maxGraph/packages/html/stories/Tree.stories.js

import mxgraph from '@mxgraph/core';

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

export default {
  title: 'Layouts/Tree',
  argTypes: {
    ...globalTypes
  }
};

const Template = ({ label, ...args }) => {
  const {
    mxGraph,
    mxConstants,
    mxCylinder,
    mxCellRenderer,
    mxGraphView,
    mxImage,
    mxClient,
    mxEdgeStyle,
    mxKeyHandler,
    mxCompactTreeLayout,
    mxLayoutManager,
    mxRectangle,
    mxPoint
  } = 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';

  mxClient.setImageBasePath('/images');

  /*
    Defines a custom shape for the tree node that includes the
    upper half of the outgoing edge(s).
  */
  class TreeNodeShape extends mxCylinder {
    // Defines the length of the upper edge segment.
    static segment = 20;

    constructor(bounds, fill, stroke, strokewidth) {
      super(bounds, fill, stroke, strokewidth);
    }

    // Needs access to the cell state for rendering
    apply(state) {
      super.apply(state);
      this.state = state;
    }

    redrawPath(path, x, y, w, h, isForeground) {
      const { graph } = this.state.view;
      const hasChildren =
        graph.model.getOutgoingEdges(this.state.cell).length > 0;

      if (isForeground) {
        if (hasChildren) {
          // Painting outside of vertex bounds is used here
          path.moveTo(w / 2, h + this.segment);
          path.lineTo(w / 2, h);
          path.end();
        }
      } else {
        path.moveTo(0, 0);
        path.lineTo(w, 0);
        path.lineTo(w, h);
        path.lineTo(0, h);
        path.close();
      }
    }
  }
  mxCellRenderer.registerShape('treenode', TreeNodeShape);

  class MyCustomGraphView extends mxGraphView {
    updateFloatingTerminalPoint(edge, start, end, source) {
      // Defines a custom perimeter for the nodes in the tree
      let pt = null;

      if (source) {
        pt = new mxPoint(
          start.x + start.width / 2,
          start.y + start.height + TreeNodeShape.segment
        );
      } else {
        pt = new mxPoint(start.x + start.width / 2, start.y);
      }

      edge.setAbsoluteTerminalPoint(pt, source);
    }
  }

  class MyCustomCellRenderer extends mxCellRenderer {
    getControlBounds(state) {
      // Defines the position of the folding icon
      if (state.control != null) {
        const oldScale = state.control.scale;
        const w = state.control.bounds.width / oldScale;
        const h = state.control.bounds.height / oldScale;
        const s = state.view.scale;

        return new mxRectangle(
          state.x + state.width / 2 - (w / 2) * s,
          state.y +
            state.height +
            TreeNodeShape.segment * s -
            (h / 2) * s,
          w * s,
          h * s
        );
      }
      return null;
    }
  }

  // Make the layout instance accessible by MyCustomGraph
  let layout;

  class MyCustomGraph extends mxGraph {
    // Sets the collapse and expand icons. The values below are the default
    // values, but this is how to replace them if you need to.
    collapsedImage = new mxImage(
      `${mxClient.imageBasePath}/collapsed.gif`,
      9,
      9
    );

    expandedImage = new mxImage(
      `${mxClient.imageBasePath}/expanded.gif`,
      9,
      9
    );

    isCellFoldable(cell) {
      // Defines the condition for showing the folding icon
      return this.model.getOutgoingEdges(cell).length > 0;
    }

    createCellRenderer() {
      return new MyCustomCellRenderer();
    }

    createGraphView() {
      return new MyCustomGraphView(this);
    }

    foldCells(collapse, recurse, cells) {
      // Implements the click on a folding icon
      this.model.beginUpdate();
      try {
        this.toggleSubtree(this, cells[0], !collapse);
        this.model.setCollapsed(cells[0], collapse);

        // Executes the layout for the new graph since
        // changes to visiblity and collapsed state do
        // not trigger a layout in the current manager.
        layout.execute(this.getDefaultParent());
      } finally {
        this.model.endUpdate();
      }
    }

    toggleSubtree(cell, show) {
      // Updates the visible state of a given subtree taking into
      // account the collapsed state of the traversed branches
      show = show != null ? show : true;
      const cells = [];

      this.traverse(cell, true, function(vertex) {
        if (vertex !== cell) {
          cells.push(vertex);
        }

        // Stops recursion if a collapsed cell is seen
        return vertex === cell || !this.isCellCollapsed(vertex);
      });

      this.toggleCells(show, cells, true);
    }
  }

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

  // Disallow any selections
  graph.setCellsSelectable(false);

  // Avoids overlap of edges and collapse icons
  graph.keepEdgesInBackground = true;

  // Set some stylesheet options for the visual appearance
  let style = graph.getStylesheet().getDefaultVertexStyle();
  style.shape = 'treenode';
  style.gradientColor = 'white';
  style.shadow = true;

  style = graph.getStylesheet().getDefaultEdgeStyle();
  style.edge = mxEdgeStyle.TopToBottom;
  style.rounded = true;

  // Enables automatic sizing for vertices after editing and
  // panning by using the left mouse button.
  graph.setAutoSizeCells(true);
  graph.setPanning(true);
  graph.panningHandler.useLeftButtonForPanning = true;

  // Stops editing on enter or escape keypress
  const keyHandler = new mxKeyHandler(graph);

  // Enables automatic layout on the graph and installs
  // a tree layout for all groups who's children are
  // being changed, added or removed.
  layout = new mxCompactTreeLayout(graph, false);
  layout.useBoundingBox = false;
  layout.edgeRouting = false;
  layout.levelDistance = 30;
  layout.nodeDistance = 10;

  const layoutMgr = new mxLayoutManager(graph);

  layoutMgr.getLayout = function(cell) {
    if (cell.getChildCount() > 0) {
      return layout;
    }
  };

  // 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 the root vertex of the tree
  graph.getModel().beginUpdate();
  try {
    const w = graph.container.offsetWidth;
    const root = graph.insertVertex(
      parent,
      'treeRoot',
      'Root',
      w / 2 - 30,
      20,
      60,
      40
    );

    const v1 = graph.insertVertex(parent, 'v1', 'Child 1', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', root, v1);

    const v2 = graph.insertVertex(parent, 'v2', 'Child 2', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', root, v2);

    const v3 = graph.insertVertex(parent, 'v3', 'Child 3', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', root, v3);

    const v11 = graph.insertVertex(parent, 'v11', 'Child 1.1', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', v1, v11);

    const v12 = graph.insertVertex(parent, 'v12', 'Child 1.2', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', v1, v12);

    const v21 = graph.insertVertex(parent, 'v21', 'Child 2.1', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', v2, v21);

    const v22 = graph.insertVertex(parent, 'v22', 'Child 2.2', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', v2, v22);

    const v221 = graph.insertVertex(
      parent,
      'v221',
      'Child 2.2.1',
      0,
      0,
      60,
      40
    );
    graph.insertEdge(parent, null, '', v22, v221);

    const v222 = graph.insertVertex(
      parent,
      'v222',
      'Child 2.2.2',
      0,
      0,
      60,
      40
    );
    graph.insertEdge(parent, null, '', v22, v222);

    const v31 = graph.insertVertex(parent, 'v31', 'Child 3.1', 0, 0, 60, 40);
    graph.insertEdge(parent, null, '', v3, v31);
  } finally {
    // Updates the display
    graph.getModel().endUpdate();
  }

  return container;
}

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