项目初始化

Houjie

2025-04-11 1bf977929dd324f3ac64b70debd8a79443c54392

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/**
 * @fileoverview
 * Core storage related APIs.
 * 
 * @author mebjas <minhazav@gmail.com>
 * 
 * The word "QR Code" is registered trademark of DENSO WAVE INCORPORATED
 * http://www.denso-wave.com/qrcode/faqpatent-e.html
 */
 
interface PersistedData {
    hasPermission: boolean;
    lastUsedCameraId: string | null;
}
 
class PersistedDataFactory {
    static createDefault(): PersistedData {
        return {
            hasPermission: false,
            lastUsedCameraId: null
        };
    }
}
 
export class PersistedDataManager {
 
    private data: PersistedData = PersistedDataFactory.createDefault();
    private static LOCAL_STORAGE_KEY: string = "HTML5_QRCODE_DATA";
 
    constructor() {
        let data = localStorage.getItem(PersistedDataManager.LOCAL_STORAGE_KEY);
        if (!data) {
            this.reset();
        } else {
            this.data = JSON.parse(data);
        }
    }
 
    public hasCameraPermissions(): boolean {
        return this.data.hasPermission;
    }
 
    public getLastUsedCameraId(): string | null {
        return this.data.lastUsedCameraId;
    }
 
    public setHasPermission(hasPermission: boolean) {
        this.data.hasPermission = hasPermission;
        this.flush();
    }
 
    public setLastUsedCameraId(lastUsedCameraId: string) {
        this.data.lastUsedCameraId = lastUsedCameraId;
        this.flush();
    }
 
    public resetLastUsedCameraId() {
        this.data.lastUsedCameraId = null;
        this.flush();
    }
 
    public reset() {
        this.data = PersistedDataFactory.createDefault();
        this.flush();
    }
 
    private flush(): void {
        localStorage.setItem(
            PersistedDataManager.LOCAL_STORAGE_KEY,
            JSON.stringify(this.data));
    }
}