Add isMobile context key (microsoft#160676)

Author: joyceerhl

src/vs/base/common/platform.ts

@@ -15,6 +15,7 @@ let _isWeb = false;
 let _isElectron = false;
 let _isIOS = false;
 let _isCI = false;
+let _isMobile = false;
 let _locale: string | undefined = undefined;
 let _language: string = LANGUAGE_DEFAULT;
 let _translationsConfigFile: string | undefined = undefined;
@@ -79,6 +80,7 @@ if (typeof navigator === 'object' && !isElectronRenderer) {
 	_isMacintosh = _userAgent.indexOf('Macintosh') >= 0;
 	_isIOS = (_userAgent.indexOf('Macintosh') >= 0 || _userAgent.indexOf('iPad') >= 0 || _userAgent.indexOf('iPhone') >= 0) && !!navigator.maxTouchPoints && navigator.maxTouchPoints > 0;
 	_isLinux = _userAgent.indexOf('Linux') >= 0;
+	_isMobile = _userAgent?.indexOf('Mobi') >= 0;
 	_isWeb = true;
 
 	const configuredLocale = nls.getConfiguredDefaultLocale(
@@ -157,6 +159,7 @@ export const isElectron = _isElectron;
 export const isWeb = _isWeb;
 export const isWebWorker = (_isWeb && typeof globals.importScripts === 'function');
 export const isIOS = _isIOS;
+export const isMobile = _isMobile;
 /**
  * Whether we run inside a CI environment, such as
  * GH actions or Azure Pipelines.

src/vs/platform/contextkey/common/contextkeys.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { isIOS, isLinux, isMacintosh, isWeb, isWindows } from 'vs/base/common/platform';
+import { isIOS, isLinux, isMacintosh, isMobile, isWeb, isWindows } from 'vs/base/common/platform';
 import { localize } from 'vs/nls';
 import { RawContextKey } from 'vs/platform/contextkey/common/contextkey';
 
@@ -14,6 +14,7 @@ export const IsWindowsContext = new RawContextKey<boolean>('isWindows', isWindow
 export const IsWebContext = new RawContextKey<boolean>('isWeb', isWeb, localize('isWeb', "Whether the platform is a web browser"));
 export const IsMacNativeContext = new RawContextKey<boolean>('isMacNative', isMacintosh && !isWeb, localize('isMacNative', "Whether the operating system is macOS on a non-browser platform"));
 export const IsIOSContext = new RawContextKey<boolean>('isIOS', isIOS, localize('isIOS', "Whether the operating system is iOS"));
+export const IsMobileContext = new RawContextKey<boolean>('isMobile', isMobile, localize('isMobile', "Whether the platform is a mobile web browser"));
 
 export const IsDevelopmentContext = new RawContextKey<boolean>('isDevelopment', false, true);
 export const ProductQualityContext = new RawContextKey<string>('productQualityType', '', localize('productQualityType', "Quality type of VS Code"));