main_process.js

const electron = require("electron");
// Inter-process Communication for the Main Process
const ipcMain = electron.ipcMain;
const app = electron.app;
const BrowserWindow = electron.BrowserWindow;

const path = require("path");
const url = require("url");

// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is garbage collected.
let mainWindow;

let isWindowSmall = false;

function createWindow() {
    // Create the browser window.
    mainWindow = new BrowserWindow({width: 350, height: 700});
    mainWindow.setMenu(null);

    resetPos(); // Move window into position

    // and load the index.html of the app.
    mainWindow.loadURL(url.format({
        pathname: path.join(__dirname, "/public/index.html"),
        protocol: "file:",
        slashes: true,
    }));

    // Open the DevTools.
    //mainWindow.webContents.openDevTools();

    // Makes the window stay always on top
    mainWindow.setAlwaysOnTop(true, "floating");
    mainWindow.setVisibleOnAllWorkspaces(true);
    mainWindow.setFullScreenable(false);

    // Emitted when the window is closed.
    mainWindow.on("closed", function () {
        // Dereference the window object, usually you would store windows
        // in an array if your app supports multi windows, this is the time
        // when you should delete the corresponding element.
        mainWindow = null;
    })
}

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.on("ready", createWindow);

// Quit when all windows are closed.
app.on("window-all-closed", function () {
    // On OS X it is common for applications and their menu bar
    // to stay active until the user quits explicitly with Cmd + Q
    if (process.platform !== "darwin") {
        app.quit();
    }
});

app.on("activate", function () {
    // On OS X it's common to re-create a window in the app when the
    // dock icon is clicked and there are no other windows open.
    if (mainWindow === null) {
        createWindow();
    }
});

const expandWindow = function () {
    isWindowSmall = false;
    mainWindow.setSize(335, 700);
    resetPos();
};

const shrinkWindow = function () {
    isWindowSmall = true;
    mainWindow.setSize(335, 350);
    resetPos();
};

// When the Main process receives a Receive message
// Shrink if expanded and Expand if the window is shrunk
ipcMain.on("resize", function (e) {
    isWindowSmall ? expandWindow() : shrinkWindow()
});

// Resets the window position to bottom right of the screen
const resetPos = function () {
    screenSize = electron.screen.getPrimaryDisplay().workAreaSize;
    windowSize = mainWindow.getSize();
    mainWindow.setPosition(screenSize.width - windowSize[0], screenSize.height - windowSize[1]);
};