package com.easternedgerobotics.rov.fx;

import javafx.geometry.Insets;
import javafx.scene.Parent;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.BorderPane;

import javax.inject.Inject;

public class MainView implements View {
    static final int SPACING = 10;

    static final int TOGGLE_BOX_W = 256;

    static final int TOGGLE_BOX_H = 64;

    final BorderPane box = new BorderPane();

    final ToggleButton button = new ToggleButton("Start");

    @Inject
    public MainView() {
        button.setMaxWidth(Double.MAX_VALUE);
        button.setMaxHeight(Double.MAX_VALUE);
        button.setPrefSize(TOGGLE_BOX_W, TOGGLE_BOX_H);
        box.setPadding(new Insets(SPACING));
        box.setCenter(button);
    }

    @Override
    public final Parent getParent() {
        return box;
    }
}

package com.easternedgerobotics.rov.fx;

import javafx.geometry.Insets;
import javafx.scene.Parent;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.BorderPane;

import javax.inject.Inject;

public class MainView implements View {
    static final int SPACING = 10;

    final BorderPane box = new BorderPane();

    final ToggleButton button = new ToggleButton("Start");

    @Inject
    public MainView() {
        button.setMaxWidth(Double.MAX_VALUE);
        button.setMaxHeight(Double.MAX_VALUE);
        box.setPadding(new Insets(SPACING));
        box.setCenter(button);
    }

    @Override
    public final Parent getParent() {
        return box;
    }
}

--- 
+++ 
@@ -10,6 +10,10 @@
 public class MainView implements View {
     static final int SPACING = 10;
 
+    static final int TOGGLE_BOX_W = 256;
+
+    static final int TOGGLE_BOX_H = 64;
+
     final BorderPane box = new BorderPane();
 
     final ToggleButton button = new ToggleButton("Start");
@@ -18,6 +22,7 @@
     public MainView() {
         button.setMaxWidth(Double.MAX_VALUE);
         button.setMaxHeight(Double.MAX_VALUE);
+        button.setPrefSize(TOGGLE_BOX_W, TOGGLE_BOX_H);
         box.setPadding(new Insets(SPACING));
         box.setCenter(button);
     }
Set initial size for main toggle box
