175.HarmonyOS NEXT系列教程之列表交换组件状态管理机制

// 操作状态枚举
enum OperationStatus {
    IDLE,       // 空闲状态
    PRESSING,   // 长按状态
    MOVING,     // 移动状态
    DROPPING,   // 放置状态
    DELETE      // 删除状态
}

// 组件状态
@Observed
export class ListExchangeCtrl<T> {
    // 列表数据
    private deductionData: Array<T> = [];
    // 当前状态
    state: OperationStatus = OperationStatus.IDLE;
    // 偏移量
    offsetY: number = 0;
}

class StateManager {
    private static instance: StateManager;
    private currentState: OperationStatus = OperationStatus.IDLE;
    private listeners: Set<(state: OperationStatus) => void> = new Set();

    static getInstance(): StateManager {
        if (!StateManager.instance) {
            StateManager.instance = new StateManager();
        }
        return StateManager.instance;
    }

    setState(newState: OperationStatus): void {
        this.currentState = newState;
        this.notifyListeners();
    }

    private notifyListeners(): void {
        this.listeners.forEach(listener => listener(this.currentState));
    }
}

@Observed
export class ListInfo {
    icon: ResourceStr = '';
    name: ResourceStr = '';

    constructor(icon: ResourceStr = '', name: ResourceStr = '') {
        this.icon = icon;
        this.name = name;
    }
}

class StateObserver {
    // 监听状态变化
    static observe(target: any, callback: () => void): void {
        Watch(target)(() => {
            callback();
        })
    }

    // 取消监听
    static unobserve(target: any): void {
        // 取消监听逻辑
    }
}

class ListExchangeCtrl<T> {
    // 更新状态
    private updateState(newState: OperationStatus): void {
        // 状态转换验证
        if (this.isValidStateTransition(this.state, newState)) {
            this.state = newState;
            this.handleStateChange();
        }
    }

    // 验证状态转换
    private isValidStateTransition(
        currentState: OperationStatus, 
        newState: OperationStatus
    ): boolean {
        // 状态转换验证逻辑
        return true;
    }
}

class BatchUpdater {
    private static updates: Array<() => void> = [];
    private static isProcessing: boolean = false;

    static addUpdate(update: () => void): void {
        this.updates.push(update);
        this.processUpdates();
    }

    private static async processUpdates(): Promise<void> {
        if (this.isProcessing) return;
        this.isProcessing = true;

        while (this.updates.length > 0) {
            const update = this.updates.shift();
            await update();
        }

        this.isProcessing = false;
    }
}

class UISynchronizer {
    // 同步UI状态
    static syncUI(state: OperationStatus): void {
        switch (state) {
            case OperationStatus.PRESSING:
                this.applyPressingStyle();
                break;
            case OperationStatus.MOVING:
                this.applyMovingStyle();
                break;
            case OperationStatus.DROPPING:
                this.applyDroppingStyle();
                break;
            default:
                this.applyDefaultStyle();
        }
    }

    private static applyPressingStyle(): void {
        // 应用长按状态样式
    }
}

class DataSynchronizer {
    // 同步数据状态
    static syncData(data: Array<any>): void {
        // 数据同步逻辑
    }

    // 处理数据冲突
    static resolveConflict(localData: any, remoteData: any): any {
        // 冲突解决逻辑
        return mergedData;
    }
}

class StatePersistence {
    // 保存状态
    static async saveState(state: any): Promise<void> {
        try {
            await localStorage.setItem('appState', JSON.stringify(state));
        } catch (error) {
            console.error('Failed to save state:', error);
        }
    }

    // 恢复状态
    static async restoreState(): Promise<any> {
        try {
            const state = await localStorage.getItem('appState');
            return JSON.parse(state);
        } catch (error) {
            console.error('Failed to restore state:', error);
            return null;
        }
    }
}

class StateRecovery {
    // 恢复到上一个状态
    static async recoverToPreviousState(): Promise<void> {
        const previousState = await StatePersistence.restoreState();
        if (previousState) {
            StateManager.getInstance().setState(previousState);
        }
    }
}

class StateCache {
    private static cache: Map<string, any> = new Map();

    static set(key: string, value: any): void {
        this.cache.set(key, value);
    }

    static get(key: string): any {
        return this.cache.get(key);
    }

    static clear(): void {
        this.cache.clear();
    }
}

class UpdateOptimizer {
    private static updateQueue: Array<() => void> = [];
    private static updateScheduled: boolean = false;

    static scheduleUpdate(update: () => void): void {
        this.updateQueue.push(update);
        if (!this.updateScheduled) {
            this.updateScheduled = true;
            requestAnimationFrame(() => this.processUpdates());
        }
    }

    private static processUpdates(): void {
        while (this.updateQueue.length > 0) {
            const update = this.updateQueue.shift();
            update();
        }
        this.updateScheduled = false;
    }
}