Move all the old code into a package named tp3, and create a new package for...

Move all the old code into a package named tp3, and create a new package for tp5, then add  the Shape interface within it

src/main/java/serializer/DrawerWithSave.java

 package serializer;
 
-import javafx.scene.canvas.Canvas;
 import javafx.scene.control.Alert;
 import javafx.stage.FileChooser;
-import shape.Shape;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.List;
-import java.util.stream.Collectors;
 
 
 public class DrawerWithSave extends state.Drawer {

src/main/java/serializer/ShapeReader.java

 package serializer;
 
-import shape.Shape;
+import shape.tp3.Shape;
 
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.List;
-import java.util.stream.Collector;
 
 public class ShapeReader {
     public static List<Shape> read(File file) throws IOException {

src/main/java/serializer/ShapeWriter.java

 package serializer;
 
-import shape.Shape;
+import shape.tp3.Shape;
 
 import java.io.File;
 import java.io.IOException;

src/main/java/shape/App.java

@@ -8,6 +8,7 @@ import javafx.scene.canvas.Canvas;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.paint.Color;
 import javafx.stage.Stage;
+import shape.tp3.*;
 
 public class App extends Application {
 

src/main/java/shape/AbstractShape.java → src/main/java/shape/tp3/AbstractShape.java

-package shape;
+package shape.tp3;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
+
 import java.util.ArrayList;
 import java.util.List;
 

src/main/java/shape/BorderDecorator.java → src/main/java/shape/tp3/BorderDecorator.java

-package shape;
+package shape.tp3;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.paint.Color;

src/main/java/shape/CenterDecorator.java → src/main/java/shape/tp3/CenterDecorator.java

-package shape;
+package shape.tp3;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.paint.Color;

src/main/java/shape/Circle.java → src/main/java/shape/tp3/Circle.java

-package shape;
+package shape.tp3;
 
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;

src/main/java/shape/Decorator.java → src/main/java/shape/tp3/Decorator.java

-package shape;
+package shape.tp3;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.geometry.Point2D;
 

src/main/java/shape/Polygon.java → src/main/java/shape/tp3/Polygon.java

-package shape;
+package shape.tp3;
 
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;

src/main/java/shape/Rectangle.java → src/main/java/shape/tp3/Rectangle.java

-package shape;
+package shape.tp3;
 
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;

src/main/java/shape/Shape.java → src/main/java/shape/tp3/Shape.java

-package shape;
+package shape.tp3;
 
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;

src/main/java/shape/ShapeContainer.java → src/main/java/shape/tp3/ShapeContainer.java

-package shape;
+package shape.tp3;
 
 import javafx.scene.canvas.GraphicsContext;
+
 import java.util.ArrayList;
 import java.util.List;
 

src/main/java/shape/tp5/Shape.java

+package shape.tp5;
+
+import javafx.scene.canvas.GraphicsContext;
+
+public interface Shape {
+    void paint(GraphicsContext graphicsContext);
+    boolean contains(double x, double y);
+    void translate(double dx, double dy);
+}

src/main/java/state/Drawer.java

 package state;
 
 import javafx.scene.canvas.Canvas;
-import shape.Circle;
-import shape.Shape;
+import shape.tp3.Shape;
 
 import java.util.ArrayList;
 import java.util.List;