弹出式全屏导航菜单

HTML

在HTML结构中，我们需要一个触发菜单的按钮，如： .cd-bouncy-nav-trigger 就是一个用来触发弹出式菜单的按钮。

.cd-bouncy-nav-modal 是一个弹出模态窗口，默认隐藏。它用来全屏展示菜单列表，当然也有关闭按钮 .cd-close 。

<section class="cd-section">
    <a class="cd-bouncy-nav-trigger" href="#0">点击查看分类</a>
</section> <!-- .cd-section -->

<div class="cd-bouncy-nav-modal">
    <nav>
        <ul class="cd-bouncy-nav">
            <li><a href="#0">Category 1</a></li>
            <li><a href="#0">Category 2</a></li>
            <li><a href="#0">Category 3</a></li>
            <li><a href="#0">Category 4</a></li>
            <li><a href="#0">Category 5</a></li>
            <li><a href="#0">Category 6</a></li>
        </ul>
    </nav>
    
    <a href="#0" class="cd-close">Close modal</a>
</div>

CSS

我们使用CSS3的transitions动画效果，默认情况下，菜单是隐藏的，当点击 .cd-bouncy-nav-trigger 按钮后， .fade-in 添加到 .cd-bouncy-nav 中，设置它的透明度和可见性。

.cd-move-in 用来设置菜单项的动画效果。

.cd-bouncy-nav-modal {
  position: fixed;
  width: 100%;
  height: 100%;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s 0.6s, visibility 0s 0.9s;
}
.cd-bouncy-nav-modal.fade-in {
  visibility: visible;
  opacity: 1;
  transition: opacity 0.1s 0s, visibility 0s 0s;
}
.cd-bouncy-nav li {
  transform: translateY(100vh);
}
.fade-in .cd-bouncy-nav li {
  animation: cd-move-in 0.4s;
  animation-fill-mode: forwards;
}
@keyframes cd-move-in {
  0% {
    transform: translateY(100vh);
  }
  65% {
    transform: translateY(-1.5vh);
  }
  100% {
    transform: translateY(0vh);
  }
}

Javascript

我们使用jQuery去监听 .cd-bouncy-nav-trigger 的点击事件，以及控制 .fade-in / .fade-out 样式的添加和删除操作。

jQuery(document).ready(function($){
    var is_bouncy_nav_animating = false;
    //open bouncy navigation
    $('.cd-bouncy-nav-trigger').on('click', function(){
        triggerBouncyNav(true);
    });
    //close bouncy navigation
    $('.cd-bouncy-nav-modal .cd-close').on('click', function(){
        triggerBouncyNav(false);
    });
    $('.cd-bouncy-nav-modal').on('click', function(event){
        if($(event.target).is('.cd-bouncy-nav-modal')) {
            triggerBouncyNav(false);
        }
    });

    function triggerBouncyNav($bool) {
        //check if no nav animation is ongoing
        if( !is_bouncy_nav_animating) {
            is_bouncy_nav_animating = true;
            
            //toggle list items animation
            $('.cd-bouncy-nav-modal').toggleClass('fade-in', $bool).toggleClass('fade-out', !$bool).find('li:last-child').one('webkitAnimationEnd oanimationend msAnimationEnd animationend', function(){
                $('.cd-bouncy-nav-modal').toggleClass('is-visible', $bool);
                if(!$bool) $('.cd-bouncy-nav-modal').removeClass('fade-out');
                is_bouncy_nav_animating = false;
            });
            
            //check if CSS animations are supported... 
            if($('.cd-bouncy-nav-trigger').parents('.no-csstransitions').length > 0 ) {
                $('.cd-bouncy-nav-modal').toggleClass('is-visible', $bool);
                is_bouncy_nav_animating = false;
            }
        }
    }
});