Fix issue with drawing not being drawn when opening from central button.

src/main/org/insa/graphics/MainWindow.java

@@ -465,6 +465,9 @@ public class MainWindow extends JFrame {
         if (!(mainPanel.getLeftComponent() instanceof Drawing)) {
             mainPanel.setLeftComponent((Component) this.drawing);
             mainPanel.setDividerLocation(oldLocation);
+            // Need to re-validate or the drawing will not have the
+            // correct size prior to drawing, which can cause issue.
+            this.revalidate();
         }
 
         boolean isNewGraph = newClass == null;
@@ -510,6 +513,7 @@ public class MainWindow extends JFrame {
                 notifyDrawingLoaded(basicDrawing, mapViewDrawing);
                 drawing.clear();
                 isNewGraph = true;
+                mainPanel.revalidate();
             }
             if (isNewGraph) {
                 drawing.clear();