Device Input (Cangjie)

Note:

Currently in the beta phase.

When developing a camera application, you need to first refer to the Development Preparation to apply for relevant permissions.

The camera application can perform basic operations such as preview, photo capture, and video recording by invoking and controlling the camera device.

Development Steps

For detailed API descriptions, please refer to the Camera API Reference.

1. Import the camera interface, which provides camera-related properties and methods. The import method is as follows:

   import kit.CameraKit.*
   import ohos.business_exception.BusinessException
   import ohos.hilog.Hilog
   import ohos.callback_invoke.Callback0Argument
   

   Note:

   Camera device management must be completed before configuring camera device input. For detailed development steps, refer to Camera Management.

2. Create a camera input stream using the createCameraInput method in the CameraManager class.

   class ErrorCallBack <: Callback0Argument {
       public open func invoke(error:?BusinessException): Unit {
           if (let Some(e) <- error) {
               Hilog.error(0,"","Camera input error code: ${e.code}","")
           }
   
       }
   }
   
   func createInput(cameraDevice: CameraDevice, cameraManager: CameraManager): CameraInput {
       // Create camera input stream.
       let cameraInput: CameraInput = cameraManager.createCameraInput(cameraDevice)
       // Monitor cameraInput error messages.
       cameraInput.on(CameraEvents.CameraError, cameraDevice, ErrorCallBack())
       // Open the camera.
       cameraInput.open()
       return cameraInput
   }
   

3. Use the getSupportedSceneModes method to obtain the list of supported modes for the current camera device. The list contains all supported SceneMode values.

   func getSupportedSceneMode(cameraDevice: CameraDevice, cameraManager: CameraManager): Array<SceneMode> {
   // Get the list of supported modes for the camera device.
       let sceneModeArray: Array<SceneMode> = cameraManager.getSupportedSceneModes(cameraDevice)
       if (sceneModeArray.size > 0) {
           for (index in 0..sceneModeArray.size) {
               Hilog.info(0,"","Camera SceneMode : ${sceneModeArray[index]}")
           }
           return sceneModeArray
       } else {
           Hilog.error(0,"","cameraManager.getSupportedSceneModes error")
           return []
       }
   }
   

4. Use the getSupportedOutputCapability method to obtain all supported output streams for the current camera device, such as preview stream, photo capture stream, and video recording stream. The output streams are contained in various profile fields of CameraOutputCapability. Depending on the specified SceneMode of the camera device, different types of output streams need to be added.

   func getSupportedOutputCapability(cameraDevice: CameraDevice, cameraManager: CameraManager, sceneMode: SceneMode): CameraOutputCapability {
       // Get the supported output capability of the camera device.
       let cameraOutputCapability: CameraOutputCapability = cameraManager.getSupportedOutputCapability(cameraDevice, sceneMode)
       // Taking NormalPhoto mode as an example, preview stream and photo capture stream need to be added.
       // The previewProfiles property retrieves the supported preview output streams for the current device.
       let previewProfilesArray: Array<Profile> = cameraOutputCapability.previewProfiles
       if (!previewProfilesArray.size == 0) {
           Hilog.error(0,"","createOutput previewProfilesArray is empty")
       }
       // The photoProfiles property retrieves the supported photo capture output streams for the current device.
       let photoProfilesArray: Array<Profile> = cameraOutputCapability.photoProfiles
       if (photoProfilesArray.size == 0) {
           Hilog.error(0,"","createOutput photoProfilesArray is empty")
       }
       return cameraOutputCapability
   }