semesterprojekt: implement full text adventure (phases 1-7)

Walking skeleton through Swing GUI: YAML-driven world (4 rooms,
4 items, 1 NPC), HashMap command dispatch with parser, three-tier
item hierarchy (readable / switchable / plain), and end-to-end
NPC give/receive flow. 67 tests green.

Semesterprojekt/src/main/java/thb/jeanluc/adventure/io/ConsoleIO.java

@@ -0,0 +1,57 @@
+package thb.jeanluc.adventure.io;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintStream;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * {@link GameIO} backed by {@code System.in} and {@code System.out}.
+ * Each {@code write} appends a newline so output blocks are visually
+ * separated. {@code readLine} prints a {@code > } prompt before
+ * blocking.
+ */
+public class ConsoleIO implements GameIO {
+
+    /** Input source. */
+    private final BufferedReader in;
+
+    /** Output sink. */
+    private final PrintStream out;
+
+    /**
+     * Creates a console IO using standard input and output.
+     */
+    public ConsoleIO() {
+        this(new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8)), System.out);
+    }
+
+    /**
+     * Test-friendly constructor allowing custom streams.
+     *
+     * @param in  reader to consume player input
+     * @param out stream to write player output
+     */
+    public ConsoleIO(BufferedReader in, PrintStream out) {
+        this.in = in;
+        this.out = out;
+    }
+
+    @Override
+    public String readLine() {
+        out.print("> ");
+        out.flush();
+        try {
+            String line = in.readLine();
+            return line == null ? "" : line;
+        } catch (IOException e) {
+            return "";
+        }
+    }
+
+    @Override
+    public void write(String s) {
+        out.println(s);
+    }
+}

Semesterprojekt/src/main/java/thb/jeanluc/adventure/io/GameIO.java

@@ -0,0 +1,24 @@
+package thb.jeanluc.adventure.io;
+
+/**
+ * Bidirectional text channel between the engine and the player. Implemented
+ * by both {@code ConsoleIO} and {@code SwingIO} so the game loop is agnostic
+ * to the actual interface.
+ */
+public interface GameIO {
+
+    /**
+     * Blocks until a line of input is available.
+     *
+     * @return the next user input line, or an empty string at end of input
+     */
+    String readLine();
+
+    /**
+     * Writes a message to the player. Each call corresponds to one logical
+     * output block; the implementation handles line breaks at the boundary.
+     *
+     * @param s message text; must not be null
+     */
+    void write(String s);
+}

Semesterprojekt/src/main/java/thb/jeanluc/adventure/io/SwingIO.java

@@ -0,0 +1,85 @@
+package thb.jeanluc.adventure.io;
+
+import javax.swing.BorderFactory;
+import javax.swing.JFrame;
+import javax.swing.JScrollPane;
+import javax.swing.JTextArea;
+import javax.swing.JTextField;
+import javax.swing.SwingUtilities;
+import java.awt.BorderLayout;
+import java.awt.Color;
+import java.awt.Font;
+import java.util.concurrent.LinkedBlockingQueue;
+
+/**
+ * {@link GameIO} backed by a Swing window. A read-only output area shows
+ * game text; a bottom text field collects player input. The input from
+ * the EDT is handed to the (worker-thread) game loop through a
+ * {@link LinkedBlockingQueue}.
+ */
+public class SwingIO implements GameIO {
+
+    /** Bridge between the EDT and the game loop. One element = one line. */
+    private final LinkedBlockingQueue<String> inputs = new LinkedBlockingQueue<>();
+
+    /** Main window. */
+    private final JFrame frame;
+
+    /** Output text area; appended to from any thread via {@link SwingUtilities#invokeLater}. */
+    private final JTextArea output;
+
+    /** Input text field; ENTER pushes the line into {@link #inputs}. */
+    private final JTextField input;
+
+    /**
+     * Creates and shows the window with the given title. Must be called on
+     * the EDT (typical pattern: from {@code SwingUtilities.invokeLater}).
+     *
+     * @param title window title
+     */
+    public SwingIO(String title) {
+        frame = new JFrame(title);
+        output = new JTextArea();
+        input = new JTextField();
+
+        output.setEditable(false);
+        output.setLineWrap(true);
+        output.setWrapStyleWord(true);
+        output.setBackground(Color.BLACK);
+        output.setForeground(Color.LIGHT_GRAY);
+        output.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 14));
+        output.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
+
+        input.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 14));
+        input.addActionListener(e -> {
+            String line = input.getText();
+            input.setText("");
+            output.append("> " + line + "\n");
+            inputs.offer(line);
+        });
+
+        frame.setLayout(new BorderLayout());
+        frame.add(new JScrollPane(output), BorderLayout.CENTER);
+        frame.add(input, BorderLayout.SOUTH);
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        frame.setSize(800, 600);
+        frame.setLocationRelativeTo(null);
+        frame.setVisible(true);
+        input.requestFocusInWindow();
+    }
+
+    @Override
+    public String readLine() {
+        try {
+            return inputs.take();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            return "";
+        }
+    }
+
+    @Override
+    public void write(String s) {
+        SwingUtilities.invokeLater(() -> output.append(s + "\n"));
+    }
+}