add support for handling user interrupts

.gitignore

@@ -20,6 +20,7 @@ bin/
 *.iws
 .idea/
 out/
+classes/
 
 hs_err_pid*
 _ignore*

text-io-demo/src/main/java/org/beryx/textio/demo/TextIoDemo.java

@@ -22,6 +22,7 @@
 import org.beryx.textio.console.ConsoleTextTerminalProvider;
 import org.beryx.textio.jline.AnsiTextTerminal;
 import org.beryx.textio.jline.JLineTextTerminalProvider;
+import org.beryx.textio.swing.SwingTextTerminal;
 import org.beryx.textio.swing.SwingTextTerminalProvider;
 import org.beryx.textio.system.SystemTextTerminal;
 import org.beryx.textio.system.SystemTextTerminalProvider;
@@ -57,9 +58,19 @@ public String toString() {
     }
 
     public static void main(String[] args) {
+        System.setProperty(SwingTextTerminal.PROP_USER_INTERRUPT_KEY, "ctrl C");
         TextIO textIO = chooseTextIO();
+
+        // Uncomment the line below to ignore user interrupts.
+//        textIO.getTextTerminal().registerUserInterruptHandler(term -> System.out.println("\n\t### User interrupt ignored."), false);
+
         if(textIO.getTextTerminal() instanceof WebTextTerminal) {
-            WebTextIoExecutor webTextIoExecutor = new WebTextIoExecutor().withPort(webServerPort);
+            WebTextTerminal webTextTerm = (WebTextTerminal)textIO.getTextTerminal();
+
+            // Uncomment the line below to trigger a user interrupt in the web terminal by typing Ctrl+C (instead of the default Ctrl+Q).
+//            webTextTerm.setUserInterruptKey('C', true, false, false);
+
+            WebTextIoExecutor webTextIoExecutor = new WebTextIoExecutor(webTextTerm).withPort(webServerPort);
             webTextIoExecutor.execute(SimpleApp::execute);
         } else {
             SimpleApp.execute(textIO);
@@ -125,8 +136,7 @@ private static WebTextTerminal createWebTextTerminal(TextIO textIO) {
                 .withDefaultValue(Service.SPARK_DEFAULT_PORT)
                 .read("Server port number");
 
-        // The returned WebTextTerminal is not actually used, but treated as a marker that triggers the creation of a WebTextIoExecutor.
-        // This WebTextIoExecutor will instantiate a new WebTextTerminal each time a client starts a new session.
+        // The returned WebTextTerminal is used as a template by the WebTextIoExecutor, which instantiates a new WebTextTerminal each time a client starts a new session.
         return new WebTextTerminal();
     }
 }

text-io-demo/src/main/java/org/beryx/textio/demo/WebTextIoExecutor.java

@@ -18,9 +18,12 @@
 import org.beryx.textio.TextIO;
 import org.beryx.textio.web.SparkDataServer;
 import org.beryx.textio.web.SparkTextIoApp;
+import org.beryx.textio.web.WebTextTerminal;
 
 import java.awt.*;
 import java.net.URI;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
 import static spark.Spark.staticFiles;
@@ -31,26 +34,27 @@
  * by configuring and initializing a {@link SparkDataServer}.
  */
 public class WebTextIoExecutor {
+    private final WebTextTerminal termTemplate;
     private int port = -1;
 
+    public WebTextIoExecutor(WebTextTerminal termTemplate) {
+        this.termTemplate = termTemplate;
+    }
+
     public WebTextIoExecutor withPort(int port) {
         this.port = port;
         return this;
     }
 
     public void execute(Consumer<TextIO> textIoRunner) {
-        SparkTextIoApp app = new SparkTextIoApp(textIoRunner);
+        SparkTextIoApp app = new SparkTextIoApp(textIoRunner, termTemplate);
         app.setMaxInactiveSeconds(600);
-        app.setOnDispose(sessionId -> {
-            new Thread(() -> {
-                try {
-                    Thread.sleep(1000L);
-                } catch (InterruptedException e) {
-                    e.printStackTrace();
-                }
-                stop();
-            }).start();
-        });
+        Consumer<String> stopServer = sessionId -> Executors.newSingleThreadScheduledExecutor().schedule(() -> {
+            stop();
+            System.exit(0);
+        }, 2, TimeUnit.SECONDS);
+        app.setOnDispose(stopServer);
+        app.setOnAbort(stopServer);
 
         SparkDataServer server = app.getServer();
         if(port > 0) {

text-io-demo/src/main/resources/public-html/web-demo.html

@@ -19,10 +19,12 @@ <h3 id="app-done"> </h3>
 <script src="textterm.js"></script>
 <script>
     var textTerm = TextTerm.init(document.getElementById("textterm"));
-
     textTerm.onDispose = function() {
         document.getElementById("app-done").textContent = "You can now close this window.";
     }
+    textTerm.onAbort = function() {
+        document.getElementById("app-done").textContent = "Program aborted by the user. You can now close this window.";
+    }
 </script>
 
 </body>

text-io-web/src/main/java/org/beryx/textio/web/DataApi.java

@@ -24,4 +24,10 @@ public interface DataApi {
 
     /** This method is called by the web component to post the user input */
     void postUserInput(String input);
+
+    /**
+     * This method is called by the web component in response to a user interrupt (typically triggered by typing Ctrl+Q).
+     * @param partialInput the partially entered input when the user interrupt occurred.
+     */
+    void postUserInterrupt(String partialInput);
 }

text-io-web/src/main/java/org/beryx/textio/web/SparkDataServer.java

@@ -97,9 +97,15 @@ public void init() {
         post(pathForPostInput, (request, response) -> {
             logger.trace("Received POST");
             DataApi dataApi = getDataApi(request);
+            boolean userInterrupt = Boolean.parseBoolean(request.headers("textio-user-interrupt"));
             String input = new String(request.body().getBytes(), "UTF-8");
-            logger.trace("Posting input...");
-            dataApi.postUserInput(input);
+            if(userInterrupt) {
+                logger.trace("Posting user interrupted input...");
+                dataApi.postUserInterrupt(input);
+            } else {
+                logger.trace("Posting input...");
+                dataApi.postUserInput(input);
+            }
             return "OK";
         });
     }

text-io-web/src/main/java/org/beryx/textio/web/SparkTextIoApp.java

@@ -30,15 +30,18 @@ public class SparkTextIoApp {
     private static final Logger logger =  LoggerFactory.getLogger(SparkTextIoApp.class);
 
     private final Map<String, WebTextTerminal> dataApiMap = new HashMap<>();
+    private final WebTextTerminal termTemplate;
 
     private final Consumer<TextIO> textIoRunner;
     private final SparkDataServer server;
     private Integer maxInactiveSeconds = null;
 
     private Consumer<String> onDispose;
+    private Consumer<String> onAbort;
 
-    public SparkTextIoApp(Consumer<TextIO> textIoRunner) {
+    public SparkTextIoApp(Consumer<TextIO> textIoRunner, WebTextTerminal termTemplate) {
         this.textIoRunner = textIoRunner;
+        this.termTemplate = termTemplate;
         this.server = new SparkDataServer(this::getDataApi);
     }
 
@@ -50,18 +53,26 @@ public void setOnDispose(Consumer<String> onDispose) {
         this.onDispose = onDispose;
     }
 
+    public void setOnAbort(Consumer<String> onAbort) {
+        this.onAbort = onAbort;
+    }
+
     public void setMaxInactiveSeconds(Integer maxInactiveSeconds) {
         this.maxInactiveSeconds = maxInactiveSeconds;
     }
 
-    private final WebTextTerminal getDataApi(String sessionId, Session session) {
+    private WebTextTerminal getDataApi(String sessionId, Session session) {
         synchronized (dataApiMap) {
             WebTextTerminal terminal = dataApiMap.get(sessionId);
             if(terminal == null) {
-                terminal = new WebTextTerminal();
+                logger.debug("Creating terminal for sessionId: " + sessionId);
+                terminal = termTemplate.createCopy();
                 if(onDispose != null) {
                     terminal.setOnDispose(() -> onDispose.accept(sessionId));
                 }
+                if(onAbort != null) {
+                    terminal.setOnAbort(() -> onAbort.accept(sessionId));
+                }
                 dataApiMap.put(sessionId, terminal);
 
                 if(maxInactiveSeconds != null) {

text-io-web/src/main/java/org/beryx/textio/web/TextTerminalData.java

@@ -20,23 +20,50 @@
 
 /**
  * The data sent by the server to a polling web component.
- * Includes a list of prompt messages and an action to be executed by the web component (NONE, READ, READ_MASKED, DISPOSE).
+ * Includes a list of settings, a list of prompt messages and an action to be executed by the web component (NONE, READ, READ_MASKED, DISPOSE or ABORT).
  */
 public class TextTerminalData {
-    public enum Action {NONE, READ, READ_MASKED, DISPOSE}
+    public enum Action {NONE, READ, READ_MASKED, DISPOSE, ABORT}
 
+    public static class KeyValue {
+        public final String key;
+        public final Object value;
+
+        public KeyValue(String key, Object value) {
+            this.key = key;
+            this.value = value;
+        }
+    }
+
+    private final List<KeyValue> settings = new ArrayList<>() ;
     private final List<String> messages = new ArrayList<>();
     private Action action = Action.NONE;
     private boolean resetRequired = true;
 
     public TextTerminalData getCopy() {
         TextTerminalData data = new TextTerminalData();
+        data.settings.addAll(settings);
         data.messages.addAll(messages);
         data.action = action;
         data.resetRequired = resetRequired;
         return data;
     }
 
+    public void addSetting(String key, Object value) {
+        KeyValue keyVal = new KeyValue(key, value);
+        int size = settings.size();
+        for(int i = 0; i < size; i++) {
+            if(settings.get(i).key.equals(key)) {
+                settings.set(i, keyVal);
+                return;
+            }
+        }
+        settings.add(keyVal);
+    }
+
+    public List<KeyValue> getSettings() {
+        return settings;
+    }
     public List<String> getMessages() {
         return messages;
     }
@@ -65,6 +92,7 @@ public boolean hasAction() {
     }
 
     public void clear() {
+        settings.clear();
         messages.clear();
         action = Action.NONE;
         resetRequired = false;
@@ -73,6 +101,7 @@ public void clear() {
     @Override
     public String toString() {
         return "resetRequired: " + resetRequired +
+                ", settings: " + settings +
                 ", messages: " + messages +
                 ", action: " + action;
     }