zulip-desktop/app/renderer/js/pages/preference/badge-settings.ts

import electron, {app} from 'electron';

import * as ConfigUtil from '../../utils/config-util';

function showBadgeCount(messageCount: number, mainWindow: electron.BrowserWindow): void {
	if (process.platform === 'win32') {
		updateOverlayIcon(messageCount, mainWindow);
	} else {
		app.badgeCount = messageCount;
	}
}

function hideBadgeCount(mainWindow: electron.BrowserWindow): void {
	if (process.platform === 'win32') {
		mainWindow.setOverlayIcon(null, '');
	} else {
		app.badgeCount = 0;
	}
}

export function updateBadge(badgeCount: number, mainWindow: electron.BrowserWindow): void {
	if (ConfigUtil.getConfigItem('badgeOption', true)) {
		showBadgeCount(badgeCount, mainWindow);
	} else {
		hideBadgeCount(mainWindow);
	}
}

function updateOverlayIcon(messageCount: number, mainWindow: electron.BrowserWindow): void {
	if (!mainWindow.isFocused()) {
		mainWindow.flashFrame(ConfigUtil.getConfigItem('flashTaskbarOnMessage'));
	}

	if (messageCount === 0) {
		mainWindow.setOverlayIcon(null, '');
	} else {
		mainWindow.webContents.send('render-taskbar-icon', messageCount);
	}
}

export function updateTaskbarIcon(data: string, text: string, mainWindow: electron.BrowserWindow): void {
	const img = electron.nativeImage.createFromDataURL(data);
	mainWindow.setOverlayIcon(img, text);
}