gojs
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Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams
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JavaScript
/*
* Copyright (C) 1998-2020 by Northwoods Software Corporation. All Rights Reserved.
*/
/*
* This is an extension and not part of the main GoJS library.
* 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 extensionsTS folders.
* See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
*/
import * as go from '../release/go-module.js';
/**
* Perform two TreeLayouts, one going rightwards and one going leftwards.
* The choice of direction is determined by the mandatory predicate {@link #directionFunction},
* which is called on each child Node of the root Node.
*
* You can also set {@link #vertical} to true if you want the DoubleTreeLayout to
* perform TreeLayouts both downwards and upwards.
*
* Normally there should be a single root node. Hoewver if there are multiple root nodes
* found in the nodes and links that this layout is responsible for, this will pretend that
* there is a real root node and make all of the apparent root nodes children of that pretend root.
*
* If there is no root node, all nodes are involved in cycles, so the first given node is chosen.
*
* If you want to experiment with this extension, try the <a href="../../samples/doubleTree.html">Double Tree</a> sample.
* @category Layout Extension
*/
export class DoubleTreeLayout extends go.Layout {
constructor() {
super(...arguments);
this._vertical = false;
this._directionFunction = function (node) { return true; };
this._bottomRightOptions = null;
this._topLeftOptions = null;
}
/**
* When false, the layout should grow towards the left and towards the right;
* when true, the layout show grow upwards and downwards.
* The default value is false.
*/
get vertical() { return this._vertical; }
set vertical(value) {
if (typeof value !== "boolean")
throw new Error("new value for DoubleTreeLayout.vertical must be a boolean value.");
if (this._vertical !== value) {
this._vertical = value;
this.invalidateLayout();
}
}
/**
* This function is called on each child node of the root node
* in order to determine whether the subtree starting from that child node
* will grow towards larger coordinates or towards smaller ones.
* The value must be a function and must not be null.
* It must return true if {@link #isPositiveDirection} should return true; otherwise it should return false.
*/
get directionFunction() { return this._directionFunction; }
set directionFunction(value) {
if (typeof value !== "function") {
throw new Error("new value for DoubleTreeLayout.directionFunction must be a function taking a node data object and returning a boolean.");
}
if (this._directionFunction !== value) {
this._directionFunction = value;
this.invalidateLayout();
}
}
/**
* Gets or sets the options to be applied to a {@link TreeLayout}.
* By default this is null -- no properties are set on the TreeLayout
* other than the {@link TreeLayout#angle}, depending on {@link #vertical} and
* the result of calling {@link #directionFunction}.
*/
get bottomRightOptions() { return this._bottomRightOptions; }
set bottomRightOptions(value) {
if (this._bottomRightOptions !== value) {
this._bottomRightOptions = value;
this.invalidateLayout();
}
}
/**
* Gets or sets the options to be applied to a {@link TreeLayout}.
* By default this is null -- no properties are set on the TreeLayout
* other than the {@link TreeLayout#angle}, depending on {@link #vertical} and
* the result of calling {@link #directionFunction}.
*/
get topLeftOptions() { return this._topLeftOptions; }
set topLeftOptions(value) {
if (this._topLeftOptions !== value) {
this._topLeftOptions = value;
this.invalidateLayout();
}
}
/**
* @ignore
* Copies properties to a cloned Layout.
*/
cloneProtected(copy) {
super.cloneProtected(copy);
copy._vertical = this._vertical;
copy._directionFunction = this._directionFunction;
copy._bottomRightOptions = this._bottomRightOptions;
copy._topLeftOptions = this._topLeftOptions;
}
/**
* Perform two {@link TreeLayout}s by splitting the collection of Parts
* into two separate subsets but sharing only a single root Node.
* @param coll
*/
doLayout(coll) {
const coll2 = this.collectParts(coll);
if (coll2.count === 0)
return;
const diagram = this.diagram;
if (diagram !== null)
diagram.startTransaction("Double Tree Layout");
// split the nodes and links into two Sets, depending on direction
const leftParts = new go.Set();
const rightParts = new go.Set();
this.separatePartsForLayout(coll2, leftParts, rightParts);
// but the ROOT node will be in both collections
// create and perform two TreeLayouts, one in each direction,
// without moving the ROOT node, on the different subsets of nodes and links
const layout1 = this.createTreeLayout(false);
layout1.angle = this.vertical ? 270 : 180;
layout1.arrangement = go.TreeLayout.ArrangementFixedRoots;
const layout2 = this.createTreeLayout(true);
layout2.angle = this.vertical ? 90 : 0;
layout2.arrangement = go.TreeLayout.ArrangementFixedRoots;
layout1.doLayout(leftParts);
layout2.doLayout(rightParts);
if (diagram !== null)
diagram.commitTransaction("Double Tree Layout");
}
/**
* This just returns an instance of {@link TreeLayout}.
* The caller will set the {@link TreeLayout#angle}.
* @param {boolean} positive true for growth downward or rightward
* @return {TreeLayout}
*/
createTreeLayout(positive) {
const lay = new go.TreeLayout();
let opts = this.topLeftOptions;
if (positive)
opts = this.bottomRightOptions;
if (opts)
for (const p in opts) {
lay[p] = opts[p];
}
return lay;
}
/**
* This is called by {@link #doLayout} to split the collection of Nodes and Links into two Sets,
* one for the subtrees growing towards the left or upwards, and one for the subtrees
* growing towards the right or downwards.
*/
separatePartsForLayout(coll, leftParts, rightParts) {
let root = null; // the one root
const roots = new go.Set(); // in case there are multiple roots
coll.each(function (node) {
if (node instanceof go.Node && node.findTreeParentNode() === null)
roots.add(node);
});
if (roots.count === 0) { // just choose the first node as the root
const it = coll.iterator;
while (it.next()) {
if (it.value instanceof go.Node) {
root = it.value;
break;
}
}
}
else if (roots.count === 1) { // normal case: just one root node
root = roots.first();
}
else { // multiple root nodes -- create a dummy node to be the one real root
root = new go.Node(); // the new root node
root.location = new go.Point(0, 0);
const forwards = (this.diagram ? this.diagram.isTreePathToChildren : true);
// now make dummy links from the one root node to each node
roots.each(function (child) {
const link = new go.Link();
if (forwards) {
link.fromNode = root;
link.toNode = child;
}
else {
link.fromNode = child;
link.toNode = root;
}
});
}
if (root === null)
return;
// the ROOT node is shared by both subtrees
leftParts.add(root);
rightParts.add(root);
const lay = this;
// look at all of the immediate children of the ROOT node
root.findTreeChildrenNodes().each(function (child) {
// in what direction is this child growing?
const bottomright = lay.isPositiveDirection(child);
const parts = bottomright ? rightParts : leftParts;
// add the whole subtree starting with this child node
parts.addAll(child.findTreeParts());
// and also add the link from the ROOT node to this child node
const plink = child.findTreeParentLink();
if (plink !== null)
parts.add(plink);
});
}
/**
* This predicate is called on each child node of the root node,
* and only on immediate children of the root.
* It should return true if this child node is the root of a subtree that should grow
* rightwards or downwards, or false otherwise.
* @param {Node} child
* @returns {boolean} true if grows towards right or towards bottom; false otherwise
*/
isPositiveDirection(child) {
const f = this.directionFunction;
if (!f)
throw new Error("No DoubleTreeLayout.directionFunction supplied on the layout");
return f(child);
}
}