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, . . .,
//     . . .
//       $(go.TextBlock, { textEditor: window.TextEditorSelectBox, . . . })
//     . . .
//   )
// ```
// see /samples/customTextEditingTool.html
// see also textEditorRadioButton.js for another custom editor
// see also textEditor.html for a re-implementation of the default text editor
((window) => {
    const inputElement = document.createElement('nav');
    const customEditor = new go.HTMLInfo();
    customEditor.show = (textBlock, diagram, tool) => {
        if (!(textBlock instanceof go.TextBlock))
            return;
        // Populate the select box:
        inputElement.innerHTML = '';
        var part = textBlock.part;
        const choices = textBlock.choices; // Array of choice strings
        const initialValue = textBlock.text; // Selected option initially
        const loc = textBlock.getDocumentPoint(go.Spot.TopLeft);
        const pos = diagram.transformDocToView(loc);
        inputElement.style.border = '1px solid #ccc';
        inputElement.style.padding = '8px';
        inputElement.style.cursor = 'pointer';
        inputElement.style.backgroundColor = '#fff';
        inputElement.style.borderRadius = '4px'; // Rounded corners
        inputElement.style.boxShadow = '0 2px 5px rgba(0, 0, 0, 0.1)';
        inputElement.style.position = 'absolute';
        inputElement.style.left = `${pos.x}px`;
        inputElement.style.top = `${pos.y + 13}px`;
        inputElement.style.zIndex = '100';
        // Add transition for smooth effect
        inputElement.style.transition = 'border-color 0.2s';
        inputElement.value = initialValue;  // ensure value is set to current text
        
        const dropdownList = document.createElement('ul');
        dropdownList.style.listStyleType = 'none';
        dropdownList.style.margin = '0';
        dropdownList.style.padding = '0';
        dropdownList.style.border = '1px solid #ccc';
        dropdownList.style.borderRadius = '4px'; // Rounded corners
        dropdownList.style.maxHeight = '200px'; // Maximum height
        dropdownList.style.overflowY = 'auto'; // Scroll if too many items
        dropdownList.style.backgroundColor = '#fff';
        // Populate the dropdown list
        choices.forEach(choice => {
          const listItem = document.createElement('li');
          listItem.innerText = choice;
          listItem.style.padding = '8px'; // Padding for list items
          listItem.style.cursor = 'pointer';
          listItem.style.width = '20rem';
          listItem.style.border = '0.1rem solid #e7e7e7';
          initialValue === choice ? listItem.style.backgroundColor = 'blue' : true;

          // Add hover effect
          listItem.addEventListener('mouseenter', () => {
            initialValue !== choice ? listItem.style.backgroundColor = '#e9e9e9' : true; // Highlight on hover
          });
          listItem.addEventListener('mouseleave', () => {
            initialValue !== choice ? listItem.style.backgroundColor = 'white' : true;
          });

          // Handle the selection
          listItem.addEventListener('click', () => selectChoice(choice));
          dropdownList.appendChild(listItem);
        });
       inputElement.appendChild(dropdownList);
        diagram.div?.appendChild(inputElement);

        var selectChoice = (choice) => {
          inputElement.value = choice;
          tool.acceptText(go.TextEditingAccept.Tab);
        };
    };
    customEditor.hide = (diagram, tool) => {
        if (diagram.div !== null)
            diagram.div.removeChild(inputElement);
    };
    customEditor.valueFunction = () => inputElement.value;
    window.TextEditorSelectBox = customEditor;
})(window);