How to switch stages in JavaFX - javafx

Question

I have a login stage (300 x 250), I want to open another main stage (fullscreen) if the credentials are correct.
I have figured out how to check the login credentials, but how can I close the login stage and open another stage?

Answer 1

If my application is supposed to work in one window I prefer using a GUI manager singleton class, which manages changing windows. Below I provided the complete code of a simple application which uses this mechanism. Let's assume all the files are in one package, called sample.
Main.java - you initialize the JavaFX components here:
package sample;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import java.io.IOException;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(Main.class.getResource("/sample/root.fxml"));
try{
StackPane rootPane;
rootPane = loader.load();
GuiManager guiModel = GuiManager.getInstance();
guiModel.setRootPane(rootPane);
Scene scene = new Scene(rootPane);
primaryStage.setScene(scene);
primaryStage.show();
guiModel.changeWindow("/sample/firstwindow.fxml");
} catch (IOException exception) {
exception.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
root.fxml - all the windows are supposed to be based on it:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.StackPane?>
<StackPane fx:id="rootPane"
xmlns="http://javafx.com/javafx/8.0.60"
xmlns:fx="http://javafx.com/fxml/1"
prefWidth="1" prefHeight="1"/>
firstwindow.fxml - first actual window which will be displayed:
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>
<VBox xmlns:fx="http://javafx.com/fxml" fx:controller="sample.FirstWindowController">
<Label text="First window"/>
<Button text="Change window" onAction="#changeWindow"/>
</VBox>
FirstWindowController.java - a controller class of the first window:
package sample;
import javafx.fxml.FXML;
public class FirstWindowController {
#FXML
private void changeWindow() {
GuiManager.getInstance().changeWindow("/sample/secondwindow.fxml");
}
}
secondwindow.fxml - it will be displayed after clicking the button of the first window:
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>
<VBox xmlns:fx="http://javafx.com/fxml" fx:controller="sample.SecondWindowController" >
<Label text="Second window"/>
<Button text="Change window" onAction="#changeWindow"/>
</VBox>
SecondWindowController.java - a controller class of the second window:
package sample;
import javafx.fxml.FXML;
public class SecondWindowController {
#FXML
private void changeWindow() {
GuiManager.getInstance().changeWindow("/sample/firstwindow.fxml");
}
}
GuiManager.java - a class that manages changing windows based on the root:
package sample;
import javafx.collections.ObservableList;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.stage.Window;
import java.io.IOException;
public class GuiManager {
private StackPane rootPane;
private static GuiManager instance;
public static GuiManager getInstance() {
if (instance == null) {
instance = new GuiManager();
}
return instance;
}
private GuiManager() {}
public void changeWindow(String path) {
changeWindow(rootPane, path, this);
rootPane.setPrefWidth(-1);
rootPane.setPrefHeight(-1);
}
public static void changeWindow(Pane pane, String newWindowPath, Object callingController) {
Window window = pane.getScene().getWindow();
double x = window.getX() + getHorizontalMidpoint(window);
double y = window.getY() + getVerticalMidpoint(window);
ObservableList<Node> childrenList = pane.getChildren();
removeAllIncludedChildren(childrenList);
FXMLLoader loader = new FXMLLoader(callingController.getClass().getResource(newWindowPath));
try {
pane.getChildren().add(loader.load());
Stage primaryStage = (Stage) window;
primaryStage.setMinHeight(0);
primaryStage.setMinWidth(0);
window.sizeToScene();
window.setX(x - getHorizontalMidpoint(window));
window.setY(y - getVerticalMidpoint(window));
primaryStage.setMinHeight(window.getHeight());
primaryStage.setMinWidth(window.getWidth());
} catch (IOException exception) {
exception.printStackTrace();
}
}
private static double getHorizontalMidpoint(Window window) {
int horizontalBisectionCoefficient = 2;
return window.getWidth() / horizontalBisectionCoefficient;
}
private static double getVerticalMidpoint(Window window) {
int verticalBisectionCoefficient = 2;
return window.getHeight() / verticalBisectionCoefficient;
}
private static void removeAllIncludedChildren(ObservableList<Node> childrenList) {
for (int childIndex = 0; childIndex < childrenList.size(); childIndex++) {
childrenList.remove(childIndex);
}
}
public void setRootPane(StackPane rootPane) {
this.rootPane = rootPane;
}
}

Answer 2

I just run in the same issue and this answer solved my issue perfectly while being short and clean.
#FXML
private void handleButtonAction(ActionEvent event) {
System.out.println("You clicked me!");
label.setText("Hello World!");
//Here I want to swap the screen!
Stage stageTheEventSourceNodeBelongs = (Stage) ((Node)event.getSource()).getScene().getWindow();
// OR
Stage stageTheLabelBelongs = (Stage) label.getScene().getWindow();
// these two of them return the same stage
// Swap screen
stage.setScene(new Scene(new Pane()));
}
PS.: Remember to click the original answer and upvote it. The guy deserves...
PPS.: I am not sure just copying an answer is okay(instead of just share the link through a comment) but since this doesnt have a correct answer yet i decided to do it for visibility.