JavaFX - SplitPane, resize & proportions - resize

Question

How can I achieve proportional resize of whole SplitPane?
public class JfxSplitPaneTest extends Application {
#Override
public void start(Stage stage) throws Exception {
SplitPane split = new SplitPane();
StackPane child1 = new StackPane();
child1.setStyle("-fx-background-color: #0000AA;");
StackPane child2 = new StackPane();
child2.setStyle("-fx-background-color: #00AA00;");
StackPane child3 = new StackPane();
child3.setStyle("-fx-background-color: #AA0000;");
split.getItems().addAll(child1, child2, child3);
//split.setDividerPositions(0.1f, 0.6f, 0.9f)
stage.setScene(new Scene(split, 400, 300));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Start the program:
Set dividers how I like them:
Make window width really small (I continued and made it even smaller, no pic):
Resize back and observe that dividers are neither how I set them nor how they were when program started.
Doing this makes it closer to what I'd expect:
child1.setMinWidth(Region.USE_PREF_SIZE)
child1.setPrefWidth(100)
child2.setMinWidth(Region.USE_PREF_SIZE)
child2.setPrefWidth(200)
child3.setMinWidth(Region.USE_PREF_SIZE)
child3.setPrefWidth(300)
except that dividers are initally at wrong position (until I resize SplitPane, 1px is enough) and when shrinking window width, dividers are inside components.
How can I make this work please?

Answer 1

Try to set the divisors like AS3Boyan said
split.setDividerPositions(0.1f, 0.6f, 0.9f)
and add this:
How can I avoid a SplitPane to resize one of the panes when the window resizes?

Answer 2

Try to add Change Listener to stage.widthProperty() and stage.heightProperty(). And call this:
split.setDividerPositions(0.1f, 0.6f, 0.9f)

Answer 3

The rule of thumb is to use setDividerPositions with Platform.runLater when the resize event is triggered.
You probably want to start with a default ratio, let the user change that ratio, and maintain this ratio whatever it is when there's a resize event. Let's consider a 25/75 vertical FX splitPane in some stage:
splitPane.setDividerPositions(0.25f, 0.75f);
stage.heightProperty().addListener((obs, oldVal, newVal) -> {
double[] positions = splitPane.getDividerPositions(); // reccord the current ratio
Platform.runLater(() -> splitPane.setDividerPositions(positions)); // apply the now former ratio
});