lib/network/modules/LayoutEngine.js
'use strict';
/**
* There's a mix-up with terms in the code. Following are the formal definitions:
*
* tree - a strict hierarchical network, i.e. every node has at most one parent
* forest - a collection of trees. These distinct trees are thus not connected.
*
* So:
* - in a network that is not a tree, there exist nodes with multiple parents.
* - a network consisting of unconnected sub-networks, of which at least one
* is not a tree, is not a forest.
*
* In the code, the definitions are:
*
* tree - any disconnected sub-network, strict hierarchical or not.
* forest - a bunch of these sub-networks
*
* The difference between tree and not-tree is important in the code, notably within
* to the block-shifting algorithm. The algorithm assumes formal trees and fails
* for not-trees, often in a spectacular manner (search for 'exploding network' in the issues).
*
* In order to distinguish the definitions in the following code, the adjective 'formal' is
* used. If 'formal' is absent, you must assume the non-formal definition.
*
* ----------------------------------------------------------------------------------
* NOTES
* =====
*
* A hierarchical layout is a different thing from a hierarchical network.
* The layout is a way to arrange the nodes in the view; this can be done
* on non-hierarchical networks as well. The converse is also possible.
*/
let util = require('../../util');
var NetworkUtil = require('../NetworkUtil').default;
var {HorizontalStrategy, VerticalStrategy} = require('./components/DirectionStrategy.js');
/**
* Container for derived data on current network, relating to hierarchy.
*
* @private
*/
class HierarchicalStatus {
/**
* @ignore
*/
constructor() {
this.childrenReference = {}; // child id's per node id
this.parentReference = {}; // parent id's per node id
this.trees = {}; // tree id per node id; i.e. to which tree does given node id belong
this.distributionOrdering = {}; // The nodes per level, in the display order
this.levels = {}; // hierarchy level per node id
this.distributionIndex = {}; // The position of the node in the level sorting order, per node id.
this.isTree = false; // True if current network is a formal tree
this.treeIndex = -1; // Highest tree id in current network.
}
/**
* Add the relation between given nodes to the current state.
*
* @param {Node.id} parentNodeId
* @param {Node.id} childNodeId
*/
addRelation(parentNodeId, childNodeId) {
if (this.childrenReference[parentNodeId] === undefined) {
this.childrenReference[parentNodeId] = [];
}
this.childrenReference[parentNodeId].push(childNodeId);
if (this.parentReference[childNodeId] === undefined) {
this.parentReference[childNodeId] = [];
}
this.parentReference[childNodeId].push(parentNodeId);
}
/**
* Check if the current state is for a formal tree or formal forest.
*
* This is the case if every node has at most one parent.
*
* Pre: parentReference init'ed properly for current network
*/
checkIfTree() {
for (let i in this.parentReference) {
if (this.parentReference[i].length > 1) {
this.isTree = false;
return;
}
}
this.isTree = true;
}
/**
* Return the number of separate trees in the current network.
* @returns {number}
*/
numTrees() {
return (this.treeIndex + 1); // This assumes the indexes are assigned consecitively
}
/**
* Assign a tree id to a node
* @param {Node} node
* @param {string|number} treeId
*/
setTreeIndex(node, treeId) {
if (treeId === undefined) return; // Don't bother
if (this.trees[node.id] === undefined) {
this.trees[node.id] = treeId;
this.treeIndex = Math.max(treeId, this.treeIndex);
}
}
/**
* Ensure level for given id is defined.
*
* Sets level to zero for given node id if not already present
*
* @param {Node.id} nodeId
*/
ensureLevel(nodeId) {
if (this.levels[nodeId] === undefined) {
this.levels[nodeId] = 0;
}
}
/**
* get the maximum level of a branch.
*
* TODO: Never entered; find a test case to test this!
* @param {Node.id} nodeId
* @returns {number}
*/
getMaxLevel(nodeId) {
let accumulator = {};
let _getMaxLevel = (nodeId) => {
if (accumulator[nodeId] !== undefined) {
return accumulator[nodeId];
}
let level = this.levels[nodeId];
if (this.childrenReference[nodeId]) {
let children = this.childrenReference[nodeId];
if (children.length > 0) {
for (let i = 0; i < children.length; i++) {
level = Math.max(level,_getMaxLevel(children[i]));
}
}
}
accumulator[nodeId] = level;
return level;
};
return _getMaxLevel(nodeId);
}
/**
*
* @param {Node} nodeA
* @param {Node} nodeB
*/
levelDownstream(nodeA, nodeB) {
if (this.levels[nodeB.id] === undefined) {
// set initial level
if (this.levels[nodeA.id] === undefined) {
this.levels[nodeA.id] = 0;
}
// set level
this.levels[nodeB.id] = this.levels[nodeA.id] + 1;
}
}
/**
* Small util method to set the minimum levels of the nodes to zero.
*
* @param {Array.<Node>} nodes
*/
setMinLevelToZero(nodes) {
let minLevel = 1e9;
// get the minimum level
for (let nodeId in nodes) {
if (nodes.hasOwnProperty(nodeId)) {
if (this.levels[nodeId] !== undefined) {
minLevel = Math.min(this.levels[nodeId], minLevel);
}
}
}
// subtract the minimum from the set so we have a range starting from 0
for (let nodeId in nodes) {
if (nodes.hasOwnProperty(nodeId)) {
if (this.levels[nodeId] !== undefined) {
this.levels[nodeId] -= minLevel;
}
}
}
}
/**
* Get the min and max xy-coordinates of a given tree
*
* @param {Array.<Node>} nodes
* @param {number} index
* @returns {{min_x: number, max_x: number, min_y: number, max_y: number}}
*/
getTreeSize(nodes, index) {
let min_x = 1e9;
let max_x = -1e9;
let min_y = 1e9;
let max_y = -1e9;
for (let nodeId in this.trees) {
if (this.trees.hasOwnProperty(nodeId)) {
if (this.trees[nodeId] === index) {
let node = nodes[nodeId];
min_x = Math.min(node.x, min_x);
max_x = Math.max(node.x, max_x);
min_y = Math.min(node.y, min_y);
max_y = Math.max(node.y, max_y);
}
}
}
return {
min_x: min_x,
max_x: max_x,
min_y: min_y,
max_y: max_y
};
}
/**
* Check if two nodes have the same parent(s)
*
* @param {Node} node1
* @param {Node} node2
* @return {boolean} true if the two nodes have a same ancestor node, false otherwise
*/
hasSameParent(node1, node2) {
let parents1 = this.parentReference[node1.id];
let parents2 = this.parentReference[node2.id];
if (parents1 === undefined || parents2 === undefined) {
return false;
}
for (let i = 0; i < parents1.length; i++) {
for (let j = 0; j < parents2.length; j++) {
if (parents1[i] == parents2[j]) {
return true;
}
}
}
return false;
}
/**
* Check if two nodes are in the same tree.
*
* @param {Node} node1
* @param {Node} node2
* @return {Boolean} true if this is so, false otherwise
*/
inSameSubNetwork(node1, node2) {
return (this.trees[node1.id] === this.trees[node2.id]);
}
/**
* Get a list of the distinct levels in the current network
*
* @returns {Array}
*/
getLevels() {
return Object.keys(this.distributionOrdering);
}
/**
* Add a node to the ordering per level
*
* @param {Node} node
* @param {number} level
*/
addToOrdering(node, level) {
if (this.distributionOrdering[level] === undefined) {
this.distributionOrdering[level] = [];
}
var isPresent = false;
var curLevel = this.distributionOrdering[level];
for (var n in curLevel) {
//if (curLevel[n].id === node.id) {
if (curLevel[n] === node) {
isPresent = true;
break;
}
}
if (!isPresent) {
this.distributionOrdering[level].push(node);
this.distributionIndex[node.id] = this.distributionOrdering[level].length - 1;
}
}
}
/**
* The Layout Engine
*/
class LayoutEngine {
/**
* @param {Object} body
*/
constructor(body) {
this.body = body;
this.initialRandomSeed = Math.round(Math.random() * 1000000);
this.randomSeed = this.initialRandomSeed;
this.setPhysics = false;
this.options = {};
this.optionsBackup = {physics:{}};
this.defaultOptions = {
randomSeed: undefined,
improvedLayout: true,
hierarchical: {
enabled:false,
levelSeparation: 150,
nodeSpacing: 100,
treeSpacing: 200,
blockShifting: true,
edgeMinimization: true,
parentCentralization: true,
direction: 'UD', // UD, DU, LR, RL
sortMethod: 'hubsize' // hubsize, directed
}
};
util.extend(this.options, this.defaultOptions);
this.bindEventListeners();
}
/**
* Binds event listeners
*/
bindEventListeners() {
this.body.emitter.on('_dataChanged', () => {
this.setupHierarchicalLayout();
});
this.body.emitter.on('_dataLoaded', () => {
this.layoutNetwork();
});
this.body.emitter.on('_resetHierarchicalLayout', () => {
this.setupHierarchicalLayout();
});
this.body.emitter.on('_adjustEdgesForHierarchicalLayout', () => {
if (this.options.hierarchical.enabled !== true) {
return;
}
// get the type of static smooth curve in case it is required
let type = this.direction.curveType();
// force all edges into static smooth curves.
this.body.emitter.emit('_forceDisableDynamicCurves', type, false);
});
}
/**
*
* @param {Object} options
* @param {Object} allOptions
* @returns {Object}
*/
setOptions(options, allOptions) {
if (options !== undefined) {
let hierarchical = this.options.hierarchical;
let prevHierarchicalState = hierarchical.enabled;
util.selectiveDeepExtend(["randomSeed", "improvedLayout"],this.options, options);
util.mergeOptions(this.options, options, 'hierarchical');
if (options.randomSeed !== undefined) {this.initialRandomSeed = options.randomSeed;}
if (hierarchical.enabled === true) {
if (prevHierarchicalState === true) {
// refresh the overridden options for nodes and edges.
this.body.emitter.emit('refresh', true);
}
// make sure the level separation is the right way up
if (hierarchical.direction === 'RL' || hierarchical.direction === 'DU') {
if (hierarchical.levelSeparation > 0) {
hierarchical.levelSeparation *= -1;
}
}
else {
if (hierarchical.levelSeparation < 0) {
hierarchical.levelSeparation *= -1;
}
}
this.setDirectionStrategy();
this.body.emitter.emit('_resetHierarchicalLayout');
// because the hierarchical system needs it's own physics and smooth curve settings,
// we adapt the other options if needed.
return this.adaptAllOptionsForHierarchicalLayout(allOptions);
}
else {
if (prevHierarchicalState === true) {
// refresh the overridden options for nodes and edges.
this.body.emitter.emit('refresh');
return util.deepExtend(allOptions,this.optionsBackup);
}
}
}
return allOptions;
}
/**
*
* @param {Object} allOptions
* @returns {Object}
*/
adaptAllOptionsForHierarchicalLayout(allOptions) {
if (this.options.hierarchical.enabled === true) {
let backupPhysics = this.optionsBackup.physics;
// set the physics
if (allOptions.physics === undefined || allOptions.physics === true) {
allOptions.physics = {
enabled: backupPhysics.enabled === undefined ? true : backupPhysics.enabled,
solver :'hierarchicalRepulsion'
};
backupPhysics.enabled = backupPhysics.enabled === undefined ? true : backupPhysics.enabled;
backupPhysics.solver = backupPhysics.solver || 'barnesHut';
}
else if (typeof allOptions.physics === 'object') {
backupPhysics.enabled = allOptions.physics.enabled === undefined ? true : allOptions.physics.enabled;
backupPhysics.solver = allOptions.physics.solver || 'barnesHut';
allOptions.physics.solver = 'hierarchicalRepulsion';
}
else if (allOptions.physics !== false) {
backupPhysics.solver ='barnesHut';
allOptions.physics = {solver:'hierarchicalRepulsion'};
}
// get the type of static smooth curve in case it is required
let type = this.direction.curveType();
// disable smooth curves if nothing is defined. If smooth curves have been turned on,
// turn them into static smooth curves.
if (allOptions.edges === undefined) {
this.optionsBackup.edges = {smooth:{enabled:true, type:'dynamic'}};
allOptions.edges = {smooth: false};
}
else if (allOptions.edges.smooth === undefined) {
this.optionsBackup.edges = {smooth:{enabled:true, type:'dynamic'}};
allOptions.edges.smooth = false;
}
else {
if (typeof allOptions.edges.smooth === 'boolean') {
this.optionsBackup.edges = {smooth:allOptions.edges.smooth};
allOptions.edges.smooth = {enabled: allOptions.edges.smooth, type:type}
}
else {
let smooth = allOptions.edges.smooth;
// allow custom types except for dynamic
if (smooth.type !== undefined && smooth.type !== 'dynamic') {
type = smooth.type;
}
// TODO: this is options merging; see if the standard routines can be used here.
this.optionsBackup.edges = {
smooth : smooth.enabled === undefined ? true : smooth.enabled,
type : smooth.type === undefined ? 'dynamic': smooth.type,
roundness : smooth.roundness === undefined ? 0.5 : smooth.roundness,
forceDirection: smooth.forceDirection === undefined ? false : smooth.forceDirection
};
// NOTE: Copying an object to self; this is basically setting defaults for undefined variables
allOptions.edges.smooth = {
enabled : smooth.enabled === undefined ? true : smooth.enabled,
type : type,
roundness : smooth.roundness === undefined ? 0.5 : smooth.roundness,
forceDirection: smooth.forceDirection === undefined ? false: smooth.forceDirection
}
}
}
// Force all edges into static smooth curves.
// Only applies to edges that do not use the global options for smooth.
this.body.emitter.emit('_forceDisableDynamicCurves', type);
}
return allOptions;
}
/**
*
* @returns {number}
*/
seededRandom() {
let x = Math.sin(this.randomSeed++) * 10000;
return x - Math.floor(x);
}
/**
*
* @param {Array.<Node>} nodesArray
*/
positionInitially(nodesArray) {
if (this.options.hierarchical.enabled !== true) {
this.randomSeed = this.initialRandomSeed;
let radius = nodesArray.length + 50;
for (let i = 0; i < nodesArray.length; i++) {
let node = nodesArray[i];
let angle = 2 * Math.PI * this.seededRandom();
if (node.x === undefined) {
node.x = radius * Math.cos(angle);
}
if (node.y === undefined) {
node.y = radius * Math.sin(angle);
}
}
}
}
/**
* Use Kamada Kawai to position nodes. This is quite a heavy algorithm so if there are a lot of nodes we
* cluster them first to reduce the amount.
*/
layoutNetwork() {
if (this.options.hierarchical.enabled !== true && this.options.improvedLayout === true) {
let indices = this.body.nodeIndices;
// first check if we should Kamada Kawai to layout. The threshold is if less than half of the visible
// nodes have predefined positions we use this.
let positionDefined = 0;
for (let i = 0; i < indices.length; i++) {
let node = this.body.nodes[indices[i]];
if (node.predefinedPosition === true) {
positionDefined += 1;
}
}
// if less than half of the nodes have a predefined position we continue
if (positionDefined < 0.5 * indices.length) {
let MAX_LEVELS = 10;
let level = 0;
let clusterThreshold = 150; // TODO add this to options
//
// Define the options for the hidden cluster nodes
// These options don't propagate outside the clustering phase.
//
// Some options are explicitly disabled, because they may be set in group or default node options.
// The clusters are never displayed, so most explicit settings here serve as performance optimizations.
//
// The explicit setting of 'shape' is to avoid `shape: 'image'`; images are not passed to the hidden
// cluster nodes, leading to an exception on creation.
//
// All settings here are performance related, except when noted otherwise.
//
let clusterOptions = {
clusterNodeProperties:{
shape: 'ellipse', // Bugfix: avoid type 'image', no images supplied
label: '', // avoid label handling
group: '', // avoid group handling
font: {multi: false}, // avoid font propagation
},
clusterEdgeProperties:{
label: '', // avoid label handling
font: {multi: false}, // avoid font propagation
smooth: {
enabled: false // avoid drawing penalty for complex edges
}
}
};
// if there are a lot of nodes, we cluster before we run the algorithm.
// NOTE: this part fails to find clusters for large scale-free networks, which should
// be easily clusterable.
// TODO: examine why this is so
if (indices.length > clusterThreshold) {
let startLength = indices.length;
while (indices.length > clusterThreshold && level <= MAX_LEVELS) {
//console.time("clustering")
level += 1;
let before = indices.length;
// if there are many nodes we do a hubsize cluster
if (level % 3 === 0) {
this.body.modules.clustering.clusterBridges(clusterOptions);
}
else {
this.body.modules.clustering.clusterOutliers(clusterOptions);
}
let after = indices.length;
if (before == after && level % 3 !== 0) {
this._declusterAll();
this.body.emitter.emit("_layoutFailed");
console.info("This network could not be positioned by this version of the improved layout algorithm."
+ " Please disable improvedLayout for better performance.");
return;
}
//console.timeEnd("clustering")
//console.log(before,level,after);
}
// increase the size of the edges
this.body.modules.kamadaKawai.setOptions({springLength: Math.max(150, 2 * startLength)})
}
if (level > MAX_LEVELS){
console.info("The clustering didn't succeed within the amount of interations allowed,"
+ " progressing with partial result.");
}
// position the system for these nodes and edges
this.body.modules.kamadaKawai.solve(indices, this.body.edgeIndices, true);
// shift to center point
this._shiftToCenter();
// perturb the nodes a little bit to force the physics to kick in
let offset = 70;
for (let i = 0; i < indices.length; i++) {
// Only perturb the nodes that aren't fixed
let node = this.body.nodes[indices[i]];
if (node.predefinedPosition === false) {
node.x += (0.5 - this.seededRandom())*offset;
node.y += (0.5 - this.seededRandom())*offset;
}
}
// uncluster all clusters
this._declusterAll();
// reposition all bezier nodes.
this.body.emitter.emit("_repositionBezierNodes");
}
}
}
/**
* Move all the nodes towards to the center so gravitational pull wil not move the nodes away from view
* @private
*/
_shiftToCenter() {
let range = NetworkUtil.getRangeCore(this.body.nodes, this.body.nodeIndices);
let center = NetworkUtil.findCenter(range);
for (let i = 0; i < this.body.nodeIndices.length; i++) {
let node = this.body.nodes[this.body.nodeIndices[i]];
node.x -= center.x;
node.y -= center.y;
}
}
/**
* Expands all clusters
* @private
*/
_declusterAll() {
let clustersPresent = true;
while (clustersPresent === true) {
clustersPresent = false;
for (let i = 0; i < this.body.nodeIndices.length; i++) {
if (this.body.nodes[this.body.nodeIndices[i]].isCluster === true) {
clustersPresent = true;
this.body.modules.clustering.openCluster(this.body.nodeIndices[i], {}, false);
}
}
if (clustersPresent === true) {
this.body.emitter.emit('_dataChanged');
}
}
}
/**
*
* @returns {number|*}
*/
getSeed() {
return this.initialRandomSeed;
}
/**
* This is the main function to layout the nodes in a hierarchical way.
* It checks if the node details are supplied correctly
*
* @private
*/
setupHierarchicalLayout() {
if (this.options.hierarchical.enabled === true && this.body.nodeIndices.length > 0) {
// get the size of the largest hubs and check if the user has defined a level for a node.
let node, nodeId;
let definedLevel = false;
let undefinedLevel = false;
this.lastNodeOnLevel = {};
this.hierarchical = new HierarchicalStatus();
for (nodeId in this.body.nodes) {
if (this.body.nodes.hasOwnProperty(nodeId)) {
node = this.body.nodes[nodeId];
if (node.options.level !== undefined) {
definedLevel = true;
this.hierarchical.levels[nodeId] = node.options.level;
}
else {
undefinedLevel = true;
}
}
}
// if the user defined some levels but not all, alert and run without hierarchical layout
if (undefinedLevel === true && definedLevel === true) {
throw new Error('To use the hierarchical layout, nodes require either no predefined levels'
+ ' or levels have to be defined for all nodes.');
}
else {
// define levels if undefined by the users. Based on hubsize.
if (undefinedLevel === true) {
let sortMethod = this.options.hierarchical.sortMethod;
if (sortMethod === 'hubsize') {
this._determineLevelsByHubsize();
}
else if (sortMethod === 'directed') {
this._determineLevelsDirected();
}
else if (sortMethod === 'custom') {
this._determineLevelsCustomCallback();
}
}
// fallback for cases where there are nodes but no edges
for (let nodeId in this.body.nodes) {
if (this.body.nodes.hasOwnProperty(nodeId)) {
this.hierarchical.ensureLevel(nodeId);
}
}
// check the distribution of the nodes per level.
let distribution = this._getDistribution();
// get the parent children relations.
this._generateMap();
// place the nodes on the canvas.
this._placeNodesByHierarchy(distribution);
// condense the whitespace.
this._condenseHierarchy();
// shift to center so gravity does not have to do much
this._shiftToCenter();
}
}
}
/**
* @private
*/
_condenseHierarchy() {
// Global var in this scope to define when the movement has stopped.
let stillShifting = false;
let branches = {};
// first we have some methods to help shifting trees around.
// the main method to shift the trees
let shiftTrees = () => {
let treeSizes = getTreeSizes();
let shiftBy = 0;
for (let i = 0; i < treeSizes.length - 1; i++) {
let diff = treeSizes[i].max - treeSizes[i+1].min;
shiftBy += diff + this.options.hierarchical.treeSpacing;
shiftTree(i + 1, shiftBy);
}
};
// shift a single tree by an offset
let shiftTree = (index, offset) => {
let trees = this.hierarchical.trees;
for (let nodeId in trees) {
if (trees.hasOwnProperty(nodeId)) {
if (trees[nodeId] === index) {
this.direction.shift(nodeId, offset);
}
}
}
};
// get the width of all trees
let getTreeSizes = () => {
let treeWidths = [];
for (let i = 0; i < this.hierarchical.numTrees(); i++) {
treeWidths.push(this.direction.getTreeSize(i));
}
return treeWidths;
};
// get a map of all nodes in this branch
let getBranchNodes = (source, map) => {
if (map[source.id]) {
return;
}
map[source.id] = true;
if (this.hierarchical.childrenReference[source.id]) {
let children = this.hierarchical.childrenReference[source.id];
if (children.length > 0) {
for (let i = 0; i < children.length; i++) {
getBranchNodes(this.body.nodes[children[i]], map);
}
}
}
};
// get a min max width as well as the maximum movement space it has on either sides
// we use min max terminology because width and height can interchange depending on the direction of the layout
let getBranchBoundary = (branchMap, maxLevel = 1e9) => {
let minSpace = 1e9;
let maxSpace = 1e9;
let min = 1e9;
let max = -1e9;
for (let branchNode in branchMap) {
if (branchMap.hasOwnProperty(branchNode)) {
let node = this.body.nodes[branchNode];
let level = this.hierarchical.levels[node.id];
let position = this.direction.getPosition(node);
// get the space around the node.
let [minSpaceNode, maxSpaceNode] = this._getSpaceAroundNode(node,branchMap);
minSpace = Math.min(minSpaceNode, minSpace);
maxSpace = Math.min(maxSpaceNode, maxSpace);
// the width is only relevant for the levels two nodes have in common. This is why we filter on this.
if (level <= maxLevel) {
min = Math.min(position, min);
max = Math.max(position, max);
}
}
}
return [min, max, minSpace, maxSpace];
}
// check what the maximum level is these nodes have in common.
let getCollisionLevel = (node1, node2) => {
let maxLevel1 = this.hierarchical.getMaxLevel(node1.id);
let maxLevel2 = this.hierarchical.getMaxLevel(node2.id);
return Math.min(maxLevel1, maxLevel2);
};
/**
* Condense elements. These can be nodes or branches depending on the callback.
*
* @param {function} callback
* @param {Array.<number>} levels
* @param {*} centerParents
*/
let shiftElementsCloser = (callback, levels, centerParents) => {
let hier = this.hierarchical;
for (let i = 0; i < levels.length; i++) {
let level = levels[i];
let levelNodes = hier.distributionOrdering[level];
if (levelNodes.length > 1) {
for (let j = 0; j < levelNodes.length - 1; j++) {
let node1 = levelNodes[j];
let node2 = levelNodes[j+1];
// NOTE: logic maintained as it was; if nodes have same ancestor,
// then of course they are in the same sub-network.
if (hier.hasSameParent(node1, node2) && hier.inSameSubNetwork(node1, node2) ) {
callback(node1, node2, centerParents);
}
}
}
}
};
// callback for shifting branches
let branchShiftCallback = (node1, node2, centerParent = false) => {
//window.CALLBACKS.push(() => {
let pos1 = this.direction.getPosition(node1);
let pos2 = this.direction.getPosition(node2);
let diffAbs = Math.abs(pos2 - pos1);
let nodeSpacing = this.options.hierarchical.nodeSpacing;
//console.log("NOW CHECKING:", node1.id, node2.id, diffAbs);
if (diffAbs > nodeSpacing) {
let branchNodes1 = {};
let branchNodes2 = {};
getBranchNodes(node1, branchNodes1);
getBranchNodes(node2, branchNodes2);
// check the largest distance between the branches
let maxLevel = getCollisionLevel(node1, node2);
let branchNodeBoundary1 = getBranchBoundary(branchNodes1, maxLevel);
let branchNodeBoundary2 = getBranchBoundary(branchNodes2, maxLevel);
let max1 = branchNodeBoundary1[1];
let min2 = branchNodeBoundary2[0];
let minSpace2 = branchNodeBoundary2[2];
//console.log(node1.id, getBranchBoundary(branchNodes1, maxLevel), node2.id,
// getBranchBoundary(branchNodes2, maxLevel), maxLevel);
let diffBranch = Math.abs(max1 - min2);
if (diffBranch > nodeSpacing) {
let offset = max1 - min2 + nodeSpacing;
if (offset < -minSpace2 + nodeSpacing) {
offset = -minSpace2 + nodeSpacing;
//console.log("RESETTING OFFSET", max1 - min2 + this.options.hierarchical.nodeSpacing, -minSpace2, offset);
}
if (offset < 0) {
//console.log("SHIFTING", node2.id, offset);
this._shiftBlock(node2.id, offset);
stillShifting = true;
if (centerParent === true)
this._centerParent(node2);
}
}
}
//this.body.emitter.emit("_redraw");})
};
let minimizeEdgeLength = (iterations, node) => {
//window.CALLBACKS.push(() => {
// console.log("ts",node.id);
let nodeId = node.id;
let allEdges = node.edges;
let nodeLevel = this.hierarchical.levels[node.id];
// gather constants
let C2 = this.options.hierarchical.levelSeparation * this.options.hierarchical.levelSeparation;
let referenceNodes = {};
let aboveEdges = [];
for (let i = 0; i < allEdges.length; i++) {
let edge = allEdges[i];
if (edge.toId != edge.fromId) {
let otherNode = edge.toId == nodeId ? edge.from : edge.to;
referenceNodes[allEdges[i].id] = otherNode;
if (this.hierarchical.levels[otherNode.id] < nodeLevel) {
aboveEdges.push(edge);
}
}
}
// differentiated sum of lengths based on only moving one node over one axis
let getFx = (point, edges) => {
let sum = 0;
for (let i = 0; i < edges.length; i++) {
if (referenceNodes[edges[i].id] !== undefined) {
let a = this.direction.getPosition(referenceNodes[edges[i].id]) - point;
sum += a / Math.sqrt(a * a + C2);
}
}
return sum;
};
// doubly differentiated sum of lengths based on only moving one node over one axis
let getDFx = (point, edges) => {
let sum = 0;
for (let i = 0; i < edges.length; i++) {
if (referenceNodes[edges[i].id] !== undefined) {
let a = this.direction.getPosition(referenceNodes[edges[i].id]) - point;
sum -= (C2 * Math.pow(a * a + C2, -1.5));
}
}
return sum;
};
let getGuess = (iterations, edges) => {
let guess = this.direction.getPosition(node);
// Newton's method for optimization
let guessMap = {};
for (let i = 0; i < iterations; i++) {
let fx = getFx(guess, edges);
let dfx = getDFx(guess, edges);
// we limit the movement to avoid instability.
let limit = 40;
let ratio = Math.max(-limit, Math.min(limit, Math.round(fx/dfx)));
guess = guess - ratio;
// reduce duplicates
if (guessMap[guess] !== undefined) {
break;
}
guessMap[guess] = i;
}
return guess;
};
let moveBranch = (guess) => {
// position node if there is space
let nodePosition = this.direction.getPosition(node);
// check movable area of the branch
if (branches[node.id] === undefined) {
let branchNodes = {};
getBranchNodes(node, branchNodes);
branches[node.id] = branchNodes;
}
let branchBoundary = getBranchBoundary(branches[node.id]);
let minSpaceBranch = branchBoundary[2];
let maxSpaceBranch = branchBoundary[3];
let diff = guess - nodePosition;
// check if we are allowed to move the node:
let branchOffset = 0;
if (diff > 0) {
branchOffset = Math.min(diff, maxSpaceBranch - this.options.hierarchical.nodeSpacing);
}
else if (diff < 0) {
branchOffset = -Math.min(-diff, minSpaceBranch - this.options.hierarchical.nodeSpacing);
}
if (branchOffset != 0) {
//console.log("moving branch:",branchOffset, maxSpaceBranch, minSpaceBranch)
this._shiftBlock(node.id, branchOffset);
//this.body.emitter.emit("_redraw");
stillShifting = true;
}
};
let moveNode = (guess) => {
let nodePosition = this.direction.getPosition(node);
// position node if there is space
let [minSpace, maxSpace] = this._getSpaceAroundNode(node);
let diff = guess - nodePosition;
// check if we are allowed to move the node:
let newPosition = nodePosition;
if (diff > 0) {
newPosition = Math.min(nodePosition + (maxSpace - this.options.hierarchical.nodeSpacing), guess);
}
else if (diff < 0) {
newPosition = Math.max(nodePosition - (minSpace - this.options.hierarchical.nodeSpacing), guess);
}
if (newPosition !== nodePosition) {
//console.log("moving Node:",diff, minSpace, maxSpace);
this.direction.setPosition(node, newPosition);
//this.body.emitter.emit("_redraw");
stillShifting = true;
}
};
let guess = getGuess(iterations, aboveEdges);
moveBranch(guess);
guess = getGuess(iterations, allEdges);
moveNode(guess);
//})
};
// method to remove whitespace between branches. Because we do bottom up, we can center the parents.
let minimizeEdgeLengthBottomUp = (iterations) => {
let levels = this.hierarchical.getLevels();
levels = levels.reverse();
for (let i = 0; i < iterations; i++) {
stillShifting = false;
for (let j = 0; j < levels.length; j++) {
let level = levels[j];
let levelNodes = this.hierarchical.distributionOrdering[level];
for (let k = 0; k < levelNodes.length; k++) {
minimizeEdgeLength(1000, levelNodes[k]);
}
}
if (stillShifting !== true) {
//console.log("FINISHED minimizeEdgeLengthBottomUp IN " + i);
break;
}
}
};
// method to remove whitespace between branches. Because we do bottom up, we can center the parents.
let shiftBranchesCloserBottomUp = (iterations) => {
let levels = this.hierarchical.getLevels();
levels = levels.reverse();
for (let i = 0; i < iterations; i++) {
stillShifting = false;
shiftElementsCloser(branchShiftCallback, levels, true);
if (stillShifting !== true) {
//console.log("FINISHED shiftBranchesCloserBottomUp IN " + (i+1));
break;
}
}
};
// center all parents
let centerAllParents = () => {
for (let nodeId in this.body.nodes) {
if (this.body.nodes.hasOwnProperty(nodeId))
this._centerParent(this.body.nodes[nodeId]);
}
};
// center all parents
let centerAllParentsBottomUp = () => {
let levels = this.hierarchical.getLevels();
levels = levels.reverse();
for (let i = 0; i < levels.length; i++) {
let level = levels[i];
let levelNodes = this.hierarchical.distributionOrdering[level];
for (let j = 0; j < levelNodes.length; j++) {
this._centerParent(levelNodes[j]);
}
}
};
// the actual work is done here.
if (this.options.hierarchical.blockShifting === true) {
shiftBranchesCloserBottomUp(5);
centerAllParents();
}
// minimize edge length
if (this.options.hierarchical.edgeMinimization === true) {
minimizeEdgeLengthBottomUp(20);
}
if (this.options.hierarchical.parentCentralization === true) {
centerAllParentsBottomUp()
}
shiftTrees();
}
/**
* This gives the space around the node. IF a map is supplied, it will only check against nodes NOT in the map.
* This is used to only get the distances to nodes outside of a branch.
* @param {Node} node
* @param {{Node.id: vis.Node}} map
* @returns {number[]}
* @private
*/
_getSpaceAroundNode(node, map) {
let useMap = true;
if (map === undefined) {
useMap = false;
}
let level = this.hierarchical.levels[node.id];
if (level !== undefined) {
let index = this.hierarchical.distributionIndex[node.id];
let position = this.direction.getPosition(node);
let ordering = this.hierarchical.distributionOrdering[level];
let minSpace = 1e9;
let maxSpace = 1e9;
if (index !== 0) {
let prevNode = ordering[index - 1];
if ((useMap === true && map[prevNode.id] === undefined) || useMap === false) {
let prevPos = this.direction.getPosition(prevNode);
minSpace = position - prevPos;
}
}
if (index != ordering.length - 1) {
let nextNode = ordering[index + 1];
if ((useMap === true && map[nextNode.id] === undefined) || useMap === false) {
let nextPos = this.direction.getPosition(nextNode);
maxSpace = Math.min(maxSpace, nextPos - position);
}
}
return [minSpace, maxSpace];
}
else {
return [0, 0];
}
}
/**
* We use this method to center a parent node and check if it does not cross other nodes when it does.
* @param {Node} node
* @private
*/
_centerParent(node) {
if (this.hierarchical.parentReference[node.id]) {
let parents = this.hierarchical.parentReference[node.id];
for (var i = 0; i < parents.length; i++) {
let parentId = parents[i];
let parentNode = this.body.nodes[parentId];
let children = this.hierarchical.childrenReference[parentId];
if (children !== undefined) {
// get the range of the children
let newPosition = this._getCenterPosition(children);
let position = this.direction.getPosition(parentNode);
let [minSpace, maxSpace] = this._getSpaceAroundNode(parentNode);
let diff = position - newPosition;
if ((diff < 0 && Math.abs(diff) < maxSpace - this.options.hierarchical.nodeSpacing) ||
(diff > 0 && Math.abs(diff) < minSpace - this.options.hierarchical.nodeSpacing)) {
this.direction.setPosition(parentNode, newPosition);
}
}
}
}
}
/**
* This function places the nodes on the canvas based on the hierarchial distribution.
*
* @param {Object} distribution | obtained by the function this._getDistribution()
* @private
*/
_placeNodesByHierarchy(distribution) {
this.positionedNodes = {};
// start placing all the level 0 nodes first. Then recursively position their branches.
for (let level in distribution) {
if (distribution.hasOwnProperty(level)) {
// sort nodes in level by position:
let nodeArray = Object.keys(distribution[level]);
nodeArray = this._indexArrayToNodes(nodeArray);
this.direction.sort(nodeArray);
let handledNodeCount = 0;
for (let i = 0; i < nodeArray.length; i++) {
let node = nodeArray[i];
if (this.positionedNodes[node.id] === undefined) {
let spacing = this.options.hierarchical.nodeSpacing;
let pos = spacing * handledNodeCount;
// We get the X or Y values we need and store them in pos and previousPos.
// The get and set make sure we get X or Y
if (handledNodeCount > 0) {
pos = this.direction.getPosition(nodeArray[i-1]) + spacing;
}
this.direction.setPosition(node, pos, level);
this._validatePositionAndContinue(node, level, pos);
handledNodeCount++;
}
}
}
}
}
/**
* This is a recursively called function to enumerate the branches from the largest hubs and place the nodes
* on a X position that ensures there will be no overlap.
*
* @param {Node.id} parentId
* @param {number} parentLevel
* @private
*/
_placeBranchNodes(parentId, parentLevel) {
let childRef = this.hierarchical.childrenReference[parentId];
// if this is not a parent, cancel the placing. This can happen with multiple parents to one child.
if (childRef === undefined) {
return;
}
// get a list of childNodes
let childNodes = [];
for (let i = 0; i < childRef.length; i++) {
childNodes.push(this.body.nodes[childRef[i]]);
}
// use the positions to order the nodes.
this.direction.sort(childNodes);
// position the childNodes
for (let i = 0; i < childNodes.length; i++) {
let childNode = childNodes[i];
let childNodeLevel = this.hierarchical.levels[childNode.id];
// check if the child node is below the parent node and if it has already been positioned.
if (childNodeLevel > parentLevel && this.positionedNodes[childNode.id] === undefined) {
// get the amount of space required for this node. If parent the width is based on the amount of children.
let spacing = this.options.hierarchical.nodeSpacing;
let pos;
// we get the X or Y values we need and store them in pos and previousPos.
// The get and set make sure we get X or Y
if (i === 0) {
pos = this.direction.getPosition(this.body.nodes[parentId]);
} else {
pos = this.direction.getPosition(childNodes[i-1]) + spacing;
}
this.direction.setPosition(childNode, pos, childNodeLevel);
this._validatePositionAndContinue(childNode, childNodeLevel, pos);
}
else {
return;
}
}
// center the parent nodes.
let center = this._getCenterPosition(childNodes);
this.direction.setPosition(this.body.nodes[parentId], center, parentLevel);
}
/**
* This method checks for overlap and if required shifts the branch. It also keeps records of positioned nodes.
* Finally it will call _placeBranchNodes to place the branch nodes.
* @param {Node} node
* @param {number} level
* @param {number} pos
* @private
*/
_validatePositionAndContinue(node, level, pos) {
// This method only works for formal trees and formal forests
// Early exit if this is not the case
if (!this.hierarchical.isTree) return;
// if overlap has been detected, we shift the branch
if (this.lastNodeOnLevel[level] !== undefined) {
let previousPos = this.direction.getPosition(this.body.nodes[this.lastNodeOnLevel[level]]);
if (pos - previousPos < this.options.hierarchical.nodeSpacing) {
let diff = (previousPos + this.options.hierarchical.nodeSpacing) - pos;
let sharedParent = this._findCommonParent(this.lastNodeOnLevel[level], node.id);
this._shiftBlock(sharedParent.withChild, diff);
}
}
this.lastNodeOnLevel[level] = node.id; // store change in position.
this.positionedNodes[node.id] = true;
this._placeBranchNodes(node.id, level);
}
/**
* Receives an array with node indices and returns an array with the actual node references.
* Used for sorting based on node properties.
* @param {Array.<Node.id>} idArray
* @returns {Array.<Node>}
*/
_indexArrayToNodes(idArray) {
let array = [];
for (let i = 0; i < idArray.length; i++) {
array.push(this.body.nodes[idArray[i]])
}
return array;
}
/**
* This function get the distribution of levels based on hubsize
*
* @returns {Object}
* @private
*/
_getDistribution() {
let distribution = {};
let nodeId, node;
// we fix Y because the hierarchy is vertical,
// we fix X so we do not give a node an x position for a second time.
// the fix of X is removed after the x value has been set.
for (nodeId in this.body.nodes) {
if (this.body.nodes.hasOwnProperty(nodeId)) {
node = this.body.nodes[nodeId];
let level = this.hierarchical.levels[nodeId] === undefined ? 0 : this.hierarchical.levels[nodeId];
this.direction.fix(node, level);
if (distribution[level] === undefined) {
distribution[level] = {};
}
distribution[level][nodeId] = node;
}
}
return distribution;
}
/**
* Return the active (i.e. visible) edges for this node
*
* @param {Node} node
* @returns {Array.<vis.Edge>} Array of edge instances
* @private
*/
_getActiveEdges(node) {
let result = [];
util.forEach(node.edges, (edge) => {
if (this.body.edgeIndices.indexOf(edge.id) !== -1) {
result.push(edge);
}
});
return result;
}
/**
* Get the hubsizes for all active nodes.
*
* @returns {number}
* @private
*/
_getHubSizes() {
let hubSizes = {};
let nodeIds = this.body.nodeIndices;
util.forEach(nodeIds, (nodeId) => {
let node = this.body.nodes[nodeId];
let hubSize = this._getActiveEdges(node).length;
hubSizes[hubSize] = true;
});
// Make an array of the size sorted descending
let result = [];
util.forEach(hubSizes, (size) => {
result.push(Number(size));
});
result.sort(function(a, b) {
return b - a;
});
return result;
}
/**
* this function allocates nodes in levels based on the recursive branching from the largest hubs.
*
* @private
*/
_determineLevelsByHubsize() {
let levelDownstream = (nodeA, nodeB) => {
this.hierarchical.levelDownstream(nodeA, nodeB);
}
let hubSizes = this._getHubSizes();
for (let i = 0; i < hubSizes.length; ++i ) {
let hubSize = hubSizes[i];
if (hubSize === 0) break;
util.forEach(this.body.nodeIndices, (nodeId) => {
let node = this.body.nodes[nodeId];
if (hubSize === this._getActiveEdges(node).length) {
this._crawlNetwork(levelDownstream, nodeId);
}
});
}
}
/**
* TODO: release feature
* TODO: Determine if this feature is needed at all
*
* @private
*/
_determineLevelsCustomCallback() {
let minLevel = 100000;
// TODO: this should come from options.
let customCallback = function(nodeA, nodeB, edge) { // eslint-disable-line no-unused-vars
};
// TODO: perhaps move to HierarchicalStatus.
// But I currently don't see the point, this method is not used.
let levelByDirection = (nodeA, nodeB, edge) => {
let levelA = this.hierarchical.levels[nodeA.id];
// set initial level
if (levelA === undefined) { levelA = this.hierarchical.levels[nodeA.id] = minLevel;}
let diff = customCallback(
NetworkUtil.cloneOptions(nodeA,'node'),
NetworkUtil.cloneOptions(nodeB,'node'),
NetworkUtil.cloneOptions(edge,'edge')
);
this.hierarchical.levels[nodeB.id] = levelA + diff;
};
this._crawlNetwork(levelByDirection);
this.hierarchical.setMinLevelToZero(this.body.nodes);
}
/**
* Allocate nodes in levels based on the direction of the edges.
*
* @private
*/
_determineLevelsDirected() {
let minLevel = 10000;
/**
* Check if there is an edge going the opposite direction for given edge
*
* @param {Edge} edge edge to check
* @returns {boolean} true if there's another edge going into the opposite direction
*/
let isBidirectional = (edge) => {
util.forEach(this.body.edges, (otherEdge) => {
if (otherEdge.toId === edge.fromId && otherEdge.fromId === edge.toId) {
return true;
}
});
return false;
};
let levelByDirection = (nodeA, nodeB, edge) => {
let levelA = this.hierarchical.levels[nodeA.id];
let levelB = this.hierarchical.levels[nodeB.id];
if (isBidirectional(edge) && levelA !== undefined && levelB !== undefined) {
// Don't redo the level determination if already done in this case.
return;
}
// set initial level
if (levelA === undefined) { levelA = this.hierarchical.levels[nodeA.id] = minLevel;}
if (edge.toId == nodeB.id) {
this.hierarchical.levels[nodeB.id] = levelA + 1;
}
else {
this.hierarchical.levels[nodeB.id] = levelA - 1;
}
};
this._crawlNetwork(levelByDirection);
this.hierarchical.setMinLevelToZero(this.body.nodes);
}
/**
* Update the bookkeeping of parent and child.
* @private
*/
_generateMap() {
let fillInRelations = (parentNode, childNode) => {
if (this.hierarchical.levels[childNode.id] > this.hierarchical.levels[parentNode.id]) {
this.hierarchical.addRelation(parentNode.id, childNode.id);
}
};
this._crawlNetwork(fillInRelations);
this.hierarchical.checkIfTree();
}
/**
* Crawl over the entire network and use a callback on each node couple that is connected to each other.
* @param {function} [callback=function(){}] | will receive nodeA, nodeB and the connecting edge. A and B are distinct.
* @param {Node.id} startingNodeId
* @private
*/
_crawlNetwork(callback = function() {}, startingNodeId) {
let progress = {};
let crawler = (node, tree) => {
if (progress[node.id] === undefined) {
this.hierarchical.setTreeIndex(node, tree);
progress[node.id] = true;
let childNode;
let edges = this._getActiveEdges(node);
for (let i = 0; i < edges.length; i++) {
let edge = edges[i];
if (edge.connected === true) {
if (edge.toId == node.id) { // Not '===' because id's can be string and numeric
childNode = edge.from;
}
else {
childNode = edge.to;
}
if (node.id != childNode.id) { // Not '!==' because id's can be string and numeric
callback(node, childNode, edge);
crawler(childNode, tree);
}
}
}
}
};
if (startingNodeId === undefined) {
// Crawl over all nodes
let treeIndex = 0; // Serves to pass a unique id for the current distinct tree
for (let i = 0; i < this.body.nodeIndices.length; i++) {
let nodeId = this.body.nodeIndices[i];
if (progress[nodeId] === undefined) {
let node = this.body.nodes[nodeId];
crawler(node, treeIndex);
treeIndex += 1;
}
}
}
else {
// Crawl from the given starting node
let node = this.body.nodes[startingNodeId];
if (node === undefined) {
console.error("Node not found:", startingNodeId);
return;
}
crawler(node);
}
}
/**
* Shift a branch a certain distance
* @param {Node.id} parentId
* @param {number} diff
* @private
*/
_shiftBlock(parentId, diff) {
let progress = {};
let shifter = (parentId) => {
if (progress[parentId]) {
return;
}
progress[parentId] = true;
this.direction.shift(parentId, diff);
let childRef = this.hierarchical.childrenReference[parentId];
if (childRef !== undefined) {
for (let i = 0; i < childRef.length; i++) {
shifter(childRef[i]);
}
}
};
shifter(parentId);
}
/**
* Find a common parent between branches.
* @param {Node.id} childA
* @param {Node.id} childB
* @returns {{foundParent, withChild}}
* @private
*/
_findCommonParent(childA,childB) {
let parents = {};
let iterateParents = (parents,child) => {
let parentRef = this.hierarchical.parentReference[child];
if (parentRef !== undefined) {
for (let i = 0; i < parentRef.length; i++) {
let parent = parentRef[i];
parents[parent] = true;
iterateParents(parents, parent)
}
}
};
let findParent = (parents, child) => {
let parentRef = this.hierarchical.parentReference[child];
if (parentRef !== undefined) {
for (let i = 0; i < parentRef.length; i++) {
let parent = parentRef[i];
if (parents[parent] !== undefined) {
return {foundParent:parent, withChild:child};
}
let branch = findParent(parents, parent);
if (branch.foundParent !== null) {
return branch;
}
}
}
return {foundParent:null, withChild:child};
};
iterateParents(parents, childA);
return findParent(parents, childB);
}
/**
* Set the strategy pattern for handling the coordinates given the current direction.
*
* The individual instances contain all the operations and data specific to a layout direction.
*
* @param {Node} node
* @param {{x: number, y: number}} position
* @param {number} level
* @param {boolean} [doNotUpdate=false]
* @private
*/
setDirectionStrategy() {
var isVertical = (this.options.hierarchical.direction === 'UD'
|| this.options.hierarchical.direction === 'DU');
if(isVertical) {
this.direction = new VerticalStrategy(this);
} else {
this.direction = new HorizontalStrategy(this);
}
}
/**
* Determine the center position of a branch from the passed list of child nodes
*
* This takes into account the positions of all the child nodes.
* @param {Array.<Node|vis.Node.id>} childNodes Array of either child nodes or node id's
* @return {number}
* @private
*/
_getCenterPosition(childNodes) {
let minPos = 1e9;
let maxPos = -1e9;
for (let i = 0; i < childNodes.length; i++) {
let childNode;
if (childNodes[i].id !== undefined) {
childNode = childNodes[i];
} else {
let childNodeId = childNodes[i];
childNode = this.body.nodes[childNodeId];
}
let position = this.direction.getPosition(childNode);
minPos = Math.min(minPos, position);
maxPos = Math.max(maxPos, position);
}
return 0.5 * (minPos + maxPos);
}
}
export default LayoutEngine;