cytoscape.js

Target Arrow Opacity


I have a cytoscape graph with directional edges. They are set like that:

style: {
          ...
          'line-color': '#FFFFFF',
          'target-arrow-shape': 'triangle',
          'target-arrow-color': '#FFFFFF',
          'source-arrow-color': '#FFFFFF',
          ....
},

I try to low the opacity of some edges like that:

cyElement.animate({
        style: {
          opacity: 0.2,
        },
        duration: 500,
      });

The style is set perfectly for the edges except for the tip of the arrow as you can see on the screenshot below:

arrows with low opacity but tip is black

Does someone has a solution for this ?


Solution

  • I prepared a snippet with your desired outcome. As you can see, the style can be set by calling .animate(); on a collection of nodes and/or edges. I choose the closedNeighborhood function, but you can use any other collection as you please. I can't reproduce your problem, though you should be able to use my code to achieve the correct behaviour in your code.

    document.addEventListener("DOMContentLoaded", function () {
      var cy = (window.cy = cytoscape({
        container: document.getElementById("cy"),
    
        // demo your layout
        layout: {
          name: "klay"
        },
    
        style: [
          {
            selector: "node",
            style: {
              "background-color": "#dd4de2"
            }
          },
          {
            selector: "edge",
            style: {
              'curve-style': 'bezier',
              'target-arrow-shape': 'triangle',
              'line-color': '#000',
              'target-arrow-color': '#000',
              'source-arrow-color': '#000',
              'opacity': 1,
            }
          },
        ],
        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" } }
          ],
          edges: [
            { data: { source: "n0", target: "n1" } },
            { data: { source: "n1", target: "n2" } },
            { data: { source: "n1", target: "n3" } },
            { data: { source: "n2", target: "n4" } },
            { data: { source: "n4", target: "n5" } },
            { data: { source: "n4", target: "n6" } },
            { data: { source: "n6", target: "n7" } },
            { data: { source: "n6", target: "n8" } },
            { data: { source: "n8", target: "n9" } },
            { data: { source: "n8", target: "n10" } },
            { data: { source: "n10", target: "n11" } },
            { data: { source: "n11", target: "n12" } },
            { data: { source: "n12", target: "n13" } },
            { data: { source: "n13", target: "n14" } },
            { data: { source: "n13", target: "n15" } }
          ]
        }
      }));
      
      cy.off('tap');
      cy.on('tap', 'node', function(event) {
        let elements = event.target.closedNeighborhood(); 
        elements.animate({ 
          style: { opacity: 0.1 }, 
          duration: 1000,
        });
      });
    });
    body {
      font-family: helvetica neue, helvetica, liberation sans, arial, sans-serif;
      font-size: 14px;
    }
    
    #cy {
      position: absolute;
      left: 0;
      top: 0;
      bottom: 0;
      right: 0;
      z-index: 999;
    }
    <html>
    
    <head>
      <script src="https://unpkg.com/cytoscape/dist/cytoscape.min.js"></script>
      <script src="https://unpkg.com/klayjs@0.4.1/klay.js"></script>
      <script src="https://cdn.jsdelivr.net/npm/cytoscape-klay@3.1.3/cytoscape-klay.min.js"></script>
    </head>
    
    <body>
      <div id="cy"></div>
    </body>
    
    </html>