How to center a Tab Bar in Material Design Lite

Question

The Material Design Guidelines specify a centered Tab Bar (https://material.io/guidelines/components/tabs.html). Is there a class for that in MDL. If not, how can I achieve this with CSS?

Answer 1

By default the MDL Tab Bar (v.1.3.0) will be centered, like this:

<script src="https://code.getmdl.io/1.3.0/material.min.js"></script>
<link href="https://code.getmdl.io/1.3.0/material.indigo-pink.min.css" rel="stylesheet" />
<div class="mdl-tabs mdl-js-tabs mdl-js-ripple-effect">
  <div class="mdl-tabs__tab-bar">
    <a href="#starks-panel" class="mdl-tabs__tab is-active">Starks</a>
    <a href="#lannisters-panel" class="mdl-tabs__tab">Lannisters</a>
    <a href="#targaryens-panel" class="mdl-tabs__tab">Targaryens</a>
  </div>

  <div class="mdl-tabs__panel is-active" id="starks-panel">
    <ul>
      <li>Eddard</li>
      <li>Catelyn</li>
      <li>Robb</li>
      <li>Sansa</li>
      <li>Brandon</li>
      <li>Arya</li>
      <li>Rickon</li>
    </ul>
  </div>
  <div class="mdl-tabs__panel" id="lannisters-panel">
    <ul>
      <li>Tywin</li>
      <li>Cersei</li>
      <li>Jamie</li>
      <li>Tyrion</li>
    </ul>
  </div>
  <div class="mdl-tabs__panel" id="targaryens-panel">
    <ul>
      <li>Viserys</li>
      <li>Daenerys</li>
    </ul>
  </div>
</div>

This is accomplished by the default styling of .mdl-tabs__tab-bar {justify-content: center;}

If you wanted to left (or right) align the Tab Bar you could add justify-content: flex-start or justify-content: flex-end to the .mdl-tabs__tab-bar selector.

.mdl-tabs__tab-bar  {
  justify-content: flex-start;
}

.mdl-tabs__tab-bar  {
  justify-content: flex-start !important;
}

<script src="https://code.getmdl.io/1.3.0/material.min.js"></script>
<link href="https://code.getmdl.io/1.3.0/material.indigo-pink.min.css" rel="stylesheet"/>

<div class="mdl-tabs mdl-js-tabs mdl-js-ripple-effect">
  <div class="mdl-tabs__tab-bar">
      <a href="#starks-panel" class="mdl-tabs__tab is-active">Starks</a>
      <a href="#lannisters-panel" class="mdl-tabs__tab">Lannisters</a>
      <a href="#targaryens-panel" class="mdl-tabs__tab">Targaryens</a>
  </div>

  <div class="mdl-tabs__panel is-active" id="starks-panel">
    <ul>
      <li>Eddard</li>
      <li>Catelyn</li>
      <li>Robb</li>
      <li>Sansa</li>
      <li>Brandon</li>
      <li>Arya</li>
      <li>Rickon</li>
    </ul>
  </div>
  <div class="mdl-tabs__panel" id="lannisters-panel">
    <ul>
      <li>Tywin</li>
      <li>Cersei</li>
      <li>Jamie</li>
      <li>Tyrion</li>
    </ul>
  </div>
  <div class="mdl-tabs__panel" id="targaryens-panel">
    <ul>
      <li>Viserys</li>
      <li>Daenerys</li>
    </ul>
  </div>
</div>

Another location for a Tab Bar is in the navigation. Here's an example of centering in that case. The solution is the same as the other case, apply a justify-content: center to the .mdl-layout__tab-bar selector.

.mdl-layout__tab-bar {
  justify-content: center;
}

<script src="https://code.getmdl.io/1.3.0/material.min.js"></script>
<link href="https://code.getmdl.io/1.3.0/material.indigo-pink.min.css" rel="stylesheet"/>

<div class="mdl-layout mdl-js-layout mdl-layout--fixed-header">
  <header class="mdl-layout__header">
    <div class="mdl-layout__header-row">
      <!-- Title -->
      <span class="mdl-layout-title">Title</span>
    </div>
    <!-- Tabs -->
    <div class="mdl-layout__tab-bar mdl-js-ripple-effect">
      <a href="#scroll-tab-1" class="mdl-layout__tab is-active">Tab 1</a>
      <a href="#scroll-tab-2" class="mdl-layout__tab">Tab 2</a>
      <a href="#scroll-tab-3" class="mdl-layout__tab">Tab 3</a>
      <a href="#scroll-tab-4" class="mdl-layout__tab">Tab 4</a>
      <a href="#scroll-tab-5" class="mdl-layout__tab">Tab 5</a>
      <a href="#scroll-tab-6" class="mdl-layout__tab">Tab 6</a>
    </div>
  </header>
  <div class="mdl-layout__drawer">
    <span class="mdl-layout-title">Title</span>
  </div>
  <main class="mdl-layout__content">
    <section class="mdl-layout__tab-panel is-active" id="scroll-tab-1">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
    <section class="mdl-layout__tab-panel" id="scroll-tab-2">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
    <section class="mdl-layout__tab-panel" id="scroll-tab-3">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
    <section class="mdl-layout__tab-panel" id="scroll-tab-4">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
    <section class="mdl-layout__tab-panel" id="scroll-tab-5">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
    <section class="mdl-layout__tab-panel" id="scroll-tab-6">
      <div class="page-content"><!-- Your content goes here --></div>
    </section>
  </main>
</div>