Add new terminal components and tooling settings

src/main/java/dev/jakub/terminal/interactive/Prompt.java

@@ -0,0 +1,89 @@
+package dev.jakub.terminal.interactive;
+
+import dev.jakub.terminal.Terminal;
+import dev.jakub.terminal.core.TerminalSupport;
+
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.util.Scanner;
+
+/**
+ * Input prompt for reading user input. Use via {@link Terminal#prompt(String)}.
+ * Supports masked input for passwords. Injectable input/output for tests.
+ */
+public final class Prompt {
+
+    private final String message;
+    private final TerminalSupport support;
+    private boolean masked;
+    private PrintStream out = System.out;
+    private InputStream in = System.in;
+
+    public Prompt(String message, TerminalSupport support) {
+        this.message = message != null ? message : "";
+        this.support = support;
+    }
+
+    /**
+     * Hides input (e.g. for passwords). Shows * per character or blank.
+     */
+    public Prompt masked() {
+        this.masked = true;
+        return this;
+    }
+
+    /**
+     * Sets the output stream (default: stdout).
+     */
+    public Prompt output(PrintStream out) {
+        this.out = out != null ? out : System.out;
+        return this;
+    }
+
+    /**
+     * Sets the input stream (default: stdin). Useful for tests.
+     */
+    public Prompt input(InputStream in) {
+        this.in = in != null ? in : System.in;
+        return this;
+    }
+
+    /**
+     * Prompts and returns the entered string. Blocks until a line is read.
+     */
+    public String ask() {
+        out.print(message);
+        out.flush();
+        if (masked) {
+            return readMasked();
+        }
+        try (Scanner scan = new Scanner(in)) {
+            return scan.hasNextLine() ? scan.nextLine() : "";
+        }
+    }
+
+    /**
+     * Prompts and returns the next line from the given scanner. Use this when
+     * sharing one scanner (e.g. in a demo) so input blocks correctly.
+     */
+    public String ask(Scanner sharedScanner) {
+        if (sharedScanner == null) return ask();
+        out.print(message);
+        out.flush();
+        if (masked && System.console() != null) {
+            char[] chars = System.console().readPassword();
+            return chars != null ? new String(chars) : "";
+        }
+        return sharedScanner.hasNextLine() ? sharedScanner.nextLine() : "";
+    }
+
+    private String readMasked() {
+        if (System.console() != null) {
+            char[] chars = System.console().readPassword();
+            return chars != null ? new String(chars) : "";
+        }
+        try (Scanner scan = new Scanner(in)) {
+            return scan.hasNextLine() ? scan.nextLine() : "";
+        }
+    }
+}