team2_jj/assets/scripts/core/ui/drag/DragSource.ts

import { Component, EventHandler, EventTouch, v3, Vec3, _decorator } from "cc";
import { DragSystem } from "./DragSystem";
import { DragTarget } from "./DragTarget";
const { ccclass, property } = _decorator;
/**
 * 可以被拖拽的组件
 * @description 如果需要新创建UI，那么请自己创建预制体，并在预制体的update中更新其坐标为本组件的worldPosition
 * @author 袁浩
 */
@ccclass("DragSource")
export class DragSource extends Component {
    @property({ tooltip: "所属分组" })
    public group: string = "group";
    @property({ tooltip: "是否更新自己的坐标" })
    public updatePosition = false;
    @property({ tooltip: "当被拖拽", type: EventHandler })
    public onDrag: EventHandler[] = [];
    @property({ tooltip: "当被拖拽放下", type: EventHandler })
    public onDrop: EventHandler[] = [];
    @property({ tooltip: "当被拖拽中", type: EventHandler })
    public onDraging: EventHandler[] = [];
    /**
     * 当前世界位置
     */
    public worldPosition: Vec3;
    start() {
        DragSystem.addSource(this);
    }
    onDestroy() {
        DragSystem.removeSource(this);
    }
    update() {
        if (this.updatePosition && this.worldPosition) {
            this.node.worldPosition = this.worldPosition;
        }
    }
    public draging(event: EventTouch) {
        for (let i = 0; i < this.onDraging.length; i++) {
            this.onDraging[i] && this.onDraging[i].emit([event]);
        }
    }
    public drop(event: EventTouch) {
        for (let i = 0; i < this.onDrop.length; i++) {
            this.onDrop[i] && this.onDrop[i].emit([event]);
        }
    }
    public drag(event: EventTouch) {
        for (let i = 0; i < this.onDrag.length; i++) {
            this.onDrag[i] && this.onDrag[i].emit([event]);
        }
    }
}