JavaFX TextField: Alternative for Swing InputVerifier? - javafx

Question

I am looking for an alternative of Swing InputVerifier to JavaFX TextField.
The Swing InputVerifier will prevent input that does verify.
Consider the following Swing JTextField code:
InputVerifier iv = new InputVerifier() {
/* (non-Javadoc)
* #see javax.swing.InputVerifier#verify(javax.swing.JComponent)
*/
#Override
public boolean verify(JComponent input) {
JTextField tf = (JTextField) input;
if (!myRegExTool.matches(tf.getText())) {
return false;
}
return true;
}
};
jinstance.setInputVerifier(iv);
I could use TextField.setOnKeyTyped or a listener to TextField.textProperty to check the typed text. However that will not prevent invalid text to get into the TextField. I could however delete typed text that does not verify, but that is not a good solution.
Solution:
As suggested by James_D a TextFormatter with a filter was the perfect solution
UnaryOperator<Change> textFilter = change -> {
String input = change.getText();
if (!myRegExTool.matches(input)) {
return null;
}
return change;
};
instance.setTextFormatter(new TextFormatter<String>(textFilter));

Answer 1

I have IntegerField control with StringConverter, UnaryOperator and TextFormatter. Maybe helpful for you!
import javafx.scene.control.TextField;
import javafx.scene.control.TextFormatter;
import javafx.util.StringConverter;
import javafx.util.converter.IntegerStringConverter;
import java.util.function.UnaryOperator;
public class IntegerField extends TextField {
public IntegerField() {
super();
StringConverter<Integer> integerStringConverter = new IntegerStringConverter();
UnaryOperator<TextFormatter.Change> filter = getFilter();
setTextFormatter(new TextFormatter<>(integerStringConverter, null, filter));
setOnAction(event -> integerStringConverter.fromString(this.getText()));
}
private UnaryOperator<TextFormatter.Change> getFilter() {
return change -> {
String text = change.getText();
if (!change.isContentChange()) {
return change;
}
if (text.matches("[0-9]*")) {
return change;
}
return null;
};
}
public Integer getValue() {
return Integer.valueOf(this.getText());
}
}

Answer 2

As first suggested by James_D a TextFormatter with filter was the solution.
TextField instance = new TextField();
UnaryOperator<Change> textFilter = change -> {
String input = change.getText();
if (!change.isContentChange()) {
return change;
}
if (!myRegExTool.matches(input)) {
return null;
}
return change;
};
instance.setTextFormatter(new TextFormatter<String>(textFilter));