This is a modified samples/swimBands.html:
// this controls whether the layout is horizontal and the layer bands are vertical, or vice-versa:
var HORIZONTAL = true; // this constant parameter can only be set here, not dynamically
// Perform a LayeredDigraphLayout where commitLayers is overridden to modify the background Part whose key is "_BANDS".
function BandedLDLayout() {
go.LayeredDigraphLayout.call(this);
}
go.Diagram.inherit(BandedLDLayout, go.LayeredDigraphLayout);
/** @override */
BandedLDLayout.prototype.assignLayers = function() {
go.LayeredDigraphLayout.prototype.assignLayers.call(this);
var maxlayer = this.maxLayer;
// now assign specific layers
var it = this.network.vertexes.iterator;
while (it.next()) {
var v = it.value;
if (v.node !== null) {
var lay = v.node.data.layer;
if (typeof lay === "number" && lay >= 0 && lay <= maxlayer) {
v.layer = lay;
}
}
}
};
/** @override */
BandedLDLayout.prototype.commitLayers = function(layerRects, offset) {
// update the background object holding the visual "bands"
var bands = this.diagram.findPartForKey("_BANDS");
if (bands) {
var model = this.diagram.model;
bands.location = this.arrangementOrigin.copy().add(offset);
// make each band visible or not, depending on whether there is a layer for it
for (var it = bands.elements; it.next(); ) {
var idx = it.key;
var elt = it.value; // the item panel representing a band
elt.visible = idx < layerRects.length;
}
// set the bounds of each band via data binding of the "bounds" property
var arr = bands.data.itemArray;
for (var i = 0; i < layerRects.length; i++) {
var itemdata = arr[i];
if (itemdata) {
model.setDataProperty(itemdata, "bounds", layerRects[i]);
}
}
}
};
// end BandedLDLayout
function init() {
if (window.goSamples) goSamples(); // init for these samples -- you don't need to call this
var $ = go.GraphObject.make;
myDiagram = $(go.Diagram, "myDiagramDiv",
{
initialContentAlignment: go.Spot.Center,
layout: $(BandedLDLayout,
{
direction: HORIZONTAL ? 0 : 90
}), // custom layout is defined above
"undoManager.isEnabled": true
});
myDiagram.nodeTemplate =
$(go.Node, go.Panel.Auto,
$(go.Shape, "Rectangle",
{ fill: "white" }),
$(go.TextBlock, { margin: 5 },
new go.Binding("text", "key")));
// There should be at most a single object of this category.
// This Part will be modified by BandedLDLayout.commitLayers to display visual "bands"
// where each "layer" is a layer of the tree.
// This template is parameterized at load time by the HORIZONTAL parameter.
// You also have the option of showing rectangles for the layer bands or
// of showing separator lines between the layers, but not both at the same time,
// by commenting in/out the indicated code.
myDiagram.nodeTemplateMap.add("Bands",
$(go.Part, "Position",
new go.Binding("itemArray"),
{
isLayoutPositioned: false, // but still in document bounds
locationSpot: new go.Spot(0, 0, HORIZONTAL ? 0 : 16, HORIZONTAL ? 16 : 0), // account for header height
layerName: "Background",
pickable: false,
selectable: false,
itemTemplate:
$(go.Panel, HORIZONTAL ? "Vertical" : "Horizontal",
new go.Binding("position", "bounds", function(b) { return b.position; }),
$(go.TextBlock,
{
angle: HORIZONTAL ? 0 : 270,
textAlign: "center",
wrap: go.TextBlock.None,
font: "bold 11pt sans-serif",
background: $(go.Brush, "Linear", { 0: "aqua", 1: go.Brush.darken("aqua") })
},
new go.Binding("text"),
// always bind "width" because the angle does the rotation
new go.Binding("width", "bounds", function(r) { return HORIZONTAL ? r.width : r.height; })
),
// option 1: rectangular bands:
$(go.Shape,
{ stroke: null, strokeWidth: 0 },
new go.Binding("desiredSize", "bounds", function(r) { return r.size; }),
new go.Binding("fill", "itemIndex", function(i) { return i % 2 == 0 ? "whitesmoke" : go.Brush.darken("whitesmoke"); }).ofObject())
// option 2: separator lines:
//(HORIZONTAL
// ? $(go.Shape, "LineV",
// { stroke: "gray", alignment: go.Spot.TopLeft, width: 1 },
// new go.Binding("height", "bounds", function(r) { return r.height; }),
// new go.Binding("visible", "itemIndex", function(i) { return i > 0; }).ofObject())
// : $(go.Shape, "LineH",
// { stroke: "gray", alignment: go.Spot.TopLeft, height: 1 },
// new go.Binding("width", "bounds", function(r) { return r.width; }),
// new go.Binding("visible", "itemIndex", function(i) { return i > 0; }).ofObject())
//)
)
}
));
myDiagram.linkTemplate =
$(go.Link,
$(go.Shape)); // simple black line, no arrowhead needed
// define the tree node data
var nodearray = [
{ // this is the information needed for the headers of the bands
key: "_BANDS",
category: "Bands",
itemArray: [
{ text: "Zero" },
{ text: "One" },
{ text: "Two" },
{ text: "Three" },
{ text: "Four" },
{ text: "Five" }
]
},
// these are the regular nodes in the TreeModel
{ key: "root" },
{ key: "oneB", parent: "root" },
{ key: "twoA", parent: "oneB", layer: 0 },
{ key: "twoC", parent: "root" },
{ key: "threeC", parent: "twoC" },
{ key: "threeD", parent: "twoC" },
{ key: "fourB", parent: "threeD", layer: 2 },
{ key: "fourC", parent: "twoC", layer: 0 },
{ key: "fourD", parent: "fourB" },
{ key: "twoD", parent: "root", layer: 1 }
];
myDiagram.model = new go.TreeModel(nodearray);
}
