Modify connection between MainWindow and the NotesInputPanel.

src/main/org/insa/graphics/drawing/BasicDrawing.java

@@ -99,6 +99,11 @@ public class BasicDrawing extends JPanel implements Drawing {
             return point;
         }
 
+        @Override
+        public Color getColor() {
+            return color;
+        }
+
         @Override
         public void moveTo(Point point) {
             this.point = point;
@@ -440,7 +445,7 @@ public class BasicDrawing extends JPanel implements Drawing {
 
     @Override
     public void drawGraph(Graph graph, GraphPalette palette) {
-        clear();
+        this.clear();
         initialize(graph);
         for (Node node: graph.getNodes()) {
             for (Arc arc: node.getSuccessors()) {