Bootstrap - Plugin Scrollspy
O plugin Scroll Spy (atualização automática de navegação) permite que você direcione seções da página com base na posição de rolagem. Em sua implementação básica, conforme você rola, você pode adicionar.active classes para a barra de navegação com base na posição de rolagem.
Se você deseja incluir esta funcionalidade de plug-in individualmente, você precisará scrollspy.js. Além disso, conforme mencionado no capítulo Visão geral dos plug-ins de bootstrap , você pode incluir bootstrap.js ou bootstrap.min.js minimizado .
Uso
Você pode adicionar o comportamento de rolagem à sua navegação na barra superior -
Via data attributes - adicionar data-spy = "scroll"ao elemento que você deseja espionar (normalmente o corpo). Em seguida, adicione o atributodata-target com o ID ou classe do elemento pai de qualquer Bootstrap .navcomponente. Para que isso funcione, você deve ter elementos no corpo da página que tenham IDs correspondentes dos links que você está espionando.
<body data-spy = "scroll" data-target = ".navbar-example">
...
<div class = "navbar-example">
<ul class = "nav nav-tabs">
...
</ul>
</div>
...
</body>Via JavaScript - Você pode invocar o scrollspy com JavaScript em vez de usar os atributos de dados, selecionando o elemento para espiar e invocando o .scrollspy() função -
$('body').scrollspy({ target: '.navbar-example' })Exemplo
O exemplo a seguir mostra o uso do plugin scrollspy por meio de atributos de dados -
<nav id = "navbar-example" class = "navbar navbar-default navbar-static" role = "navigation">
<div class = "navbar-header">
<button class = "navbar-toggle" type = "button" data-toggle = "collapse"
data-target = ".bs-js-navbar-scrollspy">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorial Name</a>
</div>
<div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
<ul class = "nav navbar-nav">
<li><a href = "#ios">iOS</a></li>
<li><a href = "#svn">SVN</a></li>
<li class = "dropdown">
<a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle = "dropdown">
Java
<b class = "caret"></b>
</a>
<ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
<li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
<li><a href = "#ejb" tabindex = "-1">ejb</a></li>
<li class = "divider"></li>
<li><a href = "#spring" tabindex = "-1">spring</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<div data-spy = "scroll" data-target = "#navbar-example" data-offset = "0"
style = "height:200px; overflow:auto; position: relative;">
<h4 id = "ios">iOS</h4>
<p>iOS is a mobile operating system developed and distributed by Apple
Inc. Originally released in 2007 for the iPhone, iPod Touch, and Apple
TV. iOS is derived from OS X, with which it shares the Darwin
foundation. iOS is Apple's mobile version of the OS X operating system
used on Apple computers.</p>
<h4 id = "svn">SVN</h4>
<p>Apache Subversion which is often abbreviated as SVN, is a software
versioning and revision control system distributed under an open source
license. Subversion was created by CollabNet Inc. in 2000, but now it
is developed as a project of the Apache Software Foundation, and as
such is part of a rich community of developers and users.</p>
<h4 id = "jmeter">jMeter</h4>
<p>jMeter is an Open Source testing software. It is 100% pure Java
application for load and performance testing.</p>
<h4 id = "ejb">EJB</h4>
<p>Enterprise Java Beans (EJB) is a development architecture for building
highly scalable and robust enterprise level applications to be deployed
on J2EE compliant Application Server such as JBOSS, Web Logic etc.</p>
<h4 id = "spring">Spring</h4>
<p>Spring framework is an open source Java platform that provides
comprehensive infrastructure support for developing robust Java
applications very easily and very rapidly.</p>
<p>Spring framework was initially written by Rod Johnson and was first
released under the Apache 2.0 license in June 2003.</p>
</div>Opções
As opções podem ser passadas por meio de atributos de dados ou JavaScript. A tabela a seguir lista as opções -
| Nome da Opção | Tipo / valor padrão | Nome do atributo de dados | Descrição |
|---|---|---|---|
| Deslocamento | número Padrão: 10 | deslocamento de dados | Pixels para deslocar a partir do topo ao calcular a posição da rolagem. |
Métodos
.scrollspy('refresh') - Ao chamar o scrollspy por meio do método JavaScript, você precisa chamar o .refreshmétodo para atualizar o DOM. Isso é útil se algum elemento do DOM foi alterado, ou seja, se você adicionou ou removeu alguns elementos. A seguir está a sintaxe para usar este método.
$('[data-spy = "scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
})Exemplo
O exemplo a seguir demonstra o uso de .scrollspy('refresh') método -
<nav id = "myScrollspy" class = "navbar navbar-default navbar-static" role = "navigation">
<div class = "navbar-header">
<button class = "navbar-toggle" type = "button" data-toggle = "collapse"
data-target = ".bs-js-navbar-scrollspy">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorial Name</a>
</div>
<div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
<ul class = "nav navbar-nav">
<li class = "active"><a href = "#ios">iOS</a></li>
<li><a href = "#svn">SVN</a></li>
<li class = "dropdown">
<a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle = "dropdown">
Java
<b class = "caret"></b>
</a>
<ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
<li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
<li><a href = "#ejb" tabindex = "-1">ejb</a></li>
<li class = "divider"></li>
<li><a href = "#spring" tabindex = "-1">spring</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<div data-spy = "scroll" data-target = "#myScrollspy" data-offset = "0"
style = "height:200px; overflow:auto; position: relative;">
<div class = "section">
<h4 id = "ios">iOS<small><a href = "#" onclick = "removeSection(this);">
× Remove this section</a></small>
</h4>
<p>iOS is a mobile operating system developed and distributed by
Apple Inc. Originally released in 2007 for the iPhone, iPod Touch, and
Apple TV. iOS is derived from OS X, with which it shares the Darwin
foundation. iOS is Apple's mobile version of the OS X operating system
used on Apple computers.</p>
</div>
<div class = "section">
<h4 id = "svn">SVN<small></small></h4>
<p>Apache Subversion which is often abbreviated as SVN, is a software
versioning and revision control system distributed under an open source
license. Subversion was created by CollabNet Inc. in 2000, but
now it is developed as a project of the Apache Software Foundation,
and as such is part of a rich community of developers and users.</p>
</div>
<div class = "section">
<h4 id = "jmeter">jMeter<small><a href = "#" onclick = "removeSection(this);">
× Remove this section</a></small>
</h4>
<p>jMeter is an Open Source testing software. It is 100% pure Java
application for load and performance testing.</p>
</div>
<div class = "section">
<h4 id = "ejb">EJB</h4>
<p>Enterprise Java Beans (EJB) is a development architecture for
building highly scalable and robust enterprise level applications
to be deployed on J2EE compliant Application Server such as
JBOSS, Web Logic etc.</p>
</div>
<div class = "section">
<h4 id = "spring">Spring</h4>
<p>Spring framework is an open source Java platform that provides
comprehensive infrastructure support for developing robust Java
applications very easily and very rapidly.</p>
<p>Spring framework was initially written by Rod Johnson and was first
released under the Apache 2.0 license in June 2003.</p>
</div>
</div>
<script type = "text/javascript">
$(function(){
removeSection = function(e) {
$(e).parents(".section").remove();
$('[data-spy = "scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
});
}
$("#myScrollspy").scrollspy();
});
</script>Eventos
A tabela a seguir lista os eventos para trabalhar com scrollspy. Este evento pode ser usado para conectar-se à função.
| Evento | Descrição | Exemplo |
|---|---|---|
| activate.bs.scrollspy | Este evento é disparado sempre que um novo item é ativado pelo scrollspy. |
|
Exemplo
O exemplo a seguir demonstra o uso de activate.bs.scrollspy evento -
<html>
<head>
<link rel = "stylesheet" href = "bootstrap/css/bootstrap.min.css">
<script src = "bootstrap/scripts/jquery.min.js"></script>
<script src = "bootstrap/js/bootstrap.min.js"></script>
<script>
$(document).ready(function(){
removeSection = function(e) {
$(e).parents(".subject").remove();
$('[data-spy="scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
});
}
$("#Navexample").scrollspy();
// The event is fired when an item gets actived with the scrollspy
$("#Navexample").on('activate.bs.scrollspy', function () {
var currentSection = $(".nav li.active > a").text();
$("#spyevent").html("Current Item being viewed >> " + currentSection);
})
});
</script>
<style>
.scroll-box {
height: 250px;
position: relative;
overflow: auto;
font-size:2em;
}
</style>
</head>
<body>
<div class = "container">
<nav id = "Navexample" class = "navbar navbar-default" role = "navigation">
<!-- Nav Bar -->
<div class = "navbar-header">
<button type = "button" class = "navbar-toggle"
data-toggle = "collapse" data-target = "#navbarCollapse">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorials Point</a>
</div>
<!-- Links and Sublinks -->
<div class = "collapse navbar-collapse" id = "navbarCollapse">
<ul class = "nav navbar-nav">
<li class = "active"><a href = "#subject-1">Subject 1</a></li>
<li><a href = "#subject-2">Subject 2</a></li>
<li class = "dropdown"><a href = "#" class = "dropdown-toggle"
data-toggle = "dropdown">Subject 3<b class = "caret"></b></a>
<ul class = "dropdown-menu">
<li><a href = "#subject-3-1">Subject 3.1</a></li>
<li><a href = "#subject-3-2">Subject 3.2</a></li>
<li><a href = "#subject-3-3">Subject 3.3</a></li>
</ul>
</li>
<li><a href = "#subject-4">Subject 4</a></li>
</ul>
</div>
</nav>
<div class = "scroll-box" data-spy = "scroll" data-offset = "0">
<div class = "subject">
<h3 id = "subject-1">Subject 1
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-2">Subject 2
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-3">Subject 3
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><
</div>
<hr>
<div class = "subject">
<h4 id = "subject-3-1">Subject 3.1
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<div class = "subject">
<h4 id = "subject-3-2">Subject 3.2
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<div class = "subject">
<h4 id = "subject-3-3">Subject 3.3
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-4">Subject 4
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
</div>
<hr>
<h4 id = "spyevent" class = "text-info"></h4>
</div>
</body>
</html>