Add duck typing equals check to TextBox

src/TextBox.java

@@ -56,6 +56,14 @@ public class TextBox extends Rectangle {
 
     @Override
     public boolean equals(Object o) {
-        return this == o;
+        try {
+            TextBox t = (TextBox)o;
+            // duck typing equals check
+            // if it shows the same id, assume that it is equal; this is because ids should be unique
+            // also makes some corner cases easier
+            return this.id.equals(t.id);
+        } catch (ClassCastException e) {
+            return false;
+        }
     }
 }