i am working on a simple javafx banking app for practise. I have created a starting scene that basically has a progress bar.i have been lloking for way to change the scene to something like a login scene lets say, after the progress bar is full.
But since i have written the code to control the progress bar in the Controllers initialize method trying to access the stage gives me Nullpointer exception. any idea how i can acieve this using fxml
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I am using JavaFX 11 and a newbie.
I have a single stage with two scenes: a primary scene that shows on start and a secondary scene that is switched to and shown when I press a certain button on the main scene. On the secondary scene, I want to be able to switch back to the main scene when I click the close X button on the top right of the window instead of having the entire application close.
I currently have a method for the cancel button that looks like this:
public void cancelButtonPushed(ActionEvent event) throws IOException {
Parent parent = FXMLLoader.load(getClass().getResource("ExampleMainScreen.fxml"));
Scene scene = new Scene(parent);
Stage window = (Stage) ((Node) event.getSource()).getScene().getWindow();
window.setScene(scene);
window.show();
}
This method allows me to switch back to the main scene when the Cancel button is pushed. However, I am lost trying to find something that can be used any time the user clicks the close X on the secondary scene.
First, get the terminology right, my guess is that you have two Stages. Scenes can be displayed inside those.
Second, Scene Builder (and the FXML it produces) does not manage stages, it only constructs nodes (and event handling for those nodes) that are placed inside scenes. So, you won't find the hooks you need to integrate with the window close functions in SceneBuilder or FXML.
Third, when a user wants to close a window (a stage is a kind of window), then an event will be emitted, which you can action onCloseRequest.
Fourth, somehow you have already managed to create a second stage, probably by calling new Stage(). This will provide you with a reference to the stage which you can set your close request on:
Stage secondaryStage = new Stage();
Stage setScene(secondaryScene);
secondaryStage.setOnCloseRequest(e -> primaryStage.show());
This will show your primary stage (which I guess you hid earlier), when the secondary stage is being closed, but before it has actually closed.
Next, read up on the Application lifecycle, specifically see the section which references Platform.setImplicitExit(boolean implicitExit):
If this attribute is true, the JavaFX runtime will implicitly shutdown when the last window is closed; the JavaFX launcher will call the Application.stop() method and terminate the JavaFX application thread. If this attribute is false, the application will continue to run normally even after the last window is closed, until the application calls exit(). The default value is true.
Note, that, you probably don't need to explicitly set the implicit exit flag if you handle the stage switching as outlined previously, but I provide the info for you in case you need to understand it.
Finally, consider whether you really should be creating new stages for your application and this particular task or just replacing the content in a single stage (similar to how a web browser works).
A stage in javafx requires exactly one scene, and a scene requires exactly one root node.
So I want to know what's the main role of the scene? It seems like a scene connects two sides that can be connected directly without an intermediate.
I want juste to understand the logic.
Thank you.
Stage represents a native system window. Scene is the content of this window with JavaFX controls, nodes, stylesheets, etc.
You can change Scenes inside a Stage during your UI workflow without a need to create a new system window each time.
I need to pass to a native method the handle of a javaFX window on which to render a world made with OSG (Open Scene Graph).
I understood that on javaFX only the Stage has this native handle, all the other objects, for example Nodes and Pane do not have a native handle.
So I thought, if it were possible to insert the Stage (for native rendering) and javafx widgets into the primary Stage, I would have the possibility to manage different levels, so that I could superimpose javaFX objects on the OSG rendering.
Do you have any idea?
I am working on a JavaFX project and the problem that I am facing is that I can't connect the different pages for my application. I can't go from another FXML file to another FXML File. For example I have two FXML Files. One for the Login Screen and one for the Menu. What I want is that when I click on the login button of my Login screen that I immediately go to my Menu Screen.
One way to transition from one screen to another is to assign a new Scene to a Stage using the setScene method of Stage.
Another way is to assign a root node like BorderPane to the Scene and swap FXML using its set methods(setTop, setCenter etc.) as per your application needs (In your case, on logging in).
Actually I want to switch from one scene to another scene on particular event. So i can do that by setting scene of the stage without binding but i want to bind my stage with scene as soon as a flag changes my scene will change automatically....pls help
The JavaFX Demos and Samples Downloads contains an application called FXML-LoginDemo. It demonstrates how to change scenes in a stage. The important part happens in the method replaceSceneContent. As for automatically changing the stage when a flag in your application is updated, there are several ways to do that. I recommend using a PropertyChangeListener or using JavaFX withCDI and then using CDI events. I used the latter approach in my application and it works really well.