我有n个
元素,每个元素都有标题和
标题和列表。
我想把它们浮动到画布上,并从id为"x"的
元素的列表项y绘制到id为"z"的元素。我正在使用jQuery UI使
我想把它们浮动到画布上,并从id为"x"的
元素的列表项y绘制到id为"z"的
元素。我正在使用jQuery UI使
我有n个
我想把它们浮动到画布上,并从id为"x"的
//Get the absolute position of a DOM object on a page
function findPos(obj) {
var curLeft = curTop = 0;
if (obj.offsetParent) {
do {
curLeft += obj.offsetLeft;
curTop += obj.offsetTop;
} while (obj = obj.offsetParent);
}
return {x:curLeft, y:curTop};
}
var centerX = findPos(document.getElementById('x'));
centerX.x += document.getElementById('x').style.width;
centerX.y += document.getElementById('x').style.height;
var centerZ = findPos(document.getElementById('Z'));
centerZ.x += document.getElementById('z').style.width;
centerZ.y += document.getElementById('z').style.height;
//Now you've got both centers in reference to the page
var canvasPos = findPos(document.getElementById('canvas'));
centerX.x -= canvasPos.x;
centerX.y -= canvasPos.y;
centerZ.x -= canvasPos.x;
centerZ.y -= canvasPos.y;
//Now both points are in reference to the canvas
var ctx = document.getElementById('canvas').getContext('2d');
ctx.beginPath();
ctx.moveTo(centerX.x, centerX.y);
ctx.lineTo(centerZ.x, centerZ.y);
ctx.stroke();
//Now you should have a line between both divs. You should call this code each time the position changes
编辑 顺便说一下,使用findPos函数,你还可以将div的初始位置设置为相对于画布的位置(这里是在(30;40)处):
var position = {x: 30, y: 40};
var canvasPos = findPos(document.getElementById('canvas'));
var xPos = canvasPos.x + position.x;
var yPos = canvasPos.y + position.y;
document.getElementById('x').style.left = xPos+"px";
document.getElementById('x').style.top = yPos+"px";