I modified the existing Custom Context Menu sample by adding a second context menu in HTML and by setting the class of both context menu elements to be “contextMenu”, and by registering “contextmenu” and “blur” event handlers on both context menus.
Then I modified the showContextMenu
function to look at the Part.data of the object that was context-clicked and decide which context menu HTML element should become visible.
<!DOCTYPE html>
<html>
<head>
<title>HTML Context Menu</title>
<meta name="description" content="Context menus implemented in HTML rather than as GoJS objects." />
<!-- Copyright 1998-2016 by Northwoods Software Corporation. -->
<meta charset="UTF-8">
<style type="text/css">
/* CSS for the traditional context menu */
.contextMenu {
z-index: 300;
position: absolute;
left: 5px;
border: 1px solid #444;
background-color: #F5F5F5;
display: none;
box-shadow: 0 0 10px rgba( 0, 0, 0, .4 );
font-size: 12px;
font-family: sans-serif;
font-weight:bold;
}
.contextMenu ul {
list-style: none;
top: 0;
left: 0;
margin: 0;
padding: 0;
}
.contextMenu li {
position: relative;
min-width: 60px;
color: #444;
display: inline-block;
padding: 6px;
text-decoration: none;
cursor: default;
}
.contextMenu li:hover { background: #444; }
.contextMenu li:hover { color: #EEE; }
</style>
<script src="go.js"></script>
<link href="../assets/css/goSamples.css" rel="stylesheet" type="text/css" /> <!-- you don't need to use this -->
<script src="goSamples.js"></script> <!-- this is only for the GoJS Samples framework -->
<script id="code">
var myDiagram = null;
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
myDiagram =
$(go.Diagram, "myDiagramDiv", // create a Diagram for the DIV HTML element
{ initialContentAlignment: go.Spot.Center, "undoManager.isEnabled": true });
// define a simple Node template (but use the default Link template)
myDiagram.nodeTemplate =
$(go.Node, "Auto",
// We make a dummy context menu so that the contextMenuTool will activate,
// but we don't use this adornment
{ contextMenu: $(go.Adornment) },
$(go.Shape, "RoundedRectangle",
// Shape.fill is bound to Node.data.color
new go.Binding("fill", "color")),
$(go.TextBlock,
{ margin: 3 }, // some room around the text
// TextBlock.text is bound to Node.data.key
new go.Binding("text", "key"))
);
// create the model data that will be represented by Nodes and Links
myDiagram.model = new go.GraphLinksModel(
[
{ key: "Alpha", color: "lightblue" },
{ key: "Beta", color: "orange" },
{ key: "Gamma", color: "lightgreen" },
{ key: "Delta", color: "pink" }
],
[
{ from: "Alpha", to: "Beta" },
{ from: "Alpha", to: "Gamma" },
{ from: "Beta", to: "Beta" },
{ from: "Gamma", to: "Delta" },
{ from: "Delta", to: "Alpha" }
]);
// This is a dummy context menu for the whole Diagram:
myDiagram.contextMenu = $(go.Adornment);
// Override the ContextMenuTool.showContextMenu and hideContextMenu methods
// in order to modify the HTML appropriately.
var cxTool = myDiagram.toolManager.contextMenuTool;
// This is the override of ContextMenuTool.showContextMenu:
// This does not not need to call the base method.
cxTool.showContextMenu = function(contextmenu, obj) {
var diagram = this.diagram;
if (diagram === null) return;
// Hide any other existing context menu
if (contextmenu !== this.currentContextMenu) {
this.hideContextMenu();
}
// Show only the relevant buttons given the current state.
var cmd = diagram.commandHandler;
var objExists = obj !== null;
document.getElementById("cut").style.display = objExists && cmd.canCutSelection() ? "block" : "none";
document.getElementById("copy").style.display = objExists && cmd.canCopySelection() ? "block" : "none";
document.getElementById("paste1").style.display = cmd.canPasteSelection() ? "block" : "none";
document.getElementById("paste2").style.display = cmd.canPasteSelection() ? "block" : "none";
document.getElementById("delete").style.display = objExists && cmd.canDeleteSelection() ? "block" : "none";
document.getElementById("color").style.display = objExists ? "block" : "none";
if (objExists && obj.part.data.color === "orange") {
// Now show the whole context menu element
cxElement1.style.display = "block";
// we don't bother overriding positionContextMenu, we just do it here:
var mousePt = diagram.lastInput.viewPoint;
cxElement1.style.left = mousePt.x + "px";
cxElement1.style.top = mousePt.y + "px";
} else {
// Now show the whole context menu element
cxElement2.style.display = "block";
// we don't bother overriding positionContextMenu, we just do it here:
var mousePt = diagram.lastInput.viewPoint;
cxElement2.style.left = mousePt.x + "px";
cxElement2.style.top = mousePt.y + "px";
}
// Remember that there is now a context menu showing
this.currentContextMenu = contextmenu;
}
// This is the corresponding override of ContextMenuTool.hideContextMenu:
// This does not not need to call the base method.
cxTool.hideContextMenu = function() {
if (this.currentContextMenu === null) return;
cxElement1.style.display = "none";
cxElement2.style.display = "none";
this.currentContextMenu = null;
}
function oncontextmenu(e) {
this.focus();
e.preventDefault();
return false;
}
function onblur(e) {
cxTool.stopTool();
// maybe start another context menu
if (cxTool.canStart()) {
myDiagram.currentTool = cxTool;
cxTool.doMouseUp();
}
}
// This is the actual HTML context menu:
var cxElement1 = document.getElementById("contextMenu1");
// We don't want the div acting as a context menu to have a (browser) context menu!
cxElement1.addEventListener("contextmenu", oncontextmenu, false);
cxElement1.addEventListener("blur", onblur, false);
cxElement1.tabIndex = "1";
// This is the actual HTML context menu:
var cxElement2 = document.getElementById("contextMenu2");
// We don't want the div acting as a context menu to have a (browser) context menu!
cxElement2.addEventListener("contextmenu", oncontextmenu, false);
cxElement2.addEventListener("blur", onblur, false);
cxElement2.tabIndex = "1";
}
// This is the general menu command handler, parameterized by the name of the command.
function cxcommand(val) {
var diagram = myDiagram;
if (!(diagram.currentTool instanceof go.ContextMenuTool)) return;
switch (val) {
case "Cut": diagram.commandHandler.cutSelection(); break;
case "Copy": diagram.commandHandler.copySelection(); break;
case "Paste": diagram.commandHandler.pasteSelection(diagram.lastInput.documentPoint); break;
case "Delete": diagram.commandHandler.deleteSelection(); break;
case "Color": changeColor(diagram); break;
}
diagram.currentTool.stopTool();
}
// A custom command, for changing the color of the selected node(s).
function changeColor(diagram) {
// the object with the context menu, in this case a Node, is accessible as:
var cmObj = diagram.toolManager.contextMenuTool.currentObject;
// but this function operates on all selected Nodes, not just the one at the mouse pointer.
// Always make changes in a transaction, except when initializing the diagram.
diagram.startTransaction("change color");
diagram.selection.each(function(node) {
if (node instanceof go.Node) { // ignore any selected Links and simple Parts
// Examine and modify the data, not the Node directly.
var data = node.data;
if (data.color === "red") {
// Call setDataProperty to support undo/redo as well as
// automatically evaluating any relevant bindings.
diagram.model.setDataProperty(data, "color", go.Brush.randomColor());
} else {
diagram.model.setDataProperty(data, "color", "red");
}
}
});
diagram.commitTransaction("change color");
}
</script>
</head>
<body onload="init()">
<div id="sample">
<p>HTML Context menu <b>GoJS</b> Sample</p>
<div style="display: inline-block;">
<!-- We make a div to contain both the Diagram div and the context menu (such that they are siblings)
so that absolute positioning works easily.
This DIV containing both MUST have a non-static CSS position (we use position: relative)
so that our context menu's absolute coordinates work correctly. -->
<div style="position: relative;" >
<div id="myDiagramDiv" style="border: solid 1px black; width:400px; height:400px"></div>
<div id="contextMenu1" class="contextMenu">
<ul>
<li id="cut" onclick="cxcommand(this.textContent)">Cut</li>
<li id="copy" onclick="cxcommand(this.textContent)">Copy</li>
<li id="paste1" onclick="cxcommand(this.textContent)">Paste</li>
<li id="delete" onclick="cxcommand(this.textContent)">Delete</li>
</ul>
</div>
<div id="contextMenu2" class="contextMenu">
<ul>
<li id="paste2" onclick="cxcommand(this.textContent)">Paste</li>
<li id="color" onclick="cxcommand('Color')">Color</li>
</ul>
</div>
</div>
<div id="description">
</div>
</div>
</div>
</body>
</html>