create-gojs-kit/dist/extensionsJSM/FishboneLayout.ts

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/*
 *  Copyright 1998-2025 by Northwoods Software Corporation. All Rights Reserved.
 */

/*
 * This is an extension and not part of the main GoJS library.
 * The source code for this is at extensionsJSM/FishboneLayout.ts.
 * Note that the API for this class may change with any version, even point releases.
 * If you intend to use an extension in production, you should copy the code to your own source directory.
 * Extensions can be found in the GoJS kit under the extensions or extensionsJSM folders.
 * See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
 */

import * as go from 'gojs';

/**
 * FishboneLayout is a custom {@link go.Layout} derived from {@link go.TreeLayout} for creating "fishbone" diagrams.
 * A fishbone diagram also requires a {@link go.Link} class that implements custom routing, {@link FishboneLink}.
 *
 * This only works for angle === 0 or angle === 180.
 *
 * This layout assumes Links are automatically routed in the way needed by fishbone diagrams,
 * by using the FishboneLink class instead of go.Link.
 *
 * If you want to experiment with this extension, try the <a href="../../samples/Fishbone.html">Fishbone Layout</a> sample.
 * @category Layout Extension
 */
export class FishboneLayout extends go.TreeLayout {
  /**
   * Constructs a FishboneLayout and sets the following properties:
   *   - {@link TreeLayout.alignment} = {@link go.TreeAlignment.BusBranching}
   *   - {@link TreeLayout.setsPortSpot} = false
   *   - {@link TreeLayout.setsChildPortSpot} = false
   */
  constructor(init?: Partial<FishboneLayout>) {
    super();
    this.alignment = go.TreeAlignment.BusBranching;
    this.setsPortSpot = false;
    this.setsChildPortSpot = false;
    if (init) Object.assign(this, init);
  }

  /**
   * Create and initialize a {@link go.LayoutNetwork} with the given nodes and links.
   * This override creates dummy vertexes, when necessary, to allow for proper positioning within the fishbone.
   * @param coll - A {@link go.Diagram} or a {@link go.Group} or a collection of {@link go.Part}s.
   */
  override makeNetwork(
    coll: go.Diagram | go.Group | go.Iterable<go.Part>
  ): go.LayoutNetwork {
    // assert(this.angle === 0 || this.angle === 180);
    // assert(this.alignment === go.TreeAlignment.BusBranching);
    // assert(this.path !== go.TreePath.Source);

    // call base method for standard behavior
    const net = super.makeNetwork(coll);
    // make a copy of the collection of TreeVertexes
    // because we will be modifying the TreeNetwork.vertexes collection in the loop
    const verts = new go.List<go.TreeVertex>().addAll(
      net.vertexes.iterator as go.Iterator<go.TreeVertex>
    );
    verts.each((v: go.TreeVertex) => {
      // ignore leaves of tree
      if (v.destinationEdges.count === 0) return;
      this.prepareParent(v, net as go.TreeNetwork);
      if (v.destinationEdges.count % 2 === 1) {
        // if there's an odd number of real children, add two dummies
        const dummy = net.createVertex();
        dummy.bounds = new go.Rect();
        dummy.focus = new go.Point();
        net.addVertex(dummy);
        net.linkVertexes(v, dummy, null);
      }
      // make sure there's an odd number of children, including at least one dummy;
      // commitNodes will move the parent node to where this dummy child node is placed
      const dummy2 = net.createVertex();
      dummy2.bounds = v.bounds;
      dummy2.focus = v.focus;
      net.addVertex(dummy2);
      net.linkVertexes(v, dummy2, null);
    });
    return net;
  }

  /** @hidden */
  prepareParent(v: go.TreeVertex, net: go.TreeNetwork) {}

  /**
   * Add a direction property to each vertex and modify {@link go.TreeVertex.layerSpacing}.
   */
  override assignTreeVertexValues(v: go.TreeVertex): void {
    super.assignTreeVertexValues(v);
    (v as any)['_direction'] = 0; // add this property to each TreeVertex
    if (v.parent !== null) {
      // The parent node will be moved to where the last dummy will be;
      // reduce the space to account for the future hole.
      if (v.angle === 0 || v.angle === 180) {
        v.layerSpacing -= v.bounds.width;
      } else {
        v.layerSpacing -= v.bounds.height;
      }
    }
  }

  /**
   * Assigns {@link go.Link.fromSpot}s and {@link go.Link.toSpot}s based on branching and angle
   * and moves vertexes based on dummy locations.
   */
  override commitNodes(): void {
    if (this.network === null) return;
    // vertex Angle is set by BusBranching "inheritance";
    // assign spots assuming overall Angle === 0 or 180
    // and links are always connecting horizontal with vertical
    this.network.edges.each((e) => {
      const link = e.link;
      if (link === null) return;
      link.fromSpot = go.Spot.None;
      link.toSpot = go.Spot.None;

      const v: go.TreeVertex = e.fromVertex as go.TreeVertex;
      const w: go.TreeVertex = e.toVertex as go.TreeVertex;

      if (v.angle === 0) {
        link.fromSpot = go.Spot.Left;
      } else if (v.angle === 180) {
        link.fromSpot = go.Spot.Right;
      }

      if (w.angle === 0) {
        link.toSpot = go.Spot.Left;
      } else if (w.angle === 180) {
        link.toSpot = go.Spot.Right;
      }
    });

    this.moveParentNodesToDummies();

    this.network.vertexes.each(v => {
      const w = v as go.TreeVertex;
      if (w.parent === null) {
        this.shift(w);
      }
    });

    // now actually change the Node.location of all nodes
    super.commitNodes();
  }

  /**
   * Move each parent node to the location of the last dummy.
   */
  moveParentNodesToDummies() {
    const vit = this.network!.vertexes.iterator;
    while (vit.next()) {
      const v = vit.value as go.TreeVertex;
      const len = v.children.length;
      if (len === 0) continue; // ignore leaf nodes
      if (v.parent === null) continue; // don't move root node
      const dummy2 = v.children[len - 1];
      v.centerX = dummy2.centerX;
      v.centerY = dummy2.centerY;
    }
  }

  /**
   * This override stops links from being committed since the work is done by the {@link FishboneLink} class.
   */
  override commitLinks(): void {}

  /**
   * Shifts subtrees within the fishbone based on angle and node spacing.
   */
  shift(v: go.TreeVertex): void {
    const p = v.parent;
    if (p !== null && (v.angle === 90 || v.angle === 270)) {
      const g = p.parent;
      if (g !== null) {
        const shift = v.nodeSpacing;
        if ((g as any)['_direction'] > 0) {
          if (g.angle === 90) {
            if (p.angle === 0) {
              (v as any)['_direction'] = 1;
              if (v.angle === 270) this.shiftAll(2, -shift, p, v);
            } else if (p.angle === 180) {
              (v as any)['_direction'] = -1;
              if (v.angle === 90) this.shiftAll(-2, shift, p, v);
            }
          } else if (g.angle === 270) {
            if (p.angle === 0) {
              (v as any)['_direction'] = 1;
              if (v.angle === 90) this.shiftAll(2, -shift, p, v);
            } else if (p.angle === 180) {
              (v as any)['_direction'] = -1;
              if (v.angle === 270) this.shiftAll(-2, shift, p, v);
            }
          }
        } else if ((g as any)['_direction'] < 0) {
          if (g.angle === 90) {
            if (p.angle === 0) {
              (v as any)['_direction'] = 1;
              if (v.angle === 90) this.shiftAll(2, -shift, p, v);
            } else if (p.angle === 180) {
              (v as any)['_direction'] = -1;
              if (v.angle === 270) this.shiftAll(-2, shift, p, v);
            }
          } else if (g.angle === 270) {
            if (p.angle === 0) {
              (v as any)['_direction'] = 1;
              if (v.angle === 270) this.shiftAll(2, -shift, p, v);
            } else if (p.angle === 180) {
              (v as any)['_direction'] = -1;
              if (v.angle === 90) this.shiftAll(-2, shift, p, v);
            }
          }
        }
      } else {
        // g === null: V is a child of the tree ROOT
        const dir = p.angle === 0 ? 1 : -1;
        (v as any)['_direction'] = dir;
        this.shiftAll(dir, 0, p, v);
      }
    }
    for (let i = 0; i < v.children.length; i++) {
      const c = v.children[i];
      this.shift(c);
    }
  }

  /**
   * Shifts a subtree.
   */
  shiftAll(
    direction: number,
    absolute: number,
    root: go.TreeVertex,
    v: go.TreeVertex
  ): void {
    // assert(root.angle === 0 || root.angle === 180);
    let locx = v.centerX;
    locx += (direction * Math.abs(root.centerY - v.centerY)) / 2;
    locx += absolute;
    v.centerX = locx;
    for (let i = 0; i < v.children.length; i++) {
      const c = v.children[i];
      this.shiftAll(direction, absolute, root, c);
    }
  }
  // end FishboneLayout
}

/**
 * Custom {@link go.Link} class for {@link FishboneLayout}.
 * @category Part Extension
 */
export class FishboneLink extends go.Link {
  constructor(init?: Partial<FishboneLink>) {
    super();
    if (init) Object.assign(this, init);
  }

  override computeAdjusting(): go.LinkAdjusting {
    return this.adjusting;
  }
  /**
   * Determines the points for this link based on spots and maintains horizontal lines.
   */
  override computePoints(): boolean {
    const result = super.computePoints();
    if (result) {
      // insert middle point to maintain horizontal lines
      if (this.fromSpot.equals(go.Spot.Right) || this.fromSpot.equals(go.Spot.Left)) {
        let p1: go.Point;
        // deal with root node being on the "wrong" side
        const fromnode = this.fromNode;
        const fromport = this.fromPort;
        if (fromnode !== null && fromport !== null && fromnode.findLinksInto().count === 0) {
          // pretend the link is coming from the opposite direction than the declared FromSpot
          const fromctr = fromport.getDocumentPoint(go.Spot.Center);
          const fromfar = fromctr.copy();
          fromfar.x += this.fromSpot.equals(go.Spot.Left) ? 99999 : -99999;
          p1 = this.getLinkPointFromPoint(fromnode, fromport, fromctr, fromfar, true).copy();
          // update the route points
          this.setPoint(0, p1);
          let endseg = this.fromEndSegmentLength;
          if (isNaN(endseg)) endseg = fromport.fromEndSegmentLength;
          p1.x += this.fromSpot.equals(go.Spot.Left) ? endseg : -endseg;
          this.setPoint(1, p1);
        } else {
          p1 = this.getPoint(1); // points 0 & 1 should be OK already
        }
        const tonode = this.toNode;
        const toport = this.toPort;
        if (tonode !== null && toport !== null) {
          const toctr = toport.getDocumentPoint(go.Spot.Center);
          const far = toctr.copy();
          far.x += this.fromSpot.equals(go.Spot.Left) ? -99999 / 2 : 99999 / 2;
          far.y += toctr.y < p1.y ? 99999 : -99999;
          const p2 = this.getLinkPointFromPoint(tonode, toport, toctr, far, false);
          this.setPoint(2, p2);
          let dx = Math.abs(p2.y - p1.y) / 2;
          if (this.fromSpot.equals(go.Spot.Left)) dx = -dx;
          this.insertPoint(2, new go.Point(p2.x + dx, p1.y));
        }
      } else if (this.toSpot.equals(go.Spot.Right) || this.toSpot.equals(go.Spot.Left)) {
        const p1: go.Point = this.getPoint(1); // points 1 & 2 should be OK already
        const fromnode = this.fromNode;
        const fromport = this.fromPort;
        if (fromnode !== null && fromport !== null) {
          const parentlink = fromnode.findLinksInto().first();
          const fromctr = fromport.getDocumentPoint(go.Spot.Center);
          const far = fromctr.copy();
          far.x +=
            parentlink !== null && parentlink.fromSpot.equals(go.Spot.Left)
              ? -99999 / 2
              : 99999 / 2;
          far.y += fromctr.y < p1.y ? 99999 : -99999;
          const p0 = this.getLinkPointFromPoint(fromnode, fromport, fromctr, far, true);
          this.setPoint(0, p0);
          let dx = Math.abs(p1.y - p0.y) / 2;
          if (parentlink !== null && parentlink.fromSpot.equals(go.Spot.Left)) dx = -dx;
          this.insertPoint(1, new go.Point(p0.x + dx, p1.y));
        }
      }
    }
    return result;
  }
}