See attached video.

        Stop[] stops = new Stop[]{new Stop(0, Color.WHITE), new Stop(1, Color.BLACK)};
        LinearGradient lg = new LinearGradient(0, 0, 200, 200, false, CycleMethod.REPEAT, stops);
        private Rectangle content = new Rectangle(200, 200, lg);

            Button increaseScaleButton = ButtonBuilder.create().text("Increase scale").build();
            increaseScaleButton.setOnAction(new EventHandler<ActionEvent>() {
                public void handle(ActionEvent t) {
                    content.setScaleX(content.getScaleX() + 0.15);
                    content.setScaleY(content.getScaleY() + 0.15);
                }
            });

            Button decreaseScaleButton = ButtonBuilder.create().text("Decrease scale").build();
            decreaseScaleButton.setOnAction(new EventHandler<ActionEvent>() {
                public void handle(ActionEvent t) {
                    content.setScaleX(content.getScaleX() - 0.15);
                    content.setScaleY(content.getScaleY() - 0.15);
                }
            });

I have no possibility to see parts of scaled content. But it seems to be important feature.