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这是之前敌人问我的一个性能:他感觉看网页有时候注意力会被转移,心愿能够有个蒙层帮忙他集中注意力
反手我就用 box-shadow 把性能写了进去。
(function(){
let lastEl = null;
let styleEl = null;
document.body.addEventListener('mouseover', (e)=>{e.stopPropagation();
if(!styleEl){styleEl = document.createElement('style');
document.body.appendChild(styleEl);
styleEl.innerHTML = `
.lilnong-focus{box-shadow: 0 0 0px 9999px rgba(0,0,0,.8);
z-index: 99999;
position: relative;
}
`
}
const el = e.target;
lastEl?.classList?.remove('lilnong-focus');
lastEl = el;
el.classList.add('lilnong-focus');
})
})()
因为 z-index 无奈超过非 static 层级导致的 bug
在我测试中 发现了一些比拟阳间的成果
所以咱们要小改变一下。间接给父级 ZIndex 全副晋升。
(function(){
let lastEl = null;
let styleEl = null;
let ZIndex = 1;
document.body.addEventListener('mouseover', (e)=>{e.stopPropagation();
if(!styleEl){styleEl = document.createElement('style');
document.body.appendChild(styleEl);
styleEl.innerHTML = `
.lilnong-focus{box-shadow: 0 0 0px 9999px rgba(0,0,0,.8);
z-index: 99999;
position: relative;
}
`
}
const el = e.target;
lastEl?.classList?.remove('lilnong-focus');
lastEl = el;
el.classList.add('lilnong-focus');
let parent = el;
ZIndex++;
while(parent){console.log(parent?.style)
if(parent.style) parent.style.zIndex = 10000 + ZIndex;
parent = parent.parentNode;
}
})
})()
因为 overflow 导致款式无奈超出盒子
那好了,咱们再把 overflow 还原一下。
(function(){
let lastEl = null;
let styleEl = null;
let ZIndex = 1;
document.body.addEventListener('mouseover', (e)=>{e.stopPropagation();
if(!styleEl){styleEl = document.createElement('style');
document.body.appendChild(styleEl);
styleEl.innerHTML = `
.lilnong-focus{box-shadow: 0 0 0px 9999px rgba(0,0,0,.8);
z-index: 99999;
position: relative;
}
.lilnong
`
}
const el = e.target;
lastEl?.classList?.remove('lilnong-focus');
lastEl = el;
el.classList.add('lilnong-focus');
let parent = el;
ZIndex++;
while(parent){// console.log(parent?.style)
if(parent.style){
// parent.style.zIndex = 10000 + ZIndex;
// overflow: visible !important;
// parent.style.overflow = 'visible !important'
parent.setAttribute('style', `${parent.getAttribute('style')};z-index: ${10000 + ZIndex};overflow: visible !important;`)
}
parent = parent.parentNode;
}
})
})()
最佳实现?
通过咱们个别操作,终于性能能实现了。
然而这种的性能真的是咱们想要的嘛? 咱们只是想实现一下 聚焦性能 ,并 不心愿页面布局受到毁坏。
那咱们应该怎么做呢?从下面的例子能够看到,box-shadow 是最佳的实现,他能够给咱们一个视口,将视口外的内容全副盖住,那么咱们只有管制好视口的大小即可。
这样咱们还能够对视口做一些非凡的款式解决。
当然你会说如果下面盖一层货色,会导致元素无奈选中,这里咱们能够应用 pointer-events: none;
来阻止元素接管事件。(这个罕用在头像挂件显示,一般来说单击头像是弹出资料卡。挂件咱们阻止接管事件即可。)
(function(){let maskEl = document.querySelector('.lilnong-mask') || document.createElement('div');
maskEl.className="lilnong-mask"
document.body.appendChild(maskEl);
let styleEl = document.createElement('style');
document.body.appendChild(styleEl);
styleEl.innerHTML = `
.lilnong-mask{box-shadow: 0 0 0px 9999px rgba(0,0,0,.8);
z-index: 99999;
position: fixed;
top: 0;
left: 0;
width: 40px;
height: 40px;
pointer-events: none;
}
`
document.body.addEventListener('mousemove', (e)=>{e.stopPropagation();
const el = e.target;
const {x,y,width,height,top,left} = el.getBoundingClientRect();
maskEl.style.left = left + 'px'
maskEl.style.top = top + 'px'
maskEl.style.width = width + 'px'
maskEl.style.height = height + 'px'
})
})()
甚至说咱们还能够 批改一下聚焦视口的款式
(function(){let maskEl = document.querySelector('.lilnong-mask') || document.createElement('div');
maskEl.className="lilnong-mask"
document.body.appendChild(maskEl);
let styleEl = document.createElement('style');
document.body.appendChild(styleEl);
styleEl.innerHTML = `
.lilnong-mask{box-shadow: 0 0 0px 9999px rgba(0,0,0,.8);
z-index: 99999;
position: fixed;
top: 0;
left: 0;
width: 40px;
height: 40px;
pointer-events: none;
padding: 10px;
box-sizing: content-box;
transform: translate(-10px,-10px);
border-radius: 10px
}
.lilnong-mask:before{
content: '';
position: absolute;
top: -6px;right: -6px;bottom: -6px;left: -6px;
border: 1px dashed #eee;
border-radius: 10px
}
`
document.body.addEventListener('mousemove', (e)=>{e.stopPropagation();
const el = e.target;
const {x,y,width,height,top,left} = el.getBoundingClientRect();
maskEl.style.left = left + 'px'
maskEl.style.top = top + 'px'
maskEl.style.width = width + 'px'
maskEl.style.height = height + 'px'
})
})()
因为是 left、top、width、height 的变动,所以咱们还能够 transition: .2s all;
让动画会有一个过渡成果
正文完
发表至: javascript
2022-05-11