JavaFX: FXML: How to make the child to extend its size to fit the parent pane?

Question

I have managed to load a child fxml(sub UI) under a parent fxml (mainMenu UI). I have created an AnchorPane with id "mainContent". This pane is bound to 4 sides and changes in accords to the stage.

The child window will be loaded into the "mainContent" anchorpane. However, I can't figure out how to make the child to change along with its parent "mainContent".

My child UI is called like this.

@FXML
private void mnuUserLevel_onClick(ActionEvent event) {
    FXMLLoader loader = new FXMLLoader(getClass().getResource("DBedit.fxml"));
    loader.setController(new DBeditEntityUserlevel());

    try {
           Node n = (Node)loader.load();
           mainContent.getChildren().add(n);
    } catch (IOException e){
           System.out.println(e.getMessage());
    }
}

To further illustrate my question, please see my snap shot. The red square is the child. The yellow square is the "mainContent" AnchorPane of the MainMenu parent.

Answer 1

If you set the static methods setTopAnchor( child, value ), setBottomAnchor( ... ), setLeftAnchor( ... ), setRightAnchor( ... ) of class AnchorPane to 0.0, the child Node will get stretched to the full extend of the parent AnchorPane.

Documentation Link: AnchorPane

edit: in the documentation link you can also see how you can set these values in your java code.

FXML example:

<AnchorPane fx:id="mainContent" ...>
<StackPane fx:id="subPane" AnchorPane.topAnchor="0.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" ></StackPane>
</AnchorPane>