1. Wanda Dann wpdann@andrew.cmu.edu Don Slater dslater@cmu.edu Methods Panel & Object Tree Copyright 2012 Wanda Dann, Don Slater All rights reserved

2.  Object Tree in Scene Editor  Instance List in Code Editor  Methods Panel  Ancestry & Class Hierarchy

3. Scene Editor -- Object tree In the scene editor, Alice generates an object tree to show a list of all objects in this scene. Click on Edit Code to return to the Code Editor

4. Code Editor – Instance list In the code editor, Alice generates an instance list, containing all objects in this scene. Instance list Object tree

5. In this scene Alice World Remember, every Alice world has a scene (this), a ground (or water) surface, and a camera. Objects you create in the scene editor are added to the instance list. Every scene

6. Methods Panel In the code editor, the methods panel contains a set of tiles. Each tile describes an action an object can perform (or have performed on it) or a property of the object.

7. Ancestry Each object in the scene is an instance of a class that belongs to a family of classes. The class’s ancestry is shown in the methods panel.

8. Inheritance In a family, each new generation inherits certain characteristics from the previous generations.

9. Inheritance: Order BabyDragonQuadruped Ancestry can be ordered from specific to most generic (similar to youngest to oldest).

10.  The ancestry list tells you that fergie, an instance of the BabyDragon class…  inherits all properties and methods of the Quadruped class Why do you care?

11. In computer science, we often use a more abstract representation of class inheritance, known as a class hierarchy. JointedModel ├ SQuadruped ├ Quadruped ├ Camel Class hierarchy Note that horaceCamel is NOT specified in the class hierarchy because horaceCamel is NOT a class. Not shown in Alice