How to grab a node index inside an Hbox - javafx

Question

I tried to add Buttons in to an Hbox i wanna grab the index when a button clicked
here is what i have done.
HBox gp = new HBox(10);
gp.setPadding(new Insets(3));
for (int i = 0; i < 20; i++) {
JFXButton jb = new JFXButton("Number " + i);
jb.setStyle("-fx-background-color: rgb(230, 126, 34)");
jb.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("index no?");
}
});
jb.setMinWidth(100);
jb.setMinHeight(50);
gp.getChildren().add(jb);
}
gp.prefWidthProperty().bind(topscroll.widthProperty());
topscroll.setContent(gp);
gp.prefWidthProperty().bind(topscroll.widthProperty());
topscroll.setContent(gp);
any suggestion to achieve that?

Answer 1

You can just copy the index into a final variable:
for (int i = 0; i < 20; i++) {
JFXButton jb = new JFXButton("Number " + i);
jb.setStyle("-fx-background-color: rgb(230, 126, 34)");
int index = i ;
jb.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("index no: " + index);
}
});
jb.setMinWidth(100);
jb.setMinHeight(50);
gp.getChildren().add(jb);
}
Note you can get the button directly (in case that is all you need) without creating another variable:
for (int i = 0; i < 20; i++) {
JFXButton jb = new JFXButton("Number " + i);
jb.setStyle("-fx-background-color: rgb(230, 126, 34)");
jb.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("Click on "+jb.getText());
}
});
jb.setMinWidth(100);
jb.setMinHeight(50);
gp.getChildren().add(jb);
}