maxGraph/packages/html/stories/EdgeTolerance.stories.js

import mxgraph from '@mxgraph/core';

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

export default {
  title: 'Connections/EdgeTolerance',
  argTypes: {
    ...globalTypes
  }
};

const Template = ({ label, ...args }) => {
  const {
    mxGraph, 
    mxUtils
  } = mxgraph;

  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';

  class MyCustomGraph extends mxGraph {
    fireMouseEvent(evtName, me, sender) {
      // Overrides the mouse event dispatching mechanism to update the
      // cell which is associated with the event in case the native hit
      // detection did not return anything.

      // Checks if native hit detection did not return anything
      if (me.getState() == null) {
        // Updates the graph coordinates in the event since we need
        // them here. Storing them in the event means the overridden
        // method doesn't have to do this again.
        if (me.graphX == null || me.graphY == null) {
          const pt = mxUtils.convertPoint(container, me.getX(), me.getY());

          me.graphX = pt.x;
          me.graphY = pt.y;
        }

        const cell = this.getCellAt(me.graphX, me.graphY);
        
        if (cell?.isEdge()) {
          me.state = this.view.getState(cell);

          if (me.state != null && me.state.shape != null) {
            this.container.style.cursor = me.state.shape.node.style.cursor;
          }
        }
      }

      if (me.state == null) {
        this.container.style.cursor = 'default';
      }

      super.fireMouseEvent(evtName, me, sender);
    }

    dblClick(evt, cell) {
      // Overrides double click handling to use the tolerance
      if (cell == null) {
        const pt = mxUtils.convertPoint(
          el,
          mxEventUtils.getClientX(evt),
          mxEventUtils.getClientY(evt)
        );
        cell = this.getCellAt(pt.x, pt.y);
      }
      super.dblClick(evt, cell);
    }
  }

  // Creates the graph inside the given container
  const graph = new MyCustomGraph(container);
  graph.setTolerance(20);

  // Gets the default parent for inserting new cells. This
  // is normally the first child of the root (ie. layer 0).
  const parent = graph.getDefaultParent();

  // Adds cells to the model in a single step
  graph.batchUpdate(() => {
    const v1 = graph.insertVertex({
      parent,
      value: 'Hello,',
      position: [120, 120],
      size: [80, 30],
    });
    const v2 = graph.insertVertex({
      parent,
      value: 'World!',
      position: [400, 250],
      size: [80, 30],
    });
    const e1 = graph.insertEdge({
      parent,
      source: v1,
      target: v2,
      style: 'edgeStyle=orthogonalEdgeStyle;',
    });
    const e2 = graph.insertEdge({
      parent,
      source: v2,
      target: v1,
      style: 'edgeStyle=orthogonalEdgeStyle;',
    });
  });

  return container;
}

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