raphael.js 拖动扩展

(function (R) {
R.el.draggable = function (move, start, up) {
this._ui = this._ui || {};

var that = this;

this._ui.onMove = R.is(move, 'function') ?
move : function (distanceX, distanceY, x, y, deltaX, deltaY) {
that.translate(deltaX, deltaY);
};

this._ui.onStart = R.is(start, 'function') ? start : function (x, y) {
};

function onMove(distanceX, distanceY, x, y) {
var deltaX = x - that._ui.lastX;
var deltaY = y - that._ui.lastY;
that._ui.lastX = x;
that._ui.lastY = y;
that._ui.onMove(distanceX, distanceY, x, y, deltaX, deltaY);
that.paper.safari();
};

function onStart(x, y) {
that._ui.lastX = x;
that._ui.lastY = y;
that._ui.onStart(x, y);
};

return this.drag(onMove, onStart, up);
};
})(Raphael);

//调用方法
rect.draggable();