Why JavaFX TextField listener repeats 3 times?
I am trying to track input to TextField and allow user to input only 1 symbol per TextField, here is my code:
package sample;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
TextField textField = new TextField(); //creating new textfield
Pane window = new Pane();
Parent root = window;
window.getChildren().addAll(textField); //adding textfield to the window
primaryStage.setScene(new Scene(root, 200, 50));
primaryStage.show();
textField.textProperty().addListener(event ->
{
try {
if (textField.getLength() > 1) { //check if the length of the textfield text exceeds 1
System.out.println("NOT Accepted");
textField.setText(String.valueOf(textField.getText().charAt(0))); //set textfield text to first char only
} else {
System.out.println("Accepted");
}
} catch (IndexOutOfBoundsException Bound) {}
}
);
}
public static void main(String args) {
launch(args);
}
}
When I press any symbol first time, everything works good, but when I press second time, event listener repeats 3 times. Here the exapmle:
"a" key has been pressed, console output:
Accepted //<---Correct
"a" key (or any another key) has been pressed second time, console output:
NOT Accepted //<---Correct
Accepted //<---Not correct
Accepted //<---Not correct
As shown above listener repeats 3 times.
But I expect that console should show only "NOT Accepted" and shouldn't repeat 2 times more.
javafx listener textfield keypress
add a comment |
I am trying to track input to TextField and allow user to input only 1 symbol per TextField, here is my code:
package sample;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
TextField textField = new TextField(); //creating new textfield
Pane window = new Pane();
Parent root = window;
window.getChildren().addAll(textField); //adding textfield to the window
primaryStage.setScene(new Scene(root, 200, 50));
primaryStage.show();
textField.textProperty().addListener(event ->
{
try {
if (textField.getLength() > 1) { //check if the length of the textfield text exceeds 1
System.out.println("NOT Accepted");
textField.setText(String.valueOf(textField.getText().charAt(0))); //set textfield text to first char only
} else {
System.out.println("Accepted");
}
} catch (IndexOutOfBoundsException Bound) {}
}
);
}
public static void main(String args) {
launch(args);
}
}
When I press any symbol first time, everything works good, but when I press second time, event listener repeats 3 times. Here the exapmle:
"a" key has been pressed, console output:
Accepted //<---Correct
"a" key (or any another key) has been pressed second time, console output:
NOT Accepted //<---Correct
Accepted //<---Not correct
Accepted //<---Not correct
As shown above listener repeats 3 times.
But I expect that console should show only "NOT Accepted" and shouldn't repeat 2 times more.
javafx listener textfield keypress
In your listener you modify the content of yourTextField
, then it triggers your listener :textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.
– Pagbo
Nov 19 '18 at 14:16
add a comment |
I am trying to track input to TextField and allow user to input only 1 symbol per TextField, here is my code:
package sample;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
TextField textField = new TextField(); //creating new textfield
Pane window = new Pane();
Parent root = window;
window.getChildren().addAll(textField); //adding textfield to the window
primaryStage.setScene(new Scene(root, 200, 50));
primaryStage.show();
textField.textProperty().addListener(event ->
{
try {
if (textField.getLength() > 1) { //check if the length of the textfield text exceeds 1
System.out.println("NOT Accepted");
textField.setText(String.valueOf(textField.getText().charAt(0))); //set textfield text to first char only
} else {
System.out.println("Accepted");
}
} catch (IndexOutOfBoundsException Bound) {}
}
);
}
public static void main(String args) {
launch(args);
}
}
When I press any symbol first time, everything works good, but when I press second time, event listener repeats 3 times. Here the exapmle:
"a" key has been pressed, console output:
Accepted //<---Correct
"a" key (or any another key) has been pressed second time, console output:
NOT Accepted //<---Correct
Accepted //<---Not correct
Accepted //<---Not correct
As shown above listener repeats 3 times.
But I expect that console should show only "NOT Accepted" and shouldn't repeat 2 times more.
javafx listener textfield keypress
I am trying to track input to TextField and allow user to input only 1 symbol per TextField, here is my code:
package sample;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
TextField textField = new TextField(); //creating new textfield
Pane window = new Pane();
Parent root = window;
window.getChildren().addAll(textField); //adding textfield to the window
primaryStage.setScene(new Scene(root, 200, 50));
primaryStage.show();
textField.textProperty().addListener(event ->
{
try {
if (textField.getLength() > 1) { //check if the length of the textfield text exceeds 1
System.out.println("NOT Accepted");
textField.setText(String.valueOf(textField.getText().charAt(0))); //set textfield text to first char only
} else {
System.out.println("Accepted");
}
} catch (IndexOutOfBoundsException Bound) {}
}
);
}
public static void main(String args) {
launch(args);
}
}
When I press any symbol first time, everything works good, but when I press second time, event listener repeats 3 times. Here the exapmle:
"a" key has been pressed, console output:
Accepted //<---Correct
"a" key (or any another key) has been pressed second time, console output:
NOT Accepted //<---Correct
Accepted //<---Not correct
Accepted //<---Not correct
As shown above listener repeats 3 times.
But I expect that console should show only "NOT Accepted" and shouldn't repeat 2 times more.
javafx listener textfield keypress
javafx listener textfield keypress
asked Nov 19 '18 at 14:02
YerbolYerbol
82
82
In your listener you modify the content of yourTextField
, then it triggers your listener :textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.
– Pagbo
Nov 19 '18 at 14:16
add a comment |
In your listener you modify the content of yourTextField
, then it triggers your listener :textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.
– Pagbo
Nov 19 '18 at 14:16
In your listener you modify the content of your
TextField
, then it triggers your listener : textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.– Pagbo
Nov 19 '18 at 14:16
In your listener you modify the content of your
TextField
, then it triggers your listener : textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.– Pagbo
Nov 19 '18 at 14:16
add a comment |
1 Answer
1
active
oldest
votes
Instead of using a ChangeListener
, I recommend a simple TextFormatter
instead. This allows you to prevent the change without triggering another event.
textField.setTextFormatter(new TextFormatter<String>((TextFormatter.Change change) -> {
String newText = change.getControlNewText();
if (newText.length() == 1) {
System.out.println("Accepted");
} else if (newText.length() > 1) {
System.out.println("NOT Accepted");
return null;
}
return change;
}));
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
add a comment |
Your Answer
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Instead of using a ChangeListener
, I recommend a simple TextFormatter
instead. This allows you to prevent the change without triggering another event.
textField.setTextFormatter(new TextFormatter<String>((TextFormatter.Change change) -> {
String newText = change.getControlNewText();
if (newText.length() == 1) {
System.out.println("Accepted");
} else if (newText.length() > 1) {
System.out.println("NOT Accepted");
return null;
}
return change;
}));
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
add a comment |
Instead of using a ChangeListener
, I recommend a simple TextFormatter
instead. This allows you to prevent the change without triggering another event.
textField.setTextFormatter(new TextFormatter<String>((TextFormatter.Change change) -> {
String newText = change.getControlNewText();
if (newText.length() == 1) {
System.out.println("Accepted");
} else if (newText.length() > 1) {
System.out.println("NOT Accepted");
return null;
}
return change;
}));
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
add a comment |
Instead of using a ChangeListener
, I recommend a simple TextFormatter
instead. This allows you to prevent the change without triggering another event.
textField.setTextFormatter(new TextFormatter<String>((TextFormatter.Change change) -> {
String newText = change.getControlNewText();
if (newText.length() == 1) {
System.out.println("Accepted");
} else if (newText.length() > 1) {
System.out.println("NOT Accepted");
return null;
}
return change;
}));
Instead of using a ChangeListener
, I recommend a simple TextFormatter
instead. This allows you to prevent the change without triggering another event.
textField.setTextFormatter(new TextFormatter<String>((TextFormatter.Change change) -> {
String newText = change.getControlNewText();
if (newText.length() == 1) {
System.out.println("Accepted");
} else if (newText.length() > 1) {
System.out.println("NOT Accepted");
return null;
}
return change;
}));
edited Nov 19 '18 at 14:39
answered Nov 19 '18 at 14:34
ZephyrZephyr
3,8382931
3,8382931
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
add a comment |
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
Thank you! It works!
– Yerbol
Nov 19 '18 at 16:42
add a comment |
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In your listener you modify the content of your
TextField
, then it triggers your listener :textField.setText(String.valueOf(textField.getText().charAt(0)));
. Everything works as coded.– Pagbo
Nov 19 '18 at 14:16