Cytoscape.js - Toggle Dark-Mode

Question

I understand that I can edit the color of nodes and edges in cytoscape.js

• For nodes, I can use selector: 'node'
• For edges, I can use selector: 'edge'
• Similar to this: Cytoscape.js - Set core background to dark?

What selector should I use for the background color? I want to toggle between a light and dark background (like a toggle for light/dark mode).

Thank you very much for anyone who can answer.

Answer 1

You can toggle the background color with some simple js code. I implemented this functionality with .addEventListener() on a button click:

var cy = window.cy = cytoscape({
  container: document.getElementById('cy'),

  boxSelectionEnabled: false,
  autounselectify: true,

  style: [{
      selector: 'node',
      css: {
        'content': 'data(id)',
        'text-valign': 'center',
        'text-halign': 'center',
        'height': '60px',
        'width': '60px',
        'border-color': '#fff',
        'border-opacity': '1',
        'border-width': '10px'
      }
    },
    {
      selector: '$node > node',
      css: {
        'padding-top': '10px',
        'padding-left': '10px',
        'padding-bottom': '10px',
        'padding-right': '10px',
        'text-valign': 'top',
        'text-halign': 'center',
        'background-color': '#bbb'
      }
    },
    {
      selector: 'edge',
      css: {
        'target-arrow-shape': 'triangle'
      }
    },
    {
      selector: ':selected',
      css: {
        'background-color': 'black',
        'line-color': 'black',
        'target-arrow-color': 'black',
        'source-arrow-color': 'black'
      }
    }
  ],

  elements: {
    nodes: [{
        data: {
          id: 'n0'
        }
      },
      {
        data: {
          id: 'n1'
        }
      },
      {
        data: {
          id: 'n2'
        }
      },
      {
        data: {
          id: 'n3'
        }
      },
      {
        data: {
          id: 'n4'
        }
      },
      {
        data: {
          id: 'n5'
        }
      },
      {
        data: {
          id: 'n6'
        }
      },
      {
        data: {
          id: 'n7'
        }
      },
      {
        data: {
          id: 'n8'
        }
      },
      {
        data: {
          id: 'n9'
        }
      },
      {
        data: {
          id: 'n10'
        }
      },
      {
        data: {
          id: 'n11'
        }
      },
      {
        data: {
          id: 'n12'
        }
      },
      {
        data: {
          id: 'n13'
        }
      },
      {
        data: {
          id: 'n14'
        }
      },
      {
        data: {
          id: 'n15'
        }
      },
      {
        data: {
          id: 'n16'
        }
      }
    ],
    edges: [{
        data: {
          source: 'n0',
          target: 'n1'
        }
      },
      {
        data: {
          source: 'n1',
          target: 'n2'
        }
      },
      {
        data: {
          source: 'n1',
          target: 'n3'
        }
      },
      {
        data: {
          source: 'n2',
          target: 'n7'
        }
      },
      {
        data: {
          source: 'n2',
          target: 'n11'
        }
      },
      {
        data: {
          source: 'n2',
          target: 'n16'
        }
      },
      {
        data: {
          source: 'n3',
          target: 'n4'
        }
      },
      {
        data: {
          source: 'n3',
          target: 'n16'
        }
      },
      {
        data: {
          source: 'n4',
          target: 'n5'
        }
      },
      {
        data: {
          source: 'n4',
          target: 'n6'
        }
      },
      {
        data: {
          source: 'n6',
          target: 'n8'
        }
      },
      {
        data: {
          source: 'n8',
          target: 'n9'
        }
      },
      {
        data: {
          source: 'n8',
          target: 'n10'
        }
      },
      {
        data: {
          source: 'n11',
          target: 'n12'
        }
      },
      {
        data: {
          source: 'n12',
          target: 'n13'
        }
      },
      {
        data: {
          source: 'n13',
          target: 'n14'
        }
      },
      {
        data: {
          source: 'n13',
          target: 'n15'
        }
      },
    ]
  },

  layout: {
    name: 'dagre',
    padding: 5
  }
});

document.getElementById("toggleBackgroundColor").addEventListener("click", function() {
  let cy = document.getElementById('cy')
  cy.style.background = (cy.style.background == "black") ? "white" : "black"
});

body {
  font: 14px helvetica neue, helvetica, arial, sans-serif;
}

#cy {
  position: absolute;
  z-index: 999;
  width: 100%;
  height: 100%;
  float: left;
}

<html>

<head>
  <meta charset=utf-8 />
  <meta name="viewport" content="user-scalable=no, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, minimal-ui">
  <script src="https://unpkg.com/[email protected]/dist/cytoscape.min.js">
  </script>
  <script src="https://unpkg.com/[email protected]/dist/jquery.js"></script>
  <!-- cyposcape dagre -->
  <script src="https://unpkg.com/[email protected]/dist/dagre.js"></script>
  <script src="https://cdn.rawgit.com/cytoscape/cytoscape.js-dagre/1.5.0/cytoscape-dagre.js"></script>
</head>

<body>
  <b id="toggleBackgroundColor" style="cursor: pointer;color: green; z-index: 1">Toggle background-color</b>
  <div id="cy"></div>
</body>

</html>