export class ObProperty<T> {
    private value:T;    // 值
    private onChanges:((newValue:T, oldValue:T)=>void)[]=[];

    constructor(initValue:T){
        this.value = initValue;
    }

    public get Value():T{ return this.value;}

    public set Value(newValue:T) {
        if(newValue != this.value){
            const oldValue = this.value;
            this.value = newValue;
            this.onChanges.forEach(callback=>callback(newValue, oldValue));
        }
    }

    // 注册变更回调
    public RegisterOnChange(callback:(newValue:T, oldValue:T)=>void):void{
        this.onChanges.push(callback);
    }

    // 移除变更回调
    public UnregisterOnChange(callback:(newValue:T, oldValue:T)=>void):void {
        const idx = this.onChanges.indexOf(callback);
        if (idx !== -1){
            this.onChanges.splice(idx, 1);
        }
    }
}