javafx button positoning in scene - javafx

Question

how can I set a button's position in the middle for all size of anchorpane in javafx scenebuilder.....
like this code...
the button should be in the middle even if i set the scene into the middle
i have tried so many times but couldent get it...
thanks in advance
if you dont understand try to run the code in IDE and then maximize it and again minimize it...
observe the position of the button
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.StackPane;
import javafx.stage.*;
import javafx.stage.WindowEvent;
import java.util.Optional;
public class Javafxpopupmessage extends Application {
private Stage mainStage;
#Override
public void start(Stage stage) throws Exception {
this.mainStage = stage;
stage.setOnCloseRequest(confirmCloseEventHandler);
Button closeButton = new Button("Close Application");
closeButton.setOnAction(event ->
stage.fireEvent(
new WindowEvent(
stage,
WindowEvent.WINDOW_CLOSE_REQUEST
)
)
);
StackPane layout = new StackPane(closeButton);
layout.setPadding(new Insets(100));
stage.setScene(new Scene(layout));
stage.show();
}
private EventHandler<WindowEvent> confirmCloseEventHandler = event -> {
Alert closeConfirmation = new Alert(
Alert.AlertType.CONFIRMATION,
"Are you sure you want to exit?"
);
Button exitButton = (Button)
closeConfirmation.getDialogPane().lookupButton(
ButtonType.OK
);
exitButton.setText("Exit");
closeConfirmation.setHeaderText("Confirm Exit");
closeConfirmation.initModality(Modality.APPLICATION_MODAL);
closeConfirmation.initOwner(mainStage);
// normally, you would just use the default alert positioning,
// but for this simple sample the main stage is small,
// so explicitly position the alert so that the main window can still be
seen.
closeConfirmation.setX(mainStage.getX());
closeConfirmation.setY(mainStage.getY() + mainStage.getHeight());
Optional<ButtonType> closeResponse = closeConfirmation.showAndWait();
if (!ButtonType.OK.equals(closeResponse.get())) {
event.consume();
}
};
public static void main(String[] args) {
launch(args);
}
}

Answer 1

This can not be done directly in AnchorPane because positions are fixed there. You must use a container that allows "floating positioning". For example HBox.
<AnchorPane xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1">
<children>
<HBox alignment="CENTER" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<Button text="Exit" />
</children>
</HBox>
</children>
</AnchorPane>