how to iterate a dialog box in javafx

Question

i have a custom login dialog box largely copied from here it works fine, but i am facing problem with getting it to show and get userdata at most 3 times before allowing the user forward if credentials are true or closing the program if wrong credentials are entered 3 times in a row. Heres my code....

//**************************login form*********************************
    // Create the custom dialog.
    Dialog<Pair<String, String>> dialog = new Dialog<>();
    dialog.setTitle("Login");
    dialog.setHeaderText("Welcome to MHI - LIS");

    // Set the button types.
    ButtonType loginButtonType = new ButtonType("Login", ButtonBar.ButtonData.OK_DONE);
    dialog.getDialogPane().getButtonTypes().addAll(loginButtonType, ButtonType.CANCEL);


    // Create the username and password labels and fields.
    GridPane grid = new GridPane();
    grid.setHgap(10);
    grid.setVgap(10);
    grid.setPadding(new Insets(20, 150, 10, 10));

    TextField username = new TextField();
    username.setPromptText("Username");
    PasswordField password = new PasswordField();
    password.setPromptText("Password");

    grid.add(new Label("Username:"), 0, 0);
    grid.add(username, 1, 0);
    grid.add(new Label("Password:"), 0, 1);
    grid.add(password, 1, 1);

    // Enable/Disable login button depending on whether a username was entered.
    Node loginButton = dialog.getDialogPane().lookupButton(loginButtonType);
    loginButton.setDisable(true);

    // Do some validation (using the Java 8 lambda syntax).
    username.textProperty().addListener((observable, oldValue, newValue) -> {
        loginButton.setDisable(newValue.trim().isEmpty());
    });

    dialog.getDialogPane().setContent(grid);

    // Request focus on the username field by default.
    Platform.runLater(() -> username.requestFocus());

    // Convert the result to a username-password-pair when the login button is clicked.
    dialog.setResultConverter(dialogButton -> {
        if (dialogButton == loginButtonType) {
            return new Pair<>(username.getText(), password.getText());
        }
        return null;
    });
        Optional<Pair<String, String>> result = dialog.showAndWait();

    result.ifPresent(usernamePassword -> {
        out.println("Username=" + usernamePassword.getKey() + ", Password=" + usernamePassword.getValue());
        int tryCount = 0;
        boolean check_login = true;
        do{
            if(login(usernamePassword.getKey(),usernamePassword.getValue())){
                check_login=false;
                tryCount=3;
            }else {
                ++tryCount;
                username.clear();
                password.clear();
               result= dialog.showAndWait();
            }
        }while(check_login== true && tryCount < 3);
        //if(check_login) closeProgram();

    });//***************************End of login form**********************

Now i got it to show 3 times by putting "result= dialog.ShowAndWait()" in the do-while loop, but it only captures the data a user entered the first time and not on the last 2 attempts. Sample output:

m1223 //password captured on 1st attempt

m1223//password captured on 2nd attempt but input was m222

m1223//password captured on 3rd attempt but input was m444

How can i make it recapture at every trial...? Thanks in advance.

Answer 1

I tried with standard JavaFX dialogs, and this works:

TextInputDialog dialog = new TextInputDialog("password");
dialog.setContentText("Please enter your password:");

String pwd = null;
int numAttempted = 0;
int MAX_ATTEMPTS = 3;

Optional<String> result;
boolean isCorrectPwd = false;
do {
    result = dialog.showAndWait();
    numAttempted++;
    if (result.isPresent()) {
        String res = result.get();
        isCorrectPwd = login(res);
        if (isCorrectPwd) {
            pwd = res;
            System.out.println("CORRECT PASSWORD: " + res);
        } else {// try again -> loop
            System.out.println("WRONG PASSWORD: " + res);
        }
    }
} while (numAttempted < MAX_ATTEMPTS && !isCorrectPwd);

Problem with your code was that result.ifPresent was out of the do-while loop... So the usernamePassword was assigned only once.