automatic dark/light theme - fixes #3934

tabby-electron/src/services/electron.service.ts

@@ -1,5 +1,5 @@
 import { Injectable } from '@angular/core'
-import { App, IpcRenderer, Shell, Dialog, Clipboard, GlobalShortcut, Screen, AutoUpdater, TouchBar, BrowserWindow, Menu, MenuItem, PowerSaveBlocker } from 'electron'
+import { App, IpcRenderer, Shell, Dialog, Clipboard, GlobalShortcut, Screen, AutoUpdater, TouchBar, BrowserWindow, Menu, MenuItem, PowerSaveBlocker, NativeTheme } from 'electron'
 import * as remote from '@electron/remote'
 
 export interface MessageBoxResponse {
@@ -20,6 +20,7 @@ export class ElectronService {
     process: any
     autoUpdater: AutoUpdater
     powerSaveBlocker: PowerSaveBlocker
+    nativeTheme: NativeTheme
     TouchBar: typeof TouchBar
     BrowserWindow: typeof BrowserWindow
     Menu: typeof Menu
@@ -43,5 +44,7 @@ export class ElectronService {
         this.BrowserWindow = remote.BrowserWindow
         this.Menu = remote.Menu
         this.MenuItem = remote.MenuItem
+        this.MenuItem = remote.MenuItem
+        this.nativeTheme = remote.nativeTheme
     }
 }

tabby-electron/src/services/platform.service.ts

@@ -10,6 +10,7 @@ import { ElectronService } from '../services/electron.service'
 import { ElectronHostWindow } from './hostWindow.service'
 import { ShellIntegrationService } from './shellIntegration.service'
 import { ElectronHostAppService } from './hostApp.service'
+import { PlatformTheme } from '../../../tabby-core/src/api/platform'
 const fontManager = require('fontmanager-redux') // eslint-disable-line
 
 /* eslint-disable block-scoped-var */
@@ -40,6 +41,10 @@ export class ElectronPlatformService extends PlatformService {
         electron.ipcRenderer.on('host:display-metrics-changed', () => {
             this.zone.run(() => this.displayMetricsChanged.next())
         })
+
+        electron.nativeTheme.on('updated', () => {
+            this.zone.run(() => this.themeChanged.next(this.getTheme()))
+        })
     }
 
     readClipboard (): string {
@@ -243,6 +248,14 @@ export class ElectronPlatformService extends PlatformService {
             },
         )).filePaths[0]
     }
+
+    getTheme (): PlatformTheme {
+        if (this.electron.nativeTheme.shouldUseDarkColors) {
+            return 'dark'
+        } else {
+            return 'light'
+        }
+    }
 }
 
 class ElectronFileUpload extends FileUpload {