建立及使用低光增強用戶端

如要使用 Google 低光源增強功能,您需要低光源增強用戶端。您可以使用用戶端檢查是否已安裝低光源增強模組,以及應用程式執行的裝置和相機是否支援 Google 低光源增強功能。您也會使用用戶端建立 LowLightBoostSession。(您將使用工作階段開啟及關閉低光源強化功能)。您也可以設定接聽程式,在低光源增強功能啟用時接收回呼。

LowLightBoostClient 方法不會直接指出成功或失敗。而是會傳回 Task 物件。您可以使用 Task 設定成功和失敗的監聽器。這樣一來,方法就能以非同步方式發出成功或失敗信號,這是必要做法,因為方法需要與 Google Play 服務通訊。

依附元件

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 是由 Google Play 服務 com.google.android.gms.cameralowlight套件提供。如要瞭解如何存取 Google Play 服務 API,請參閱 Google Play 服務說明文件。

建立用戶端

如要執行其他操作,您需要低光源增強用戶端。下列程式碼會建立用戶端:

Kotlin

val lowLightBoostClient = LowLightBoost.getClient(context)

Java

LowLightBoostClient lowLightBoostClient = LowLightBoost.getClient(context);

這組代碼的重點

確認裝置是否支援低光源增強功能

取得用戶端後,您可以檢查應用程式執行的裝置是否支援低光源模式。下列程式碼會檢查是否支援低光源增強功能:

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
      }
    )

這組代碼的重點

檢查是否已安裝低光源增強模組

取得用戶端後,即可確認裝置上是否已安裝低光源增強模組。下列程式碼會檢查模組是否已安裝:

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);
    });

這組代碼的重點

  • 這段程式碼會開啟攝影機工作階段,連線至 cameraId 所識別的攝影機。詳情請參閱 Camera2 說明文件
  • LowLightBoostClient.isModuleInstalled() 方法會傳回 Task 物件。您可以使用這個物件設定成功和失敗監聽器。
  • 使用 Task.addOnSuccessListener() 設定事件監聽器,在呼叫 isModuleInstalled() 成功時呼叫該監聽器。重要事項:如果呼叫成功接聽程式,這只會告訴您用戶端是否成功判斷模組是否安裝在裝置上。在接聽程式主體中,您需要檢查模組是否確實已安裝。
  • 如果尚未安裝模組,這個程式碼片段會呼叫 launchInstallRequest() 方法來安裝模組。該方法定義於「安裝低光源增強模組」中的程式碼片段。

安裝低光源增強模組

如果裝置尚未安裝低光源增強模組,請從 Google Play 服務下載並安裝。以下程式碼顯示如何執行這項操作:

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);
      });
}

這組代碼的重點

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() 檢查 Android 裝置和作業系統是否支援 Google 低光源增強功能。如果不是,請勿下載模組。

  • LowLightBoostClient.installModule() 方法會傳回 Task 物件。您可以使用這個物件設定成功和失敗監聽器。

  • 安裝完成後,成功事件監聽器會開啟攝影機,驗證安裝作業。在程式碼片段中,這項操作是透過呼叫 openCamera() 完成。您必須自行撰寫該方法。