changing my textfield to upper/lower case is not working as intended - javafx

Question

After creating my GUI my next step was to have the buttons be able to change the textfield to their respective case when pressed. However none of the ways I have tried seem to demonstrate that.
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class UpperLowerClass extends Application {
private Button upperButton;
private Button lowerButton;
private String userText;
private TextField userInput;
private Stage window;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) {
window = primaryStage;
window.setTitle("Uppercase to Lowercase");
//GRID
GridPane grid = new GridPane();
grid.setPadding(new Insets(10, 10, 10, 10));
grid.setVgap(10);
grid.setHgap(10);
//UPPERCASE BUTTON
upperButton = new Button("Uppercase");
upperButton.setOnAction(this::changeTextButton);
GridPane.setConstraints(upperButton, 0, 0);
//LOWERCASE BUTTON
lowerButton = new Button("Lowercase");
lowerButton.setOnAction(this::changeTextButton);
GridPane.setConstraints(lowerButton, 0, 1);
//TEXTFIELD
TextField userInput = new TextField();
userInput.getText();
userInput.setText(String.valueOf(userText));
GridPane.setConstraints(userInput, 0, 2);
grid.getChildren().addAll(upperButton, lowerButton, userInput);
//SCENE
Scene myScene = new Scene(grid, 300, 250);
window.setScene(myScene);
window.show();
primaryStage.setScene(myScene);
primaryStage.show();
}
//EVENT
public void changeTextButton(ActionEvent event)
{
if (event.getSource() ==upperButton) {
userText = userText.toUpperCase();
}
if (event.getSource() ==lowerButton) {
userInput.setText(String.valueOf(userText.toLowerCase()));
}
}
}
There must be a problem with how I am retrieving the text or is it entirely because of the manipulation I am trying to do in the If statements? Each button is the two versions I have tried which leads me to think that I am retrieving the text wrong or manipulating wrong. Thank you in advance!

Answer 1

Is the String userText needed elsewhere? Getting and setting the text of userInput directly through getText() and setText() would be better imo. Additionally, there is no need to create a local variable for userInput when you have it as a global variable already.
This is your code tested working: (I removed the changeTextButton method and just made the changes from the buttons directly, but this could be split out easily enough.)
public class UpperLowerClass extends Application {
private Button upperButton;
private Button lowerButton;
private TextField userInput;
private Stage window;
#Override
public void start(Stage primaryStage) {
try {
window = primaryStage;
//GRID
GridPane grid = new GridPane();
grid.setPadding(new Insets(10, 10, 10, 10));
grid.setVgap(10);
grid.setHgap(10);
//UPPERCASE BUTTON
upperButton = new Button("Uppercase");
upperButton.setOnAction(event -> {
if(userInput.getText()!=null) {
userInput.setText(userInput.getText().toUpperCase());
}
});
// upperButton.setOnAction(this::changeTextButton);
GridPane.setConstraints(upperButton, 0, 0);
//LOWERCASE BUTTON
lowerButton = new Button("Lowercase");
//lowerButton.setOnAction(this::changeTextButton);
lowerButton.setOnAction(event -> {
if(userInput.getText()!=null) {
userInput.setText(userInput.getText().toLowerCase());
}
});
GridPane.setConstraints(lowerButton, 0, 1);
//TEXTFIELD
userInput = new TextField(); //don't need to create new Textfield here
GridPane.setConstraints(userInput, 0, 2);
grid.getChildren().addAll(upperButton, lowerButton, userInput);
//SCENE
Scene myScene = new Scene(grid, 300, 250);
window.setScene(myScene);
window.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}