Bootstrap burger menu optimized as an icon

Burger menu icons are everywhere in today’s web sites and application interfaces. Good or bad for user experience, this debate is not the subject here.

Design request

I had a design request where desktop interface get a button with both a “Menu” label and a burger menu icon next to it and the mobile interface get a simplified burger menu icon on the far right of the header.

screenshot Ztele.com bootstrap grid desktop VS mobile interface

Bootstrap been very popular these days for building fast responsive HTML layouts it’s not surprising to get burger menu in it’s Glyphs library … D’oupssss! There is NO burger menu available in the Glyphicons Free Edition used by Bootstrap’s Components.

Burger menu from Bootstrap

In fact by default Bootstrap use burger menu only within the Navbar Component when responsive kicks in.

Even worst for designers, it is not a define object (image or graph), you can’t use it out of the Navbar context. It is a pure semantic hack that takes 3 HTML <span> tags wrapped within a <button>. OK there is the <span class="sr-only"> fix but that is really a minimum to pass accessibility QA.

 A web-inspector view of Bootstrap navbar <span.icon-bar>

 

So I have designed a custom burger menu based on Bootstrap’s “icon-bar” LESS code lines.

HTML source code

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<button id="main-menu-dropdown" class="btn btn-primary dropdown-toggle" type="button" data-toggle="dropdown" title="Toggle navigation">
    <span class="string">Menu</span>
    <span class="ico ico-burger-menu" title="Menu">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
    </span>
</button>

The get the burger wrapped within a border you just add the class “border” to <span class="ico ico-burger-menu border">

Layout “Bootstrap style” by default

  1. Default icon layout (whitout border)

    <span class="ico ico-burger-menu">

  2. Icon wrapped within border

    <span class="ico ico-burger-menu border">

Default burger menu layout within a <button>Burger menu layout wrapped within border

LESS code lines

variables.less
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// ico-burger-menu is generated with the glyphicon icon method from bootstrap
@burger-menu-color:                 lighten(@dropdown-caret-color, 50%);
// ico-burger-menu within bootstrap buttons
@burger-menu-default-color:         lighten(@btn-default-color, 20%);
@burger-menu-primary-color:         @btn-primary-color;
// ico-burger-menu hover
@burger-menu-hover-color:           darken(@burger-menu-color, 30%);
base.less
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/*
 * -------------------
 * Burger Menu
 */
.ico {
    .glyphicon;
    &.ico-burger-menu {
        display: inline-block;
        min-width: 18px;
        max-width: 32px;
        min-height: 18px;
        text-align: center;
        vertical-align: middle;
        background-color: transparent;
        &.border {
            min-width: 20px;
            margin-top: -4px;
            padding: 1px 2px;
            border: 1px solid @burger-menu-color;
            border-radius: 2px;
            // within bootstrap buttons
            .btn-default & {
                border-color: @burger-menu-default-color;
            }
            .btn-primary & {
                border-color: @burger-menu-primary-color;
            }
        }
        // Bars (style from navbar.less)
        .icon-bar {
            display: block;
            min-height: 2px;
            margin: 2px auto;
            border-radius: @border-radius-small;
            background-color: @burger-menu-color;
            // within bootstrap buttons
            .btn-default & {
                background-color: @burger-menu-default-color;
            }
            .btn-primary & {
                background-color: @burger-menu-primary-color;
            }
            .dropdown.open .btn &,
            .btn:hover & {
                background-color: @burger-menu-hover-color;
            }
        }
        &:focus {
            outline: 0;
        }
        &:hover,
        &:focus,
        .btn:hover & {
            text-decoration: none;
        }
        .btn-primary & {
            text-decoration: none;
        }
    }
}