Vibrator Development

When to Use

You can set different vibration effects as needed, for example, customizing the vibration intensity, frequency, and duration for button touches, alarm clocks, and incoming calls.

For details about the APIs, see Vibrator.

Available APIs

Vibration Effect Description

Currently, three types of vibration effects are supported.

Fixed-Duration Vibration

Only a fixed duration is passed in, and the device vibrates based on the default intensity and frequency. For details about the vibration effect, see VibrateTime.

Preset Vibration

Certain vibration effects are preset for fixed scenes. For example, the effect "haptic.clock.timer" is preset to provide feedback when a user adjusts the timer. For details about the vibration effect, see VibratePreset.

Custom Vibration

Custom vibration enables you to design vibration effects by customizing a vibration configuration file and orchestrating vibration forms based on the corresponding rules. For details about the vibration effect, see VibrateFromFile.

The custom vibration configuration file is in JSON format. An example file is as follows:

{
    "MetaData": {
        "Create": "2023-01-09",
        "Description": "a haptic case",
        "Version": 1.0,
        "ChannelNumber": 1
    },
    "Channels": [
        {
            "Parameters": {
                "Index": 0
            },
            "Pattern": [
                {
                    "Event": {
                        "Type": "transient",
                        "StartTime": 0,
                        "Parameters": {
                            "Frequency": 31,
                            "Intensity": 100
                        }
                    }
                },
                {
                    "Event": {
                        "Type": "continuous",
                        "StartTime": 40,
                        "Duration": 54,
                        "Parameters": {
                            "Frequency": 30,
                            "Intensity": 38,
                            "Curve": [
                                {
                                    "Time": 0,
                                    "Frequency": 0,
                                    "Intensity": 0
                                },
                                {
                                    "Time": 1,
                                    "Frequency": 15,
                                    "Intensity": 0.5
                                },
                                {
                                    "Time": 40,
                                    "Frequency": -8,
                                    "Intensity": 1.0
                                },
                                {
                                    "Time": 54,
                                    "Frequency": 0,
                                    "Intensity": 0
                                }
                            ]
                        }
                    }
                }
            ]
        }
    ]
}

This JSON file contains two attributes: MetaData and Channels.

• MetaData contains information about the file header. You can add the following attributes under MetaData.

• Channels provides information about the vibration channel. It is a JSON array that holds information about each channel. It contains two attributes: Parameters and Pattern.

 **Pattern** is a JSON array that holds the vibration events. Under it, **Event** indicates a vibration event, which can be either of the following types:

 A vibration event contains the following attributes:

 **Parameters** provides the following parameters related to the vibration event and is mandatory.

The following requirements must be met:

How to Develop

1. Before using the vibrator on a device, you must declare the ohos.permission.VIBRATE permission. For details, see Declaring Permissions.

2. Start vibration with the specified effect and attribute.

• Scenario 1: Trigger vibration with the specified duration.

  import vibrator from '@ohos.vibrator';
  import { BusinessError } from '@ohos.base';
  
  try {
    // Start vibration.
    vibrator.startVibration({
      type: 'time',
      duration: 1000,
    }, {
      id: 0,
      usage: 'alarm'
    }, (error: BusinessError) => {
      if (error) {
        console.error(`Failed to start vibration. Code: ${error.code}, message: ${error.message}`);
        return;
      }
      console.info('Succeed in starting vibration');
    });
  } catch (err) {
    let e: BusinessError = err as BusinessError;
    console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
  }
  

• Scenario 2: Trigger vibration with a preset effect. You can check whether the preset effect is supported before calling startVibration().

  import vibrator from '@ohos.vibrator';
  import { BusinessError } from '@ohos.base';
  
  try {
    // Check whether 'haptic.clock.timer' is supported.
    vibrator.isSupportEffect('haptic.clock.timer', (err: BusinessError, state: boolean) => {
      if (err) {
        console.error(`Failed to query effect. Code: ${err.code}, message: ${err.message}`);
        return;
      }
      console.info('Succeed in querying effect');
      if (state) {
        try {
          // Start vibration.
          vibrator.startVibration({
            type: 'preset',
            effectId: 'haptic.clock.timer',
            count: 1,
          }, {
            usage: 'unknown'
          }, (error: BusinessError) => {
            if (error) {
              console.error(`Failed to start vibration. Code: ${error.code}, message: ${error.message}`);
            } else {
              console.info('Succeed in starting vibration');
            }
          });
        } catch (error) {
          let e: BusinessError = error as BusinessError;
          console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
        }
      }
    })
  } catch (error) {
    let e: BusinessError = error as BusinessError;
    console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
  }
  

• Scenario 3: Trigger vibration according to a custom vibration configuration file.

  import vibrator from '@ohos.vibrator';
  import resourceManager from '@ohos.resourceManager';
  import { BusinessError } from '@ohos.base';
  
  const fileName: string = 'xxx.json';
  
  // Obtain the file descriptor of the vibration configuration file.
  let rawFd: resourceManager.RawFileDescriptor = getContext().resourceManager.getRawFdSync(fileName);
  
  // Start vibration.
  try {
    vibrator.startVibration({
      type: "file",
      hapticFd: { fd: rawFd.fd, offset: rawFd.offset, length: rawFd.length }
    }, {
      id: 0,
      usage: 'alarm'
    }, (error: BusinessError) => {
      if (error) {
        console.error(`Failed to start vibration. Code: ${error.code}, message: ${error.message}`);
        return;
      }
      console.info('Succeed in starting vibration');
    });
  } catch (err) {
    let e: BusinessError = err as BusinessError;
    console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
  }
  
  // Close the file descriptor of the vibration configuration file.
  getContext().resourceManager.closeRawFdSync(fileName);
  

3. Stop vibration.

• Method 1: Stop vibration in the specified mode. This method is invalid for custom vibration.

  • Stop fixed-duration vibration.

    import vibrator from '@ohos.vibrator';
    import { BusinessError } from '@ohos.base';
    
    try {
      // Stop vibration in VIBRATOR_STOP_MODE_TIME mode.
      vibrator.stopVibration(vibrator.VibratorStopMode.VIBRATOR_STOP_MODE_TIME, (error: BusinessError) => {
        if (error) {
          console.error(`Failed to stop vibration. Code: ${error.code}, message: ${error.message}`);
          return;
        }
        console.info('Succeed in stopping vibration');
      })
    } catch (err) {
      let e: BusinessError = err as BusinessError;
      console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
    }
    

  • Stop preset vibration.

    import vibrator from '@ohos.vibrator';
    import { BusinessError } from '@ohos.base';
    
    try {
      // Stop vibration in VIBRATOR_STOP_MODE_PRESET mode.
      vibrator.stopVibration(vibrator.VibratorStopMode.VIBRATOR_STOP_MODE_PRESET, (error: BusinessError) => {
        if (error) {
          console.error(`Failed to stop vibration. Code: ${error.code}, message: ${error.message}`);
          return;
        }
        console.info('Succeed in stopping vibration');
      })
    } catch (err) {
      let e: BusinessError = err as BusinessError;
      console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
    }
    

• Method 2: Stop vibration in all modes, including custom vibration.

  import vibrator from '@ohos.vibrator';
  import { BusinessError } from '@ohos.base';
  
  try {
    // Stop vibration in all modes.
    vibrator.stopVibration((error: BusinessError) => {
      if (error) {
        console.error(`Failed to stop vibration. Code: ${error.code}, message: ${error.message}`);
        return;
      }
      console.info('Succeed in stopping vibration');
    })
  } catch (error) {
    let e: BusinessError = error as BusinessError;
    console.error(`An unexpected error occurred. Code: ${e.code}, message: ${e.message}`);
  }