# XComponent

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

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



## Required Permissions

None

## Child Components

Not supported

## APIs

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

**Parameters**

| 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

### onLoad

onLoad(callback: (event?: object) => void )

Triggered when the plug-in is loaded.

**Parameters**

| Name          | Type  | Mandatory | Description                     |
| ------------- | ------ | ---- | ----------------------- |
| event  | object |   No | Context of the **\<XComponent>** object. The APIs contained in the context are defined at the C++ layer by developers.|

### onDestroy

onDestroy(event: () => 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()

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

**System API**: This is a system API.

**Return value**

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


### setXComponentSurfaceSize

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

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

**System API**: This is a system API.

**Parameters**

| Name          | Type  | Mandatory | 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()

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

**Return value**

| Type    | Description                                      |
| ------ | ---------------------------------------- |
| Object | Context of the **\<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})
  }
}
```