JavaFX: Make comboBox cell to change disable state dynamically - javafx

Question

Except for the first item, all items of a comboBox are initially disabled (I used setCellFactory to accomplish this).
If I click on the option 0, I want for it to unlock option 1 and so on.
I tried to use some boolean variables inside a comboBox Listener but it seems like the setCellFactory is called only once. Is this correct?
If so, how could I achieve what I want?
SSCCE below adapted from here
Main.java
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.stage.Stage;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ListCell;
public class Main extends Application {
boolean isZeroLocked = false;
boolean isOneLocked = true;
boolean isTwoLocked = true;
boolean isThreeLocked = true;
#Override
public void start(Stage stage) throws Exception {
ComboBox<Integer> box = new ComboBox<Integer>();
ObservableList<Integer> values = FXCollections.observableArrayList(0,1,2,3);
box.setItems(values);
box.getSelectionModel().selectedIndexProperty().addListener((observable,oldValue,newValue)->{
System.out.println(newValue + " was clicked. The next option will be unlocked.");
if(newValue.intValue() == 0)
isOneLocked = false;
if(newValue.intValue() == 1)
isTwoLocked = false;
if(newValue.intValue() == 2)
isThreeLocked = false;
});
box.setCellFactory(lv -> new ListCell<Integer>() {
#Override
public void updateItem(Integer item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
} else {
setText(item.toString());
if(item.intValue() == 0)
setDisable(isZeroLocked);
if(item.intValue() == 1)
setDisable(isOneLocked);
if(item.intValue() == 2)
setDisable(isTwoLocked);
if(item.intValue() == 3)
setDisable(isThreeLocked);
}
}
});
Scene scene = new Scene(new Group(box));
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
application.css
.combo-box-popup .list-cell:disabled {
-fx-opacity: 0.4 ;
}

Answer 1

I created an Object called CustomNumber to keep up with the disabled property.
Key code:
This code sets the ComboBox's text and enables its cell.
Callback<ListView<CustomNumber>, ListCell<CustomNumber>> factory = lv -> new ListCell<CustomNumber>() {
#Override
protected void updateItem(CustomNumber item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
} else {
System.out.println(item.getNum());
setText(Integer.toString(item.getNum()));
setDisable(item.isDisable());
}
}
};
This code gets the cell below the clicked cell and updates its disable property
box.getSelectionModel().selectedIndexProperty().addListener((observable,oldValue,newValue)->{
if(newValue.intValue() + 1 < box.getItems().size())
{
CustomNumber tempCustomNumber = (CustomNumber)box.getItems().get(newValue.intValue() + 1);
tempCustomNumber.setDisable(false);
System.out.println(tempCustomNumber.getNum() + " " + tempCustomNumber.isDisable() + " was unlocked.");
box.getItems().set(newValue.intValue() + 1, tempCustomNumber);
}
});
Full Code:
import java.util.ArrayList;
import java.util.List;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.stage.Stage;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.util.Callback;
public class Main extends Application {
#Override
public void start(Stage stage) throws Exception {
ComboBox<CustomNumber> box = new ComboBox();
List<CustomNumber> customNumbers = new ArrayList();
customNumbers.add(new CustomNumber(0, false));
customNumbers.add(new CustomNumber(1, true));
customNumbers.add(new CustomNumber(2, true));
customNumbers.add(new CustomNumber(3, true));
ObservableList<CustomNumber> values = FXCollections.observableArrayList(customNumbers);
box.setItems(values);
Callback<ListView<CustomNumber>, ListCell<CustomNumber>> factory = lv -> new ListCell<CustomNumber>() {
#Override
protected void updateItem(CustomNumber item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
} else {
System.out.println(item.getNum());
setText(Integer.toString(item.getNum()));
setDisable(item.isDisable());
}
}
};
box.setCellFactory(factory);
box.setButtonCell(factory.call(null));
box.getSelectionModel().selectedIndexProperty().addListener((observable,oldValue,newValue)->{
if(newValue.intValue() + 1 < box.getItems().size())
{
CustomNumber tempCustomNumber = (CustomNumber)box.getItems().get(newValue.intValue() + 1);
tempCustomNumber.setDisable(false);
System.out.println(tempCustomNumber.getNum() + " " + tempCustomNumber.isDisable() + " was unlocked.");
box.getItems().set(newValue.intValue() + 1, tempCustomNumber);
}
});
Scene scene = new Scene(new Group(box));
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
CustomNumber
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package javafxapplication9;
/**
*
* #author sedrick
*/
public class CustomNumber {
private int num;
private boolean disable;
public CustomNumber(int num, boolean disable) {
this.num = num;
this.disable = disable;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
public boolean isDisable() {
return disable;
}
public void setDisable(boolean isDisable) {
this.disable = isDisable;
}
}