I am new to JavaFX and trying to create an Confirmation Dialogbox. I know already that there is no real build in dialogbox in JavaFX so I created one myself like this:
@FXML
public void delBox() {
try {
Stage dialogStage = new Stage();
AnchorPane root = FXMLLoader.load(getClass().getResource("Dialog.fxml"));
Scene scene = new Scene(root);
dialogStage.setScene(scene);
dialogStage.showAndWait();
} catch(Exception e) {
e.printStackTrace();
}
}
It looks pretty good already, but what I dont understand is, how those two Stages can communicate with each other? I want to pass a String to the dialog which is than shown in the message, also when one of the buttons in the dialog window is clicked I wanna react to this in the accordingly.
Can anyone explain me how communication between the stages works?
btw: I use .FXML
files and controller classes.
You need a reference to the controller for the dialog. To do this, create an instance of FXMLLoader
instead of using the static FXMLLoader.load(URL)
method.
For example, suppose you have a class DialogController
, so your Dialog.fxml
looks like:
<AnchorPane xmlns:fx="..." fx:controller="DialogController.fxml">
...
</AnchorPane>
Then you can access the DialogController
in the delBox()
method above with
Stage dialogStage = new Stage();
FXMLLoader loader = new FXMLLoader(getClass().getResource("Dialog.fxml"));
AnchorPane root = (AnchorPane)loader.load();
DialogController controller = (DialogController) loader.getController();
Scene scene = new Scene(root);
dialogStage.setScene(scene);
dialogStage.showAndWait();
And now you can communicate between the two controllers. For example, in DialogController
you could define a message
property, and bind it to a Label
:
public class DialogController {
private final StringProperty message = new SimpleStringProperty("");
public void setMessage(String message) {
this.message.set(message);
}
public String getMessage() {
return message.get();
}
public StringProperty messageProperty() {
return message ;
}
@FXML
private Label label ;
public void initialize() {
label.textProperty().bind(message);
// ...
}
}
And then back in your delBox() method:
//... as before:
AnchorPane root = (AnchorPane)loader.load();
DialogController controller = (DialogController) loader.getController();
controller.setMessage("Hello World");
// ...
Similarly, you can define properties which are set when controls are pressed in the dialog itself, and either observe them or query them after the showAndWait() call.
There are a bunch of other similar techniques. Some examples:
https://github.com/james-d/Shared-Data-Controller/tree/master/src
https://github.com/james-d/Dialog-FXML-Example/tree/master/src
https://github.com/james-d/Nested-Controller-Example/tree/master/src/nestedcontrollerexample