I'm trying to implemenet GUI on some kind of Doubly Linked list - javafx

Question

I've so far done this, it's adding labels on the stage but removing thing is working but not as intended...
How can I store data of labels in an array or something so I can compare the remove.getText(); with that and delete that typed value if previous added as a label on stage.
public class Main extends Application {
Group root;
Label label1,label;
int count=1,count1=1;
public static void main(String[] args) {launch(args);}
public void start(Stage stage) throws Exception {
stage.setTitle("LinkedList GUI");
stage.setResizable(false);
root = new Group();
LinkedList<Integer> Linked =new LinkedList<Integer>();
Button Addfirst = new Button("AddFirst");
Addfirst.setTranslateX(40);
Addfirst.setTranslateY(350);
TextField first=new TextField();
first.setPrefWidth(60);
first.setTranslateX(120);
first.setTranslateY(350);
Addfirst.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
int a = Integer.parseInt(first.getText());
Linked.addFirst(a);
label1=new Label(" "+first.getText());
label1.setFont(Font.font("Buxton Sketch",FontWeight.BOLD,FontPosture.ITALIC,12));
label1.setPrefWidth(25);
label1.setPrefHeight(25);
label1.setTranslateY(60);
label1.setTextFill(Color.GREEN );
label1.setStyle("-fx-border-color: Blue;");
root.getChildren().addAll(label1);
label1.setTranslateX(250-(20*count++));
count++;
}
});
Button Addlast = new Button("AddLast");
Addlast.setTranslateX(200);
Addlast.setTranslateY(350);
TextField last=new TextField();
last.setPrefWidth(60);
last.setTranslateX(270);
last.setTranslateY(350);
Addlast.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
int b= Integer.parseInt(last.getText());
Linked.addLast(b);
label=new Label(" "+last.getText());
label.setFont(Font.font("Buxton Sketch",FontWeight.BOLD,FontPosture.ITALIC,12));
label.setPrefWidth(25);
label.setPrefHeight(25);
label.setTranslateY(60);
label.setTextFill(Color.GREEN );
label.setStyle("-fx-border-color: Blue;");
root.getChildren().add(label);
label.setTranslateX(250+(20*count1++));
count1++;
}
});
Button delete = new Button("Delete");
delete.setTranslateX(350);
delete.setTranslateY(350);
TextField remove=new TextField();
remove.setPrefWidth(60);
remove.setTranslateX(420);
remove.setTranslateY(350);
delete.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
if(remove.getText().equals(first.getText())) {
Linked.remove(first.getText());
root.getChildren().remove(label1);
}
else if(remove.getText().equals(last.getText())) {
Linked.remove(last.getText());
root.getChildren().remove(label);
}
else {
Alert alert = new Alert(AlertType.ERROR);
alert.setTitle("Error");
alert.setContentText("Not in List");
alert.showAndWait();
}
}
});
Text text =new Text("Doubly LinkedList GUI");
text.setStyle("-fx-border-color: Blak;");
text.setFont(Font.font("Buxton Sketch",FontWeight.BOLD,FontPosture.ITALIC,16));
text.setTranslateX(150);
text.setTranslateY(30);
root.getChildren().addAll(text,Addfirst,first,Addlast,last,delete,remove);
Scene scene = new Scene(root,500,400);
stage.setScene(scene);
stage.show();
}
}

Answer 1

I recommend using a layout that positions the children for you instead of positioning them yourself. E.g. using a HBox as parent for the labels allows you to simply add/remove the child at the same index as the one added/removed in the list:
#Override
public void start(Stage stage) throws Exception {
HBox container = new HBox(20);
container.setPrefHeight(40);
Button addFirst = new Button("add head");
Button addLast = new Button("add tail");
Button remove = new Button("remove");
TextField textField = new TextField();
HBox buttonContainer = new HBox(10, textField, addFirst, addLast, remove);
final LinkedList<Integer> list = new LinkedList<>();
addFirst.setOnAction(evt -> {
String text = textField.getText();
Integer value = Integer.parseInt(text);
list.addFirst(value);
container.getChildren().add(0, new Label(text));
});
addLast.setOnAction(evt -> {
String text = textField.getText();
Integer value = Integer.parseInt(text);
list.addLast(value);
container.getChildren().add(new Label(text));
});
remove.setOnAction(evt -> {
String text = textField.getText();
int value = Integer.parseInt(text);
ListIterator<Integer> iterator = list.listIterator();
while (iterator.hasNext()) {
Integer element = iterator.next();
if (element == value) {
container.getChildren().remove(iterator.nextIndex() - 1);
iterator.remove();
break;
}
}
});
VBox root = new VBox(container, buttonContainer);
Scene scene = new Scene(root, 500, 400);
stage.setScene(scene);
stage.show();
}