e)
  }
}

Java

private void launchInstallRequest() {
  Log.v(TAG, "Launching install request");
  // Check if this device can support Google LLB.
  lowLightBoostClient
    .isDeviceSupported(context)
    .addOnSuccessListener(
      (isDeviceSupported) -> {
        if (isDeviceSupported) {
          Log.d(TAG, "Device is supported");
          // Show download indicator, if needed.
          lowLightBoostClient
            .installModule(
              this,
              createInstallStatusCallback()
            )
            .addOnSuccessListener(
              (result) -> {
                if (result) {
                  Log.d(TAG, "Module installed");
                  // Hide download indicator, if needed.
                  try {
                    openCamera();
                  } catch (CameraAccessException e) {
                    Log.e(TAG, "Failed to open camera", e);
                  }
                } else {
                  Log.d(TAG, "Module install failed");
                }
              }
            );
        } else {
          Log.d(TAG, "Device is not supported");
        }
      })
    .addOnFailureListener(
      (e) -> {
        Log.e(TAG, "Failed to check device support", e);
      });
}

Key points about this code

  • When you call LowLightBoostClient.installModule() you pass a callback object, which implements LowLightBoostClient.InstallStatusCallback. installModule() calls methods in that callback to indicate the status of the download. For example, if the download is paused, installModule() calls the callback object's onDownloadPause() method.
  • In this code snippet, the callback object is created by the createInstallStatusCallback() method. You'd need to write that method yourself, along these lines:

Kotlin

private fun createInstallStatusCallback(): LowLightBoostClient.InstallStatusCallback =
        object : LowLightBoostClient.InstallStatusCallback() {
    override fun onDownloadPending() {
      Log.d(TAG, "onDownloadPending")
      // Code here...
    }

    override fun onDownloadStart() {
      Log.d(TAG, "onDownloadStart")
      // Code here...
    }

    // other overrides here...
  }

Java

private InstallStatusCallback createInstallStatusCallback() {
  new LowLightBoostClient.InstallStatusCallback() {
    @Override
    public void onDownloadPending() {
      Log.d(TAG, "onDownloadPending");
      // Code here...
    }

    @Override
    public void onDownloadStart() {
      Log.d(TAG, "onDownloadStart");
      // Code here...
    }

  // other overrides here...
}

  • LowLightBoostClient.isDeviceSupported() checks whether the Android-powered device and operating system support Google Low Light Boost. If not, don't download the module.

  • The method LowLightBoostClient.installModule() returns a Task object. You use this object to set up success and failure listeners.

  • When the install finishes, the success listener verifies the install by opening the camera. In the snippet, this is done with a call to openCamera(). You'll need to write that method yourself.

Check if low light boost is supported

Once you have a client, you can check if low light boost is supported by the device the app is running on. The following code checks if low light boost is supported:

Kotlin

launch {
  try {
    // Await the result of the Task in a non-blocking way
    val isSupported: Boolean = lowLightBoostClient
      .isCameraSupported(cameraId).await()
    Log.d(TAG, "isCameraSupported: $isSupported")
    if (isSupported) {
      // Create the low light boost session here
    }
  } catch (e: Exception) {
    Log.e(TAG, "isCameraSupported failed", e)
  }
}

Java

lowLightBoostClient
  .isCameraSupported(cameraId)
  .addOnSuccessListener(
    lowLightBoostExecutor,
    (isSupported) -> {
      Log.d(TAG, "isCameraSupported: " + isSupported);
      if (isSupported) {
        // Create the low light boost session here
      }
    )

Key points about this code