Editor con JavaFX

hello-view.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.RowConstraints?>


<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="768.0" prefWidth="1024.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.example.compi.HelloController">
   <top>
      <MenuBar BorderPane.alignment="CENTER">
        <menus>
          <Menu mnemonicParsing="false" text="Archivo">
            <items>
                  <MenuItem mnemonicParsing="false" text="Nuevo" onAction="#handleNew" />
                  <MenuItem mnemonicParsing="false" text="Abrir" onAction="#handleOpen" />
              <MenuItem mnemonicParsing="false" text="Guardar" onAction="#handleSave" />
              <MenuItem mnemonicParsing="false" text="Salir" onAction="#handleExit" />
            </items>
          </Menu>
        </menus>
      </MenuBar>
   </top>
   <bottom>
      <HBox prefWidth="200.0" spacing="10.0" BorderPane.alignment="CENTER">
         <children>
            <Label text="Posicion del cursor" />
            <Label text="x,y" fx:id="cursorPosition" />
         </children>
         <padding>
            <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
         </padding>
      </HBox>
   </bottom>
   <center>
      <GridPane hgap="10.0" vgap="10.0" BorderPane.alignment="CENTER">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <children>
            <TextArea prefHeight="200.0" prefWidth="200.0" fx:id="sourceText" promptText="Source code" onKeyPressed="#changeSourceText">
               <padding>
                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
               </padding>
            </TextArea>
            <TextArea prefHeight="200.0" prefWidth="200.0" fx:id="resultText" promptText="Results here" style="-fx-background-color: #1e1e1e; -fx-foreground-color: #ffffff;" editable="false" wrapText="true" GridPane.columnIndex="1">
               <padding>
                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
               </padding>
            </TextArea>
         </children>
         <padding>
            <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
         </padding>
      </GridPane>
   </center>
</BorderPane>

HelloApplication.java

package com.example.compi;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.stage.Stage;

import java.io.IOException;

public class HelloApplication extends Application {
    @Override
    public void start(Stage stage) throws IOException {
        FXMLLoader fxmlLoader = new FXMLLoader(HelloApplication.class.getResource("hello-view.fxml"));
        Scene scene = new Scene(fxmlLoader.load(), 1024, 768);
        stage.isMaximized();
        stage.isResizable();
        stage.setTitle("Compi Editor");
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch();
    }
}

HelloController.java

package com.example.compi;

import Grammar.JLexer;
import Grammar.JParser;
import javafx.fxml.FXML;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.stage.FileChooser;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CommonTokenStream;

import java.io.*;

import static org.antlr.v4.runtime.CharStreams.fromString;

public class HelloController {
    @FXML
    private TextArea sourceText;
    @FXML
    private TextArea resultText;
    @FXML
    private Label cursorPosition;

    @FXML
    private void handleNew() {
        sourceText.setText("");
        resultText.setText("");
    }
    @FXML
    private void handleOpen() {
        FileChooser fileChooser = new FileChooser();
        fileChooser.setTitle("Open File");
        fileChooser.getExtensionFilters().addAll(
                new FileChooser.ExtensionFilter("Text Files", "*.txt"),
                new FileChooser.ExtensionFilter("Java Files", "*.java")
        );
        fileChooser.setInitialDirectory(new File(System.getProperty("user.home")));
        File file = fileChooser.showOpenDialog(null);
        try {
            BufferedReader reader = new BufferedReader(new FileReader(file));
            String line;
            StringBuilder sb = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                sb.append(line).append("\n");
            }
            sourceText.setText(sb.toString());
        } catch (FileNotFoundException e) {
            resultText.setText("File not found");
        } catch (IOException e) {
            resultText.setText("Error reading file");
        }
    }
    @FXML
    private void handleSave() {
        FileChooser fileChooser = new FileChooser();
        fileChooser.setTitle("Save File");
        fileChooser.getExtensionFilters().addAll(
                new FileChooser.ExtensionFilter("Text Files", "*.txt"),
                new FileChooser.ExtensionFilter("Java Files", "*.java")
        );
        fileChooser.setInitialDirectory(new File(System.getProperty("user.home")));
        File file = fileChooser.showSaveDialog(null);
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter(file));
            writer.write(sourceText.getText());
            writer.close();
        } catch (IOException e) {
            resultText.setText("Error writing file");
        }
    }
    @FXML
    private void handleExit() {
        System.exit(0);
    }
}