CHANGELOG.md

Changelog

All notable changes to this repository will be documented in this file.

The format is loosely inspired by Keep a Changelog.

[Unreleased]

Added

• Web 0.8.0, VisuObject: a third world next to VisuStruct and VisuBot, for object-oriented programming from year 12 (?visuobject, petrol colours). On the left the Java code, on the right the class diagram, both linked: typing classes builds the diagram (attributes, methods, constructors, static, abstract, inheritance, interfaces, associations with multiplicity from attributes like ArrayList<Hund>); adding classes, interfaces, attributes and methods in the diagram, double-clicking to change them in UML notation (- name: String, + bark(): void), choosing the superclass or making a class abstract writes Java at exactly that spot, method bodies and comments stay. Plan for the next stages: docs/visuobject/PLAN.md (#167).
• Web 0.7.0, VisuBot upload to the mBot2: a new button “⬆ Upload” (Chrome/Edge, USB) saves the finished program on the mBot2, like uploading in mBlock. Then it drives without a cable, for example through a maze: after switching on, the screen shows “A = Start”, and button A starts the program. VisuStruct translates the structogram or Java code into MicroPython for the CyberPi in the background (case selection as if/elif, Java string concatenation with numbers). The upload frames are identical to mBlock 5's (protocol from cyberpi-uploader, MIT). New step “Driving without a cable” in VisuBot lesson 2 and in the reference.
• Web 0.6.3, elements width: the line between the elements and the structogram can be dragged (also with the arrow keys); a double-click resets it. Narrow elements show their name small below the symbol, wide ones next to it. The width is remembered.
• Web 0.6.2, programming large: a ⇄ button in Programming and in the structogram toolbar makes Programming the large main area and the structogram narrow; another click swaps back. Both widths can be dragged at the line between them, and the choice is remembered.
• Web 0.6.1, VisuBot reference in plain words: the mBot2 commands and sensors in the reference use the same groups as the elements (driving and turning, wheels separately, light/sound/screen, emotions, waiting and stopwatch; distance, line, colours, buttons and joystick, light and loudness, tilt and shaking, stopwatch and battery) and are explained in short, simple sentences for beginners (de/en): what a command and a sensor is, every line says what the mBot2 does, LEDs, tones and angles explained.
• Web 0.6.0, VisuBot “mBot2 live”: a new window next to the structogram and the code shows right away where the program drives the mBot2: after every change the program is run in the background in the world of the exercise, the robot stands where it ends up and leaves its track; ▶ plays the drive with tones, LEDs and screen. The window can be its own column (width adjustable) or sit below the code in Programming (height adjustable), and it collapses into a narrow bar. Programs that need an input or run endlessly get a note.
• Web 0.6.0, VisuBot elements in groups: the mBot2 commands and sensors under Elements are grouped like the reference (driving and turning, wheels separately, light/sound/screen, emotions, waiting and stopwatch; distance, line, colours, buttons and joystick, light and loudness, tilt and shaking, stopwatch and battery); each group folds up.
• Web 0.5.0, VisuBot basics with the robot: five new VisuBot lessons teach the Java basics with the mBot2 as the example: 3 “Variables and output”, 9 “Case selection with colours”, 17 “Arrays and melodies”, 19 “Strings” and 22 “Your own methods” (de/en). Each has a structogram exercise, a Java exercise and ends with “Now without the robot”: plain Java with console output and no mbot, because real Java is the goal. The other VisuBot lessons move to 4–8, 10–16, 18, 20 and 21; learning progress is carried over.
• Web 0.5.0, VisuStruct or VisuBot: two separate worlds instead of the VisuBot modes Off / In the course / Separate series. VisuStruct shows the course without any robot; VisuBot shows only the robot lessons, robot tasks and the mBot2 reference. You choose at the top of the start dialog or the gear menu. The address shows ?visubot or ?visustruct, so a link opens the right world. The 🤖 course steps of “In the course” were removed (a saved “In the course” now opens VisuBot). The website's lesson links open VisuStruct.
• Web 0.4.7, Programming: a book button in the Programming header opens the reference (commands and terms) in the learning area, also when only Programming is open.
• Web 0.4.7, VisuBot colour sensor: mbot.getColor() gives the colour under the mBot2 as text (“rot”/“red”, “grün”/“green”, “blau”, “gelb”, “schwarz”, “weiß”, in the language of the lessons) and replaces isRed(), isGreen(), isBlue() and isYellow(). Conditions are written as mbot.getColor().equals("rot"); lesson 7 explains why texts are compared with .equals and not ==. Course steps, tasks, model solutions and the reference were updated. Confirmed on a real mBot2 (red, white, black).
• Web 0.4.5, VisuBot in the course: with VisuBot “In the course”, the VisuBot tour comes first as lesson 0 (same learning progress as in the separate series). The robot steps are now called “🤖 Now with VisuBot: …”. New LED steps: a running light in lesson 13 (for loop) and a rainbow colour array in lesson 15 (arrays).
• Web 0.4.4, VisuBot single LEDs: new command mbot.led(i).setColor("green") (box “set LED colour”): LEDs 0 to 4 like an array, colours by name in German or English, "off" switches off; the 3D simulator lights each LED on its own. New VisuBot lesson 13 “Single LEDs” (de/en) with three lights and a running light (lessons 13–16 become 14–17) and new tasks Morse SOS, Knight Rider and counting in binary.
• Web 0.4.4, VisuBot screen: after connecting, the real mBot2 shows “VisuBot” in large letters; every text clears the screen first, so nothing is left over. Colours are not set because the CyberPi changes the text colour on its own. The mBot2 lab page highlights the current tests and shows its round in the title and log.
• Web 0.4.3, VisuBot motors, course and projects: new command mbot.drive(left, right) (wheels separately, in percent; the robot keeps going until mbot.stop()), the stopwatch (mbot.resetTimer(), mbot.getTimer()), the battery level (mbot.getBattery()) and the middle line probes (mbot.isLineLeft(), mbot.isLineRight()), in the simulator and on the real mBot2. World maps can contain tape lines (linie:). New VisuBot lessons 15 “Motors and speed” with a line follower and 16 “Stopwatch and battery”. “In the course” now adds 🤖 steps to lessons 6, 8, 9, 10, 11, 12, 14, 15, 17 and 18 (input/output, branch, combined conditions, case selection, loops, nesting, arrays, strings, subprograms). New tasks: alarm system, avoid obstacles, line follower with stop, night watchman and reverse parking. Exercises can check the text on the screen (screen "…") and whether the robot drives at all (drives).
• Web 0.4.3, VisuBot: with a real mBot2 connected, “🔧 Test the mBot2” below the world tries each actuator (LEDs, tone, screen, wheels) and shows all sensor values live. Lesson 1 (de/en) explains it.
• Web 0.4.3, VisuBot logo and homepage: with VisuBot switched on, the web app's header shows the VisuBot robot and name. The homepage (de/en/pt) gets a VisuBot section with logo, screenshot and a “Try VisuBot” link (app/?visubot switches the mode on).
• Web 0.4.3, VisuBot feelings: new command “show a feeling” mbot.emotion("smile") (hello, sad, angry, dizzy, zzz …) plays the CyberPi's little show with LEDs, sound and wiggling; lesson 13 and the reference explain it, the mBot2 test has a button for it.
• Web 0.4.2, VisuBot sensors and actuators: one lesson per sensor and actuator (de/en), each first in the structure chart and then in Java: ultrasonic, line, colours, buttons and joystick, light, loudness, tilt, LEDs, speaker and screen (lessons 5–14). New sensors mbot.isRed() … isYellow(), isButtonA/B(), isJoystickUp/Down/Left/Right(), getPitch(), getRoll(), isShaken() and the command mbot.showText(…), also for the real mBot2. Worlds can have coloured fields; below the 3D world “Try the sensors” has sliders and buttons for light, loudness, tilt, buttons, joystick and shaking. Tones are audible in the simulation, text appears on the 3D screen. The tour in lesson 1 now shows all sensors and actuators and has the game “Sensor or actuator?”. Exercises can check sensor values (messwerte:) and LED/tone/screen commands (befehle:). Lesson 1 explains step by step how to connect the real mBot2 (USB-C, switch, restart with the joystick, button B, choose “USB Serial”). All new sensor commands were tested on a real mBot2; yes/no sensors answer 0/1 and are now read correctly.
• Web 0.4.1, VisuBot: ▶ and single step in the Programming area run programs with mBot2 commands in the simulation, so the 3D world and a connected mBot2 drive along (before, they only ran in the console). While simulating, the current command is marked yellow in the code and blue in the structure chart.
• Web 0.4.0, VisuBot (mBot2): a new mode in the settings (Off / In the course / Separate series) for programming the Makeblock mBot2 robot with structure charts or Java. mBot2 commands (drive, turn, LEDs, tone) and sensors (mbot.getDistance(), mbot.getLine()) in the elements list, a 3D simulator with a model built from photos of a real mBot2, worlds with walls, black fields and a goal flag (Kara-style maps), and exercises checked by the drive or by reaching the goal without bumping. Own lessons (tour of the robot with a parts quiz, the square with nested loops, sensors, until the wall) and tasks (staircase, maze, triangle, spiral, slalom, clover in the forest, tunnel finder, maze with exits). “In the course” adds 🤖 steps to lessons 5 and 13. With 🔌 mBot2 next to the simulation button a real mBot2 is connected over USB (Chrome/Edge) and drives every simulation step along with real sensor values; a second click disconnects cleanly.
• Web, reference: categories that fold open (basics, branches, loops, subprograms, calculating, arrays, glossary); with VisuBot also mBot2 commands and sensors.

Changed

• Web: the simulation button has a label: “▶ Simulation starten”, while simulating “■ Simulation beenden” (21 languages). The pencil icon is gone, also in the simulation panel after the program has ended. In a narrow toolbar only the symbol stays, so the collapse button stays in the same row. Lesson 7 (de/en/pt) uses the new names.
• Web, lesson 4 (de/en/pt): % is explained like division with remainder in primary school (17 : 5 = 3 remainder 2), with a small table comparing / and % and a hint on even numbers.
• Web, lesson 4 (de/en/pt): variable names start with a lowercase letter, and names of several words use camelCase (preisMitSteuer), with an Angeberwissen box about the camel humps. camelCase is in the glossary. The boolean example is now simply boolean volljaehrig = false instead of a comparison.
• Web, Files column: no class folders any more. Saving goes straight into a folder with today’s date in the workspace (VisuStruct-Dateien/2026-10-24/…), without asking for a class. The learning progress file is now called learnProgress.json; an existing lernstand.json is read in and then removed.
• Web: the button that collapses the structure chart editor sits in the toolbar right of the simulation button. In the tab bar it was pushed out of sight when several tabs were open.
• Web, lesson 2 (de/en/pt): the Programming area is now introduced as used from lesson 4 on (it said lesson 20). Step 2 now explains that a simple click on an element inserts it without dragging, and that the keyboard way is Tab then Enter. Lessons 2 and 3 also name the Mac shortcuts (⌘Z, ⌘⇧Z, ⌘S, ⌘O, ⌘P), and the shortcut quiz in lesson 2 shows both, e.g. “Strg+Z / ⌘Z”.
• Web, learning area: a lesson step that explains areas of the structure chart editor (e.g. lesson 2) opens that editor if it was collapsed. Steps that point to Run, the console or single step open the Programming area. The step about the Files column (lesson 3) opens that column and collapses the structure chart editor to make room. Lesson 2 (de/en/pt) now says that there are two editors: the structure chart editor and the Programming area.
• Web, lesson 1 (de/en/pt): the three building blocks have their own colours (statements light blue, branch light orange, loop light green) in the diagrams of steps 3–7, and the words in the text are marked in the same colours. Step 7 now really shows all three forms: the structure chart was missing next to the flowchart and the pseudocode. The links “More Angeberwissen” in lessons 1, 2, 14 and 21 are gone.
• Web: structure charts show the background colour stored in a file (bgcolor), as the Java version does. Lesson texts can mark a word with [word]{.blau}, {.orange} or {.gruen}.
• Web, tasks: tasks without a checked exercise (the Swing tasks “Unit converter” and “Rolling dice with MVC”) no longer show up green with a tick in the task list.
• Web, lesson 20 (de/en/pt) is now called “Structure chart and code”: it starts by pointing back to the Java steps in lessons 4 to 16, and “The elements in Java” is a table with the Java form of every element and the lesson where it is taught.
• Web: the column “Code live” is now called “Programming” (de: „Programmieren“, pt: „Programação“) in all 21 UI languages and in the lessons (de/en/pt). The step in lesson 20 is now “Write Java directly”.

Added

• Web: the Export menu also offers the VisuStruct file (.visustruct), to pass a diagram on to someone who should keep editing it. Lesson 3 (de/en/pt) lists it. Lesson 3 also walks through creating the workspace folder VisuStruct-Dateien step by step, asks the learner to do it right away, and has it on the checklist. A small folder tree shows the workspace with its day folders, and the Files column's hint names “VisuStruct-Dateien” as the suggested workspace.

• Web, lessons and tasks (de/en/pt): 16 new “Angeberwissen” boxes, mostly about Java itself: Oak and the coffee name (L4), Java Card on SIM and bank cards (L6), the Duke mascot (L8), case -> since Java 14 (L10), CA FE BA BE at the start of every class file (L20), how JavaScript got its name and why the two are mixed up (L21). Also: Ariane 5 and the data type (L4), the moth in the Harvard Mark II (L7), George Boole (L9), Python without do-while (L12), why the counter is called i (L13), line endings (L24), JSON “for Good, not Evil” (L26), four-digit PINs, Fibonacci’s rabbits and the Leitner box (tasks).

• Web, lessons 12–19 (de/en/pt): gap texts and “Find the bug” in Java, part 2. Gap texts for do-while, for up and down, nested loops, arrays (int[], length), tables (int[][]), String methods (length, toUpperCase, charAt, equals), a method with return plus while (true)/break, and bubble sort. Bugs to find: a do-while that stops too early, i < 10 in a times table, output inside the loop, max = 0 with negative temperatures, swapped 2D indices, charAt(1), counting after break, and a linear search that does not stop at the first hit. A gap text can now have several code blocks (method and main program).

• Web, lessons 4–11 (de/en/pt): more Java typing practice. New block ::: lückentext (fill in the gaps): finished Java code with input fields for single missing words such as public, int, <=, && or switch, a Check button that colours each gap, “Show solution” after a wrong try, alternative answers and an explanation. Every lesson from 4 to 11 gets one, plus an exercise “Find the bug” with Java code that runs but gives a wrong result (swapped / and %, wrong order, "Sum: " + a + b, <= instead of <, && instead of ||, b - a, a loop that runs once too often). A test makes sure every gap text is valid Java with each accepted answer.

• Web, lessons (de/en/pt): new section “Files” with lessons 23–27. 23 “Reading and saving text” (Scanner(new File(…)), hasNextLine/nextLine, PrintWriter, throws/try), 24 “Line by line with BufferedReader” (readLine until null, try-with-resources, Files.readString as a shortcut), 25 “Tables as CSV” (split(";"), skipping the header, Integer.parseInt), 26 “Data as JSON” (objects, keys and lists, getting values with indexOf/substring, writing JSON with + and \") and 27 “Comparing formats” (the same data as txt, CSV and JSON, converting between them). Every lesson shows its files, has two Java exercises and a game: “What is in the file?”, “File detective”, “Broken line” (bomb with CSV files, daten: csv), “Which key?” and “Which format fits?” (new block ::: spiel frage). The Swing lessons move to 28–36, progress is carried over.

• Web, simulation, export and real Java: files can be read with Scanner(new File(…)) and BufferedReader(new FileReader(…)) and written with PrintWriter (written only on close(), as in Java); readLine() returns null at the end. After a run, written files are shown below the output. Python/JavaScript export get small helper classes, real Java gets the lesson files and returns written ones. Exercises can check a saved file (datei: name.txt -> line | line); ::: datei also accepts .csv and .json.

• Web, tasks (de/en/pt): Java versions for 13 tasks. Every structure chart task from lesson 8 on (even or odd, of age, menu, calculator, Collatz, binary number, PIN, Fibonacci, grade average, board duty, battleships, rental menu, leaderboard) now has a second exercise “… in Java” with the same tests and Java hints. PIN and rental menu have their own Java solutions: input into an existing variable goes through a helper variable, and the menu uses if/else if because a break inside a switch would only leave the switch.

• Web, tasks (de/en/pt): five new tasks for the later lessons. “Leaderboard” (after 19, bubble sort in descending order), “Ball throw results” (after 25, CSV with count, average and the winner saved to a file), “Vocabulary trainer” (after 27, words from a CSV file with input and equals), “Unit converter” (after 35, Swing window with Double.parseDouble and try/catch) and “Rolling dice with MVC” (after 40, a finished model, two views and a controller to build). The first three are checked automatically.

• Web, lessons (de/en/pt): games for the basics lessons 14–16 and 18–22. “Inside and outside” (nested loops and branches), “Defuse the bomb” (one array mistake per program: <= instead of <, index 0, length - 1, sum, maximum), “Which seat?” (2D arrays), “What comes back?” (methods, return, call by value and by reference, break), “Search pro” (linear and binary search, one bubble sort pass), “Which box?” (Java line to structure chart element, Snippet or Class, debugger), “Which language?” (Java, Python or JavaScript) and “Does the net catch it?” (try and catch).

• Web, lessons (de/en/pt): games for the basics lessons 1–8 and 10–12. “Which building block?” (sequence, branch or loop in everyday life), “Editor pro”, “How do you pass it on?” (.visustruct, PNG, SVG or PDF), “Which data type?”, “Sort the boxes” (::: spiel reihenfolge, incl. swapping with a helper variable), “What is output?” (+ in outputs, IPO), “Defuse the bomb” (desk check with one wrong line), “Which way?” (if/else), “Which case?” (switch), “How often?” (while) and “At least once?” (do-while).

• Web, lessons (de/en/pt): games for the Swing lessons 28, 29, 31, 34 and 35. “What happens?” (predict what a window program does), “Defuse the bomb” (one wrong line in a window program), “What is in the window afterwards?” (text field, parseInt, try/catch), “Which grade?” (else if chains, wrong order, && instead of ||) and “What does the calculator show?” ("" + a + b, integer division, dividing by 0 with int and double).

• Web, lessons (de/en/pt): new lesson 40 “Model View Controller”. The click counter is split into a model (Counter without Swing, tested without a window), a view (update(int value)) and a controller (the listener); a second view (JProgressBar) shows the same count without changing the model. An animated picture shows the four messages after a click. Games: “Where does the code belong?” and “Whose turn is it?” (new block ::: spiel reihenfolge: tap the shuffled steps in the right order).

• Web, lessons (de/en/pt): three more Swing lessons 37–39. 37 “Many buttons, one listener” (a code lock: one ActionListener in a variable, e.getActionCommand(), e.getSource() == button, buttons created in a loop on a JPanel), 38 “Inner classes” (the click counter with a named inner class, an anonymous class and a lambda compared) and 39 “Two tabs” (a shopping list with JTabbedPane, JTextArea.append and saving with PrintWriter inside a listener). Games: “Who clicked?”, “Which way of writing?” and “Where does it end up?”.

• Web, Swing round games: listeners in ::: spiel zuhoerer can be stored in a variable and signed up at several buttons, and may use if/else, e.getActionCommand() and e.getSource().

• Web, real Java with Swing: files that a program writes while its windows are open (e.g. after clicking Save) now show up below the output.

• Web, simulation: "a\"" + b + "\"c" is now joined like Java instead of being read as one text.

• Web, lesson 17 (de/en/pt): new game “Rescue the princess” (new block ::: spiel prinzessin). The fox has locked Princess Zora in his tower. At six stations a piece of Java code with string methods gives a number, alphabet.charAt(number) turns it into a letter for a small crossword with Java terms, and the yellow squares spell the secret word that opens the gate with equals (with a hint if only the capital letters are wrong).

• Web, lesson 17 (de/en/pt): three new steps. “Even more methods” (lastIndexOf, isEmpty, equalsIgnoreCase, compareTo, repeat, concat, Integer.parseInt, Double.parseDouble, String.valueOf), “Text from a file” with a text file shown in the lesson (new block ::: datei name.txt) that Files.readString(Path.of(…)) reads in the simulation, Python/JavaScript export and real Java (exercise “Read the letter”), and “The Java API” with a link to the String documentation and a quiz where methods have to be looked up. A missing file is reported in the simulation.

• Web, simulation: output: age + 1 now adds like Java (numbers are added until the first text, then joined), before it printed “71”.

• Web, task Caesar cipher (de/en/pt): a fun fact box with Ludwig: Caesar shifted letters in his head (Suetonius), the cipher wheel only came with Alberti around 1467.

• Web, lessons 17, 18 and 19 (de/en/pt) end with the step “Now in Java”: lesson 17 compares texts with equals (exercise “Check the password”), lesson 18 shows a method and while (true) with break (exercise “Till with break”), lesson 19 shows the linear search in Java (exercise “Count cards”). Lesson 20 now points back to lessons 4 to 19 and lists String in its table.

• Web, tasks (de/en/pt): new task “Caesar cipher” after lesson 17 with a drawn cipher wheel, an interactive wheel to turn (new block ::: caesar), two solutions (array vs. ASCII with (int)/(char)) and decryption. The simulation now calculates with character codes like Java ('A' = 65, (int) word.charAt(i), (char) code); Python and JavaScript code use ord/chr and charCodeAt/String.fromCharCode.

• Web, Code live: Scanner without import java.util.Scanner; (or java.util.*) is an error, as with javac: a hint under the code, and ▶ Run stops with the message. Code generated from the structure chart now writes the real import line at the very top (also around main and the class); typed imports are moved in front of the class when running real Java. Suggestions now also offer public, private, static, void, class, public class, try … catch, the usual import lines and the Swing types. New glossary terms Scanner and import (de/en/pt).

• Web, lesson 28 (de/en/pt): new step “Which layout for what?” with a table comparing FlowLayout, GridLayout and BorderLayout, a Ludwig tip for choosing one and a checklist item.

• Web, lessons (de/en/pt): three Swing games (new lesson blocks ::: spiel zuhoerer, vertrag and layout). Lesson 25 gets “Who is listening?” (code, a mock window and clicks; after the answer the clicks are played, the event goes to the listener and its lines light up, then the buttons can be tried freely) and “Contract fulfilled?” (ten classes and lambdas, does it fulfil ActionListener? every answer checked with javac). Lesson 27 gets “Who is counting?” with the static field, lesson 28 “Where does the button go?” with small window pictures for FlowLayout, GridLayout and BorderLayout as answers.

• Web, settings: separate text sizes for the structure chart and for Live code (code, console, input), each Small, Medium, Large or Extra large, so the code can be enlarged without the rest.

• Web, lessons (de/en/pt): five more Swing lessons, each with one new building block: 27 “Click counter with reset” (static field instead of a local variable in the lambda, with the real compiler error), 28 “A traffic light with colours” (Color, setOpaque/setBackground, state variable, BorderLayout), 29 “Grade calculator in a window” (else if, range check and try/catch; IHK scale in de, A–F in en, levels 1–5 in pt), 30 “A calculator” (GridLayout(0, 2), "" + (a + b), division by 0) and 31 “Guess the number” (Math.random(), guess counter, setEnabled(false), binary search as expert knowledge). New glossary term Attribut/Atributo.

• Web, Code live: new button “Indent” (next to ▶ Run) indents the code like Eclipse or IntelliJ, four spaces per level, only the selected lines if there is a selection. It counts brackets, so half-finished code and pseudocode are indented too. After a change in the structure chart, the changed lines are indented to fit the typed code. Lesson 20 (de/en/pt) mentions the button.

• Web, lessons (de/en/pt): new lesson 22 “When the program crashes: try and catch” (section “Catching errors”): a crash with an array index, switching on real Java, reading the error message, try and catch, Integer.parseInt with NumberFormatException, an expert box on exceptions as objects and the task “Dividing safely”. The Swing lessons move to 23–25 (progress is carried over). New lesson 26 “Doubling a number in a window”: JLabel, JTextField and a “Calculate” button, why only the button shows without a layout (Ludwig), GridLayout(0, 1), getText/parseInt/setText and try/catch against “abc”. New glossary term exception.

• Web, Code live: try { … } catch (…) { … } finally { … } no longer reports problems; the whole block becomes one statement box (run it with real Java).

• Web: the browser tab shows the VisuStruct app icon, as on the website.

• Web, Code live: shortcuts from Eclipse and IntelliJ in the suggestions: syso, sysout and sout insert System.out.println();, main and psvm insert the main method.

• Web: “About VisuStruct” has a section “Third-party software” (CodeMirror and Lezer, MIT; CheerpJ and javac for Swing support) with a link to licenses.txt. The build writes that file next to the app with the licence texts of all bundled packages, as the MIT License requires.

• Web, Code live: debugger. Click a line number to set a breakpoint (red dot); ▶ Run pauses before that line. The next line is yellow and its element is selected in the structure chart, a variables table below the code shows the current values and briefly highlights what changed. New Step button (own icon) runs one line and pauses again (also starts the program paused before the first line); ▶ continues to the next breakpoint. The code is read-only while the program runs. Lesson 20 (de/en/pt) gets the section “Find mistakes with the debugger” with a Ludwig tip, checklist item and quiz question.

• Web, lesson 9 (de/en/pt): truth table graphic for &&, || and !, a step on storing conditions in boolean variables, and the game “True or false?” (new lesson block ::: spiel): ten rounds with values and a condition that get harder, each answer explained step by step (15 >= 12 && 15 < 18 → true && true → true).

• Web, lessons (de/en/pt): new section “Windows with Swing” with three lessons: 22 “Your first window” (JFrame, setSize, setDefaultCloseOperation, why setVisible comes last; expert box on classes and objects), 23 “A button in the window” (JButton, add, FlowLayout; the button can be pressed but nothing happens yet) and 24 “The button reacts” (ActionListener with a lambda, several statements on a click; expert box: ActionListener is an interface, with the anonymous class). Lesson 20 now points to Swing support. New glossary terms event and interface. Ludwig boxes with a code block or long code no longer overflow the learning column.

• Web, Code live: a lambda with a block (e -> { … }) or an anonymous class (new ActionListener() { … }) inside a statement no longer reports a missing }; the whole statement becomes one statement box.

• Repository: VisuStruct is now licensed under the MIT License (LICENSE).

• Web, Code live: new setting “Swing support” (gear menu, Java section). When it is on, ▶ Run compiles the typed Java with the real javac and runs it as real Java via CheerpJ, so Swing windows appear in a “Java windows” area above the console. Runtime and compiler (about 40 MB) are loaded only on the first run. Code without a class is wrapped in public class Main. Each run closes the windows of the previous one; a program without windows ends with “Program finished”.

• Web, exercises (de/en/pt): “Ludwig’s tip” box (::: ludwig) in the lesson format. The Fibonacci exercise uses it to connect moving the values on with swapping from lesson 5 and sorting in lesson 19, plus a quiz question on the order of the two assignments.

• Web, Files: the learning progress (finished lessons and exercises, exercise diagrams, quiz answers) is also kept as lernstand.json in the workspace. Opening a workspace merges the file with the browser's progress (finished stays finished, the furthest step counts) and every change is written back about a second later.

• Web, Files: saving without a chosen class asks first: pick one of the class folders or type a new one (“Create and save”); the choice stays selected. Creating a folder and deleting now use the same in-page dialog instead of the browser's prompt/confirm, which embedded views block.

• Web, Code live: the element of the code line with the cursor is filled light blue in the structure chart, like the code line itself.

• Web, Code live: the Java editor shows line numbers (matching the line given in hints such as “Line 9: One too many }”).

• Web, lessons (de/en/pt): lesson 20 explains Live code (type Java, the structure chart builds itself; ▶ Run and the console) with the new exercise “Countdown” (code first, then check the structure chart). Lesson 3 explains the Files column with class and date folders, lesson 2 the new tools row with icons, lesson 7 the console during the simulation. New pointers for Files, Live code, Run, console and the tools.

• Web: new column “Files” (left of Learning) as a workspace for class folders such as 11FI1. Saving puts the program into the chosen class and a folder for today (2026-10-23, created automatically) as .visustruct plus .java when Code live shows Java; clicking a program opens it again. In Chrome and Edge the workspace is a real folder on the computer (remembered after reloading); on the iPad and in other browsers it lives in the browser's storage.

• Web, Code live: during the step-by-step simulation, the Code live console is cleared at the start and then shows the same output and input as running the program.

• Web, Code live: ▶ Run and ■ Stop buttons run the program (via the simulation engine, at full speed). Output and input appear in a console below the code in Code live, resizable with a draggable divider; endless loops can be stopped.

• Web: “About VisuStruct” button in the settings menu (gear), with the web app’s version number (from web/package.json), author, links and file format.

• Web, Code live: Java can be shown as a snippet, with a main method, as a class, or both (settings menu). The class name is the diagram title – typing public class Name in the code renames the diagram.

• Web, Code live: the Java column is now a real code editor (CodeMirror 6, MIT): coloured syntax, bracket matching, automatic indentation and suggestions while typing – templates for if, if … else, for, while, do … while, switch, output and input with grey placeholders, plus the variables of your own code.

• Web, Code live: type Java in the code column and the diagram builds itself as you type (unfinished code is tolerated: open blocks count as closed, missing parts become placeholders, a hint names what is still missing). Changing the diagram afterwards only rewrites the lines of the changed elements, so your own comments and formatting stay. JavaScript and Python stay display-only for now.

• Website: GitHub Actions workflow that publishes website/ to visustruct.org via SFTP after the web tests pass (tag web-v… or manual start).

Changed

• Web, Code live: the setting “Swing support” is now called “Real Java (with Swing)” in all languages.
• Web, learning area: an open lesson shows its number as a badge next to the title, like in the lesson list.
• Web: the settings menu shows the version number (now 0.3.40) right next to “About VisuStruct”.
• Web: the settings menu (gear) is grouped into sections with headings: Display (text size, language), Code live (programming language, code keywords), Java (class, main, Swing support; only shown when Java is selected) and About VisuStruct at the bottom.
• Web: toolbar buttons are icons with tooltips. The top bar keeps New, Open, Save and Settings; undo, clipboard, delete, export, code and simulation moved into a toolbar above the Elements and diagram columns. Run and Stop in Code live are icons too.
• Web: Column widths are freely adjustable: with the diagram collapsed, Learning and Code live share the width at a draggable divider; with all three open, Learning and Code live can be dragged wider until the diagram keeps 240 px.
• Web: The footer (status, home page, imprint, privacy) now runs below all three columns – Learning, diagram and Code live – instead of only under the diagram.
• App: the area below the diagram is headed “Object Inspector · ” (German „Objektinspektor · Verzweigung“ etc.), matching the web editor and the lessons. The palette keeps its heading “Elements”.
• Simulation: conditions now support string comparisons (name == "Anna", name.equals("Anna")), parentheses ((a < 3 || a > 10) && b), and negation with !. Operators inside string literals are no longer treated as operators.
• Simulation: after an error the simulation stops on the failing block instead of skipping it and running on; Reset starts over.
• Code generation: a branch whose false side holds only another branch now becomes else if (Python: elif) instead of a nested else { if … } block, in Java, Python and JavaScript.

Fixed

• Web, Code live: typing void main no longer suggests the main template, so Enter after the name doesn't insert a second main method.
• Web, Code live: pasting (or dropping) code at a grey placeholder such as // Your code now replaces the placeholder, like typing does. Before, the placeholder stayed in front of the pasted text and commented out its first line (e.g. import javax.swing.*;).
• iPhone: texts of existing elements (conditions, statements, …) can be edited again. Tapping the middle of an element now selects it and opens the text editor instead of setting an insert marker; insert before/after via the top/bottom strips or the palette. While an insert marker is set, “Edit text” is offered next to “Cancel insert”.

Planned / Notes

• Documentation polish for product/marketing surfaces only when explicitly requested.

[1.5.3] - 2026-09-06

Added

• File menu: New, Open, Open Recent, Save, Save As, Print, and Close on the menu bar / keyboard (Cmd+N/O/S/Shift+S/P/W), including on Mac (Designed for iPad). Open Recent uses the same list as the toolbar.
• Files: double-click or Open With a .visustruct or .strk file in Finder / Files opens it in VisuStruct (same XML as the Java Struktogrammeditor). The simulation layout is unchanged.

Fixed

• Tabs: warn before closing diagrams with unsaved changes, offering to save, discard, or cancel.
• File menu: recently used files show up again under Ablage / File. Nested Open Recent stayed empty because SwiftUI Commands snapshot FocusedValue; the list now comes from the shared recents store and is listed directly in Ablage.
• File menu: Open, New, Save, and the other Ablage items are enabled after launch. Commands kept a frozen empty FocusedValue, so those entries stayed grayed out. Ablage now posts notifications the editor handles, and Open starts enabled instead of waiting on a FocusedValue snapshot.
• File menu: Open was missing entirely on Mac (Designed for iPad) because SwiftUI’s Open command with ⌘O is absorbed as the system document-open item and then dropped. Ablage → Öffnen is now a UIKit UIAction in the File menu.
• File menu: recent files sit under Zuletzt verwendet again instead of filling Ablage; the nested list is built when that submenu opens.

[1.2.1] - 2026-04-20

Added

• Code generator (iPad & Mac): movable floating panel with a drag handle so the structogram stays visible; iPhone still uses a full-screen sheet.
• UI scale: independent text scaling for the diagram canvas vs the inspector (VisuStructUIScale, wired through Settings / app storage).
• Switch block: short inspector hint for the selector expression (code-style example: day).

Changed

• Inspector hints: removed the long for-loop explainer (columns and placeholders carry the UX); removed e.g. prefixes from inline examples; removed the endless-loop hint line; break placeholder copy now describes an optional comment (empty field still emits a plain break in generated code).
• Canvas: break and method call tiles center label text vertically and horizontally inside the drawable area (accounting for side bars), consistent with statement blocks.
• VisuStructCore: layout and code-generator adjustments supporting the above; localized string updates across locales.

[1.2] - 2026-04-17

Added

• Broad localization coverage across app strings + Settings bundle integration where applicable.
• Diagram clipboard UX (copy/cut/paste) plus keyboard/menu shortcuts on platforms where supported.
• Statement modes for structured diagram authoring:
  • Output prefix print: with codegen mappings per language target.
  • Input prefix input: with codegen mappings per language target (starter typing stays uniform across languages).
• JavaScript runner improvements for web-based execution (prompt() supported in WKWebView).

Changed

• Diagram layout/rendering refinements for multi-way blocks and selection overlay ordering.
• Editor typography improvements for code entry on iPad/Mac.
• Version metadata aligned for release workflow (marketing version / build numbers in Xcode project).

Fixed

• Issues where diagram sizing/selection visuals could diverge when using placeholder/display text.
• Various UX polish items discovered during multilingual rollout.