This article describes the method of dragging and dropping special effects of JS imitating iGoogle custom homepage module. Share it for your reference. The specific implementation method is as follows:
The code copy is as follows:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>JS imitate iGoogle custom home page module drag and drop effect</title>
<script type="text/javascript">
var Common = {
getEvent: function() {//ie/ff
if (document.all) {
return window.event;
}
func = getEvent.caller;
while (func != null) {
var arg0 = func.arguments[0];
if (arg0) {
if ((arg0.constructor == Event || arg0.constructor == MouseEvent) || (typeof (arg0) == "object" && arg0.preventDefault && arg0.stopPropagation)) {
return arg0;
}
}
func = func.caller;
}
return null;
},
getMousePos: function(ev) {
if (!ev) {
ev = this.getEvent();
}
if (ev.pageX || ev.pageY) {
return {
x: ev.pageX,
y: ev.pageY
};
}
if (document.documentElement && document.documentElement.scrollTop) {
return {
x: ev.clientX + document.documentElement.scrollLeft - document.documentElement.clientLeft,
y: ev.clientY + document.documentElement.scrollTop - document.documentElement.clientTop
};
}
else if (document.body) {
return {
x: ev.clientX + document.body.scrollLeft - document.body.clientLeft,
y: ev.clientY + document.body.scrollTop - document.body.clientTop
};
}
},
getElementPos: function(el) {
el = this.getItself(el);
var _x = 0, _y = 0;
do {
_x += el.offsetLeft;
_y += el.offsetTop;
} while (el = el.offsetParent);
return { x: _x, y: _y };
},
getItself: function(id) {
return "string" == typeof id ? document.getElementById(id) : id;
},
getViewportSize: { w: (window.innerWidth) ? window.innerWidth : (document.documentElement && document.documentElement.clientWidth) ? document.documentElement.clientWidth : (document.body?document.body.offsetWidth:0), h: (window.innerHeight) ? window.innerHeight : (document.documentElement && document.documentElement.clientHeight) ? document.documentElement.clientHeight : (document.body ? document.body.offsetHeight : 0) },
isIE: document.all ? true : false,
setOuterHtml: function(obj, html) {
var Objrange = document.createRange();
obj.innerHTML = html;
Objrange.selectNodeContents(obj);
var frag = Objrange.extractContents();
obj.parentNode.insertBefore(frag, obj);
obj.parentNode.removeChild(obj);
},
firstChild: function(parentObj, tagName) {
if (Common.isIE) {
return parentObj.firstChild;
}
else {
var arr = parentObj.getElementsByTagName(tagName);
return arr[0];
}
},
lastChild: function(parentObj, tagName) {
if (Common.isIE) {
return parentObj.lastChild;
}
else {
var arr = parentObj.getElementsByTagName(tagName);
return arr[arr.length - 1];
}
},
setCookie: function(name, value) {
document.cookie = name + "=" + value;
},
getCookie: function(name) {
var strCookie = document.cookie;
var arrCookie = strCookie.split("; ");
for (var i = 0; i < arrCookie.length; i++) {
var arr = arrCookie[i].split("=");
if (!arr[1]) {
return "";
}
if (arr[0] == name) {
return arr[1];
}
}
return "";
},
delCookie: function(name) {
var exp = new Date();
exp.setTime(exp.getTime() - 1);
var cval = this.getCookie(name);
if (cval != null) document.cookie = name + "=" + cval + ";expires=" + exp.toGMTString();
}
}
var Class = {
create: function() {
return function() { this.init.apply(this, arguments); }
}
}
var Drag = Class.create();
Drag.prototype = {
init: function(titleBar, dragDiv, Options) {
//Set whether clicks are transparent, default is 60% transparent
titleBar = Common.getItself(titleBar);
dragDiv = Common.getItself(dragDiv);
this.dragArea = { maxLeft: -9999, maxRight: 9999, maxTop: -9999, maxBottom: 9999 };
if (Options) {
this.opacity = Options.opacity ? (isNaN(parseInt(Options.opacity)) ? 100 : parseInt(Options.opacity)) : 100;
if (Options.area) {
if (Options.area.left && !isNaN(parseInt(Options.area.left))) { this.dragArea.maxLeft = Options.area.left };
if (Options.area.right && !isNaN(parseInt(Options.area.right))) { this.dragArea.maxRight = Options.area.right };
if (Options.area.top && !isNaN(parseInt(Options.area.top))) { this.dragArea.maxTop = Options.area.top };
if (Options.area.bottom && !isNaN(parseInt(Options.area.bottom))) { this.dragArea.maxBottom = Options.area.bottom };
}
}
else {
this.opacity = 60;
}
this.originDragDiv = null;
this.tmpX = 0;
this.tmpY = 0;
this.moveable = false;
this.dragArray = [];
var dragObj = this;
var dragTbl = document.getElementById("dragTable");
titleBar.onmousedown = function(e) {
var ev = e || window.event || Common.getEvent();
//Only drag and drop through the left mouse button, IE left mouse button is 1 FireFox is 0
if (Common.isIE && ev.button == 1 || !Common.isIE && ev.button == 0) {
}
else {
return false;
}
//Treat special cases: When the top/bottom MOVE is not encountered, it returns to the top/bottom column of the initial drag.
var tmpColId;
for (c = 0; c < dragTbl.rows[0].cells.length; c++) {
for (k = 0; k < dragTbl.rows[0].cells[c].getElementsByTagName("DIV").length; k++) {
if (dragDiv.id == dragTbl.rows[0].cells[c].getElementsByTagName("DIV")[k].id) {
tmpColId = c;
break;
}
}
}
var tmpPosFirstChild = Common.getElementPos(Common.firstChild(dragTbl.rows[0].cells[tmpColId], "DIV"));
var tmpPosLastChild = Common.getElementPos(Common.lastChild(dragTbl.rows[0].cells[tmpColId], "DIV"));
var tmpObj = { colId: tmpColId, firstChildUp: tmpPosFirstChild.y, lastChildDown: tmpPosLastChild.y + Common.lastChild(dragTbl.rows[0].cells[tmpColId], "DIV").offsetHeight };
//Save the current location where each container can be dragged and dropped
dragObj.dragArray = dragObj.RegDragsPos();
//Insert the dotted box
var dashedElement = document.createElement("div");
dashedElement.style.cssText = dragDiv.style.cssText;
dashedElement.style.border = " dashed 2px #aaa ";
dashedElement.style.marginBottom = "6px";
dashedElement.style.width = dragDiv.offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px"; // Subtract the boderWidth to keep the dotted box size consistent with dragDiv
dashedElement.style.height = dragDiv.offsetHeight - 2 * parseInt(dashedElement.style.borderWidth) + "px"; // Add px to ensure that FF is correct
dashedElement.style.position = "relative";
if (dragDiv.nextSibling) {
dragDiv.parentNode.insertBefore(dashedElement, dragDiv.nextSibling);
}
else {
dragDiv.parentNode.appendChild(dashedElement);
}
//It becomes absolute when dragging
dragDiv.style.width = dragDiv.offsetWidth + "px";
dragDiv.style.position = "absolute";
dragObj.moveable = true;
dragDiv.style.zIndex = dragObj.GetZindex() + 1;
var downPos = Common.getMousePos(ev);
dragObj.tmpX = downPos.x - dragDiv.offsetLeft;
dragObj.tmpY = downPos.y - dragDiv.offsetTop;
if (Common.isIE) {
dragDiv.setCapture();
} else {
window.captureEvents(Event.mousemove);
}
dragObj.SetOpacity(dragDiv, dragObj.opacity);
//FireFox removes the problem of dragging and dropping pictures in the container
if (ev.preventDefault) {
ev.preventDefault();
ev.stopPropagation();
}
document.onmousemove = function(e) {
if (dragObj.moveable) {
var ev = e || window.event || Common.getEvent();
//IE removes the problem of dragging and dropping pictures in the container
if (document.all) //IE
{
ev.returnValue = false;
}
var movePos = Common.getMousePos(ev);
dragDiv.style.left = Math.max(Math.min(movePos.x - dragObj.tmpX, dragObj.dragArea.maxRight), dragObj.dragArea.maxLeft) + "px";
dragDiv.style.top = Math.max(Math.min(movePos.y - dragObj.tmpY, dragObj.dragArea.maxBottom), dragObj.dragArea.maxTop) + "px";
var targetDiv = null;
for (var k = 0; k < dragObj.dragArray.length; k++) {
if (dragDiv == dragObj.dragArray[i]) {
continue;
}
if (movePos.x > dragObj.dragArray[k].PosLeft && movePos.x < dragObj.dragArray[k].PosLeft + dragObj.dragArray[k].PosWidth
&& movePos.y > dragObj.dragArray[k].PosTop && movePos.y < dragObj.dragArray[k].PosTop + dragObj.dragArray[k].PosHeight
) {
targetDiv = document.getElementById(dragObj.dragArray[k].DragId);
if (movePos.y < dragObj.dragArray[k].PosTop + dragObj.dragArray[k].PosHeight / 2) {
//Move up
dashedElement.style.width = targetDiv.offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px";
targetDiv.parentNode.insertBefore(dashedElement, targetDiv);
}
else {
//Move down
dashedElement.style.width = targetDiv.offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px";
if (targetDiv.nextSibling) {
targetDiv.parentNode.insertBefore(dashedElement, targetDiv.nextSibling);
}
else {
targetDiv.parentNode.appendChild(dashedElement);
}
}
}
}
for (j = 0; j < dragTbl.rows[0].cells.length; j++) {
var startLeft = Common.getElementPos(dragTbl.rows[0].cells[j]).x;
if (movePos.x > startLeft && movePos.x < startLeft + dragTbl.rows[0].cells[j].offsetWidth) {
/// Column has no DIV
if (dragTbl.rows[0].cells[j].getElementsByTagName("div").length == 0) {
dashedElement.style.width = dragTbl.rows[0].cells[j].offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px";
dragTbl.rows[0].cells[j].appendChild(dashedElement);
}
else {
var posFirstChild = Common.getElementPos(Common.firstChild(dragTbl.rows[0].cells[j], "DIV"));
var posLastChild = Common.getElementPos(Common.lastChild(dragTbl.rows[0].cells[j], "DIV"));
//Treat special cases: When the top/bottom MOVE is not encountered, it returns to the top/bottom column of the initial drag.
var tmpUp, tmpDown;
if (tmpObj.colId == j) {
tmpUp = tmpObj.firstChildUp;
tmpDown = tmpObj.lastChildDown;
}
else {
tmpUp = posFirstChild.y;
tmpDown = posLastChild.y + Common.lastChild(dragTbl.rows[0].cells[j], "DIV").offsetHeight;
}
if (movePos.y < tmpUp) {///Insert the dotted box from the top
dashedElement.style.width = Common.firstChild(dragTbl.rows[0].cells[j], "DIV").offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px";
dragTbl.rows[0].cells[j].insertBefore(dashedElement, Common.firstChild(dragTbl.rows[0].cells[j], "DIV"));
}
else if (movePos.y > tmpDown) {///Insert the dotted box from the bottom
dashedElement.style.width = Common.lastChild(dragTbl.rows[0].cells[j], "DIV").offsetWidth - 2 * parseInt(dashedElement.style.borderWidth) + "px";
dragTbl.rows[0].cells[j].appendChild(dashedElement);
}
}
}
}
}
};
document.onmouseup = function() {
if (dragObj.moveable) {
if (Common.isIE) {
dragDiv.releaseCapture();
}
else {
window.releaseEvents(dragDiv.mousemove);
}
dragObj.SetOpacity(dragDiv, 100);
dragObj.moveable = false;
dragObj.tmpX = 0;
dragObj.tmpY = 0;
//Be sure to write it in this IF
dragDiv.style.left = "";
dragDiv.style.top = "";
dragDiv.style.width = "";
dragDiv.style.position = "";
dashedElement.parentNode.insertBefore(dragDiv, dashedElement);
dashedElement.parentNode.removeChild(dashedElement);
}
};
}
},
SetOpacity: function(dragDiv, n) {
if (Common.isIE) {
dragDiv.filters.alpha.opacity = n;
}
else {
dragDiv.style.opacity = n / 100;
}
},
GetZindex: function() {
var maxZindex = 0;
var divs = document.getElementsByTagName("div");
for (z = 0; z < divs.length; z++) {
maxZindex = Math.max(maxZindex, divs[z].style.zIndex);
}
return maxZindex;
},
RegDragsPos: function() {
var arrDragDivs = new Array();
var dragTbl = document.getElementById("dragTable");
var tmpDiv, tmpPos;
for (i = 0; i < dragTbl.getElementsByTagName("div").length; i++) {
tmpDiv = dragTbl.getElementsByTagName("div")[i];
if (tmpDiv.className == "dragDiv") {
tmpPos = Common.getElementPos(tmpDiv);
arrDragDivs.push({ DragId: tmpDiv.id, PosLeft: tmpPos.x, PosTop: tmpPos.y, PosWidth: tmpDiv.offsetWidth, PosHeight: tmpDiv.offsetHeight });
}
}
return arrDragDivs;
}
}
window.onload = function() {
var dragTbl = document.getElementById("dragTable");
if (Common.getCookie("configArr")) {
var configArr = eval("(" + Common.getCookie("configArr") + ")");
for (i = 0; i < dragTbl.rows[0].cells.length; i++) {
for (j = 0; j < configArr[i].length; j++) {
dragTbl.rows[0].cells[i].appendChild(document.getElementById(configArr[i][j]));
}
}
}
new Drag("titleBar1", "dragDiv1");
new Drag("titleBar2", "dragDiv2");
new Drag("titleBar3", "dragDiv3");
new Drag("titleBar4", "dragDiv4");
new Drag("titleBar5", "dragDiv5");
}
window.onunload = function() {
var dragTbl = document.getElementById("dragTable");
var configArr = "";
for (i = 0; i < dragTbl.rows[0].cells.length; i++) {
var tmpStr = "";
for (j = 0; j < dragTbl.rows[0].cells[i].getElementsByTagName("DIV").length; j++) {
tmpStr += (tmpStr == "" ? "" : ",") + "'" + dragTbl.rows[0].cells[i].getElementsByTagName("DIV")[j].id + "'";
}
configArr += (configArr == "" ? "" : ",") + "[" + tmpStr + "]";
}
//format like: [['dragDiv3','dragDiv5'],['dragDiv4','dragDiv1'],['dragDiv2']]
Common.setCookie("configArr", "[" + configArr + "]");
}
</script>
<style type="text/css">
.spanDiv{
position:relative;
width:5px;
height:5px;
}
.dragDiv,.nodragDiv{
position:relative;
filter:alpha(opacity=100);
opacity:1;
margin-bottom:6px;
background-color:#FFFFF;
}
</style>
</head>
<body >
<script type="text/javascript">
</script>
<table id="dragTable" cellpadding="3" style=" border:solid 0px green;width:98%;">
<tr>
<td valign="top">
<div id="dragDiv1" >
<table cellpadding="0" cellpacing="0">
<tr id="titleBar1" style="height:22px; text-align:left; background-color:#547BC9;color:White; padding:3px;cursor:move;">
<th align="left" unselectable="on" >Title1</th>
</tr>
<tr style="height:130px;padding:3px;" align="left" valign="top" >
<td unselectable="on">The characters here are relatively long...I'm here...China...China...Foreign., see if there is any overflow!</td>
</tr>
</table>
</div>
<div id="dragDiv2">
<table cellpadding="0" cellpacing="0">
<tr id="titleBar2" style="height:22px; text-align:left; background-color:#547BC9;color:White; padding:3px;cursor:move;">
<th align="left" unselectable="on" >Title2</th>
</tr>
<tr style="height:130px;padding:3px;" align="left" valign="top" >
<td unselectable="on">Content2...</td>
</tr>
</table>
</div>
</td>
<td valign="top">
<div id="dragDiv3">
<table cellpadding="0" cellpacing="0">
<tr id="titleBar3" style="height:22px; text-align:left; background-color:#547BC9;color:White; padding:3px;cursor:move;">
<th align="left" unselectable="on" >Title3</th>
</tr>
<tr style="height:230px;padding:3px;" align="left" valign="top" >
<td unselectable="on">Content3...</td>
</tr>
</table>
</div>
</td>
<td valign="top">
<div id="dragDiv4">
<table cellpadding="0" cellpacing="0">
<tr id="titleBar4" style="height:22px; text-align:left; background-color:#547BC9;color:White; padding:3px;cursor:move;">
<th align="left" unselectable="on" >Title4</th>
</tr>
<tr style="height:130px;padding:3px;" align="left" valign="top" >
<td unselectable="on">Content4...</td>
</tr>
</table>
</div>
<div id="dragDiv5">
<table cellpadding="0" cellpacing="0">
<tr id="titleBar5" style="height:22px; text-align:left; background-color:#547BC9;color:White; padding:3px;cursor:move;">
<th align="left" unselectable="on" >Title5</th>
</tr>
<tr style="height:130px;padding:3px;" align="left" valign="top" >
<td unselectable="on">Content5...</td>
</tr>
</table>
</div>
</td>
</tr>
</table>
</body>
</html>
<br><br><hr> Collected on the Internet, only for exchange of interests and learning, and not for commercial purposes. </font></p>
I hope this article will be helpful to everyone's JavaScript programming.