Fullscreen

Click on the button on the bottom-right of the visualization to toggle the fullscreen mode.
          <!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.11.2/css/all.min.css" rel="stylesheet">
  <script src="../build/ogma.min.js"></script>
  <style>
    #graph-container {
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
      position: absolute;
      margin: 0;
      overflow: hidden;
    }

    .btn {
      display: inline-block;
      padding: 6px 12px;
      margin-bottom: 0;
      font-size: 14px;
      font-weight: 400;
      line-height: 1.42857143;
      text-align: center;
      white-space: nowrap;
      vertical-align: middle;
      cursor: pointer;
      -webkit-user-select: none;
      -moz-user-select: none;
      -ms-user-select: none;
      user-select: none;
      border: 1px solid transparent;
      border-radius: 4px;
    }

    .btn.focus,
    .btn:focus,
    .btn:hover {
      color: #333;
      text-decoration: none;
    }

    .btn-default {
      color: #333;
      background-color: #fff;
      border-color: #ccc;
    }

    .btn-default:hover {
      color: #333;
      background-color: #e6e6e6;
      border-color: #adadad;
    }

    .btn-group-vertical {
      position: relative;
      display: inline-block;
      vertical-align: middle;
    }

    .btn-group-vertical>.btn {
      border: 0;
      padding: 6px 10px;
      position: relative;
      display: block;
      float: none;
      width: 100%;
      max-width: 100%;
    }

    .btn-group-vertical>.btn:not(:first-child):not(:last-child) {
      border-radius: 0;
    }

    .btn-group-vertical>.btn:focus {
      background-color: #ffffff;
    }

    .btn-group-vertical>.btn.active {
      background-color: #cccccc;
    }

    #viewController {
      position: absolute;
      bottom: 10px;
      right: 10px;
      border-radius: 4px;
      background-color: #ffffff;
      box-shadow: 0 1px 6px rgba(0, 0, 0, 0.16), 0 1px 6px rgba(0, 0, 0, 0.23);
    }
  </style>
</head>

<body>
  <div id="graph-container">

    <div id="viewController" class="btn-group-vertical">
      <button type="button" class="btn btn-default" onclick="fullScreen();" title="Full screen">
        <i class="fa fa-expand"></i>
      </button>
    </div>
  </div>

  <script>
    'use strict';

    var ogma = new Ogma({
      container: 'graph-container'
    });

    ogma.generate.random({ nodes: 50, edges: 50 }).then(function (g) {
      ogma.setGraph(g);
      ogma.view.locateGraph();
    });

    function fullScreen() {
      ogma.view.setFullScreen(!ogma.view.isFullScreen());
    }

  </script>
</body>

</html>