491239/index.html

## index.html
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Elecrtron Bluetooth Test</title>
    <script src="renderer.js"></script>
</head>
<body>
    <h3>Elecrtron Bluetooth Test</h3>
    <button id="scan">scan</button>
    <button id="cancel">cancel</button>
    <ul id="device-list"></ul>
</body>
</html>

## main.js
const { ipcMain, app, BrowserWindow } = require('electron')
const path = require('path')

let win = null;
var callbackForBluetoothEvent = null;

// Create the browser window.
function createWindow () {

  win = new BrowserWindow({
    webPreferences: {
      preload: path.join(__dirname, 'preload.js')
    }
  })

  win.maximize();
  win.webContents.openDevTools();
  win.loadFile("index.html");

  //This sender sends the devicelist from the main process to all renderer processes
  win.webContents.on('select-bluetooth-device', (event, deviceList, callback) => {
    event.preventDefault(); //important, otherwise first available device will be selected
    let bluetoothDeviceList = deviceList;
    callbackForBluetoothEvent = callback; //to make it accessible outside createWindow()

    win.webContents.send('channelForBluetoothDeviceList', bluetoothDeviceList);
  });
}

app.on('ready', createWindow);

//cancels Discovery
ipcMain.on('channelForTerminationSignal', _ => {
  console.log("Cancel Discovery");
  if (callbackForBluetoothEvent) {
    callbackForBluetoothEvent(''); //reference to callback of win.webContents.on('select-bluetooth-device'...)
    console.log("Discovery cancelled");
  }
});

//resolves navigator.bluetooth.requestDevice() and stops device discovery
ipcMain.on('channelForSelectingDevice', (event, DeviceId) => {
  callbackForBluetoothEvent(DeviceId); //reference to callback of win.webContents.on('select-bluetooth-device'...)
  console.log("Device selected, discovery finished");
});

## package.json
{
  "name": "stormy-teaching-trick-204bh",
  "productName": "stormy-teaching-trick-204bh",
  "description": "My Electron application description",
  "keywords": [],
  "main": "./main.js",
  "version": "1.0.0",
  "author": "ENERGIZE230228",
  "scripts": {
    "start": "electron ."
  },
  "dependencies": {},
  "devDependencies": {
    "electron": "35.1.5"
  }
}

## preload.js


const { ipcRenderer, contextBridge } = require('electron');


contextBridge.exposeInMainWorld('bluetooth', {
  onFoundDevice: (callback) => {
    ipcRenderer.on('channelForBluetoothDeviceList', (event, list) => callback(list));
  },
  cancelScan: () => {
    ipcRenderer.send('channelForTerminationSignal');
  },
  selectDevice: (deviceId) => {
    ipcRenderer.send('channelForSelectingDevice', deviceId);
  }
});

## renderer.js

let deviceListEl;

window.onload = function () {
  deviceListEl = document.getElementById('device-list');
  let scanEl = document.getElementById('scan');
  let cancelEl = document.getElementById('cancel');

  scanEl.addEventListener('click', _ => {
    navigator.bluetooth.requestDevice(
      {
        // filters: [{ services: [0xffff] }],
        acceptAllDevices: true
      }
    ).then(device => {
      // console.log(device);
    }).catch(error => {
      console.log(error);
    });
  });

  cancelEl.addEventListener('click', _ => {
    bluetooth.cancelScan();
  });

  bluetooth.onFoundDevice((list) => {
    //console.log(list);
    deviceListEl.innerHTML = '';
    list.forEach(device => {
      let option = document.createElement('li');
      option.innerHTML = device.deviceName;
      option.addEventListener('click', _ => {
        bluetooth.selectDevice(device.deviceId);
      });
      // console.log(option);
      deviceListEl.appendChild(option);
    });
  })
}

## styles.css
/* styles.css */

/* Add styles here to customize the appearance of your app */
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Elecrtron Bluetooth Test</title>
	<script src="renderer.js"></script>
	</head>
	<body>
	<h3>Elecrtron Bluetooth Test</h3>
	<button id="scan">scan</button>
	<button id="cancel">cancel</button>
	<ul id="device-list"></ul>
	</body>
	</html>
	const { ipcMain, app, BrowserWindow } = require('electron')
	const path = require('path')

	let win = null;
	var callbackForBluetoothEvent = null;

	// Create the browser window.
	function createWindow () {

	win = new BrowserWindow({
	webPreferences: {
	preload: path.join(__dirname, 'preload.js')
	}
	})

	win.maximize();
	win.webContents.openDevTools();
	win.loadFile("index.html");

	//This sender sends the devicelist from the main process to all renderer processes
	win.webContents.on('select-bluetooth-device', (event, deviceList, callback) => {
	event.preventDefault(); //important, otherwise first available device will be selected
	let bluetoothDeviceList = deviceList;
	callbackForBluetoothEvent = callback; //to make it accessible outside createWindow()

	win.webContents.send('channelForBluetoothDeviceList', bluetoothDeviceList);
	});
	}

	app.on('ready', createWindow);

	//cancels Discovery
	ipcMain.on('channelForTerminationSignal', _ => {
	console.log("Cancel Discovery");
	if (callbackForBluetoothEvent) {
	callbackForBluetoothEvent(''); //reference to callback of win.webContents.on('select-bluetooth-device'...)
	console.log("Discovery cancelled");
	}
	});

	//resolves navigator.bluetooth.requestDevice() and stops device discovery
	ipcMain.on('channelForSelectingDevice', (event, DeviceId) => {
	callbackForBluetoothEvent(DeviceId); //reference to callback of win.webContents.on('select-bluetooth-device'...)
	console.log("Device selected, discovery finished");
	});
	{
	"name": "stormy-teaching-trick-204bh",
	"productName": "stormy-teaching-trick-204bh",
	"description": "My Electron application description",
	"keywords": [],
	"main": "./main.js",
	"version": "1.0.0",
	"author": "ENERGIZE230228",
	"scripts": {
	"start": "electron ."
	},
	"dependencies": {},
	"devDependencies": {
	"electron": "35.1.5"
	}
	}


	const { ipcRenderer, contextBridge } = require('electron');


	contextBridge.exposeInMainWorld('bluetooth', {
	onFoundDevice: (callback) => {
	ipcRenderer.on('channelForBluetoothDeviceList', (event, list) => callback(list));
	},
	cancelScan: () => {
	ipcRenderer.send('channelForTerminationSignal');
	},
	selectDevice: (deviceId) => {
	ipcRenderer.send('channelForSelectingDevice', deviceId);
	}
	});

	let deviceListEl;

	window.onload = function () {
	deviceListEl = document.getElementById('device-list');
	let scanEl = document.getElementById('scan');
	let cancelEl = document.getElementById('cancel');

	scanEl.addEventListener('click', _ => {
	navigator.bluetooth.requestDevice(
	{
	// filters: [{ services: [0xffff] }],
	acceptAllDevices: true
	}
	).then(device => {
	// console.log(device);
	}).catch(error => {
	console.log(error);
	});
	});

	cancelEl.addEventListener('click', _ => {
	bluetooth.cancelScan();
	});

	bluetooth.onFoundDevice((list) => {
	//console.log(list);
	deviceListEl.innerHTML = '';
	list.forEach(device => {
	let option = document.createElement('li');
	option.innerHTML = device.deviceName;
	option.addEventListener('click', _ => {
	bluetooth.selectDevice(device.deviceId);
	});
	// console.log(option);
	deviceListEl.appendChild(option);
	});
	})
	}
	/* styles.css */

	/* Add styles here to customize the appearance of your app */