// 获取工程案例的包裹
var objectlist = document.getelementsbyclassname("banner_object_list")[0];
// 获取工程案例中图片的列表
var objectitems = objectlist.getelementsbytagname("li");
// 获取工程案例的切换按钮
var objectbuttonleft = document.getelementsbyclassname("object_button_pre")[0];
var objectbuttonright = document.getelementsbyclassname("object_button_next")[0];
// 克隆工程案例列表的第一个元素、第二个元素放在列表的最后一位;
var objectfirstclone = objectitems[0].clonenode(true);
var objectsecondclone = objectitems[1].clonenode(true);
var objectlastclone = objectitems[objectitems.length - 1].clonenode(true);
var objectlasttwoclone = objectitems[objectitems.length - 2].clonenode(true);
objectlist.appendchild(objectfirstclone);
objectlist.appendchild(objectsecondclone);
objectlist.insertbefore(objectlastclone, objectitems[0]);
objectlist.insertbefore(objectlasttwoclone, objectitems[0]);
// 根据新闻的数量来决定包裹的宽度width;
var objectitemswidth = (objectitems[0].offsetwidth + 30);
objectlist.style.width = objectitemswidth * (objectitems.length) + "px";
var objectindex = 2;
objectlist.style.transform = "translatex(" + (-objectitemswidth * objectindex) + "px)";

function objectauto() {
	objectindex++;
	if (objectindex >= objectitems.length - 2) {
		objectlist.style.transitionduration = "0s";
		objectlist.style.transform = "translatex(" + (-objectitemswidth * 1) + "px)";
		objectindex = 2;
		objectlist.offsetleft;
	}
	objectlist.style.transitionduration = "0.81s";
	objectlist.style.transform = "translatex(" + (-objectitemswidth * objectindex) + "px)";
}

function objectgopre() {
	objectindex--;
	if (objectindex < 0) {
		objectlist.style.transitionduration = "0s";
		objectlist.style.transform = "translatex(" + (-objectitemswidth * (objectitems.length - 4)) + "px)";
		objectindex = objectitems.length - 5;
		objectlist.offsetleft;
	}
	objectlist.style.transitionduration = "0.81s";
	objectlist.style.transform = "translatex(" + (-objectitemswidth * objectindex) + "px)";
}
var objecttimer = setinterval(objectauto, 3600);
objectbuttonleft.addeventlistener("click", function() {
	clearobjecttimer = clearinterval(objecttimer);
	objectgopre();
	objecttimer = setinterval(objectauto, 3600);
})

objectbuttonright.addeventlistener("click", function() {
	clearobjecttimer = clearinterval(objecttimer);
	objectauto();
	objecttimer = setinterval(objectauto, 3600);
})

// function getstyle(obj, attr) {
// 	if (obj.currentstyle) {
// 		return obj.currentstyle[attr];
// 	} else {
// 		return document.defaultview.getcomputedstyle(obj, null)[attr];
// 	}
// }

// function getmarginleft(obj, index) {
// 	var arr = getstyle(obj[0], "margin").split(" ")
// 	return marginleft = parsefloat(arr[index])
// }