kralo/a_electron_auto-resize_window_to_content.md

## a_electron_auto-resize_window_to_content.md

      
    Raw
  

              a_electron_auto-resize_window_to_content.md
            
          
    resize the electron app to match the content. Might be used for web-based Asterisk BLI-Pages or other unobstrusive notifications.
Window is always on top on Ubuntu/Windows

  
## index.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
   <title>Electron Window expand/shrink Demo!</title>
</head>

<body>
  <h1>Hello World!</h1>
  We are using Node.js <span id="node-version"></span>,
  Chromium <span id="chrome-version"></span>,
  and Electron <span id="electron-version"></span>.
  <p>This Window will expand/shrink in height only. It will keep the width the user sets</p>
  <p id="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>

  <input type="button" id="addContent" value="Add Content" />
   <input type="button" id="resetter" value="Reset" />
  <!-- You can also require other files to run in this process -->
  <script src="./renderer.js"></script>
</body>

</html>

## main.js
// Modules to control application life and create native browser window
const { app, BrowserWindow } = require('electron')
const path = require('path')

let mainWindow;
function createWindow() {

  mainWindow = new BrowserWindow({
    width: 400,
    height: 600,
    alwaysOnTop: true,
    autoHideMenuBar: true,
    useContentSize: true,
    backgroundColor: '#f9f9fa',
    webPreferences: {
      preload: path.join(__dirname, 'preload.js')
    }
  })

  // and load the index.html of the app.
  mainWindow.loadFile('index.html')

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

}


moveNotification = function (event) {
  cancelMoveNotification()
}


const { ipcMain } = require('electron')
let suspected_y = -1, previous_y = -1;

cancelMoveNotification = function () {  // workaround to register potentially moved windows
  mainWindow.removeListener('move', moveNotification)
  const after = mainWindow.getBounds();

  if (after.y < previous_y) {
    // suspect that window moved upwards
    if (suspected_y < 0)
      suspected_y = previous_y;
  }
}

ipcMain.on('resize-window-content-height', (event, arg) => {
  const before = mainWindow.getContentBounds();
  const width = mainWindow.getContentSize()[0]

  mainWindow.on('move', moveNotification)

  mainWindow.setContentBounds({x:before.x, y:before.y, width:before.width,height:arg + 30}, true); // +30 because not everything is shown -.-
  const after = mainWindow.getContentBounds(); // this does not reflect potentially moved window

  if (before.height < after.height) {
    // it expanded
    previous_y = after.y
  } else {
    //it shrank
    if (suspected_y > 0) {
      //mainWindow.setContentBounds({y: suspected_y}) // does not work
      mainWindow.setContentBounds({x:after.x, y: suspected_y, width:after.width, height:after.height })
    }
    suspected_y = -1;
  }

  setTimeout(cancelMoveNotification, 200)
})

// 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.whenReady().then(() => {
  createWindow()

  app.on('activate', function () {
    // On macOS 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 (BrowserWindow.getAllWindows().length === 0) createWindow()
  })
})

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


// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and require them here.

## package.json
{
  "name": "lonely-floor-use-n68x5",
  "productName": "lonely-floor-use-n68x5",
  "description": "My Electron application description",
  "keywords": [],
  "main": "./main.js",
  "version": "1.0.0",
  "author": "max",
  "scripts": {
    "start": "electron ."
  },
  "dependencies": {},
  "devDependencies": {
    "electron": "13.1.9"
  }
}

## preload.js
// All of the Node.js APIs are available in the preload process.
// It has the same sandbox as a Chrome extension.
window.addEventListener('DOMContentLoaded', () => {
  const replaceText = (selector, text) => {
    const element = document.getElementById(selector)
    if (element) element.innerText = text
  }

  for (const type of ['chrome', 'node', 'electron']) {
    replaceText(`${type}-version`, process.versions[type])
  }
})


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

contextBridge.exposeInMainWorld(
  'electron',
  {

    resizerContent: (height) => ipcRenderer.send('resize-window-content-height', height)
  }
)


## renderer.js
// This file is required by the index.html file and will
// be executed in the renderer process for that window.
// No Node.js APIs are available in this process because
// `nodeIntegration` is turned off. Use `preload.js` to
// selectively enable features needed in the rendering
// process.


document.getElementById('addContent').addEventListener('click', (e) => {

   document.getElementById('content').innerHTML = document.getElementById('content').innerHTML + document.getElementById('content').innerHTML;
});

document.getElementById('resetter').addEventListener('click', (e) => {

   document.getElementById('content').innerText = 'this is text.';
});

// automatically resize on content change
var observer = new MutationObserver(function (mutations) {
   window.electron.resizerContent(document.body.scrollHeight)
});

var container = document.documentElement || document.body;

var config = { subtree: true, attributes: false, childList: true, characterData: false };
observer.observe(container, config);

## styles.css
/* Empty */
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>Electron Window expand/shrink Demo!</title>
	</head>

	<body>
	<h1>Hello World!</h1>
	We are using Node.js <span id="node-version"></span>,
	Chromium <span id="chrome-version"></span>,
	and Electron <span id="electron-version"></span>.
	<p>This Window will expand/shrink in height only. It will keep the width the user sets</p>
	<p id="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>

	<input type="button" id="addContent" value="Add Content" />
	<input type="button" id="resetter" value="Reset" />
	<!-- You can also require other files to run in this process -->
	<script src="./renderer.js"></script>
	</body>

	</html>
	// Modules to control application life and create native browser window
	const { app, BrowserWindow } = require('electron')
	const path = require('path')

	let mainWindow;
	function createWindow() {

	mainWindow = new BrowserWindow({
	width: 400,
	height: 600,
	alwaysOnTop: true,
	autoHideMenuBar: true,
	useContentSize: true,
	backgroundColor: '#f9f9fa',
	webPreferences: {
	preload: path.join(__dirname, 'preload.js')
	}
	})

	// and load the index.html of the app.
	mainWindow.loadFile('index.html')

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

	}


	moveNotification = function (event) {
	cancelMoveNotification()
	}


	const { ipcMain } = require('electron')
	let suspected_y = -1, previous_y = -1;

	cancelMoveNotification = function () { // workaround to register potentially moved windows
	mainWindow.removeListener('move', moveNotification)
	const after = mainWindow.getBounds();

	if (after.y < previous_y) {
	// suspect that window moved upwards
	if (suspected_y < 0)
	suspected_y = previous_y;
	}
	}

	ipcMain.on('resize-window-content-height', (event, arg) => {
	const before = mainWindow.getContentBounds();
	const width = mainWindow.getContentSize()[0]

	mainWindow.on('move', moveNotification)

	mainWindow.setContentBounds({x:before.x, y:before.y, width:before.width,height:arg + 30}, true); // +30 because not everything is shown -.-
	const after = mainWindow.getContentBounds(); // this does not reflect potentially moved window

	if (before.height < after.height) {
	// it expanded
	previous_y = after.y
	} else {
	//it shrank
	if (suspected_y > 0) {
	//mainWindow.setContentBounds({y: suspected_y}) // does not work
	mainWindow.setContentBounds({x:after.x, y: suspected_y, width:after.width, height:after.height })
	}
	suspected_y = -1;
	}

	setTimeout(cancelMoveNotification, 200)
	})

	// 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.whenReady().then(() => {
	createWindow()

	app.on('activate', function () {
	// On macOS 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 (BrowserWindow.getAllWindows().length === 0) createWindow()
	})
	})

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


	// In this file you can include the rest of your app's specific main process
	// code. You can also put them in separate files and require them here.
	{
	"name": "lonely-floor-use-n68x5",
	"productName": "lonely-floor-use-n68x5",
	"description": "My Electron application description",
	"keywords": [],
	"main": "./main.js",
	"version": "1.0.0",
	"author": "max",
	"scripts": {
	"start": "electron ."
	},
	"dependencies": {},
	"devDependencies": {
	"electron": "13.1.9"
	}
	}
	// All of the Node.js APIs are available in the preload process.
	// It has the same sandbox as a Chrome extension.
	window.addEventListener('DOMContentLoaded', () => {
	const replaceText = (selector, text) => {
	const element = document.getElementById(selector)
	if (element) element.innerText = text
	}

	for (const type of ['chrome', 'node', 'electron']) {
	replaceText(`${type}-version`, process.versions[type])
	}
	})


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

	contextBridge.exposeInMainWorld(
	'electron',
	{

	resizerContent: (height) => ipcRenderer.send('resize-window-content-height', height)
	}
	)
	// This file is required by the index.html file and will
	// be executed in the renderer process for that window.
	// No Node.js APIs are available in this process because
	// `nodeIntegration` is turned off. Use `preload.js` to
	// selectively enable features needed in the rendering
	// process.



	document.getElementById('addContent').addEventListener('click', (e) => {

	document.getElementById('content').innerHTML = document.getElementById('content').innerHTML + document.getElementById('content').innerHTML;
	});

	document.getElementById('resetter').addEventListener('click', (e) => {

	document.getElementById('content').innerText = 'this is text.';
	});

	// automatically resize on content change
	var observer = new MutationObserver(function (mutations) {
	window.electron.resizerContent(document.body.scrollHeight)
	});

	var container = document.documentElement \|\| document.body;

	var config = { subtree: true, attributes: false, childList: true, characterData: false };
	observer.observe(container, config);