Add exception dialog

sampler/src/main/java/atlantafx/sampler/DefaultExceptionHandler.java

@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: MIT */
+package atlantafx.sampler;
+
+import javafx.scene.control.Alert;
+import javafx.scene.control.Alert.AlertType;
+import javafx.scene.control.Label;
+import javafx.scene.control.TextArea;
+import javafx.scene.layout.VBox;
+import javafx.stage.Stage;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.Objects;
+
+import static java.lang.Double.MAX_VALUE;
+
+public class DefaultExceptionHandler implements Thread.UncaughtExceptionHandler {
+
+    private final Stage stage;
+
+    public DefaultExceptionHandler(Stage stage) {
+        this.stage = stage;
+    }
+
+    @Override
+    public void uncaughtException(Thread t, Throwable e) {
+        e.printStackTrace();
+
+        var dialog = createExceptionDialog(e);
+        if (dialog != null) { dialog.showAndWait(); }
+    }
+
+    private Alert createExceptionDialog(Throwable throwable) {
+        Objects.requireNonNull(throwable);
+
+        var alert = new Alert(AlertType.ERROR);
+        alert.setTitle("Error");
+        alert.setHeaderText(null);
+        alert.setContentText(throwable.getMessage());
+
+        try (var sw = new StringWriter(); var printWriter = new PrintWriter(sw)) {
+            throwable.printStackTrace(printWriter);
+
+            var label = new Label("Full stacktrace:");
+
+            var textArea = new TextArea(sw.toString());
+            textArea.setEditable(false);
+            textArea.setWrapText(false);
+            textArea.setMaxWidth(MAX_VALUE);
+            textArea.setMaxHeight(MAX_VALUE);
+
+            var content = new VBox(5, label, textArea);
+            content.setMaxWidth(MAX_VALUE);
+
+            alert.getDialogPane().setExpandableContent(content);
+            alert.initOwner(stage);
+
+            return alert;
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+}

sampler/src/main/java/atlantafx/sampler/Launcher.java

@@ -40,21 +40,13 @@ public class Launcher extends Application {
             new KeyCodeCombination(KeyCode.F, KeyCombination.CONTROL_DOWN)
     );
 
-    private static class DefaultExceptionHandler implements Thread.UncaughtExceptionHandler {
-
-        @Override
-        public void uncaughtException(Thread t, Throwable e) {
-            e.printStackTrace();
-        }
-    }
-
     public static void main(String[] args) {
         launch(args);
     }
 
     @Override
     public void start(Stage stage) {
-        Thread.currentThread().setUncaughtExceptionHandler(new DefaultExceptionHandler());
+        Thread.currentThread().setUncaughtExceptionHandler(new DefaultExceptionHandler(stage));
         loadApplicationProperties();
 
         if (IS_DEV_MODE) {

sampler/src/main/java/atlantafx/sampler/page/components/DialogPage.java

@@ -117,7 +117,7 @@ public class DialogPage extends AbstractPage {
         var button = new Button("Click", new FontIcon(Feather.MEH));
         button.setOnAction(e -> {
             var alert = new Alert(AlertType.ERROR);
-            alert.setTitle("Error Dialog");
+            alert.setTitle("Exception Dialog");
             alert.setHeaderText(randomHeader());
             alert.setContentText(FAKER.lorem().paragraph(3));