Standard Dialog Box

A Dialog Box is a secondary window (i.e., not the main application window) that is used to interact with the user ... usually to display or obtain additional information.

Dialog Boxes

Alert

Example 1 :

Alert alert = new Alert(Alert.AlertType.INFORMATION);
alert.showAndWait();

Output:

methods:

1. setTitle()

2. setHeaderText()

   setHeaderText(null) // to remove

3. setContainerText() //

4. getDialogPane(): The dialog pane is the main content area of the dialog where you can customize its appearance and content.

5. getDialogPane().setExpandableContent(expandableContent) : expandable content is additional information or details that the user can choose to show or hide by clicking on an expand/collapse button or similar control.

6. alert.getButtonTypes().setAll(); : Erase all the default buttons

7. alert.getButtonTypes().add(); : Add the buttons

   💡

   There is a limit on how many buttons would fit nicely on the window

8. getDialogPane().setContent(); : too add the content to dialog layout

Example 2:

Alert alert = new Alert(Alert.AlertType.WARNING);
alert.setTitle("Tip for the day");
alert.setHeaderText(null);
alert.setContentText("Don't eat yellow snow.");

Output:

Example 3:

Alert alert = new Alert(Alert.AlertType.ERROR);
alert.setTitle("Error"); alert.setHeaderText(null); 
alert.setContentText("Invalid Gregorian Calendar Date");
Label label = new Label("Date entered:");
TextArea textArea = new TextArea(new GregorianCalendar().toString()); 
textArea.setEditable(false); textArea.setWrapText(true); 
textArea.setMaxWidth(Double.MAX_VALUE); 
textArea.setMaxHeight(Double.MAX_VALUE);
GridPane.setVgrow(textArea, Priority.ALWAYS);
GridPane.setHgrow(textArea, Priority.ALWAYS);
GridPane expandableContent = new GridPane(); 
expandableContent.setMaxWidth(Double.MAX_VALUE); expandableContent.add(label, 0, 0);
expandableContent.add(textArea, 0, 1); 
alert.getDialogPane().setExpandableContent(expandableContent);

Output:

To store the result from the dialog box:
Optional<ButtonType> result = alert.showAndWait();

The get() method to get the value that was selected:

result.get()

Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
alert.setTitle("Answer this Question");
alert.setHeaderText(null);
alert.setContentText("Do you want me to clean up your hard drive ?");
Optional<ButtonType> result = alert.showAndWait();
if (result.get() == ButtonType.OK){
System.out.println("OK, I'm erasing it now ..."); }
else { System.out.println("Fine then, you clean it up!"); }

ChoiceDialog

Optional<ButtonType> result = alert.showAndWait();

result.isPresent() :The isPresent() method allows us to determine whether or not the user selected an item or pressed CANCEL.

Example 1:

String[] options = {"Apple", "Orange", "Strawberry", "Banana", "Peaches"};
ChoiceDialog<String> dialog = new ChoiceDialog<String>("Peaches", options); // sets default to Peaches
dialog.setTitle("Fruit Information"); dialog.setHeaderText(null);
dialog.setContentText("Choose your favorite fruit");
Optional<String> result = dialog.showAndWait();
if (result.isPresent()){
System.out.println("Your choice: " + result.get()); }

Output:

TextInputDialogBox

Example 1:

TextInputDialog dialog = new TextInputDialog("Mark");
dialog.setTitle("Input Required"); dialog.setHeaderText(null); dialog.setContentText("Please enter your name:");
Optional<String> result = dialog.showAndWait();
if (result.isPresent()){
System.out.println("Your name is: " + result.get()); }

Output:

Dialog

Example 1:

Dialog dialog = new Dialog();
dialog.setTitle("Login Dialog");
dialog.setHeaderText(null);
ButtonTypeloginButtonType= new ButtonType("Login", ButtonBar.ButtonData.OK_DONE); 
dialog.getDialogPane().getButtonTypes().addAll(loginButtonType, ButtonType.CANCEL);
Optional result = dialog.showAndWait();
if (result.isPresent()) {
System.out.println("Username = " + username.getText() + ", Password = " + password.getText());

}

Output:

In this way we cannot access the data of username and password directly if we place it somwhere else

To do that We can replace the above code with this code:

// Convert the result to a Pair containing the username and password dialog.setResultConverter( new Callback<ButtonType, Pair<String, String>>()
{
public Pair<String, String> call(ButtonType b) {
if (b == loginButtonType) { return new Pair<String,String>(username.getText(), password.getText());
}
return null;
}
});
Optional<Pair<String, String>> result = dialog.showAndWait();
if (result.isPresent()) System.out.println("Username = " + result.get().getKey() + ", Password = " + result.get().getValue());