JAVAFX event triggered when selecting a check box - javafx

Question

My JavaFx FXML application has an issue.
When I select a checkbox on a form, I want to execute a method based on the checkbox that was clicked. Is there any way that I can pass the name of the checkbox through to the method so I can perform some conditional work on it?
I have two checkboxes and only one can be selected. When I click on one, the other should be de-selected and vice versa. Obviously the code below will not work so I am looking to pass the name of the object that was clicked.
Any help would be appreciated,
many thanks.
#FXML private void updateRcs(){
if (chkRcsuri.isSelected()){
chkRcsuri2.setSelected(false);
}
if (chkRcsuri2.isSelected()){
chkRcsuri.setSelected(false);
}
}

Answer 1

You can use change tracking or use Event handling mechanism of JavaFX.
With checkboxes like this,
final CheckBox chk1 = new CheckBox("chk 1");
final CheckBox chk2 = new CheckBox("chk 2");
Change tracking
chk1.selectedProperty().addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
chk2.setSelected(!newValue);
}
});
chk2.selectedProperty().addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
chk1.setSelected(!newValue);
}
});
Using event handling
EventHandler eh = new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
if (event.getSource() instanceof CheckBox) {
CheckBox chk = (CheckBox) event.getSource();
System.out.println("Action performed on checkbox " + chk.getText());
if ("chk 1".equals(chk.getText())) {
chk2.setSelected(!chk1.isSelected());
} else if ("chk 2".equals(chk.getText())) {
chk1.setSelected(!chk2.isSelected());
}
}
}
};
chk1.setOnAction(eh);
chk2.setOnAction(eh);

Answer 2

Wouldn't radio buttons give you a mutually exclusive selection? Just make sure you set the groupname to be the same - selecting one would then automatically de-select the other and you can just put additional logic in the Action event.
Better than trying to re-write same functionality around checkboxes.

Answer 3

So I was trying to do a similar thing, except I had multiple checkboxes and then one that would be nonsensical to have selectable in conjuction with the others. I made two seperate listeners and set one general purpose one to the main boxes, and a specialized one to the exception.
#FXML private CheckBox redCB = new CheckBox();
#FXML private CheckBox blueCB = new CheckBox();
#FXML private CheckBox greenCB = new CheckBox();
#FXML private CheckBox whiteCB = new CheckBox();
#FXML private CheckBox blackCB = new CheckBox();
#FXML private CheckBox colorlessCB = new CheckBox();
//assigning listeners
redCB.selectedProperty().addListener(colorCheckChange);
blueCB.selectedProperty().addListener(colorCheckChange);
greenCB.selectedProperty().addListener(colorCheckChange);
whiteCB.selectedProperty().addListener(colorCheckChange);
blackCB.selectedProperty().addListener(colorCheckChange);
colorlessCB.selectedProperty().addListener(colorlessCheckChange);
//note: this is the only different one^^^
//making listeners
ChangeListener colorCheckChange = new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> ov,
Boolean old_val, Boolean new_val) {
if (new_val)
colorlessCB.setSelected(false);
}};
ChangeListener colorlessCheckChange = new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> ov,
Boolean old_val, Boolean new_val) {
if (new_val)
{
redCB.setSelected(false);
blueCB.setSelected(false);
greenCB.setSelected(false);
blackCB.setSelected(false);
whiteCB.setSelected(false);
}
}
};
The first one basically just makes sure that colorlessCB isn't selected while trying to select the other colors, and vice verca. This way you also avoid the problem of de-selecting one, and the other one automatically reselecting itself.

Answer 4

This is my solution. But be sure about the a variable to be appropriate for you
//First in FXML file
<CheckBox fx:id="chkbxAuto" mnemonicParsing="false" onAction="#autoConfig" text="Auto" />
// in controler
public class FXMLController implements Initializable {
private static int a = 0;
//references to lables
....
#FXML
private Label lblStateValue;
#FXML
private Group grpSetting; // a group of elements which I want to be disabled and enabled
...
#FXML
private void autoConfig(ActionEvent event) {
System.out.println("Configing automatically");
a++;
if(a%2==1){
lblStateValue.setText("Auto configuration enabled"); // it change a lable to show the state
grpSetting.setDisable(true); // it disable a group of elements
}
else{
lblStateValue.setText("Auto configuration disabled");
grpSetting.setDisable(false);
}
a%=10;
}
...

Answer 5

I know this question is pretty old, but I found when looking for the same problem. I found a solution which
a) seems clearer (at least to me comparing to the listener definition) for reading source code and
b) Defining a changeListener on a checkBox gave me some problems.
Anyway my solution was to define an onAction function for the checkbox.
yourCheckboxName.setOnAction(this::aFunctionName);
...
void aFunctionName() {
if(yourCheckboxName.isSelected()) {
doThis()
} else {
doThat()
}
}
Attention This needs Java8 or higher.

Answer 6

None of the above options take advantage of the most commpact lambda expresions that can be used to add this very repetitive listeners.
Let suppose you have two checkboxes:
chk1.selectedProperty().addListener((observable, oldValue, newValue) -> chk2.setSelected(!newValue));
chk2.selectedProperty().addListener((observable, oldValue, newValue) -> chk1.setSelected(!newValue));