如何在按下按钮之前暂停方法？

Question

I am designing a software with multiple components - each with its own actionlistener. For an example, I have a JPanel with a cardlayout that holds 10 cards - each its own JPanel and purpose.

On one side, there are multiple buttons, IE Login, Logout, Settings, etc.

When I click Login, it will switch to the card using the Login() method to the Login JPanel object where I want it to wait for a button to click IE Login, New User, or Cancel before continuing the Login() method and setting the current user.

Is there a method to pause the program until one of the buttons are clicked to retrieve the data from it? (Kind of like how JOptionPane.showInputMessage(null,"INPUT STRING") waits for you)

My Code is below: FRAME:

/**
 * Frame design
 */


public class Frame extends JFrame{
JPanel LeftSide, UpperRightSide;
EmployeeAdder employAdd;
ArrayList<ServiceView> serviceViewers;
ChartViewer viewChart;
PayByView viewPayBy;
SettingsViewer viewSettings;
LoginViewer viewLogin;
CategoryView viewCategory;
ServiceAdder serviceAdd;
Directory directory;
Employee currentEmployee;
ChargeViewer viewCharge;
JButton Login, Logout, Settings;
CardLayout LeftCard,RightCard;
String currentCard,currentRightCard;
ButtonListen listen;
public static String CARDCAT = "Category View";
public static String CARDPAY = "Pay By";
public static String CARDCHART = "Chart View";
public static String CARDLOGIN = "Log-in View";
public static String CARDSERVICEADD = "Service Adder";

Frame(){
    listen = new ButtonListen();
    //-------Current Card--------------------
    currentCard = CARDCAT;
    currentRightCard = "CHARGE";
    //-----First Find Directory Folder-------
    startDirectory();
    //-----User Interface--------------------
    //-------Left Side-----------------------
    LeftSide = new JPanel();
    LeftCard = new CardLayout();
        LeftSide.setLayout(LeftCard);
        viewPayBy = new PayByView();
        viewLogin = new LoginViewer();
        viewChart = new ChartViewer();
        viewCategory = new CategoryView();
        employAdd = new EmployeeAdder();
        serviceAdd = new ServiceAdder();
        LeftSide.add(viewCategory,"CAT");
        LeftSide.add(viewChart, "CHA");
        LeftSide.add(viewLogin,"LOG");
        LeftSide.add(viewPayBy,"PAY");
        LeftSide.add(employAdd,"EMA");
        LeftSide.add(serviceAdd,"SEA");
        LeftCard.show(LeftSide, "CAT");
        viewCategory.setEnabled(false);
        LeftSide.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.BLACK),currentCard));
        serviceViewers = new ArrayList<ServiceView>();

    //--------Right Side---------------------
    JPanel RightSide = new JPanel();
        RightSide.setLayout(new BorderLayout());
        UpperRightSide = new JPanel();
        RightCard = new CardLayout();
        UpperRightSide.setLayout(RightCard);
            viewSettings = new SettingsViewer();
            viewCharge = new ChargeViewer();
            viewCharge.setEnabled(false);
            UpperRightSide.add(viewCharge,"CHARGE");
            UpperRightSide.add(viewSettings,"SETTINGS");
            UpperRightSide.setPreferredSize(new Dimension(350,500));
        RightSide.add(UpperRightSide,BorderLayout.NORTH);
        //--------Buttons at the bottom Panel---
        JPanel Buttons = new JPanel();
            Buttons.setLayout(new GridLayout(3,1));
            Login = new JButton("LOG-IN");
                Login.addActionListener(listen);
            Logout = new JButton("LOG OUT");
                Logout.addActionListener(listen);
            Settings = new JButton("Settings");
                Settings.addActionListener(listen);
            Buttons.add(Login);
            Buttons.add(Logout);
            Buttons.add(Settings);
            Buttons.setPreferredSize(new Dimension(350,150));
        RightSide.add(Buttons,BorderLayout.SOUTH);
        RightSide.setSize(new Dimension(400,200));
    //------Other Stuff--------------------------

    //-----add Panels----------------------------
        setLayout(new BorderLayout());
        add(LeftSide,BorderLayout.WEST);
        add(RightSide,BorderLayout.EAST);
}


private void Login(){
    LeftCard.show(LeftSide, "LOG");

    //----I WANT IT TO WAIT HERE FOR AN ACTION-------
    int clicked = viewLogin.getClicked();
        if (clicked==LoginViewer.NEWUSER){
            NewUser();
        }else if (clicked==LoginViewer.LOGIN){
            if (viewLogin.checkPassword()){
                currentEmployee = directory.getEmployee(viewLogin.getSelectedName());
                viewCategory.setEnabled(true);
                viewCharge.setEnabled(true);
                viewCharge.refreshName(currentEmployee.getName());
                LeftCard.show(LeftSide, "CAT");
            }
        }else if (clicked==LoginViewer.CANCEL){
            LeftCard.show(LeftSide, "CAT");
        }


}




public class ButtonListen implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        if (!viewLogin.isWaiting()){
        if (e.getSource()==Login){
            if (currentCard.equals(CARDLOGIN)){
                LeftCard.show(LeftSide,"CAT");
                currentCard = CARDCAT;

            }else{
                Login();
                currentCard = CARDLOGIN;
            }
        }else{
            //Don't change the screen
        }
        }

    }

}

}

My Code for LoginViewer:

public class LoginViewer extends JPanel{
JComboBox User;
JPasswordField passField;
JButton NewUser, Login, Cancel;
Hashtable<String,String> namespass; //names and password
private int clicked = -1;
ButtonListen listen;
public static int NEWUSER = 1;
public static int LOGIN = 0;
public static int CANCEL = 2;
boolean waiting;

LoginViewer(){
    waiting = false;
    //---------------------------------------
    setPreferredSize(new Dimension(100,100));
    listen = new ButtonListen();
    namespass = new Hashtable<String,String>();
    //----------Panel Design-------------------
    JPanel Center = new JPanel();
        Center.setLayout(new GridLayout(3,3));
    User = new JComboBox();
    passField = new JPasswordField();
    NewUser = new JButton("New User");
        NewUser.addActionListener(listen);
    Login = new JButton("Login");
        Login.addActionListener(listen);
    Cancel = new JButton("Cancel");
        Cancel.addActionListener(listen);
    Center.add(new JLabel("Choose User"));
    Center.add(User);
    Center.add(new JLabel(""));
    Center.add(new JLabel("Type Password"));
    Center.add(passField);
    Center.add(new JLabel(""));
    Center.add(Login);
    Center.add(NewUser);
    Center.add(Cancel);
    Center.setPreferredSize(new Dimension(300,300));
    Center.setMaximumSize(new Dimension(100,100));
    Center.setAlignmentX(CENTER_ALIGNMENT);
    setAlignmentX(CENTER_ALIGNMENT);
    setLayout(new BoxLayout(this,BoxLayout.X_AXIS));
    add(Box.createHorizontalGlue());
    add(Center);
    add(Box.createHorizontalGlue());
}


public void uploadUserNames(Hashtable<String,String> names){
    namespass.clear();
    namespass.putAll(names);
    User.removeAllItems();
    Enumeration<String> name = names.keys();
    while (name.hasMoreElements()){
        User.addItem(name.nextElement());
    }
}

public boolean checkPassword(){
    boolean value = false;
    String key = User.getSelectedItem().toString();
    if (passField.getPassword().length==4){
        if (namespass.get(key).equals(String.valueOf(passField.getPassword()))){
            value = true;
        }
    }
    return value;
}

public String getSelectedName(){
    return User.getSelectedItem().toString();
}

public boolean isWaiting(){
    return waiting;
}

public int getClicked(){
    waiting = true;
    return clicked;
}

public class ButtonListen implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {

        waiting = false;
        if (e.getSource()==NewUser){
            clicked = 1;
        }else if (e.getSource()==Login){
            clicked = 0;
        }else if (e.getSource()==Cancel){
            clicked = 2;
        }

    }

}
}

Or is it easier to just use an actionlistener to listen to ALL of the objects' buttons?

There are a LOT of buttons...

NOTE: Some of the methods are incomplete or test methods until I know how to make it work...

Answer 1

You don't want to use linear console-type code in a Swing GUI. Instead, with event-driven GUI programs you will want to have user interactions change a program's state, and then have the behavior of the program depend on the state. For instance, rather than have the login method pause, have it do some housekeeping -- change the state of the program to be ready to accept a login attempt -- and then where you plan to "wait", exit the login method. Then have the rest of the code for logging in reside in the login button's ActionListener.

As an aside, you've posted a lot of code, 95% of it unrelated to your problem and thus only serving as a distraction to us and preventing us from reading the code and understanding the specifics of your problem. In the future, consider creating and posting an sscce , where you condense your code into the smallest bit that still compiles, has no extra code that's not relevant to your problem, but still demonstrates your problem for us.

Answer 2

the way the Swing framework works is that you already "wait" for everything to happen, and it only happens once the users triggers the action corresponding to your listener.

So yes, basically you only have to wait for buttons to be clicked.

HOWEVER: Designing responsive GUIs means that you won't let your user wait 10 seconds on a frozen interface until you do yout 10000 calculations and 10 million SELECT statements. Thus in case your action listeners (or whatever specific listeners you've got) have to perform heavy duty calculations, do them on a separate Thread , and inform the user if a task is done one way or another.