link map WIP

libraries/springy.js

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+/**
+ * Springy v2.7.1
+ *
+ * Copyright (c) 2010-2013 Dennis Hotson
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+(function (root, factory) {
+    if (typeof define === 'function' && define.amd) {
+        // AMD. Register as an anonymous module.
+        define(function () {
+            return (root.returnExportsGlobal = factory());
+        });
+    } else if (typeof exports === 'object') {
+        // Node. Does not work with strict CommonJS, but
+        // only CommonJS-like enviroments that support module.exports,
+        // like Node.
+        module.exports = factory();
+    } else {
+        // Browser globals
+        root.Springy = factory();
+    }
+}(this, function() {
+
+	var Springy = {};
+
+	var Graph = Springy.Graph = function() {
+		this.nodeSet = {};
+		this.nodes = [];
+		this.edges = [];
+		this.adjacency = {};
+
+		this.nextNodeId = 0;
+		this.nextEdgeId = 0;
+		this.eventListeners = [];
+	};
+
+	var Node = Springy.Node = function(id, data) {
+		this.id = id;
+		this.data = (data !== undefined) ? data : {};
+
+	// Data fields used by layout algorithm in this file:
+	// this.data.mass
+	// Data used by default renderer in springyui.js
+	// this.data.label
+	};
+
+	var Edge = Springy.Edge = function(id, source, target, data) {
+		this.id = id;
+		this.source = source;
+		this.target = target;
+		this.data = (data !== undefined) ? data : {};
+
+	// Edge data field used by layout alorithm
+	// this.data.length
+	// this.data.type
+	};
+
+	Graph.prototype.addNode = function(node) {
+		if (!(node.id in this.nodeSet)) {
+			this.nodes.push(node);
+		}
+
+		this.nodeSet[node.id] = node;
+
+		this.notify();
+		return node;
+	};
+
+	Graph.prototype.addNodes = function() {
+		// accepts variable number of arguments, where each argument
+		// is a string that becomes both node identifier and label
+		for (var i = 0; i < arguments.length; i++) {
+			var name = arguments[i];
+			var node = new Node(name, {label:name});
+			this.addNode(node);
+		}
+	};
+
+	Graph.prototype.addEdge = function(edge) {
+		var exists = false;
+		this.edges.forEach(function(e) {
+			if (edge.id === e.id) { exists = true; }
+		});
+
+		if (!exists) {
+			this.edges.push(edge);
+		}
+
+		if (!(edge.source.id in this.adjacency)) {
+			this.adjacency[edge.source.id] = {};
+		}
+		if (!(edge.target.id in this.adjacency[edge.source.id])) {
+			this.adjacency[edge.source.id][edge.target.id] = [];
+		}
+
+		exists = false;
+		this.adjacency[edge.source.id][edge.target.id].forEach(function(e) {
+				if (edge.id === e.id) { exists = true; }
+		});
+
+		if (!exists) {
+			this.adjacency[edge.source.id][edge.target.id].push(edge);
+		}
+
+		this.notify();
+		return edge;
+	};
+
+	Graph.prototype.addEdges = function() {
+		// accepts variable number of arguments, where each argument
+		// is a triple [nodeid1, nodeid2, attributes]
+		for (var i = 0; i < arguments.length; i++) {
+			var e = arguments[i];
+			var node1 = this.nodeSet[e[0]];
+			if (node1 == undefined) {
+				throw new TypeError("invalid node name: " + e[0]);
+			}
+			var node2 = this.nodeSet[e[1]];
+			if (node2 == undefined) {
+				throw new TypeError("invalid node name: " + e[1]);
+			}
+			var attr = e[2];
+
+			this.newEdge(node1, node2, attr);
+		}
+	};
+
+	Graph.prototype.newNode = function(data) {
+		var node = new Node(this.nextNodeId++, data);
+		this.addNode(node);
+		return node;
+	};
+
+	Graph.prototype.newEdge = function(source, target, data) {
+		var edge = new Edge(this.nextEdgeId++, source, target, data);
+		this.addEdge(edge);
+		return edge;
+	};
+
+
+	// add nodes and edges from JSON object
+	Graph.prototype.loadJSON = function(json) {
+	/**
+	Springy's simple JSON format for graphs.
+
+	historically, Springy uses separate lists
+	of nodes and edges:
+
+		{
+			"nodes": [
+				"center",
+				"left",
+				"right",
+				"up",
+				"satellite"
+			],
+			"edges": [
+				["center", "left"],
+				["center", "right"],
+				["center", "up"]
+			]
+		}
+
+	**/
+		// parse if a string is passed (EC5+ browsers)
+		if (typeof json == 'string' || json instanceof String) {
+			json = JSON.parse( json );
+		}
+
+		if ('nodes' in json || 'edges' in json) {
+			this.addNodes.apply(this, json['nodes']);
+			this.addEdges.apply(this, json['edges']);
+		}
+	}
+
+
+	// find the edges from node1 to node2
+	Graph.prototype.getEdges = function(node1, node2) {
+		if (node1.id in this.adjacency
+			&& node2.id in this.adjacency[node1.id]) {
+			return this.adjacency[node1.id][node2.id];
+		}
+
+		return [];
+	};
+
+	// remove a node and it's associated edges from the graph
+	Graph.prototype.removeNode = function(node) {
+		if (node.id in this.nodeSet) {
+			delete this.nodeSet[node.id];
+		}
+
+		for (var i = this.nodes.length - 1; i >= 0; i--) {
+			if (this.nodes[i].id === node.id) {
+				this.nodes.splice(i, 1);
+			}
+		}
+
+		this.detachNode(node);
+	};
+
+	// removes edges associated with a given node
+	Graph.prototype.detachNode = function(node) {
+		var tmpEdges = this.edges.slice();
+		tmpEdges.forEach(function(e) {
+			if (e.source.id === node.id || e.target.id === node.id) {
+				this.removeEdge(e);
+			}
+		}, this);
+
+		this.notify();
+	};
+
+	// remove a node and it's associated edges from the graph
+	Graph.prototype.removeEdge = function(edge) {
+		for (var i = this.edges.length - 1; i >= 0; i--) {
+			if (this.edges[i].id === edge.id) {
+				this.edges.splice(i, 1);
+			}
+		}
+
+		for (var x in this.adjacency) {
+			for (var y in this.adjacency[x]) {
+				var edges = this.adjacency[x][y];
+
+				for (var j=edges.length - 1; j>=0; j--) {
+					if (this.adjacency[x][y][j].id === edge.id) {
+						this.adjacency[x][y].splice(j, 1);
+					}
+				}
+
+				// Clean up empty edge arrays
+				if (this.adjacency[x][y].length == 0) {
+					delete this.adjacency[x][y];
+				}
+			}
+
+			// Clean up empty objects
+			if (isEmpty(this.adjacency[x])) {
+				delete this.adjacency[x];
+			}
+		}
+
+		this.notify();
+	};
+
+	/* Merge a list of nodes and edges into the current graph. eg.
+	var o = {
+		nodes: [
+			{id: 123, data: {type: 'user', userid: 123, displayname: 'aaa'}},
+			{id: 234, data: {type: 'user', userid: 234, displayname: 'bbb'}}
+		],
+		edges: [
+			{from: 0, to: 1, type: 'submitted_design', directed: true, data: {weight: }}
+		]
+	}
+	*/
+	Graph.prototype.merge = function(data) {
+		var nodes = [];
+		data.nodes.forEach(function(n) {
+			nodes.push(this.addNode(new Node(n.id, n.data)));
+		}, this);
+
+		data.edges.forEach(function(e) {
+			var from = nodes[e.from];
+			var to = nodes[e.to];
+
+			var id = (e.directed)
+				? (id = e.type + "-" + from.id + "-" + to.id)
+				: (from.id < to.id) // normalise id for non-directed edges
+					? e.type + "-" + from.id + "-" + to.id
+					: e.type + "-" + to.id + "-" + from.id;
+
+			var edge = this.addEdge(new Edge(id, from, to, e.data));
+			edge.data.type = e.type;
+		}, this);
+	};
+
+	Graph.prototype.filterNodes = function(fn) {
+		var tmpNodes = this.nodes.slice();
+		tmpNodes.forEach(function(n) {
+			if (!fn(n)) {
+				this.removeNode(n);
+			}
+		}, this);
+	};
+
+	Graph.prototype.filterEdges = function(fn) {
+		var tmpEdges = this.edges.slice();
+		tmpEdges.forEach(function(e) {
+			if (!fn(e)) {
+				this.removeEdge(e);
+			}
+		}, this);
+	};
+
+
+	Graph.prototype.addGraphListener = function(obj) {
+		this.eventListeners.push(obj);
+	};
+
+	Graph.prototype.notify = function() {
+		this.eventListeners.forEach(function(obj){
+			obj.graphChanged();
+		});
+	};
+
+	// -----------
+	var Layout = Springy.Layout = {};
+	Layout.ForceDirected = function(graph, stiffness, repulsion, damping, minEnergyThreshold, maxSpeed) {
+		this.graph = graph;
+		this.stiffness = stiffness; // spring stiffness constant
+		this.repulsion = repulsion; // repulsion constant
+		this.damping = damping; // velocity damping factor
+		this.minEnergyThreshold = minEnergyThreshold || 0.01; //threshold used to determine render stop
+		this.maxSpeed = maxSpeed || Infinity; // nodes aren't allowed to exceed this speed
+
+		this.nodePoints = {}; // keep track of points associated with nodes
+		this.edgeSprings = {}; // keep track of springs associated with edges
+	};
+
+	Layout.ForceDirected.prototype.point = function(node) {
+		if (!(node.id in this.nodePoints)) {
+			var mass = (node.data.mass !== undefined) ? node.data.mass : 1.0;
+			this.nodePoints[node.id] = new Layout.ForceDirected.Point(Vector.random(), mass);
+		}
+
+		return this.nodePoints[node.id];
+	};
+
+	Layout.ForceDirected.prototype.spring = function(edge) {
+		if (!(edge.id in this.edgeSprings)) {
+			var length = (edge.data.length !== undefined) ? edge.data.length : 1.0;
+
+			var existingSpring = false;
+
+			var from = this.graph.getEdges(edge.source, edge.target);
+			from.forEach(function(e) {
+				if (existingSpring === false && e.id in this.edgeSprings) {
+					existingSpring = this.edgeSprings[e.id];
+				}
+			}, this);
+
+			if (existingSpring !== false) {
+				return new Layout.ForceDirected.Spring(existingSpring.point1, existingSpring.point2, 0.0, 0.0);
+			}
+
+			var to = this.graph.getEdges(edge.target, edge.source);
+			from.forEach(function(e){
+				if (existingSpring === false && e.id in this.edgeSprings) {
+					existingSpring = this.edgeSprings[e.id];
+				}
+			}, this);
+
+			if (existingSpring !== false) {
+				return new Layout.ForceDirected.Spring(existingSpring.point2, existingSpring.point1, 0.0, 0.0);
+			}
+
+			this.edgeSprings[edge.id] = new Layout.ForceDirected.Spring(
+				this.point(edge.source), this.point(edge.target), length, this.stiffness
+			);
+		}
+
+		return this.edgeSprings[edge.id];
+	};
+
+	// callback should accept two arguments: Node, Point
+	Layout.ForceDirected.prototype.eachNode = function(callback) {
+		var t = this;
+		this.graph.nodes.forEach(function(n){
+			callback.call(t, n, t.point(n));
+		});
+	};
+
+	// callback should accept two arguments: Edge, Spring
+	Layout.ForceDirected.prototype.eachEdge = function(callback) {
+		var t = this;
+		this.graph.edges.forEach(function(e){
+			callback.call(t, e, t.spring(e));
+		});
+	};
+
+	// callback should accept one argument: Spring
+	Layout.ForceDirected.prototype.eachSpring = function(callback) {
+		var t = this;
+		this.graph.edges.forEach(function(e){
+			callback.call(t, t.spring(e));
+		});
+	};
+
+
+	// Physics stuff
+	Layout.ForceDirected.prototype.applyCoulombsLaw = function() {
+		this.eachNode(function(n1, point1) {
+			this.eachNode(function(n2, point2) {
+				if (point1 !== point2)
+				{
+					var d = point1.p.subtract(point2.p);
+					var distance = d.magnitude() + 0.1; // avoid massive forces at small distances (and divide by zero)
+					var direction = d.normalise();
+
+					// apply force to each end point
+					point1.applyForce(direction.multiply(this.repulsion).divide(distance * distance * 0.5));
+					point2.applyForce(direction.multiply(this.repulsion).divide(distance * distance * -0.5));
+				}
+			});
+		});
+	};
+
+	Layout.ForceDirected.prototype.applyHookesLaw = function() {
+		this.eachSpring(function(spring){
+			var d = spring.point2.p.subtract(spring.point1.p); // the direction of the spring
+			var displacement = spring.length - d.magnitude();
+			var direction = d.normalise();
+
+			// apply force to each end point
+			spring.point1.applyForce(direction.multiply(spring.k * displacement * -0.5));
+			spring.point2.applyForce(direction.multiply(spring.k * displacement * 0.5));
+		});
+	};
+
+	Layout.ForceDirected.prototype.attractToCentre = function() {
+		this.eachNode(function(node, point) {
+			var direction = point.p.multiply(-1.0);
+			point.applyForce(direction.multiply(this.repulsion / 50.0));
+		});
+	};
+
+
+	Layout.ForceDirected.prototype.updateVelocity = function(timestep) {
+		this.eachNode(function(node, point) {
+			// Is this, along with updatePosition below, the only places that your
+			// integration code exist?
+			point.v = point.v.add(point.a.multiply(timestep)).multiply(this.damping);
+			if (point.v.magnitude() > this.maxSpeed) {
+			    point.v = point.v.normalise().multiply(this.maxSpeed);
+			}
+			point.a = new Vector(0,0);
+		});
+	};
+
+	Layout.ForceDirected.prototype.updatePosition = function(timestep) {
+		this.eachNode(function(node, point) {
+			// Same question as above; along with updateVelocity, is this all of
+			// your integration code?
+			point.p = point.p.add(point.v.multiply(timestep));
+		});
+	};
+
+	// Calculate the total kinetic energy of the system
+	Layout.ForceDirected.prototype.totalEnergy = function(timestep) {
+		var energy = 0.0;
+		this.eachNode(function(node, point) {
+			var speed = point.v.magnitude();
+			energy += 0.5 * point.m * speed * speed;
+		});
+
+		return energy;
+	};
+
+	var __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; }; // stolen from coffeescript, thanks jashkenas! ;-)
+
+	Springy.requestAnimationFrame = __bind(this.requestAnimationFrame ||
+		this.webkitRequestAnimationFrame ||
+		this.mozRequestAnimationFrame ||
+		this.oRequestAnimationFrame ||
+		this.msRequestAnimationFrame ||
+		(function(callback, element) {
+			this.setTimeout(callback, 10);
+		}), this);
+
+
+	/**
+	 * Start simulation if it's not running already.
+	 * In case it's running then the call is ignored, and none of the callbacks passed is ever executed.
+	 */
+	Layout.ForceDirected.prototype.start = function(render, onRenderStop, onRenderStart) {
+		var t = this;
+
+		if (this._started) return;
+		this._started = true;
+		this._stop = false;
+
+		if (onRenderStart !== undefined) { onRenderStart(); }
+
+		Springy.requestAnimationFrame(function step() {
+			t.tick(0.03);
+
+			if (render !== undefined) {
+				render();
+			}
+
+			// stop simulation when energy of the system goes below a threshold
+			if (t._stop || t.totalEnergy() < t.minEnergyThreshold) {
+				t._started = false;
+				if (onRenderStop !== undefined) { onRenderStop(); }
+			} else {
+				Springy.requestAnimationFrame(step);
+			}
+		});
+	};
+
+	Layout.ForceDirected.prototype.stop = function() {
+		this._stop = true;
+	}
+
+	Layout.ForceDirected.prototype.tick = function(timestep) {
+		this.applyCoulombsLaw();
+		this.applyHookesLaw();
+		this.attractToCentre();
+		this.updateVelocity(timestep);
+		this.updatePosition(timestep);
+	};
+
+	// Find the nearest point to a particular position
+	Layout.ForceDirected.prototype.nearest = function(pos) {
+		var min = {node: null, point: null, distance: null};
+		var t = this;
+		this.graph.nodes.forEach(function(n){
+			var point = t.point(n);
+			var distance = point.p.subtract(pos).magnitude();
+
+			if (min.distance === null || distance < min.distance) {
+				min = {node: n, point: point, distance: distance};
+			}
+		});
+
+		return min;
+	};
+
+	// returns [bottomleft, topright]
+	Layout.ForceDirected.prototype.getBoundingBox = function() {
+		var bottomleft = new Vector(-2,-2);
+		var topright = new Vector(2,2);
+
+		this.eachNode(function(n, point) {
+			if (point.p.x < bottomleft.x) {
+				bottomleft.x = point.p.x;
+			}
+			if (point.p.y < bottomleft.y) {
+				bottomleft.y = point.p.y;
+			}
+			if (point.p.x > topright.x) {
+				topright.x = point.p.x;
+			}
+			if (point.p.y > topright.y) {
+				topright.y = point.p.y;
+			}
+		});
+
+		var padding = topright.subtract(bottomleft).multiply(0.07); // ~5% padding
+
+		return {bottomleft: bottomleft.subtract(padding), topright: topright.add(padding)};
+	};
+
+
+	// Vector
+	var Vector = Springy.Vector = function(x, y) {
+		this.x = x;
+		this.y = y;
+	};
+
+	Vector.random = function() {
+		return new Vector(10.0 * (Math.random() - 0.5), 10.0 * (Math.random() - 0.5));
+	};
+
+	Vector.prototype.add = function(v2) {
+		return new Vector(this.x + v2.x, this.y + v2.y);
+	};
+
+	Vector.prototype.subtract = function(v2) {
+		return new Vector(this.x - v2.x, this.y - v2.y);
+	};
+
+	Vector.prototype.multiply = function(n) {
+		return new Vector(this.x * n, this.y * n);
+	};
+
+	Vector.prototype.divide = function(n) {
+		return new Vector((this.x / n) || 0, (this.y / n) || 0); // Avoid divide by zero errors..
+	};
+
+	Vector.prototype.magnitude = function() {
+		return Math.sqrt(this.x*this.x + this.y*this.y);
+	};
+
+	Vector.prototype.normal = function() {
+		return new Vector(-this.y, this.x);
+	};
+
+	Vector.prototype.normalise = function() {
+		return this.divide(this.magnitude());
+	};
+
+	// Point
+	Layout.ForceDirected.Point = function(position, mass) {
+		this.p = position; // position
+		this.m = mass; // mass
+		this.v = new Vector(0, 0); // velocity
+		this.a = new Vector(0, 0); // acceleration
+	};
+
+	Layout.ForceDirected.Point.prototype.applyForce = function(force) {
+		this.a = this.a.add(force.divide(this.m));
+	};
+
+	// Spring
+	Layout.ForceDirected.Spring = function(point1, point2, length, k) {
+		this.point1 = point1;
+		this.point2 = point2;
+		this.length = length; // spring length at rest
+		this.k = k; // spring constant (See Hooke's law) .. how stiff the spring is
+	};
+
+	// Layout.ForceDirected.Spring.prototype.distanceToPoint = function(point)
+	// {
+	// 	// hardcore vector arithmetic.. ohh yeah!
+	// 	// .. see http://stackoverflow.com/questions/849211/shortest-distance-between-a-point-and-a-line-segment/865080#865080
+	// 	var n = this.point2.p.subtract(this.point1.p).normalise().normal();
+	// 	var ac = point.p.subtract(this.point1.p);
+	// 	return Math.abs(ac.x * n.x + ac.y * n.y);
+	// };
+
+	/**
+	 * Renderer handles the layout rendering loop
+	 * @param onRenderStop optional callback function that gets executed whenever rendering stops.
+	 * @param onRenderStart optional callback function that gets executed whenever rendering starts.
+	 * @param onRenderFrame optional callback function that gets executed after each frame is rendered.
+	 */
+	var Renderer = Springy.Renderer = function(layout, clear, drawEdge, drawNode, onRenderStop, onRenderStart, onRenderFrame) {
+		this.layout = layout;
+		this.clear = clear;
+		this.drawEdge = drawEdge;
+		this.drawNode = drawNode;
+		this.onRenderStop = onRenderStop;
+		this.onRenderStart = onRenderStart;
+		this.onRenderFrame = onRenderFrame;
+
+		this.layout.graph.addGraphListener(this);
+	}
+
+	Renderer.prototype.graphChanged = function(e) {
+		this.start();
+	};
+
+	/**
+	 * Starts the simulation of the layout in use.
+	 *
+	 * Note that in case the algorithm is still or already running then the layout that's in use
+	 * might silently ignore the call, and your optional <code>done</code> callback is never executed.
+	 * At least the built-in ForceDirected layout behaves in this way.
+	 *
+	 * @param done An optional callback function that gets executed when the springy algorithm stops,
+	 * either because it ended or because stop() was called.
+	 */
+	Renderer.prototype.start = function(done) {
+		var t = this;
+		this.layout.start(function render() {
+			t.clear();
+
+			t.layout.eachEdge(function(edge, spring) {
+				t.drawEdge(edge, spring.point1.p, spring.point2.p);
+			});
+
+			t.layout.eachNode(function(node, point) {
+				t.drawNode(node, point.p);
+			});
+			
+			if (t.onRenderFrame !== undefined) { t.onRenderFrame(); }
+		}, this.onRenderStop, this.onRenderStart);
+	};
+
+	Renderer.prototype.stop = function() {
+		this.layout.stop();
+	};
+
+	// Array.forEach implementation for IE support..
+	//https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/forEach
+	if ( !Array.prototype.forEach ) {
+		Array.prototype.forEach = function( callback, thisArg ) {
+			var T, k;
+			if ( this == null ) {
+				throw new TypeError( " this is null or not defined" );
+			}
+			var O = Object(this);
+			var len = O.length >>> 0; // Hack to convert O.length to a UInt32
+			if ( {}.toString.call(callback) != "[object Function]" ) {
+				throw new TypeError( callback + " is not a function" );
+			}
+			if ( thisArg ) {
+				T = thisArg;
+			}
+			k = 0;
+			while( k < len ) {
+				var kValue;
+				if ( k in O ) {
+					kValue = O[ k ];
+					callback.call( T, kValue, k, O );
+				}
+				k++;
+			}
+		};
+	}
+
+	var isEmpty = function(obj) {
+		for (var k in obj) {
+			if (obj.hasOwnProperty(k)) {
+				return false;
+			}
+		}
+		return true;
+	};
+
+  return Springy;
+}));

src/entities/link.js

@@ -19,7 +19,7 @@ const dateUtils = require('../services/date_utils');
  * @extends Entity
  */
 class Link extends Entity {
-    static get entityName() { return "links"; }
+    static get entityName() { return "link_map.js"; }
     static get primaryKeyName() { return "linkId"; }
     static get hashedProperties() { return ["linkId", "noteId", "targetNoteId", "type", "isDeleted", "utcDateCreated", "utcDateModified"]; }
 

src/public/javascripts/dialogs/link_map.js

@@ -1,20 +1,137 @@
 import server from '../services/server.js';
 import noteDetailService from "../services/note_detail.js";
+import libraryLoader from "../services/library_loader.js";
+
+const $linkMapContainer = $("#link-map-container");
+
+const uniDirectionalOverlays = [
+    [ "Arrow", {
+        location: 1,
+        id: "arrow",
+        length: 14,
+        foldback: 0.8
+    } ],
+    [ "Label", { label: "", id: "label", cssClass: "connection-label" }]
+];
+
+const biDirectionalOverlays = [
+    [ "Arrow", {
+        location: 1,
+        id: "arrow",
+        length: 14,
+        foldback: 0.8
+    } ],
+    [ "Label", { label: "", id: "label", cssClass: "connection-label" }],
+    [ "Arrow", {
+        location: 0,
+        id: "arrow2",
+        length: 14,
+        direction: -1,
+        foldback: 0.8
+    } ]
+];
+
+const inverseRelationsOverlays = [
+    [ "Arrow", {
+        location: 1,
+        id: "arrow",
+        length: 14,
+        foldback: 0.8
+    } ],
+    [ "Label", { label: "", location: 0.2, id: "label-source", cssClass: "connection-label" }],
+    [ "Label", { label: "", location: 0.8, id: "label-target", cssClass: "connection-label" }],
+    [ "Arrow", {
+        location: 0,
+        id: "arrow2",
+        length: 14,
+        direction: -1,
+        foldback: 0.8
+    } ]
+];
+
+const linkOverlays = [
+    [ "Arrow", {
+        location: 1,
+        id: "arrow",
+        length: 14,
+        foldback: 0.8
+    } ]
+];
 
 const $dialog = $("#link-map-dialog");
 
+let jsPlumbInstance = null;
+
 async function showDialog() {
     glob.activeDialog = $dialog;
 
-    const noteId = noteDetailService.getActiveNoteId();
+    await libraryLoader.requireLibrary(libraryLoader.RELATION_MAP);
+    await libraryLoader.requireLibrary(libraryLoader.SPRINGY);
 
-    const links = await server.get(`notes/${noteId}/links`);
+    jsPlumb.ready(() => {
+        initJsPlumbInstance();
 
-    console.log(links);
+        loadNotesAndRelations();
+    });
 
     $dialog.modal();
 }
 
+async function loadNotesAndRelations() {
+    const noteId = noteDetailService.getActiveNoteId();
+
+    const links = await server.get(`notes/${noteId}/link-map`);
+
+    const noteIds = new Set(links.map(l => l.noteId).concat(links.map(l => l.targetNoteId)));
+
+    const graph = new Springy.Graph();
+    graph.addNodes(...noteIds);
+    graph.addEdges(links.map(l => [l.noteId, l.targetNoteId]));
+
+    const layout = new Springy.Layout.ForceDirected(
+        graph,
+        400.0, // Spring stiffness
+        400.0, // Node repulsion
+        0.5 // Damping
+    );
+
+
+    for (const link of links) {
+
+    }
+}
+
+function initJsPlumbInstance() {
+    if (jsPlumbInstance) {
+        // delete all endpoints and connections
+        // this is done at this point (after async operations) to reduce flicker to the minimum
+        jsPlumbInstance.deleteEveryEndpoint();
+
+        // without this we still end up with note boxes remaining in the canvas
+        $linkMapContainer.empty();
+
+        return;
+    }
+
+    this.jsPlumbInstance = jsPlumb.getInstance({
+        Endpoint: ["Dot", {radius: 2}],
+        Connector: "StateMachine",
+        ConnectionOverlays: uniDirectionalOverlays,
+        HoverPaintStyle: { stroke: "#777", strokeWidth: 1 },
+        Container: this.$relationMapContainer.attr("id")
+    });
+
+    this.jsPlumbInstance.registerConnectionType("uniDirectional", { anchor:"Continuous", connector:"StateMachine", overlays: uniDirectionalOverlays });
+
+    this.jsPlumbInstance.registerConnectionType("biDirectional", { anchor:"Continuous", connector:"StateMachine", overlays: biDirectionalOverlays });
+
+    this.jsPlumbInstance.registerConnectionType("inverse", { anchor:"Continuous", connector:"StateMachine", overlays: inverseRelationsOverlays });
+
+    this.jsPlumbInstance.registerConnectionType("link", { anchor:"Continuous", connector:"StateMachine", overlays: linkOverlays });
+
+    this.jsPlumbInstance.bind("connection", (info, originalEvent) => this.connectionCreatedHandler(info, originalEvent));
+}
+
 export default {
     showDialog
 };

src/public/javascripts/services/library_loader.js

@@ -34,6 +34,8 @@ const RELATION_MAP = {
     ]
 };
 
+const SPRINGY = {js: ["libraries/springy.js"]};
+
 async function requireLibrary(library) {
     if (library.css) {
         library.css.map(cssUrl => cssLoader.requireCss(cssUrl));
@@ -67,5 +69,6 @@ export default {
     CODE_MIRROR,
     ESLINT,
     COMMONMARK,
-    RELATION_MAP
+    RELATION_MAP,
+    SPRINGY
 }

src/routes/api/link_map.js

@@ -0,0 +1,52 @@
+"use strict";
+
+const sql = require('../../services/sql');
+
+async function getLinks(noteIds) {
+    return await sql.getManyRows(`
+        SELECT noteId, targetNoteId, type
+        FROM links
+        WHERE (noteId IN (???) OR targetNoteId IN (???))
+          AND isDeleted = 0
+        UNION
+        SELECT noteId, value, 'relation'
+        FROM attributes
+        WHERE (noteId IN (???) OR value IN (???))
+          AND type = 'relation'
+          AND isDeleted = 0
+    `, noteIds);
+}
+
+async function getLinkMap(req) {
+    const {noteId} = req.params;
+
+    let noteIds = new Set([noteId]);
+    let links = [];
+
+    while (true) {
+        const newLinks = await getLinks(noteIds);
+        const newNoteIds = new Set(newLinks.map(l => l.noteId).concat(newLinks.map(l => l.targetNoteId)));
+
+        if (newNoteIds.length === noteIds.length) {
+            // no new note discovered, no need to search any further
+            break;
+        }
+
+        if (newNoteIds.length > 50) {
+            // to many notes to display
+            break;
+        }
+
+        noteIds = newNoteIds;
+        links = newLinks;
+    }
+
+    // keep only links coming from and targetting some note in the noteIds set
+    links = links.filter(l => noteIds.has(l.noteId) && noteIds.has(l.targetNoteId));
+
+    return links;
+}
+
+module.exports = {
+    getLinkMap
+};

src/routes/api/links.js

@@ -1,17 +0,0 @@
-"use strict";
-
-const sql = require('../../services/sql');
-
-async function getNoteLinks(req) {
-    const {noteId} = req.params;
-
-    return await sql.getRows(`
-        SELECT noteId, targetNoteId, type FROM links WHERE (noteId = ? OR targetNoteId = ?) AND isDeleted = 0
-        UNION
-        SELECT noteId, value, 'relation' FROM attributes WHERE (noteId = ? OR value = ?) AND type = 'relation' AND isDeleted = 0
-        `, [noteId, noteId, noteId, noteId]);
-}
-
-module.exports = {
-    getNoteLinks
-};

src/routes/routes.js

@@ -31,7 +31,7 @@ const senderRoute = require('./api/sender');
 const filesRoute = require('./api/file_upload');
 const searchRoute = require('./api/search');
 const dateNotesRoute = require('./api/date_notes');
-const linksRoute = require('./api/links');
+const linkMapRoute = require('./api/link_map');
 
 const log = require('../services/log');
 const express = require('express');
@@ -155,7 +155,7 @@ function register(app) {
     apiRoute(GET, '/api/attributes/names', attributesRoute.getAttributeNames);
     apiRoute(GET, '/api/attributes/values/:attributeName', attributesRoute.getValuesForAttribute);
 
-    apiRoute(GET, '/api/notes/:noteId/links', linksRoute.getNoteLinks);
+    apiRoute(GET, '/api/notes/:noteId/link-map', linkMapRoute.getLinkMap);
 
     apiRoute(GET, '/api/date-notes/date/:date', dateNotesRoute.getDateNote);
     apiRoute(GET, '/api/date-notes/month/:month', dateNotesRoute.getMonthNote);

src/services/sync_table.js

@@ -33,7 +33,7 @@ async function addRecentNoteSync(noteId, sourceId) {
 }
 
 async function addLinkSync(linkId, sourceId) {
-    await addEntitySync("links", linkId, sourceId);
+    await addEntitySync("link_map.js", linkId, sourceId);
 }
 
 async function addAttributeSync(attributeId, sourceId) {
@@ -94,7 +94,7 @@ async function fillAllSyncRows() {
     await fillSyncRows("recent_notes", "noteId");
     await fillSyncRows("attributes", "attributeId");
     await fillSyncRows("api_tokens", "apiTokenId");
-    await fillSyncRows("links", "linkId");
+    await fillSyncRows("link_map.js", "linkId");
     await fillSyncRows("options", "name", 'isSynced = 1');
 }
 

src/services/sync_update.js

@@ -28,7 +28,7 @@ async function updateEntity(sync, entity, sourceId) {
     else if (entityName === 'recent_notes') {
         await updateRecentNotes(entity, sourceId);
     }
-    else if (entityName === 'links') {
+    else if (entityName === 'link_map.js') {
         await updateLink(entity, sourceId);
     }
     else if (entityName === 'attributes') {
@@ -164,7 +164,7 @@ async function updateLink(entity, sourceId) {
 
     if (!origLink || origLink.utcDateModified <= entity.utcDateModified) {
         await sql.transactional(async () => {
-            await sql.replace("links", entity);
+            await sql.replace("link_map.js", entity);
 
             await syncTableService.addLinkSync(entity.linkId, sourceId);
         });

src/views/dialogs/link_map.ejs

@@ -9,6 +9,7 @@
                 </button>
             </div>
             <div class="modal-body">
+                <div id="link-map-container"></div>
             </div>
         </div>
     </div>