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JavaFX Action Event - Pull from Array

Working on a school project, I am trying to get the action of clicking a button pull the selected index of a Combo Box string array, and associated that index with an int array so that a final price can be computed. Doesn't seem to work the price just remains at zero when button is pressed.
private final String[] deckArray = {"The Master
Thrasher ", "The Dictator", "The Street King"};
private final String[] trucksArray = {"7.75-inch
axle", "8-inch axle", "8.5-inch axle"};
private final String[] wheelsArray = {"51mm", "55mm",
"58mm", "61mm"};
private final int[] deckPrice = {60,45,50};
private final int[] trucksPrice = {35,40,45};
private final int[] wheelsPrice = {20,22,24,28};
comboDecks = new ComboBox();
comboDecks.getItems().addAll(deckArray);
comboTrucks = new ComboBox();
comboTrucks.getItems().addAll(trucksArray);
comboWheels = new ComboBox();
comboWheels.getItems().addAll(wheelsArray);
btnCalc = new Button("Calculate Total");
lblFinalPrice = new Label("Final Price:");
txtSubtotal = new Text("Subtotal: " + finalSubPrice);
txtTax = new Text("Tax:" + finalTaxPrice);
txtFinalPrice = new Text("Final Price: " +
finalTotalPrice);
EventHandler<ActionEvent> calcHandler = new
EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent actionEvent) {
finalDeckPrice = deckPrice[comboDecks.getSelectionModel().getSelectedIndex()];
finalTruckPrice = trucksPrice[comboTrucks.getSelectionModel().getSelectedIndex()];
finalWheelsPrice = wheelsPrice[comboWheels.getSelectionModel().getSelectedIndex()];
finalSubPrice = finalDeckPrice + finalTruckPrice + finalWheelsPrice;
finalTaxPrice = finalSubPrice * salesTax;
finalTotalPrice = finalSubPrice + finalTaxPrice;
}
};

You made the button, you made the event handler, but you never connected the event handler to the button. Same goes for the calculation and the label, you calculated but did not update the label with the calculated value.
Add the following line to your code after you create the handler.
btnCalc.setOnAction(calcHandler);
And add txtFinalPrice.setText(""+finalTotalPrice); after you finish calculations inside handle() method.
public void handle(ActionEvent actionEvent) {
...
finalTotalPrice = finalSubPrice + finalTaxPrice;
txtFinalPrice.setText("Final Price: " + finalTotalPrice);
}
Explanation (Abstract)
(1) When you create an Event Handler object you just wrote the code you want it to run but it won't run in serial as the code executes top to bottom, since as you said you want it to work when you click the button. So you have to let the Button know that when it gets clicked to execute this code. setOnAction() method takes as parameter an Event Handler object and executes it when some action happens to the Button, the action for the Button is when it gets clicked.
(2) Just by calculating the value, doesn't mean the Label knows that the value got calculated or something. The point where you calculating the price is the point that you have to tell to the Label take this value and use this as your content.
Suggestion
Event handlers, action events etc need a bit of good understanding to use them correctly. The baseline is that all of that work asynchronously and you gotta get at least the idea of it so you can understand the rest (no offense but from the question i believe you need some work on it).

Calculate % of textbox filled in

I am working on a javafx project in which I'm providing a textbox to be filled in.I want to calculate % of textbox filled in..say for eg 100 characters is a limit and 50 are filled in so 50 should be the % value but it should change automatically as i keep typing .I don't know exactly how to do that (specially the Automatic thing). I want to show that % value on progressbar like this :
(Ignore buttons)
Need help! Thank you in advance

You can define yourself a DoubleBinding which is bound to the textProperty and on each change revaluates it's value.
final double max = 100;
TextField text = new TextField();
DoubleBinding percentage = new DoubleBinding() {
{
super.bind(text.textProperty());
}
#Override
protected double computeValue() {
return text.getText().length() / max;
}
};
In the static initializer block of the DoubleBinding you bind the textProperty of your TextField. This will cause the reevaluation of the binding through the computeValue method. Then you can bind it to the textProperty of a Label:
Label lbl = new Label();
lbl.textProperty().bind(percentage.asString());
Of course you can also bind it to other controls than a Label like a ProgressBar or ProgressIndicator:
ProgressBar bar = new ProgressBar();
bar.progressProperty().bind(percentage);
ProgressIndicator indicator = new ProgressIndicator();
indicator.progressProperty().bind(percentage);
This binding then can be used to display the percentage already filled in. You might also take a look at this documentation by Oracle. The type of this binding is a low-level binding.

Java determining if which JRadioButton was selected

I know that it is possible in an event driven program in Java to find out what object caused an event (e.g. JRadioButton was selected, therefore a certain action will take place). My question is, if you have 2 JRadioButtons in a buttongroup, both with action listeners added to them, and you keep selecting from one to the other, is it possible to find out what JRadioButton was previously selected? In other words, if I selected another JRadioButton, is it possible to write code that determines which JRadioButton was previously selected before selecting the current JRadioButton?
public class Drinks extends JPanel implements ActionListener{
double drinksPrice = 2.10;
double noDrinks = 0;
static String selectedDrink;
JRadioButton btnPepsi = new JRadioButton("Pepsi"); //add a button to choose different drinks
JRadioButton btnMtDew = new JRadioButton("Mt Dew");
JRadioButton btnDietPepsi= new JRadioButton("Diet Pepsi");
JRadioButton btnCoffee = new JRadioButton("Coffee");
JRadioButton btnTea = new JRadioButton("Tea");
JRadioButton btnNone = new JRadioButton("None");
JLabel lblDrinksHeading = new JLabel("Choose a drink (each drink is $2.10):");
ButtonGroup drinksButtonGroup = new ButtonGroup();
private static final long serialVersionUID = 1L;
public Drinks(){
setLayout(new FlowLayout()); //Using GridLayout
btnPepsi.setActionCommand(btnPepsi.getText()); //set the ActionCommand to getText so I can retrieve the name for the receipt
btnMtDew.setActionCommand(btnMtDew.getText());
btnDietPepsi.setActionCommand(btnDietPepsi.getText());
btnCoffee.setActionCommand(btnCoffee.getText());
btnTea.setActionCommand(btnTea.getText());
btnNone.setActionCommand(btnNone.getText());
drinksButtonGroup.add(btnPepsi);
drinksButtonGroup.add(btnMtDew);
drinksButtonGroup.add(btnDietPepsi);
drinksButtonGroup.add(btnCoffee);
drinksButtonGroup.add(btnTea);
drinksButtonGroup.add(btnNone);
btnNone.setSelected(true); //set default to "none"
btnPepsi.addActionListener(this);
btnMtDew.addActionListener(this);
btnDietPepsi.addActionListener(this);
btnCoffee.addActionListener(this);
btnTea.addActionListener(this);
btnNone.addActionListener(this);
add(lblDrinksHeading);
add(btnPepsi);
add(btnDietPepsi);
add(btnMtDew);
add(btnCoffee);
add(btnTea);
add(btnNone);
repaint();
revalidate();
selectedDrink = drinksButtonGroup.getSelection().getActionCommand();
//add the drink price to totalPrice, it is adding it every time though, even if its none
/*if(drinksButtonGroup.getSelection() == btnNone){
MenuFrame.totalPrice += 0;
}
else{
MenuFrame.totalPrice += drinksPrice;
}
*/
// buttonGroup1.getSelection().getActionCommand()
//String selectedDrink = drinksButtonGroup.getSelection().toString();
//class
}
#Override
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if(source == btnNone) {
MenuFrame.totalPrice += 0;
TaxAndGratuityFrame.subtotalTextField.setText("$" + MenuFrame.totalPrice);
TaxAndGratuityFrame.subtotalVariable = MenuFrame.totalPrice;
TaxAndGratuityFrame.taxVariable = TaxAndGratuityFrame.subtotalVariable * TaxAndGratuityFrame.TAX_RATE;
TaxAndGratuityFrame.taxTextField.setText("$" + TaxAndGratuityFrame.taxVariable);
Receipt.receiptTotal.setText("Total: $" + (MenuFrame.totalPrice));
Receipt.receiptsubtotal.setText("Subtotal: " + (TaxAndGratuityFrame.subtotalVariable));
}
else {
MenuFrame.totalPrice += drinksPrice;
TaxAndGratuityFrame.subtotalTextField.setText("$" + MenuFrame.totalPrice);
TaxAndGratuityFrame.subtotalVariable = MenuFrame.totalPrice;
TaxAndGratuityFrame.taxVariable = TaxAndGratuityFrame.subtotalVariable * TaxAndGratuityFrame.TAX_RATE;
TaxAndGratuityFrame.taxTextField.setText("$" + TaxAndGratuityFrame.taxVariable);
Receipt.receiptTotal.setText("Total: $" + (MenuFrame.totalPrice));
Receipt.receiptsubtotal.setText("Subtotal: " + (TaxAndGratuityFrame.subtotalVariable));
}
}
Edit: I'll be more specific. I am creating an "imaginary" restaurant program. In it, I list several drinks that have the same price (e.g. Pepsi: $2.10, Mountain Due: $2.10, etc). These listed drinks are JRadioButtons. Once a customer clicks one of these buttons to "order a drink", $2.10 will be added to a "total" variable. However, a problem occurs when a user wants to change there drink, because if they click a different JRadioButton, $2.10 will still be added to the "total" variable. I want to make it so that they can change there drink without adding $2.10 to the order every time.

I think the problem is at this line:
MenuFrame.totalPrice += drinksPrice;
Because "+=" increments a value by another value instead of simply adding two values.
So every time the user clicks on one of the radio buttons, it will continuously add 2.10 to your total value, whereas if you were you just say:
MenuFrame.totalPrice = MenuFrame.totalPrice + drinksPrice;
It will set your total price equal to the current total price plus the price of drinks, instead of adding 2.10 to the total value every time a button is pressed.

Perhaps I am misunderstanding the question, but I am thinking along the lines of creating a public variable, and then inside the action listeners updating the variable with the radio button that was just selected. When the selected event fires, you can look at the variable to see which radio button had last been selected, do what you want to about it, and then update it with the new radio button.

JTextArea append() method writes twice?

I've run into a little problem.
In my GUI, I have a text area in the center (BorderLayout). Then I have a JList on the West.
When I click on a member of the song titles I have in my list, the text area should display the title, artist, and price of the song.
I have everything working, but the problem is that when I click on a member, the title,artist, and the price is displayed TWICE.
Here is the code for "valueChanged()" and parts of codes relevant.
public void valueChanged(ListSelectionEvent e)
{
Object source = e.getSource();
int index = songList.getSelectedIndex();
Song selection = songCollection[index];
if(source == songList)
{
textArea.append(selection.getTitle() + " " + selection.getArtist() + " " + selection.getPrice() + "\n" );
}
}
private Song songCollection[] = new Song[5];
private String songTitle[] = new String[5];
//Fill song array
songCollection = getSongs();
songTitle = getSongTitle();
//Methods:
public Song[] getSongs()
{
Song[] array = new Song[5];
array[0] = new Song("Summer", "Mozart", 1.50);
array[1] = new Song("Winter", "Mozart", 1.25);
array[2] = new Song("Spring", "Mozart", 2.00);
array[3] = new Song("Baby", "Justin Bieber", 0.50);
array[4] = new Song("Firework", "Katy Perry", 1.00);
return array;
}
public String[] getSongTitle()
{
String[] names = new String[5];
for(int i = 0; i < 5; i++)
names[i] = songCollection[i].getTitle();
return names;
}
I noticed something just now when I was fiddling around with my program again. When I press a member in the list, it is still printed TWICE like before. However, I noticed that it prints once when I press and hold down my mouse, and it prints AGAIN when I let go of it. So if I press my mouse on 1 member, and drag the cursor up/down to other members, they print once, but when I let go of the mouse, it prints the one I ended in one more time.

JTextArea.append() is being called twice from your ListSelectionListener.
The reason can be found in How to Use Lists:
Many list selection events can be generated from a single user action such as a mouse click. The getValueIsAdjusting method returns true if the user is still manipulating the selection. This particular program is interested only in the final result of the user's action, so the valueChanged method does something only if getValueIsAdjusting returns false.
You need to check that the selection in the JList is no longer being manipulated. You can surround the append method with the check:
if (!e.getValueIsAdjusting()) {
textArea.append(...);
}

JCombobox and JTextfield

I'm trying to work to display a number of jtextfield according to one of the given values in a combobox.
So, I will have a drop down menu with let's say 1 to 4. If the user selects number 3, 3 textfields will be displayed. I've created the jcombobox with a selection of numbers. But I'm not sure how to implement this. If I'm not mistaken I need to use
ItemEvent.SELECTED
I think I need to create a reference to the JTextField object that will be available to the JComboBox's itemListener object.
Any help would be greatly appreciated.
I've added this to my class :
// aOption is the combobox I declared
aOptionComboBox.setModel(new DefaultComboBoxModel(new String[]{"1","2","3"}));
public void itemStateChanged(ItemEvent event) {
String num = (String)aOptionComboBox.getSelectedItem();
int num1 = Integer.parseInt(num);
JTextField[] textfields = new JTextField[num1];
for (int i = 0; i < num1; i++)
{
textfields[i] = new JTextField("Field");
getContentPane().add(textfields[i]);
textfields[i].setBounds(200, 90, 100, 25);
}
}
am I on a right track?

use the getSelectedItem() on the combobox. This will either yield a string or an integer (depending on how you implemented it). Next use a for-loop to determine the amount of JTextField's and store them in an array.
int amount = myJComboBox.getSelectedItem();
JTextField[] textfields = new JTextField[amount];
for (int i = 0; i < amount; i++) {
textfields[i] = new JTextField("awesome");
this.add(textfields[i]);
}
this way you can easily store the textfields and add them to your panel.
Some added information.
The textfield-array must be accesible outside the eventListener, so you must implement it in your class. that way the whole class can use it.