我正在学习Javascript / SVG组合(动画制作交互式SVG)的学习曲线。
我想创建一个代码片段,其中菜单元素(“库存”)可以拖到主屏幕(“画布”),而原始元素将保留在其位置(就像有人会移动它的副本一样)关闭原始元素。)
在这里,我尽可能地制作了代码片段: http://codepen.io/cmer41k/pen/f2b5eea274cdde29b0b2dc8a2424a645
所以我设法做了一些事情,但它的错误:
我可以处理1个副本并使其可拖动,但后来我不知道如何处理所有这些产生元素的ID,这会导致拖动问题
我无法理解如何让它无限期地工作(这样它可以产生任意数量的可拖动到画布上的圆圈)
画布中的可拖动元素经常重叠,我无法以不重叠的方式附加侦听器,因此我拖动的元素上的侦听器将“通过”任何其他元素传播;(
问题基本上是 - 有人可以提出我应该在这个片段中加入的逻辑,这样它就不那么麻烦了。我很确定我在这里遗漏了一些东西;((例如它不应该那么难吗?)
HTML:
<body>
<svg id="svg"
height="800"
width="480"
viewbox="0 0 480 800"
preserveAspectRatio="xMinYMin meet"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink"
>
<rect id="canvasBackground" width="480" height="480" x="0" y="0"/>
<rect id="inventoryBackground" width="480" height="100" x="0" y="480"/>
<g id="inventory">
<path id="curve4" class="inventory" d="M60,530 A35,35 0 1,1 60,531" />
<path id="curve3" class="inventory" d="M150,530 A35,35 0 1,1 150,531" />
<path id="curve2" class="inventory" d="M240,530 A35,35 0 1,1 240,531" />
<path id="curve1" class="inventory" d="M330,530 A35,35 0 1,1 330,531" />
</g>
<g id="canvas">
</g>
</svg>
</body>
使用Javascript:
// define meta objects
var drag = null;
// this stores all "curves"-circles
var curves = {};
var canvas = {};
var inventory = {};
window.onload = function() {
// creates the curve-circles in the object and at their initial x,y coords
curves.curve1 = document.getElementById("curve1");
curves.curve1.x = 0;
curves.curve1.y = 0;
curves.curve2 = document.getElementById("curve2");
curves.curve2.x = 0;
curves.curve2.y = 0;
curves.curve3 = document.getElementById("curve3");
curves.curve3.x = 0;
curves.curve3.y = 0;
curves.curve4 = document.getElementById("curve4");
curves.curve4.x = 0;
curves.curve4.y = 0;
canvas = document.getElementById("canvas");
inventory = document.getElementById("inventory");
// attach events listeners
AttachListeners();
}
function AttachListeners() {
var ttt = document.getElementsByClassName('inventory'), i;
for (i = 0; i < ttt.length; i++) {
document.getElementsByClassName("inventory")[i].onmousedown=Drag;
document.getElementsByClassName("inventory")[i].onmousemove=Drag;
document.getElementsByClassName("inventory")[i].onmouseup=Drag;
}
}
// Drag function that needs to be modified;//
function Drag(e) {
e.stopPropagation();
var t = e.target, id = t.id, et = e.type; m = MousePos(e);
if (!drag && (et == "mousedown")) {
if (t.className.baseVal=="inventory") { //if its inventory class item, this should get cloned into draggable?
copy = t.cloneNode(true);
copy.onmousedown=copy.onmousemove=onmouseup=Drag;
inventory.insertBefore(copy, inventory.firstChild);
drag = t;
dPoint = m;
}
if (t.className.baseVal=="draggable") { //if its just draggable class - it can be dragged around
drag = t;
dPoint = m;
}
}
// drag the spawned/copied draggable element now
if (drag && (et == "mousemove")) {
curves[id].x += m.x - dPoint.x;
curves[id].y += m.y - dPoint.y;
dPoint = m;
curves[id].setAttribute("transform", "translate(" +curves[id].x+","+curves[id].y+")");
}
// stop drag
if (drag && (et == "mouseup")) {
t.className.baseVal="draggable";
drag = null;
}
}
// adjust mouse position to the matrix of SVG & screen size
function MousePos(event) {
var p = svg.createSVGPoint();
p.x = event.clientX;
p.y = event.clientY;
var matrix = svg.getScreenCTM();
p = p.matrixTransform(matrix.inverse());
return {
x: p.x,
y: p.y
}
}
答案 0 :(得分:3)
你很亲密。你有几个错误。例如
copy.onmousedown=copy.onmousemove=onmouseup=Drag;
应该是:
copy.onmousedown=copy.onmousemove=copy.onmouseup=Drag;
而drag = t
应该是drag = copy
(?)
当我认为您打算将它们附加到&#34;画布&#34;时,您还将克隆附加到库存部分。部分。
但也有一些不那么明显的错误导致了不可靠性。例如,如果将mousemove和mouseup事件附加到清单和克隆形状,那么如果拖得太快,您将无法获得事件。鼠标将超出形状,并且事件不会传递给形状。修复是将这些事件处理程序移动到根SVG。
我做的另一项更改是将x
和y
位置存储在克隆的DOM中_x
和_y
。这比将它们保存在单独的数组中更容易。
无论如何,这是我的示例的修改版本,它可以更加可靠地运行。
// define meta objects
var drag = null;
var canvas = {};
var inventory = {};
window.onload = function() {
canvas = document.getElementById("canvas");
inventory = document.getElementById("inventory");
// attach events listeners
AttachListeners();
}
function AttachListeners() {
var ttt = document.getElementsByClassName('inventory'), i;
for (i = 0; i < ttt.length; i++) {
document.getElementsByClassName("inventory")[i].onmousedown=Drag;
}
document.getElementById("svg").onmousemove=Drag;
document.getElementById("svg").onmouseup=Drag;
}
// Drag function that needs to be modified;//
function Drag(e) {
var t = e.target, id = t.id, et = e.type; m = MousePos(e);
if (!drag && (et == "mousedown")) {
if (t.className.baseVal=="inventory") { //if its inventory class item, this should get cloned into draggable?
copy = t.cloneNode(true);
copy.onmousedown = Drag;
copy.removeAttribute("id");
copy._x = 0;
copy._y = 0;
canvas.appendChild(copy);
drag = copy;
dPoint = m;
}
else if (t.className.baseVal=="draggable") { //if its just draggable class - it can be dragged around
drag = t;
dPoint = m;
}
}
// drag the spawned/copied draggable element now
if (drag && (et == "mousemove")) {
drag._x += m.x - dPoint.x;
drag._y += m.y - dPoint.y;
dPoint = m;
drag.setAttribute("transform", "translate(" +drag._x+","+drag._y+")");
}
// stop drag
if (drag && (et == "mouseup")) {
drag.className.baseVal="draggable";
drag = null;
}
}
// adjust mouse position to the matrix of SVG & screen size
function MousePos(event) {
var p = svg.createSVGPoint();
p.x = event.clientX;
p.y = event.clientY;
var matrix = svg.getScreenCTM();
p = p.matrixTransform(matrix.inverse());
return {
x: p.x,
y: p.y
}
}
&#13;
/* SVG styles */
path
{
stroke-width: 4;
stroke: #000;
stroke-linecap: round;
}
path.fill
{
fill: #3ff;
}
html, body {
margin: 0;
padding: 0;
border: 0;
overflow:hidden;
background-color: #fff;
}
body {
-ms-touch-action: none;
}
#canvasBackground {
fill: lightgrey;
}
#inventoryBackground {
fill: grey;
}
.inventory {
fill: red;
}
.draggable {
fill: green;
}
svg {
position: fixed;
top:0%;
left:0%;
width:100%;
height:100%;
}
&#13;
<svg id="svg"
height="800"
width="480"
viewbox="0 0 480 800"
preserveAspectRatio="xMinYMin meet"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink"
>
<rect id="canvasBackground" width="480" height="480" x="0" y="0"/>
<rect id="inventoryBackground" width="480" height="100" x="0" y="480"/>
<g id="inventory">
<path id="curve4" class="inventory" d="M60,530 A35,35 0 1,1 60,531" />
<path id="curve3" class="inventory" d="M150,530 A35,35 0 1,1 150,531" />
<path id="curve2" class="inventory" d="M240,530 A35,35 0 1,1 240,531" />
<path id="curve1" class="inventory" d="M330,530 A35,35 0 1,1 330,531" />
</g>
<g id="canvas">
</g>
</svg>
&#13;