Dinamically changing the font size and its style in the TextArea causes padding bugs

Question

I am creating a small text editor with JavaFX.

For this purpose I use TextArea and ComboBox'es to dynamically style it: e.g. changing the font, it's size, making it bold, italic and so on. It kind of works, however there is a disturbing visual bug that I can't put up with.

I tried to narrow the problem and here is a simpler code that has the same behavior and a couple of pics to understand what I'm talking about:

(to reproduce the bug set the size to 70 then choose bold and you will see how the text steps away from the edge.)

public class Main extends Application {
    public void start(Stage stage) {
        textArea = new TextArea("TEST 112123");
        textArea.setPrefWidth(800);
        textArea.setPrefHeight(400);
        textArea.setLayoutY(40);

        CheckBox bold = new CheckBox("BOLD");
        bold.setLayoutX(20);
        bold.setOnAction(e -> {
            Font currentFont = textArea.getFont();

            if (bold.isSelected()) {
                textArea.setFont(
                        new Font("System Bold", currentFont.getSize()));
        //I set new Font each time to save all of it's past properties and
        //change only one of them, this is the only way that I found to do 
        //this as there are no setters in the Font class, only constructors

            } else {
                textArea.setFont(
                        new Font("System", currentFont.getSize()));
            }
        });

        ComboBox sizeBox = new ComboBox();
        //I removed the list of options and the input validity check
        sizeBox.setLayoutX(80);
        sizeBox.setEditable(true);
        sizeBox.setOnAction(e -> {
            textArea.setFont(new Font(textArea.getFont().getName(),
                           Double.valueOf((String)sizeBox.getValue())));
        });

        stage.setScene(new Scene(new Group(textArea, bold, sizeBox), 800, 500));
        stage.show();
    }
}

images: https://i.sstatic.net/clSQk.jpg

Answer 1

You can add the following stylesheet.

.text-area .content {
    -fx-padding: 3 7 3 7;
}

It overrides the padding from modena.css:

.text-area .content {
    /*the is 1px less top and bottom than TextInput because of scrollpane border */
    -fx-padding: 0.25em 0.583em 0.25em 0.583em; /* 3 7 3 7 */
    -fx-cursor: text;
    -fx-background-color:
        linear-gradient(from 0px 0px to 0px 4px, derive(-fx-control-inner-background, -8%), -fx-control-inner-background);
    -fx-background-radius: 2;
}