HarmonyOS 鸿蒙Next中hdsTabs如何设置左右手跟随质感握姿

刚刚实现了一下，记得加权限：

"requestPermissions": [
      {
        "name" : "ohos.permission.ACTIVITY_MOTION",
        "reason": "$string:activity_motion_reason",
        "usedScene": {
          "abilities": ["EntryAbility"],
          "when": "always"
        }
      },
      {
        "name" : "ohos.permission.DETECT_GESTURE",
        "reason": "$string:detect_gesture_reason",
        "usedScene": {
          "abilities": ["EntryAbility"],
          "when": "always"
        }
      }
    ]

import { HdsTabs, HdsTabsController } from '@kit.UIDesignKit';
import { hdsMaterial } from '@kit.UIDesignKit';
import motion from '@ohos.multimodalAwareness.motion';

@Entry
@Component
struct SmartTabsPage {
  @State barPositionValue: number = 0;
  controller: HdsTabsController = new HdsTabsController();
  @State isLeftHand: boolean = true;
  @State handStatus: string = '左手';

  aboutToAppear(): void {
    motion.on('holdingHandChanged', (data) => {
      const handValue: number = data as number;
      if (handValue === 1) {
        this.isLeftHand = true;
        this.barPositionValue = 0;
        this.handStatus = '左手';
      } else if (handValue === 2) {
        this.isLeftHand = false;
        this.barPositionValue = 1;
        this.handStatus = '右手';
      }
    });
  }

  aboutToDisappear(): void {
    motion.off('holdingHandChanged');
  }

  build() {
    Column() {
      Row() {
        Text('当前握持手: ' + this.handStatus)
          .fontSize(16)
          .fontColor(Color.Gray)
        Toggle({ type: ToggleType.Switch, isOn: this.isLeftHand })
          .onChange((isOn: boolean) => {
            this.isLeftHand = isOn;
            this.barPositionValue = isOn ? 0 : 1;
            this.handStatus = isOn ? '左手' : '右手';
          })
          .margin({ left: 16 })
      }
      .padding(16)
      .width('100%')

      HdsTabs({
        controller: this.controller
      }) {
        TabContent() {
          Column() {
            Text('珠宝首饰')
              .fontSize(30)
              .fontWeight(FontWeight.Bold)
            Text('珠宝首饰行业的百科知识')
              .fontSize(16)
              .fontColor(Color.Gray)
              .margin({ top: 8 })
          }
          .width('100%')
          .height('100%')
          .justifyContent(FlexAlign.Center)
        }
        .tabBar(new BottomTabBarStyle($r('sys.media.ohos_ic_public_clock'), '珠宝'))

        TabContent() {
          Column() {
            Text('黄金')
              .fontSize(30)
              .fontWeight(FontWeight.Bold)
            Text('黄金价格、选购知识')
              .fontSize(16)
              .fontColor(Color.Gray)
              .margin({ top: 8 })
          }
          .width('100%')
          .height('100%')
          .justifyContent(FlexAlign.Center)
        }
        .tabBar(new BottomTabBarStyle($r('sys.media.ohos_ic_public_clock'), '黄金'))

        TabContent() {
          Column() {
            Text('钻石')
              .fontSize(30)
              .fontWeight(FontWeight.Bold)
            Text('钻石4C标准、选购指南')
              .fontSize(16)
              .fontColor(Color.Gray)
              .margin({ top: 8 })
          }
          .width('100%')
          .height('100%')
          .justifyContent(FlexAlign.Center)
        }
        .tabBar(new BottomTabBarStyle($r('sys.media.ohos_ic_public_clock'), '钻石'))

        TabContent() {
          Column() {
            Text('翡翠')
              .fontSize(30)
              .fontWeight(FontWeight.Bold)
            Text('翡翠鉴定、保养知识')
              .fontSize(16)
              .fontColor(Color.Gray)
              .margin({ top: 8 })
          }
          .width('100%')
          .height('100%')
          .justifyContent(FlexAlign.Center)
        }
        .tabBar(new BottomTabBarStyle($r('sys.media.ohos_ic_public_clock'), '翡翠'))
      }
      .vertical(true)
      .barPosition(this.barPositionValue)
      .barOverlap(true)
      .barFloatingStyle({
        gradientMask: { maskColor: '#66F1F3F5', maskHeight: 92 },
        systemMaterialEffect: {
          materialType: hdsMaterial.MaterialType.IMMERSIVE,
          materialLevel: hdsMaterial.MaterialLevel.ADAPTIVE
        }
      })
    }
    .width('100%')
    .height('100%')
  }
}

export default class HoldingHandPlugin implements FlutterPlugin {
  private mEventChannel?: EventChannel;
  private sink: EventSink | undefined = undefined;
  private isListening: boolean = false;

  getUniqueClassName(): string {
    return "HoldingHandPlugin";
  }

  onAttachedToEngine(binding: FlutterPluginBinding): void {
    Log.d(TAG, "onAttachedToEngine");
    this.mEventChannel = new EventChannel(binding.getBinaryMessenger(), CHANNEL_NAME);
    const handler: StreamHandler = {
      onListen: (args: ESObject, events: EventSink) => {
        Log.d(TAG, 'EventChannel onListen');
        this.start(events);
      },
      onCancel: (args: ESObject) => {
        Log.d(TAG, 'EventChannel onCancel');
        this.stop();
      },
    };
    this.mEventChannel.setStreamHandler(handler);
  }

  onDetachedFromEngine(binding: FlutterPluginBinding): void {
    Log.d(TAG, "onDetachedFromEngine");
    this.stop();
    this.mEventChannel?.setStreamHandler(null);
    this.mEventChannel = undefined;
  }

  /**
   * 注册到 FlutterEngine（在 EntryAbility.configureFlutterEngine 中调用）
   */
  static registerWith(flutterEngine: FlutterEngine): void {
    const channel = new EventChannel(flutterEngine.dartExecutor, CHANNEL_NAME);
    const plugin = new HoldingHandPlugin();

    const handler: StreamHandler = {
      onListen: (args: ESObject, events: EventSink) => {
        Log.d(TAG, 'registerWith onListen');
        plugin.start(events);
      },
      onCancel: (args: ESObject) => {
        Log.d(TAG, 'registerWith onCancel');
        plugin.stop();
      },
    };
    channel.setStreamHandler(handler);
    Log.d(TAG, 'registerWith done');
  }

  /**
   * 开始订阅握持手状态
   * 优先尝试 holdingHandChanged (API 20)，失败后降级到 operatingHandChanged (API 15)
   */
  private start(events: EventSink): void {
    this.sink = events;

    if (this.isListening) {
      return;
    }
    this.isListening = true;

    // 优先尝试握持手回调 (API 20+)
    try {
      motion.on('holdingHandChanged', (data: motion.HoldingHandStatus) => {
        Log.d(TAG, 'holdingHandChanged: ' + data);
        this.emitStatus('holding', data as number);
      });
      Log.d(TAG, 'motion.on(holdingHandChanged) succeeded');
      this.emitStatus('holding', -1); // 初始状态未知
      return;
    } catch (err) {
      const error = err as BusinessError;
      Log.w(TAG, 'motion.on(holdingHandChanged) failed, code=' + error.code);
      // 非 801（能力未支持）错误，直接返回
      if (error.code !== 801) {
        this.emitError('holdingHandChanged', error);
        return;
      }
    }

    // 降级：尝试操作手回调 (API 15+)
    this.tryFallbackToOperating();
  }

  /**
   * 降级订阅操作手状态
   */
  private tryFallbackToOperating(): void {
    try {
      motion.on('operatingHandChanged', (data: motion.OperatingHandStatus) => {
        Log.d(TAG, 'operatingHandChanged: ' + data);
        this.emitStatus('operating', data as number);
      });
      Log.d(TAG, 'fallback: motion.on(operatingHandChanged) succeeded');

      // 尝试获取最近一次操作手状态
      try {
        const recent = motion.getRecentOperatingHandStatus();
        this.emitStatus('operating', recent as number);
      } catch (_) {
        // ignore
      }
    } catch (err) {
      const error = err as BusinessError;
      this.emitError('operatingHandChanged', error);
      Log.w(TAG, 'fallback: motion.on(operatingHandChanged) failed, code=' + error.code);
    }
  }

  /**
   * 停止订阅
   */
  private stop(): void {
    this.isListening = false;

    try { motion.off('holdingHandChanged'); } catch (_) {}
    try { motion.off('operatingHandChanged'); } catch (_) {}

    this.sink = undefined;
  }

  /**
   * 推送状态到 Flutter
   */
  private emitStatus(source: string, status: number): void {
    if (!this.sink) {
      return;
    }
    const payload: Record<string, Object> = {
      'source': source,
      'status': status,
      'ts': Date.now(),
    };
    this.sink.success(payload);
  }

  /**
   * 推送错误到 Flutter
   */
  private emitError(action: string, error: BusinessError): void {
    if (!this.sink) {
      return;
    }
    this.sink.error(
      error.code?.toString() ?? '-1',
      `${action} failed: ${error.message}`,
      error
    );
  }
}

这是我在一个flutter项目上定义的智感握姿的plugin，希望对你有帮助。