gojs
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Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams
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HTML
<html>
<head>
<meta charset="UTF-8">
<title>Virtualized Tree with custom layout</title>
<meta name="description" content="An example of virtualization where a very simple tree layout sets the bounds for each node data." />
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Copyright 1998-2020 by Northwoods Software Corporation. -->
<script src="../release/go.js"></script>
<script src="../assets/js/goSamples.js"></script> <!-- this is only for the GoJS Samples framework -->
<script id="code">
// this controls whether the tree grows deeper towards the right or downwards:
var HORIZONTAL = true;
function init() {
if (window.goSamples) goSamples(); // init for these samples -- you don't need to call this
var $ = go.GraphObject.make; // for conciseness in defining templates
// The Diagram just shows what should be visible in the viewport.
// Its model does NOT include node data for the whole graph, but only that
// which might be visible in the viewport.
myDiagram =
$(go.Diagram, "myDiagramDiv",
{
contentAlignment: go.Spot.Center,
initialDocumentSpot: go.Spot.Center,
initialViewportSpot: go.Spot.Center,
// Do manual layout in the layoutTree function below, rather than automatic layout using a
// TreeLayout which would require the Nodes and Links to exist first for an accurate layout.
//layout: $(go.TreeLayout,
// { nodeSpacing: 4, compaction: go.TreeLayout.CompactionNone }),
// Assume there's no Layout -- all data.bounds are calculated in layoutTree
layout: $(go.Layout, { isInitial: false, isOngoing: false }), // never invalidates
// Define the template for Nodes, used by virtualization.
nodeTemplate:
$(go.Node, "Auto",
{ isLayoutPositioned: false }, // optimization
new go.Binding("position", "bounds", function(b) { return b.position; })
.makeTwoWay(function(p, d) { return new go.Rect(p.x, p.y, d.bounds.width, d.bounds.height); }),
{ width: 70, height: 20 }, // in cooperation with the load function, below
$(go.Shape, "Rectangle",
new go.Binding("fill", "color")),
$(go.TextBlock,
{ margin: 2 },
new go.Binding("text", "color")),
{
toolTip:
$("ToolTip",
$(go.TextBlock, { margin: 3 },
new go.Binding("text", "",
function(d) { return "key: " + d.key + "\nbounds: " + d.bounds.toString(); }))
)
}
),
// Define the template for Links
linkTemplate:
$(go.Link,
{
isLayoutPositioned: false, // optimization
fromSpot: (HORIZONTAL ? go.Spot.Right : go.Spot.Bottom),
toSpot: (HORIZONTAL ? go.Spot.Left : go.Spot.Top)
},
$(go.Shape)
),
"animationManager.isEnabled": false
});
// This model includes all of the data
myWholeModel =
$(go.TreeModel); // must match the TreeModel used by the Diagram, below
// Do not set myDiagram.model = myWholeModel -- that would create a zillion Nodes and Links!
// In the future Diagram may have built-in support for virtualization.
// For now, we have to implement virtualization ourselves by having the Diagram's model
// be different than the "real" model.
myDiagram.model = // this only holds nodes that should be in the viewport
$(go.TreeModel); // must match the model, above
// for now, we have to implement virtualization ourselves
myDiagram.isVirtualized = true;
myDiagram.addDiagramListener("ViewportBoundsChanged", onViewportChanged);
// This is a status message
myLoading =
$(go.Part, // this has to set the location or position explicitly
{ location: new go.Point(0, 0) },
$(go.TextBlock, "loading...",
{ stroke: "red", font: "20pt sans-serif" }));
// temporarily add the status indicator
myDiagram.add(myLoading);
// Allow the myLoading indicator to be shown now,
// but allow objects added in load to also be considered part of the initial Diagram.
// If you are not going to add temporary initial Parts, don't call delayInitialization.
myDiagram.delayInitialization(load);
}
function load() {
// create a lot of data for the myWholeModel
var total = 123456;
var treedata = [];
for (var i = 0; i < total; i++) {
var d = {
key: i, // this node data's key
color: go.Brush.randomColor(), // the node's color
parent: (i > 0 ? Math.floor(Math.random() * i / 2) : undefined) // the random parent's key
};
//!!!???@@@ this needs to be customized to account for your chosen Node template
d.bounds = new go.Rect(0, 0, 70, 20);
treedata.push(d);
}
myWholeModel.nodeDataArray = treedata;
// make it faster to get from a model parent data object to all of the children data
improveNavigation(myWholeModel);
// this sets the data.bounds on each node data
// and Diagram.fixedBounds on the diagram, so the diagram knows how far it can scroll
layoutTree(myWholeModel);
// remove the status indicator
myDiagram.remove(myLoading);
}
// this adds ._parent and ._children properties on each node data
function improveNavigation(model) { // this must be a TreeModel
var ndata = model.nodeDataArray;
// create an Array of child data references for each parent data
for (var i = 0; i < ndata.length; i++) {
var child = ndata[i];
var parentkey = model.getParentKeyForNodeData(child);
var parent = model.findNodeDataForKey(parentkey);
if (parent) {
child._parent = parent;
var childarr = parent._children;
if (childarr) {
childarr.push(child);
} else {
parent._children = [child];
}
}
}
}
// The following functions implement virtualization of the Diagram
// Assume data.bounds is a Rect of the area occupied by the Node in document coordinates.
// The normal mechanism for determining the size of the document depends on all of the
// Nodes and Links existing, so we need to use a function that depends only on the model data.
function computeDocumentBounds(model) {
var b = new go.Rect();
var ndata = model.nodeDataArray;
for (var i = 0; i < ndata.length; i++) {
var d = ndata[i];
if (!d.bounds) continue;
if (i === 0) {
b.set(d.bounds);
} else {
b.unionRect(d.bounds);
}
}
return b;
}
// As the user scrolls or zooms, make sure the Parts (Nodes and Links) exist in the viewport.
function onViewportChanged(e) {
var diagram = e.diagram;
// make sure there are Nodes for each node data that is in the viewport
// or that is connected to such a Node
var viewb = diagram.viewportBounds; // the new viewportBounds
var model = diagram.model;
var oldskips = diagram.skipsUndoManager;
diagram.skipsUndoManager = true;
var b = new go.Rect();
var ndata = myWholeModel.nodeDataArray;
for (var i = 0; i < ndata.length; i++) {
var n = ndata[i];
if (!n.bounds) continue;
if (n.bounds.intersectsRect(viewb)) {
model.addNodeData(n);
}
// make sure links to all parent nodes appear
var parentkey = myWholeModel.getParentKeyForNodeData(n);
var parent = myWholeModel.findNodeDataForKey(parentkey);
if (parent !== null) {
if (n.bounds.intersectsRect(viewb)) { // N is inside viewport
model.addNodeData(parent); // so that link to parent appears
} else { // N is outside of viewport
// see if there's a parent that is in the viewport,
// or if the link might cross over the viewport
b.set(n.bounds);
b.unionRect(parent.bounds);
if (b.intersectsRect(viewb)) {
model.addNodeData(n); // add N so that link to parent appears
}
}
}
}
diagram.skipsUndoManager = oldskips;
if (myRemoveTimer === null) {
// only remove offscreen nodes after a delay
myRemoveTimer = setTimeout(function() { removeOffscreen(diagram); }, 3000);
}
updateCounts(); // only for this sample
}
// occasionally remove Parts that are offscreen from the Diagram
var myRemoveTimer = null;
function removeOffscreen(diagram) {
myRemoveTimer = null;
var viewb = diagram.viewportBounds;
var model = diagram.model;
var remove = []; // collect for later removal
var it = diagram.nodes;
while (it.next()) {
var n = it.value;
var d = n.data;
if (d === null) continue;
if (!n.actualBounds.intersectsRect(viewb) && !n.isSelected) {
// even if the node is out of the viewport, keep it if it is selected or
// if any link connecting with the node is still in the viewport
if (!n.linksConnected.any(function(l) { return l.actualBounds.intersectsRect(viewb); })) {
remove.push(d);
}
}
}
if (remove.length > 0) {
var oldskips = diagram.skipsUndoManager;
diagram.skipsUndoManager = true;
model.removeNodeDataCollection(remove);
diagram.skipsUndoManager = oldskips;
}
updateCounts(); // only for this sample
}
// end of virtualized Diagram
// A very simple tree layout.
// Basic tree layout parameters
var nodeSpacing = 4;
var layerSpacing = 50;
// Layout the whole tree just using the model, not any Nodes or Links.
function layoutTree(model) {
var ndata = model.nodeDataArray;
// layout each tree root
if (HORIZONTAL) {
var y = 0;
for (var i = 0; i < ndata.length; i++) {
var d = ndata[i];
// is this a root node?
if (!d._parent) {
y = walkTreeH(d, 0, y) + d.bounds.height + nodeSpacing;
}
}
} else { // !HORIZONTAL
var x = 0;
for (var i = 0; i < ndata.length; i++) {
var d = ndata[i];
// is this a root node?
if (!d._parent) {
x = walkTreeV(d, x, 0) + d.bounds.width + nodeSpacing;
}
}
}
// can't depend on regular bounds computation that depends on all Nodes existing
myDiagram.fixedBounds = computeDocumentBounds(model);
}
// Walk subtrees from each root node, positioning as we go.
function walkTreeH(parent, oldx, oldy) { // HORIZONTAL
var origy = oldy;
var newy = oldy;
var childarr = parent._children;
if (childarr) {
for (var i = 0; i < childarr.length; i++) {
var child = childarr[i];
newy = walkTreeH(child, oldx + child.bounds.width + layerSpacing, oldy);
oldy = newy + child.bounds.height + nodeSpacing;
}
}
parent.bounds.x = oldx;
parent.bounds.y = (origy + newy) / 2;
return newy;
}
function walkTreeV(parent, oldx, oldy) { // !HORIZONTAL
var origx = oldx;
var newx = oldx;
var childarr = parent._children;
if (childarr) {
for (var i = 0; i < childarr.length; i++) {
var child = childarr[i];
newx = walkTreeV(child, oldx, oldy + child.bounds.height + layerSpacing);
oldx = newx + child.bounds.width + nodeSpacing;
}
}
parent.bounds.x = (origx + newx) / 2;
parent.bounds.y = oldy;
return newx;
}
// end of layoutTree functionality
// This function is only used in this sample to demonstrate the effects of the virtualization.
// In a real application you would delete this function and all calls to it.
function updateCounts() {
document.getElementById("myMessage1").textContent = myWholeModel.nodeDataArray.length;
document.getElementById("myMessage2").textContent = myDiagram.nodes.count;
document.getElementById("myMessage4").textContent = myDiagram.links.count;
}
</script>
</head>
<body onload="init()">
<div id="sample">
<div id="myDiagramDiv" style="background-color: white; border: solid 1px black; width: 100%; height: 600px"></div>
<div id="description">
<p>This uses a <a>TreeModel</a> but not <a>TreeLayout</a>.</p>
Node data in Model: <span id="myMessage1"></span>.
Actual Nodes in Diagram: <span id="myMessage2"></span>.
Actual Links in Diagram: <span id="myMessage4"></span>.
</div>
</div>
</body>
</html>