raphaeljs拖放

Question

我在我的网络应用程序中使用rapaeljs.我想设置对象的可丢弃边界.对象可以在可丢弃区域中移动.一旦物体进入可伸缩区域,对象就应该没有出路.

Answer 1

拉斐尔已经建立了拖放支持.drag().在表单中使用它,element.drag(start, move, up);其中3个参数是对您编写的函数的3个函数引用,分别处理mousedown,movement和mouseup事件.

注意如何this.ox和this.oy用于存储起始位置,dx并dy用于移动.

以下实现了对框的拖放.盒子总是可以移动,但一旦它在"监狱"盒子里,它就不能移回.当盒子进入监狱时,颜色立即改变,以通知用户功能已经改变.

这是通过实施Math.min()和Math.max()后箱的位置进行调整dx,并dy添加到当前位置:

var nowX, nowY, move = function (dx, dy) {
    // move will be called with dx and dy
    if (this.attr("y") > 60 || this.attr("x") > 60)
        this.attr({x: this.ox + dx, y: this.oy + dy}); 
    else {
        nowX = Math.min(60, this.ox + dx);
        nowY = Math.min(60, this.oy + dy);
        nowX = Math.max(0, nowX);
        nowY = Math.max(0, nowY);            
        this.attr({x: nowX, y: nowY });
        if (this.attr("fill") != "#000") this.attr({fill: "#000"}); 
    }
}

您也可以这样做,以便一旦将其放入"监狱"框中,就不能再次拾取该框.这可以通过测试函数中的位置move()或start()函数中的使用来c.undrag(f)完成stop().

jsFiddle例子

window.onload = function() {
var nowX, nowY, R = Raphael("canvas", 500, 500),
    c = R.rect(200, 200, 40, 40).attr({
            fill: "hsb(.8, 1, 1)",
            stroke: "none",
            opacity: .5,
            cursor: "move"
        }),
    j = R.rect(0,0,100,100),
    // start, move, and up are the drag functions
    start = function () {
        // storing original coordinates
        this.ox = this.attr("x");
        this.oy = this.attr("y");
        this.attr({opacity: 1});
        if (this.attr("y") < 60 &&  this.attr("x") < 60)
            this.attr({fill: "#000"});        
    },
    move = function (dx, dy) {
        // move will be called with dx and dy
        if (this.attr("y") > 60 || this.attr("x") > 60)
            this.attr({x: this.ox + dx, y: this.oy + dy}); 
        else {
            nowX = Math.min(60, this.ox + dx);
            nowY = Math.min(60, this.oy + dy);
            nowX = Math.max(0, nowX);
            nowY = Math.max(0, nowY);            
            this.attr({x: nowX, y: nowY });
            if (this.attr("fill") != "#000") this.attr({fill: "#000"}); 
        }
    },
    up = function () {
        // restoring state
        this.attr({opacity: .5});
        if (this.attr("y") < 60 && this.attr("x") < 60)
            this.attr({fill: "#AEAEAE"});            
    };   
    // rstart and rmove are the resize functions;
    c.drag(move, start, up);
};?