function init() {
  var $ = go.GraphObject.make;

  myDiagram =
    $(go.Diagram, "myDiagramDiv",
      {
        // default text editor is now a SelectBox
        'textEditingTool.defaultTextEditor': window.TextEditorSelectBox, // defined in textEditorSelectBox.js
        'textEditingTool.starting': go.TextEditingStarting.SingleClick,
        "undoManager.isEnabled": true
      }
    );

  // define a simple Node template
  myDiagram.nodeTemplate =
    $(go.Node, "Auto",  // the Shape will go around the TextBlock
      $(go.Shape, "RoundedRectangle", { strokeWidth: 0 },
        // Shape.fill is bound to Node.data.color
        new go.Binding("fill", "color")),
      $(go.TextBlock,
        { margin: 8, editable: true, text: 'Alpha' },  // some room around the text
        new go.Binding('choices'))
    );

  // but use the default Link template, by not setting Diagram.linkTemplate

  // create the model data that will be represented by Nodes and Links
  myDiagram.model = new go.GraphLinksModel(
  [
    { key: "Alpha", color: "lightblue", choices: ['Alpha', 'Beta', 'Gamma', 'Theta'] },
    { key: "Beta", color: "orange", choices: ['Alpha', 'Beta', 'Gamma', 'Theta'] },
    { key: "Gamma", color: "lightgreen", choices: ['Alpha', 'Beta', 'Gamma', 'Theta'] },
    { key: "Delta", color: "pink", choices: ['Alpha', 'Beta', 'Gamma', 'Theta'] }
  ],
  [
    { from: "Alpha", to: "Beta" },
    { from: "Alpha", to: "Gamma" },
    { from: "Beta", to: "Beta" },
    { from: "Gamma", to: "Delta" },
    { from: "Delta", to: "Alpha" }
  ]);
}

/*
 *  Copyright (C) 1998-2024 by Northwoods Software Corporation. All Rights Reserved.
 */
/*
 * This is an extension and not part of the main GoJS library.
 * Note that the API for this class may change with any version, even point releases.
 * If you intend to use an extension in production, you should copy the code to your own source directory.
 * Extensions can be found in the GoJS kit under the extensions or extensionsJSM folders.
 * See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
 */

// HTML + JavaScript text editor using an HTML Select Element and HTMLInfo.
// This file exposes one instance of HTMLInfo, window.TextEditorSelectBox
// Typical usage is:
// ```js
//   new go.Diagram(...,
//      {
//        "textEditingTool.defaultTextEditor": window.TextEditorSelectBox,
//        . . .
//      })
// ```
// or:
// ```js
//    myDiagram.toolManager.textEditingTool.defaultTextEditor = window.TextEditorSelectBox;
// ```
// or:
// ```js
//   $(go.Node, . . .,
//     . . .
//       $(go.TextBlock, { textEditor: window.TextEditorSelectBox, . . . })
//     . . .
//   )
// ```
// see /samples/customTextEditingTool.html
// see also textEditorRadioButton.js for another custom editor
// see also textEditor.html for a re-implementation of the default text editor
((window) => {
    const customEditor = new go.HTMLInfo();
    const customSelectBox = document.createElement('select');
    customEditor.show = (textBlock, diagram, tool) => {
        if (!(textBlock instanceof go.TextBlock))
            return;
        // Populate the select box:
        customSelectBox.innerHTML = '';
        let list = textBlock.choices;
        // Perhaps give some default choices if textBlock.choices is null
        if (list === null)
            list = ['Default A', 'Default B', 'Default C'];
        const l = list.length;
        for (let i = 0; i < l; i++) {
            const op = document.createElement('option');
            op.text = list[i];
            op.value = list[i];
            if (list[i] === textBlock.text)
                op.selected = true;
            customSelectBox.add(op);
            // consider also adding the current value, if it is not in the choices list
        }
        // After the list is populated, set the value:
        customSelectBox.value = textBlock.text;
        customSelectBox.addEventListener('change', (e) => {
          tool.acceptText(go.TextEditingAccept.Tab);
        });
        // Do a few different things when a user presses a key
        customSelectBox.addEventListener('keydown', (e) => {
            if (e.isComposing)
                return;
            const code = e.code;
            if (code === 'Enter') {
                // Accept on Enter
                tool.acceptText(go.TextEditingAccept.Enter);
            }
            else if (code === 'Tab') {
                // Accept on Tab
                tool.acceptText(go.TextEditingAccept.Tab);
                e.preventDefault();
            }
            else if (code === 'Escape') {
                // Cancel on Esc
                tool.doCancel();
                if (tool.diagram)
                    tool.diagram.focus();
            }
        }, false);
        const loc = textBlock.getDocumentPoint(go.Spot.TopLeft);
        const pos = diagram.transformDocToView(loc);
        customSelectBox.style.left = pos.x + 'px';
        customSelectBox.style.top = pos.y + 'px';
        customSelectBox.style.position = 'absolute';
        customSelectBox.style.zIndex = (100).toString(); // place it in front of the Diagram
        if (diagram.div !== null)
            diagram.div.appendChild(customSelectBox);
        customSelectBox.focus();
    };
    customEditor.hide = (diagram, tool) => {
        if (diagram.div !== null)
            diagram.div.removeChild(customSelectBox);
    };
    customEditor.valueFunction = () => customSelectBox.value;
    window.TextEditorSelectBox = customEditor;
})(window);