Native javascript realizes picture pop-up interactive effect_javascript skills

【1】Using var to declare multiple variables is much faster than using var for each variable.

Copy code The code is as follows:

var sScrollTop = document.body.scrollTop || document.documentElement.scrollTop,
sWindow_h = document.documentElement.clientHeight,
t_h = parseInt(this.getCss(this.getId('gy_photoBox_head'),'height')),
Hold_h = sWindow_h - t_h - 20,
width = this.nImgWidth ,
height = this.nImgHeight;

【2】Dom event optimization, when window.onresize, define a timer, setTimeout, which can prevent frequent calls of events

Copy code The code is as follows:

windowResize:function(){
               var _that = this,
                 _timer = null;
// Function throttling
               window.onresize = function(){
                                                                                                                                                                                                                              “                   _timer = setTimeout(function(){
If( _that.tools.getId('gy_photoBox')){
                          _that.setBoxCss();
                 }
},100);

                                                                             }

[3] Image loading processing function

Copy code The code is as follows:

/*
           @ src [String] The address of the image
​​​​​@success[Function] Callback function for successful image loading
​​​​​@ error [Function] Callback function for image loading failure
*/
          imgLoading:function(opt){
            var _img = new Image(),
                 _that = this;
​​​​​​​ _img.onload = function(){
                   _that.nImgWidth = this.width;
                   _that.nImgHeight = this.height;
If(typeof opt.success == 'function'){
                                           setTimeout(function(){
                                          opt.success();
                      },300);
                }
            }
                _img.onerror = function(){
If(typeof opt.error){
                        opt.error();
                                                                                                  }
                                                                                       // Note: It must be placed under the onload event, otherwise BUG will appear in ie
                _img.src = opt.src;
}

Source code:

Copy code The code is as follows:

/*
author:laoguoyong
*/
(function(){
/* -------------------------Simple selector------------------ ----
@ Parameter [string]
​​---------------------------------------
★-Only the following options are supported-★
@ Supports first-level selectors: such as '#id', '.class', 'p'
@ Support descendant selection, such as '.class p', 'body span'
@ Supports sub-element selection, such as '.class>p', 'body>span'
​ ----------------------------------------
@ return [Array]
*/
var selector = function(str){
​​​​ //Define element array
var elem = [];
              /* Private method
​​​​------------------------*/
//Return the element with id
         function _getId(id){
               return document.getElementById(id);
}
//Return elements with such names - elements
         function _getByClassName(className,parent){
            var class_array = [],
Node = parent != undefined&&parent.nodeType==1?parent.getElementsByTagName('*'):document.getElementsByTagName('*'),
                 reg = new RegExp("(^|\s)" className "(\s|$)");
for(var n=0,i=node.length;n If(reg.test(node[n].className)){
                        class_array.push(node[n]);
                }
            }
                return class_array;
}
//First-level selection, such as '#id','p','.class'
              // return [Array]
         function _getDom(s){
            var array_elem = [];
If (s.indexOf('#')==0){
                   array_elem.push(_getId(s.slice(1)));
            }
                 else if(s.indexOf('.')==0){
                  array_elem = array_elem.concat(_getByClassName(s.slice(1)));
            }
            else{
              var tag = document.getElementsByTagName(s);
for(var n=0,i=tag.length;n                         array_elem.push(tag[n]);
                }
            }
               return array_elem;
}
          /*
​​​​​ @arry_elm [Array]: Element array, such as ['.demo','p'], the p element under .demo is selected. As for whether to select descendants or descendants, please see the second parameter explanation
​​​​​@ r [String] - Optional (if not passed, the default is to select descendants): '>', selects descendant elements;
        --------------------------
        @ return [Array]
        */
        function _query(array_elem,r){
            var node = array_elem,
                type_name = node[0].match(/#/)?'id_' node[0].slice(1):node[0].match(/./)?'className_' node[0].slice(1):'tagName_' node[0],
                child = _getDom(node[1]),
                type = type_name.split('_'),
                len = document.getElementsByTagName('*').length,
                reg = new RegExp("(^|\s)" type[1] "(\s|$)");;
            for(var i=0,j=child.length;i                 var par = child[i].parentNode;
                for(var n=0;n                     if(par.nodeType == 9){
                        break;
                    }
                    if(reg.test(par[type[0]])){
                        elem.push(child[i]);
                        break;                   
                    }else{
                        if(r == '>') break;
                        par = par.parentNode;
                    }       
                }
            }
        }
        /* 接口
        -----------------------*/
        var elemStr = str.replace(/(^s )|(s $)/,'');
        if(document.querySelectorAll){
            var dom = document.querySelectorAll(elemStr);
            for(var n=0,len=dom.length;n                 elem.push(dom[n]);
            }
        }else{
            var    split = /[>s]/g.exec(elemStr);
            if(split){
                var node = elemStr.split(split[0]);
                _query(node,split[0]);
            }else{
                elem = elem.concat( _getDom(elemStr) );
            }
}
         return elem;
}
/* Pop-up window function constructor
​ -----------------------*/
Function LGY_photoBox(option){
This.opt = option;
This.oTarget = typeof option.target == 'object'?option.target:selector(option.target);
If(!this.oTarget) return;
This.nLen = this.oTarget.length; //Total number
This.aBigimg_src = []; //Big image data array
This.aTitle = []; //Title data array
This.nIndex = 0; //Index
This.nImgWidth = 0; //Dynamicly obtain the width of the image
This.nImgHeight = 0; //Dynamicly obtain the height of the picture
This.nDelay = 0.2;
This.intit();
}
LGY_photoBox.prototype = {
         intit:function(){
               var _that = this;
This.getData();
for(var n=0;n This.oTarget[n].index = n;
This.oTarget[n].onclick = function(e){
                       _that.createCover();
                var e = _that.tools.getEvent(e),
Target = _that.tools.getTarget(e);
                                                                                                                                                                                                        _that.tools.setCss(document.documentElement,{'height':'100%','overflow-y':'hidden','overflow-x':'hidden'});
// Get the current index
                       _that.nIndex = this.index;
//First judgment
                      _that.firstLoad(_that.aBigimg_src[_that.nIndex], function(){
//Insert structure
                           _that.createBoxDom();
                                                                                                                                                                                That.tools.getId('gy_photoBox_close').onclick = function(){
                     _that.removeBox();                                                                                                                                            } // Determine whether the left and right buttons display
_that.btnIsShow();
// 上一张
_that.btnPrev();
// 下一张
_that.btnNext();
// 加载图片
_that.imgChange(_that.aBigimg_src[_that.nIndex]);
});
// 重置窗口大小
_that.windowResize();
// 键盘事件
_that.keyEvent();
//阻止跳转
return false;
}
}
},
createBoxDom:function(){
var doc = document,
exHtml = '',
boxHtml = doc.createElement('div');
boxHtml.id = 'gy_photoBox';
doc.body.appendChild(boxHtml);
if(typeof this.opt.appendHTML == 'string'){
exHtml = this.opt.appendHTML;
}
boxHtml.innerHTML = '

'+
                            '

'+
                            ''+
                            '

'+exHtml+'

'+
                            '

'+
                                'http://www.pconline.com.cn/blank.gif" />'+
                                ''+
                                '

'+
                                    ''+
                                        ''+
                                        '/'+this.nLen+
                                    ''+
                                    '

'+
                                '

'+
                            '

';
        },
        createCover:function(){
            // 创建覆盖层
            var    doc = document,
                coverHtml = doc.createElement('div');
                coverHtml.id = 'gy_photoBox_cover';
            doc.body.appendChild(coverHtml);
            //设置覆盖层的样式
            this.tools.setCss(this.tools.getId('gy_photoBox_cover'),{'height':(doc.body.scrollTop || doc.documentElement.scrollTop) (doc.documentElement.clientHeight) 'px'});
        },
        setBoxCss:function(){
            var    doc = document,
                nScrollTop = doc.body.scrollTop || doc.documentElement.scrollTop,
                nWindow_h = doc.documentElement.clientHeight,
                eBox_head_h = this.tools.getId('gy_photoBox_head').clientHeight,
                eBox = this.tools.getId('gy_photoBox'),
                eBoxPadding = 10,
                hold_h = nWindow_h - eBoxPadding - 50 - eBox_head_h,
                width = this.nImgWidth ,
                height = this.nImgHeight;
            // alert('nWindow_h:' nWindow_h '-' 'eBoxPadding:' eBoxPadding '-' 'eBox_head_h:' eBox_head_h);
            // 图片大小超过可见范围，进行缩放
            if(this.nImgHeight>hold_h){
                height = hold_h,
                width = Math.ceil(this.nImgWidth*(height/this.nImgHeight));
            }
            //设置盒子在整个页面居中
            this.tools.setCss(eBox,{'width':width 'px',
                                    'height':eBox_head_h height 'px',
                                    'margin-left':-(width eBoxPadding)/2 'px',
                                    'top':nScrollTop (nWindow_h-height-eBoxPadding)/2 'px'});
            this.tools.setCss(this.tools.getId('gy_photoBox_main'),{'width':width 'px','height':height 'px'});
            //设置覆盖层的样式
            this.tools.setCss(this.tools.getId('gy_photoBox_cover'),{'height':nScrollTop doc.documentElement.clientHeight 'px'});
        },
        removeBox:function(){
            var doc = document;
            if(this.tools.getId('gy_photoBox')){
                doc.body.removeChild(this.tools.getId('gy_photoBox'));
            }
            if(this.tools.getId('gy_photoBox_cover')){
                document.body.removeChild(this.tools.getId('gy_photoBox_cover'));
            }
            this.tools.setCss(document.documentElement,{'height':'auto','overflow-y':'auto','_overflow-y':'scroll','overflow-x':'auto'});
        },
        getData:function(){
            for(var n=0;n                 var src = this.oTarget[n].getAttribute('href'),
                    title = this.oTarget[n].getAttribute('title');
                this.aBigimg_src.push(src);
                if(!title) title = '';
                this.aTitle.push(title);
            }
        },
        btnIsShow:function(){
            this.tools.setCss(this.tools.getId('gy_photoBox_prev'),{'display':'block'});
            this.tools.setCss(this.tools.getId('gy_photoBox_next'),{'display':'block'});
            if(this.nIndex == 0) this.tools.setCss(this.tools.getId('gy_photoBox_prev'),{'display':'none'});
            if(this.nIndex == (this.nLen-1)) this.tools.setCss(this.tools.getId('gy_photoBox_next'),{'display':'none'});
        },
        imgChange:function(){
            var _that = this,
                _src = this.aBigimg_src[this.nIndex],
                eLoadingTips = this.tools.getId('gy_photoBox_img_loading'),
                eImg = this.tools.getId('gy_photoBox_img'),
                eTitle = this.tools.getId('gy_photoBox_title'),
                eInfor = this.tools.getId('gy_photoBox_infor');
            // 显示loading图片
            this.tools.setCss(eLoadingTips,{'display':'block'});
            this.tools.setCss(eInfor,{'display':'none'});
            // 判断左右按钮显示
            this.btnIsShow();
            // 图片加载处理
            this.imgLoading({
                'src':_src,
                'success':function(){
                    _that.tools.setCss(eLoadingTips,{'display':'none'});
                    _that.tools.setCss(eInfor,{'display':'block'});
                    // 设置真实图片路径，标题，当前页码
                       eImg.src = _src;
eTitle.innerHTML = _that.aTitle[_that.nIndex];
                       _that.tools.getId('gy_photoBox_index').innerHTML = (_that.nIndex 1);
                                                                                                                                                                                                                             _that.setBoxCss();
// Pop-up window appears
                   _that.tools.setCss(_that.tools.getId('gy_photoBox'),{'visibility':'visible'});
If(_that.tools.getId('gy_photoBox_firstLoad')){
document.body.removeChild(_that.tools.getId('gy_photoBox_firstLoad'));
                 }
// Callback function executed each time switching
If(typeof _that.opt.onChange == 'function'){
                     _that.opt.onChange({'src':_src,'index':_that.nIndex,'title':_that.aTitle[_that.nIndex]});
                                                                                                                                                                                              },
                 'error':function(){
                                           setTimeout(function(){
                        _that.tools.setCss(eLoadingTips,{'display':'none'});
                     },200);
                      eImg.src = 'gyPhotoBox/error.png';
eTitle.innerHTML = 'No related pictures';
                        _that.nImgWidth = 400;
                        _that.nImgHeight = 300;
                       _that.setBoxCss();
                   _that.tools.setCss(_that.tools.getId('gy_photoBox'),{'visibility':'visible'});
If(_that.tools.getId('gy_photoBox_firstLoad')){
document.body.removeChild(_that.tools.getId('gy_photoBox_firstLoad'));
                 }
                }
            });
},
          btnPrev:function(){
               var _that = this;
This.tools.getId('gy_photoBox_prev').onclick = function(){
                _that.nIndex--;
                _that.imgChange();
            }
        },
        btnNext:function(){
            var _that = this;
            this.tools.getId('gy_photoBox_next').onclick = function(){
                _that.nIndex ;
                _that.imgChange();
            }
        },
        keyEvent:function(){
            var _that = this;
            document.onkeydown = function(e){
                var e = e || window.event;
                switch(e.keyCode){
                    case 37:{
                        if(_that.nIndex != 0&&_that.tools.getId('gy_photoBox_prev')){
                            _that.nIndex--;
                            _that.imgChange();   
                        }   
                    };break;
                    case 39 :{
                        if(_that.nIndex != (_that.nLen-1)&&_that.tools.getId('gy_photoBox_next')){
                            _that.nIndex ;
                            _that.imgChange();   
                        }           
                    };break;
                    case 27:{
                        _that.removeBox();                           
                    };break;
                }
            }
        },
        /*
        @ src [String] 图片的地址
        @ success [Function] 图片加载成功的回调函数
        @ error [Function] 图片加载失败的回调函数
        */
        imgLoading:function(opt){
            var _img = new Image(),
                _that = this;
            _img.onload = function(){
                _that.nImgWidth = this.width;
                _that.nImgHeight = this.height;
                if(typeof opt.success == 'function'){
                    setTimeout(function(){
                        opt.success();
                    },300);
                }
            }
            _img.onerror = function(){
                if(typeof opt.error){
                    opt.error();
                }           
            }
            // 注意：要放在onload事件下面，否则ie会出现BUG
            _img.src = opt.src;
        },
        firstLoad:function(src,callback){
            var _that = this,
                html = document.createElement('div');
                html.id = 'gy_photoBox_firstLoad';
            document.body.appendChild(html);
            this.tools.setCss(this.tools.getId('gy_photoBox_firstLoad'),{'top':(document.body.scrollTop || document.documentElement.scrollTop) (document.documentElement.clientHeight/2) 'px'});
            if(typeof callback == 'function') {
                callback();
            }
        },
        windowResize:function(){
            var _that = this,
                _timer = null;
            // 函数节流
            window.onresize = function(){
                clearTimeout(_timer);
                _timer = setTimeout(function(){
                    if( _that.tools.getId('gy_photoBox')){
                        _that.setBoxCss();
                    }
                },100);
            }       
        },
        tools:function(){
            return{
                getEvent:function(e){
                    return e || window.event;
                },
                getTarget:function(e){
                    return e.target || e.srcElement;
                },
                preventDefault:function(e){
                    e.preventDefault?e.preventDefault():e.returnValue = false;
                },
                getId:function(id){
                    return document.getElementById(id);
                },
                getCss:function(node,value){
                    return node.currentStyle?node.currentStyle[value]:getComputedStyle(node,null)[value];
                },
                setCss:function(node,val){
                    for(var v in val){
                        node.style.cssText = ';' v ':' val[v];
                    }
                }
            }
        }()
    }
    window.LGY_photoBox = LGY_photoBox;
})();

最终效果图：