maxGraph/packages/html/stories/Markers.stories.js

import {
  Graph,
  EdgeHandler,
  SelectionHandler,
  CellRenderer,
  MarkerShape,
  CylinderShape,
  ArrowShape,
  Point,
} from '@maxgraph/core';

import { globalTypes } from '../.storybook/preview';

export default {
  title: 'Icon_Images/Markers',
  argTypes: {
    ...globalTypes,
  },
};

const Template = ({ label, ...args }) => {
  const container = document.createElement('div');
  container.style.position = 'relative';
  container.style.overflow = 'hidden';
  container.style.width = `${args.width}px`;
  container.style.height = `${args.height}px`;
  container.style.background = 'url(/images/grid.gif)';
  container.style.cursor = 'default';

  // Enables guides
  SelectionHandler.prototype.guidesEnabled = true;
  EdgeHandler.prototype.snapToTerminals = true;

  // Registers and defines the custom marker
  MarkerShape.addMarker(
    'dash',
    function (canvas, shape, type, pe, unitX, unitY, size, source, sw, filled) {
      const nx = unitX * (size + sw + 1);
      const ny = unitY * (size + sw + 1);

      return function () {
        canvas.begin();
        canvas.moveTo(pe.x - nx / 2 - ny / 2, pe.y - ny / 2 + nx / 2);
        canvas.lineTo(pe.x + ny / 2 - (3 * nx) / 2, pe.y - (3 * ny) / 2 - nx / 2);
        canvas.stroke();
      };
    }
  );

  // Defines custom message shape
  class MessageShape extends CylinderShape {
    redrawPath(path, x, y, w, h, isForeground) {
      if (isForeground) {
        path.moveTo(0, 0);
        path.lineTo(w / 2, h / 2);
        path.lineTo(w, 0);
      } else {
        path.moveTo(0, 0);
        path.lineTo(w, 0);
        path.lineTo(w, h);
        path.lineTo(0, h);
        path.close();
      }
    }
  }
  CellRenderer.registerShape('message', MessageShape);

  // Defines custom edge shape
  class LinkShape extends ArrowShape {
    paintEdgeShape(c, pts) {
      const width = 10;

      // Base vector (between end points)
      const p0 = pts[0];
      const pe = pts[pts.length - 1];

      const dx = pe.x - p0.x;
      const dy = pe.y - p0.y;
      const dist = Math.sqrt(dx * dx + dy * dy);
      const length = dist;

      // Computes the norm and the inverse norm
      const nx = dx / dist;
      const ny = dy / dist;
      const basex = length * nx;
      const basey = length * ny;
      const floorx = (width * ny) / 3;
      const floory = (-width * nx) / 3;

      // Computes points
      const p0x = p0.x - floorx / 2;
      const p0y = p0.y - floory / 2;
      const p1x = p0x + floorx;
      const p1y = p0y + floory;
      const p2x = p1x + basex;
      const p2y = p1y + basey;
      const p3x = p2x + floorx;
      const p3y = p2y + floory;
      // p4 not necessary
      const p5x = p3x - 3 * floorx;
      const p5y = p3y - 3 * floory;

      c.begin();
      c.moveTo(p1x, p1y);
      c.lineTo(p2x, p2y);
      c.moveTo(p5x + floorx, p5y + floory);
      c.lineTo(p0x, p0y);
      c.stroke();
    }
  }
  CellRenderer.registerShape('link', LinkShape);

  // Creates the graph
  const graph = new Graph(container);

  // Sets default styles
  let style = graph.getStylesheet().getDefaultVertexStyle();
  style.fillColor = '#FFFFFF';
  style.strokeColor = '#000000';
  style.fontColor = '#000000';
  style.fontStyle = '1';

  style = graph.getStylesheet().getDefaultEdgeStyle();
  style.strokeColor = '#000000';
  style.fontColor = '#000000';
  style.fontStyle = '0';
  style.fontStyle = '0';
  style.startSize = '8';
  style.endSize = '8';

  // Populates the graph
  const parent = graph.getDefaultParent();

  graph.batchUpdate(() => {
    const v1 = graph.insertVertex(parent, null, 'v1', 20, 20, 80, 30);
    const v2 = graph.insertVertex(parent, null, 'v2', 440, 20, 80, 30);
    const e1 = graph.insertEdge(
      parent,
      null,
      '',
      v1,
      v2,
      'dashed=1;' +
        'startArrow=oval;endArrow=block;sourcePerimeterSpacing=4;startFill=0;endFill=0;'
    );
    const e11 = graph.insertVertex(
      e1,
      null,
      'Label',
      0,
      0,
      20,
      14,
      'shape=message;labelBackgroundColor=#ffffff;labelPosition=left;spacingRight=2;align=right;fontStyle=0;'
    );
    e11.geometry.offset = new Point(-10, -7);
    e11.geometry.relative = true;
    e11.connectable = false;

    const v3 = graph.insertVertex(parent, null, 'v3', 20, 120, 80, 30);
    const v4 = graph.insertVertex(parent, null, 'v4', 440, 120, 80, 30);
    const e2 = graph.insertEdge(
      parent,
      null,
      'Label',
      v3,
      v4,
      'startArrow=dash;startSize=12;endArrow=block;labelBackgroundColor=#FFFFFF;'
    );

    const v5 = graph.insertVertex(
      parent,
      null,
      'v5',
      40,
      220,
      40,
      40,
      'shape=ellipse;perimeter=ellipsePerimeter;'
    );
    const v6 = graph.insertVertex(
      parent,
      null,
      'v6',
      460,
      220,
      40,
      40,
      'shape=doubleEllipse;perimeter=ellipsePerimeter;'
    );
    const e3 = graph.insertEdge(
      parent,
      null,
      'Link',
      v5,
      v6,
      'shape=link;labelBackgroundColor=#FFFFFF;'
    );
  });

  return container;
};

export const Default = Template.bind({});