# XComponent

  >  **NOTE**
  >
  >  This component is supported since API version 8. Updates will be marked with a superscript to indicate their earliest API version.  

  The **\<XComponent>** can accept and display the EGL/OpenGL ES and media data input.

## Required Permissions

  None

## Child Components

  Not supported

## APIs

  XComponent\(value: {id: string, type: string, libraryname?: string, controller?: XComponentController}\)

  - Name

    | Name         | Type                                    | Mandatory  | Description                                      |
    | ----------- | ---------------------------------------- | ---- | ---------------------------------------- |
    | id          | string                                   | Yes   | Unique ID of the component. The value can contain a maximum of 128 characters.                  |
    | type        | string                                   | Yes   | Type of the component. The options are as follows:<br>-**surface**: The content of this component is displayed individually, without being combined with that of other components.<br>-**component**: The content of this component is displayed after having been combined with that of other components.|
    | libraryname | string                                   | No   | Name of the dynamic library generated after compilation at the application native layer.                     |
    | controller  | [XComponentController](#XComponentController) | No   | Controller bound to the component, which can be used to invoke methods of the component.                 |


## Events

| Name                              | Description        |
| -------------------------------- | ------------ |
| onLoad(context?: object) => void | Triggered when the plug-in is loaded.|
| onDestroy() => void              | Triggered when the plug-in is destroyed.|

## XComponentController

Defines the controller of the **\<XComponent>**. You can bind the controller to the **\<XComponent>** to invoke the component methods through the controller.

### Creating an Object

```
xcomponentController: XComponentController = new XComponentController()
```

### getXComponentSurfaceId

getXComponentSurfaceId(): string

Obtains the ID of the surface held by the **\<XComponent>**. The ID can be used for @ohos interfaces, such as camera-related interfaces.

  - Return value

    | Type    | Description                     |
    | ------ | ----------------------- |
    | string | ID of the surface held by the **\<XComponent>**.|

### setXComponentSurfaceSize

setXComponentSurfaceSize(value: {surfaceWidth: number, surfaceHeight: number}): void

Sets the width and height of the surface held by the **\<XComponent>**.

- Parameters

  | Name          | Type  | Mandatory  | Default Value | Description                     |
  | ------------- | ------ | ---- | ---- | ----------------------- |
  | surfaceWidth  | number | Yes   | -    | Width of the surface held by the **\<XComponent>**.|
  | surfaceHeight | number | Yes   | -    | Height of the surface held by the **\<XComponent>**.|

### getXComponentContext

getXComponentContext(): Object

Obtains the context of an **\<XComponent>** object.

- Return value

  | Type    | Description                                      |
  | ------ | ---------------------------------------- |
  | Object | Context of an **\<XComponent>** object. The APIs contained in the context are defined by developers.|

## Example

Provide a surface-type **\<XComponent>** to support capabilities such as camera preview. 

You can preview how this component looks on a real device. The preview is not yet available in the DevEco Studio Previewer.

```ts
// xxx.ets
import camera from '@ohos.multimedia.camera';
@Entry
@Component
struct PreviewArea {
  private surfaceId : string =''
  xcomponentController: XComponentController = new XComponentController()
  build() {
    Row() {
      XComponent({
        id: 'xcomponent',
        type: 'surface',
        controller: this.xcomponentController
      })
        .onLoad(() => {
          this.xcomponentController.setXComponentSurfaceSize({surfaceWidth:1920,surfaceHeight:1080});
          this.surfaceId = this.xcomponentController.getXComponentSurfaceId();
          camera.createPreviewOutput(this.surfaceId).then((previewOutput) => {
            console.log('Promise returned with the PreviewOutput instance');
          })
        })
        .width('640px')
        .height('480px')
    }
    .backgroundColor(Color.Black)
    .position({x: 0, y: 48})
  }
}
```