kieler · Eddykasp · Sep 16, 2026 · Jul 3, 2026 · Jul 3, 2026 · Jul 3, 2026
diff --git a/frontend/blocks.js b/frontend/blocks.js
@@ -271,7 +271,7 @@ const blockDefinitionsJson = [
     message0: "%{BKY_RAILBLOCKS_CONTACT_WAIT_REACHED}",
     output: "Boolean",
     colour: 155,
-    tooltip: "Returns true if reached"
+    tooltip: "%{BKY_RAILBLOCKS_CONTACT_WAIT_REACHED_TOOLTIP}"
   },
   // Passed track sensor value
   // Shows that we passed the track sensor.
@@ -280,7 +280,7 @@ const blockDefinitionsJson = [
     message0: "%{BKY_RAILBLOCKS_CONTACT_WAIT_PASSED}",
     output: "Boolean",
     colour: 155,
-    tooltip: "Returns true if passed"
+    tooltip: "%{BKY_RAILBLOCKS_CONTACT_WAIT_PASSED_TOOLTIP}"
   },
   // Integer range
   // Is a range of integer numbers from start to end inclusive

diff --git a/frontend/index.html b/frontend/index.html
@@ -23,6 +23,7 @@
     <title> RailBlocks </title>
     <link rel="stylesheet" href="style.css">
     <link rel="icon" href="icons/favicon.png" type="image/x-icon">
+    <meta charset="UTF-8">
 </head>
 
 <body>
@@ -44,14 +45,7 @@ <h1> RailBlocks </h1>
             </button>
             <div id="language_menu" style="display: none;" class="language_menu_panel">
                 <span id="editorLanguage" class="language_menu_label">Editor language</span>
-                <button type="button" class="language_option" data-language="de">
-                    <span class="language_option_marker" aria-hidden="true"></span>
-                    <span id="language_de_label">Deutsch</span>
-                </button>
-                <button type="button" class="language_option" data-language="en">
-                    <span class="language_option_marker" aria-hidden="true"></span>
-                    <span id="language_en_label">English</span>
-                </button>
+                <div id="language_options"></div>
             </div>
         </div>
 

diff --git a/frontend/localization.js b/frontend/localization.js
@@ -19,14 +19,16 @@
 import * as Blockly from 'blockly/core'
 import { en_locale } from '../locales/en/en_locale'
 import { de_locale } from '../locales/de/de_locale'
+import { zh_locale } from '../locales/zh/zh_locale'
 
 
 const LANGUAGE_STORAGE_KEY = 'railblocks.language'
 
 // This file contains constants related to localization, such as retrieving the correct labels for the current language and applying the selected language to the Blockly editor and the page.
-const LANGUAGE_CONFIGS = {
+export const LANGUAGE_CONFIGS = {
   en: en_locale,
-  de: de_locale
+  de: de_locale,
+  zh: zh_locale
 }
 
 /**

diff --git a/frontend/main.js b/frontend/main.js
@@ -24,7 +24,7 @@ import './dynamic_blocks.js'
 import './validators.js' 
 import { blockDefinitionsJson, createToolbox } from './blocks.js'
 import { compile } from './generator.js'
-import { getLabel, getToolBoxLabels, getHtmlLabels, getStoredLanguage, applyLanguage, LANGUAGE_STORAGE_KEY } from './localization.js'
+import { getLabel, getToolBoxLabels, getHtmlLabels, getStoredLanguage, applyLanguage, LANGUAGE_STORAGE_KEY, LANGUAGE_CONFIGS } from './localization.js'
 
 // MAIN PROGRAM
 const workspaceStorageKey = 'railblocks.workspace'
@@ -54,11 +54,42 @@ const theme = Blockly.Theme.defineTheme('theme', {
 
 // language menu elements
 const languageMenu = document.getElementById('language_menu')
+const languageOptionsContainer = document.getElementById('language_options')
 const languageButton = document.getElementById('button_language')
 const simulationButton = document.getElementById('button_sim')
 const runButton = document.getElementById('button_run')
 const settingsButton = document.getElementById('button_options')
 const saveButton = document.getElementById('button_save')
+
+/**
+ * Creates a language option button for the language switcher.
+ * @param {String} languageId The id of the language to render.
+ * @param {Object} languageConfig The config entry for the language.
+ * @returns {HTMLButtonElement} The rendered language button.
+ */
+function createLanguageOptionButton (languageId, languageConfig) {
+  const button = document.createElement('button')
+  button.type = 'button'
+  button.className = 'language_option'
+  button.dataset.language = languageId
+  button.setAttribute('aria-pressed', 'false')
+
+  const marker = document.createElement('span')
+  marker.className = 'language_option_marker'
+  marker.setAttribute('aria-hidden', 'true')
+
+  const label = document.createElement('span')
+  label.className = 'language_option_label'
+  label.textContent = languageConfig.label
+
+  button.append(marker, label)
+  return button
+}
+
+Object.entries(LANGUAGE_CONFIGS).forEach(([languageId, languageConfig]) => {
+  languageOptionsContainer.appendChild(createLanguageOptionButton(languageId, languageConfig))
+})
+
 const languageOptions = Array.from(document.querySelectorAll('.language_option'))
 
 /** 
@@ -75,8 +106,13 @@ function applyHtmlLabels (languageId) {
   settingsButton.title = labels.optionsTitle
   saveButton.title = labels.saveTitle
   document.getElementById('editorLanguage').textContent = labels.languageMenuLabel
-  document.getElementById('language_de_label').textContent = getLabel('de')
-  document.getElementById('language_en_label').textContent = getLabel('en')
+  languageOptions.forEach(option => {
+    const languageId = option.dataset.language
+    const label = option.querySelector('.language_option_label')
+    if (label && languageId) {
+      label.textContent = getLabel(languageId)
+    }
+  })
   document.getElementById('fileLoadLabel').title = labels.loadTitle
   document.getElementById("generatedCodeTitle").textContent = labels.generatedCodeTitle
   document.getElementById("logsTitle").textContent = labels.logsTitle

diff --git a/locales/de/de_locale.js b/locales/de/de_locale.js
@@ -32,8 +32,8 @@ export const de_locale = {
       generatedCodeTitle: 'Generierter RailSL',
       logsTitle: 'Protokolle',
       deployConfirm: 'Wirklich auf der Anlage ausführen?',
-      saveTitle: 'Aktuellen Arbeitsbereich auf der Festplatte speichern',
-      loadTitle: 'Arbeitsbereich von der Festplatte laden',
+      saveTitle: 'Aktuellen Arbeitsbereich speichern',
+      loadTitle: 'Arbeitsbereich laden',
       attributionsTitle: 'Danksagungen',
       attributionsText: 'Bilder erstellt und verteilt von user jucy_fish (Zugsymbol), Freepik (Sanduhr-GIF), <a href="https://www.flaticon.com/" title="icons source 1">Flaticon</a> und <a href="https://www.svgrepo.com" title="icons source 2">svgrepo</a>.'
     },

diff --git a/locales/de/de_tokens.js b/locales/de/de_tokens.js
@@ -35,7 +35,9 @@ export const de_tokens = {
   RAILBLOCKS_CONTACT_WAIT_TEXT: 'Warte bis %2 Kontakt von %3 %1 wurde',
   RAILBLOCKS_CONTACT_WAIT_TOOLTIP: 'Tue nichts bis ein Zug mit einem Gleis interagiert.',
   RAILBLOCKS_CONTACT_WAIT_REACHED: 'erreicht',
+  RAILBLOCKS_CONTACT_WAIT_REACHED_TOOLTIP: 'Gibt wahr zurück wenn der Kontakt erreicht wird.',
   RAILBLOCKS_CONTACT_WAIT_PASSED: 'passiert',
+  RAILBLOCKS_CONTACT_WAIT_PASSED_TOOLTIP: 'Gibt wahr zurück wenn der Kontakt passiert wurde.',
   RAILBLOCKS_CONTACT_WAIT_FIRST: 'erster',
   RAILBLOCKS_CONTACT_WAIT_SECOND: 'zweiter',
 
@@ -75,7 +77,7 @@ export const de_tokens = {
 
   RAILBLOCKS_POINT_TEXT_START: 'Setze die Weiche',
   RAILBLOCKS_POINT_TEXT_END: 'auf',
-  RAILBLOCKS_POINT_TOOLTIP: 'Setze alle ausgewählten Weichen auf entweder abbiegen oder geradeaus.\n' + 'Klicke auf das Plus / Minus Symbol, um die Anzahl der Weichen zu steuern.',
+  RAILBLOCKS_POINT_TOOLTIP: 'Setze alle ausgewählten Weichen auf abbiegen oder geradeaus.\n' + 'Klicke auf das Plus / Minus Symbol, um die Anzahl der Weichen zu steuern.',
   RAILBLOCKS_POINT_STRAIGHT: 'geradeaus',
   RAILBLOCKS_POINT_BRANCH: 'abbiegen',
 

diff --git a/locales/en/en_locale.js b/locales/en/en_locale.js
@@ -32,8 +32,8 @@ export const en_locale = {
       generatedCodeTitle: 'Generated RailSL',
       logsTitle: 'Logs',
       deployConfirm: 'Really deploy on the railway?',
-      saveTitle: 'Save current workspace to disk',
-      loadTitle: 'Load workspace from disk',
+      saveTitle: 'Save current workspace',
+      loadTitle: 'Load workspace',
       attributionsTitle: 'Attributions',
       attributionsText: 'Images created and distributed by user jucy_fish (train icon), Freepik (hourglass gif), <a href="https://www.flaticon.com/" title="icons source 1">Flaticon</a> and <a href="https://www.svgrepo.com" title="icons source 2">svgrepo</a>.'
     },

diff --git a/locales/en/en_tokens.js b/locales/en/en_tokens.js
@@ -35,7 +35,9 @@ export const en_tokens = {
   RAILBLOCKS_CONTACT_WAIT_TEXT: 'Wait until %2 contact of %3 is %1',
   RAILBLOCKS_CONTACT_WAIT_TOOLTIP: 'Do nothing until a train interacts with a track.',
   RAILBLOCKS_CONTACT_WAIT_REACHED: 'reached',
+  RAILBLOCKS_CONTACT_WAIT_REACHED_TOOLTIP: 'Returns true if reached',
   RAILBLOCKS_CONTACT_WAIT_PASSED: 'passed',
+  RAILBLOCKS_CONTACT_WAIT_PASSED_TOOLTIP: 'Returns true if passed',
   RAILBLOCKS_CONTACT_WAIT_FIRST: 'first',
   RAILBLOCKS_CONTACT_WAIT_SECOND: 'second',
 
@@ -75,12 +77,12 @@ export const en_tokens = {
 
   RAILBLOCKS_POINT_TEXT_START: 'Set point',
   RAILBLOCKS_POINT_TEXT_END: 'to',
-  RAILBLOCKS_POINT_TOOLTIP: 'Sets a number of points to either branch or be straight.\n' + 'Click the plus/minus symbol to control the number of points.',
+  RAILBLOCKS_POINT_TOOLTIP: 'Sets a number of points to either branch or straight.\n' + 'Click the plus/minus symbol to control the number of points.',
   RAILBLOCKS_POINT_STRAIGHT: 'straight',
   RAILBLOCKS_POINT_BRANCH: 'branch',
 
-  RAILBLOCKS_WARNING_UNREACHABLE_STRONG: 'Blocks after this will not be reached because of a loop inside this.',
-  RAILBLOCKS_WARNING_UNREACHABLE_WEAK: 'Blocks after this may not be reached because of a loop inside this.',
+  RAILBLOCKS_WARNING_UNREACHABLE_STRONG: 'Blocks after this will not be reached because of a loop inside this block.',
+  RAILBLOCKS_WARNING_UNREACHABLE_WEAK: 'Blocks after this may not be reached because of a loop inside this block.',
   RAILBLOCKS_WARNING_EMPTY_INPUT: 'This block has empty inputs and will cause a syntax error!',
   RAILBLOCKS_WARNING_UNUSED: 'Unused block',
   RAILBLOCKS_WARNING_PASSED: 'The "passed" block can currently not be used in this block.',

diff --git a/locales/zh/zh_locale.js b/locales/zh/zh_locale.js
@@ -0,0 +1,48 @@
+/*
+ * RailBlocks - A Blockly RailSL Implementation
+ *
+ * https://github.com/kieler/RailBlocks
+ *
+ * Copyright 2026 by
+ *  + Kiel University and others
+ *    + Department of Computer Science
+ *      + Real-Time and Embedded Systems Group
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the MIT License which
+ * is available at https://opensource.org/license/MIT.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+import * as ZhHans from 'blockly/msg/zh-hans'
+import { zh_tokens } from './zh_tokens'
+
+export const zh_locale = {
+  label: '简体中文',
+  locale: ZhHans,
+  tokens: zh_tokens,
+  htmlLabels: {
+    title: 'RailBlocks',
+    simulationTitle: '仿真',
+    deployTitle: '部署到铁路',
+    optionsTitle: '查看开发者信息',
+    languageButton: '语言',
+    languageMenuLabel: '编辑器语言',
+    generatedCodeTitle: '生成的 RailSL',
+    logsTitle: '日志',
+    deployConfirm: '确定要部署到铁路吗？',
+    saveTitle: '保存当前工作区',
+    loadTitle: '加载工作区',
+    attributionsTitle: '鸣谢',
+    attributionsText:
+      '图片由用户 jucy_fish（火车图标）、Freepik（沙漏动图）、<a href="https://www.flaticon.com/" title="icons source 1">Flaticon</a> 和 <a href="https://www.svgrepo.com" title="icons source 2">svgrepo</a> 提供。'
+  },
+  toolboxLabels: {
+    setStatements: '设置语句',
+    waitStatements: '等待语句',
+    controlFlow: '控制流程',
+    sensorValues: '轨道传感器值',
+    numbers: '数字',
+  }
+}
diff --git a/locales/zh/zh_tokens.js b/locales/zh/zh_tokens.js
@@ -0,0 +1,108 @@
+/*
+ * RailBlocks - A Blockly RailSL Implementation
+ *
+ * https://github.com/kieler/RailBlocks
+ *
+ * Copyright 2026 by
+ *  + Kiel University and others
+ *    + Department of Computer Science
+ *      + Real-Time and Embedded Systems Group
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the MIT License which
+ * is available at https://opensource.org/license/MIT.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+// This file contains the Simplified Chinese translations for the block labels, tooltips and warnings.
+export const zh_tokens = {
+  RAILBLOCKS_PROGRAM_TEXT: '程序',
+  RAILBLOCKS_PROGRAM_TOOLTIP:
+    '需要执行的程序。\n所有后续命令都应放在此块中。',
+
+  RAILBLOCKS_LOOP_TEXT: '循环',
+  RAILBLOCKS_LOOP_TOOLTIP:
+    '重复执行此块中的所有代码。',
+
+  RAILBLOCKS_STOP_TEXT: '停止',
+  RAILBLOCKS_STOP_TOOLTIP:
+    '将轨道设为无速度。',
+
+  RAILBLOCKS_DIR_TEXT: '速度：%1 反向：%2',
+  RAILBLOCKS_DIR_TOOLTIP:
+    '设置轨道的速度和方向。',
+  RAILBLOCKS_DIR_SLOW_TEXT: '慢速',
+  RAILBLOCKS_DIR_FULL_TEXT: '全速',
+
+  RAILBLOCKS_CONTACT_WAIT_TEXT:
+    '等待直到 %3 的 %2 号触点被%1',
+  RAILBLOCKS_CONTACT_WAIT_TOOLTIP:
+    '等待列车与轨道发生交互。',
+  RAILBLOCKS_CONTACT_WAIT_REACHED: '到达',
+  RAILBLOCKS_CONTACT_WAIT_REACHED_TOOLTIP: '如果已「到达」，则返回真值。',
+  RAILBLOCKS_CONTACT_WAIT_PASSED: '通过',
+  RAILBLOCKS_CONTACT_WAIT_PASSED_TOOLTIP: '如果已「通过」，则返回真值。',
+  RAILBLOCKS_CONTACT_WAIT_FIRST: '第一',
+  RAILBLOCKS_CONTACT_WAIT_SECOND: '第二',
+
+  RAILBLOCKS_INT_RANGE_TEXT: '%1 至 %2',
+  RAILBLOCKS_INT_RANGE_TOOLTIP: '创建一个数字范围。',
+
+  RAILBLOCKS_TIME_WAIT_TEXT:
+    '等待 %1 秒',
+  RAILBLOCKS_TIME_WAIT_TOOLTIP:
+    '等待指定时间。',
+
+  RAILBLOCKS_CROSSING_TEXT: '%1 道口',
+  RAILBLOCKS_CROSSING_TOOLTIP:
+    '切换道口状态',
+  RAILBLOCKS_CROSSING_OPEN: '打开',
+  RAILBLOCKS_CROSSING_CLOSE: '关闭',
+
+  RAILBLOCKS_CONDITIONAL_TEXT:
+    '如果 %2 的第 %1 号触点最先被到达\n%3否则如果 %5 的第 %4 号触点最先被到达',
+  RAILBLOCKS_CONDITIONAL_TOOLTIP:
+    '根据列车最先到达的轨道执行不同的代码块。',
+  RAILBLOCKS_CONDITIONAL_FIRST: '第一',
+  RAILBLOCKS_CONDITIONAL_SECOND: '第二',
+  RAILBLOCKS_CONDITIONAL_TEXT_START: '如果',
+  RAILBLOCKS_CONDITIONAL_TEXT_MIDDLE: '号触点，属于轨道',
+  RAILBLOCKS_CONDITIONAL_TEXT_END_1: '被',
+  RAILBLOCKS_CONDITIONAL_TEXT_END_2: '优先',
+  RAILBLOCKS_CONDITIONAL_TITLE_TEXT: '分支',
+
+  RAILBLOCKS_PARALLEL_TEXT: '并行',
+  RAILBLOCKS_PARALLEL_TOOLTIP:
+    '同时执行多个代码块。',
+
+  RAILBLOCKS_LIGHTS_TEXT_START: '把灯',
+  RAILBLOCKS_LIGHTS_TEXT_END: '设为',
+  RAILBLOCKS_LIGHTS_TOOLTIP:
+    '将一个或多个灯设置为开启或关闭。\n点击加号/减号可调整灯数量。',
+  RAILBLOCKS_LIGHTS_ON: '开启',
+  RAILBLOCKS_LIGHTS_OFF: '关闭',
+
+  RAILBLOCKS_TRACK_TEXT: '将轨道 %1 设为 %2',
+  RAILBLOCKS_TRACK_NONE: '(空)',
+  RAILBLOCKS_TRACK_TOOLTIP:
+    '设置一个或多个轨道的速度和方向。',
+
+  RAILBLOCKS_POINT_TEXT_START: '将道岔',
+  RAILBLOCKS_POINT_TEXT_END: '设为',
+  RAILBLOCKS_POINT_TOOLTIP:
+    '将一个或多个道岔设置为直行或分岔。\n点击加号/减号可调整道岔数量。',
+  RAILBLOCKS_POINT_STRAIGHT: '直行',
+  RAILBLOCKS_POINT_BRANCH: '分岔',
+
+  RAILBLOCKS_WARNING_UNREACHABLE_STRONG:
+    '由于此处代码块包含循环，后续代码块将无法执行。',
+  RAILBLOCKS_WARNING_UNREACHABLE_WEAK:
+    '由于此处代码块包含循环，后续代码块可能无法执行。',
+  RAILBLOCKS_WARNING_EMPTY_INPUT:
+    '此代码块存在空输入，将导致语法错误！',
+  RAILBLOCKS_WARNING_UNUSED:
+    '未使用的代码块',
+  RAILBLOCKS_WARNING_PASSED: '「通过」块目前无法在此方块中使用。',
+  RAILBLOCKS_WARNING_UNSELECTED: '未选择任何轨道。',
+}
diff --git a/test/validate_translation_consistency.test.js b/test/validate_translation_consistency.test.js
@@ -1,9 +1,6 @@
 import { describe, test, expect } from 'vitest';
 
-import { en_locale } from '../locales/en/en_locale.js';
-import { de_locale } from '../locales/de/de_locale.js';
-
-const translations = { en_locale, de_locale };
+import { LANGUAGE_CONFIGS } from '../frontend/localization.js';
 
 function compare(reference, translation, path = '') {
     const missing = [];
@@ -59,8 +56,8 @@ function findNonStrings(obj, path = '') {
 
 describe('Localization', () => {
     test('all localization files contain the same keys', () => {
-        for (const [name, translation] of Object.entries(translations)) {
-            const { missing, extra } = compare(en_locale, translation);
+        for (const [name, translation] of Object.entries(LANGUAGE_CONFIGS)) {
+            const { missing, extra } = compare(LANGUAGE_CONFIGS.en, translation);
 
             expect(
                 { missing, extra },
@@ -73,7 +70,7 @@ describe('Localization', () => {
     });
 
     test('all translation values are strings', () => {
-        for (const [name, translation] of Object.entries(translations)) {
+        for (const [name, translation] of Object.entries(LANGUAGE_CONFIGS)) {
             expect(
                 findNonStrings(translation),
                 `${name} contains non-string values`