Setting+Up+Preferences

Setting preferences changes the “look and feel” of the Alice 3 IDE. The purpose of this section is to demonstrate how to set a preference. Any combination of preference settings is possible, as selected by the user.
 * How to Set Preferences**


 * Default Preferences
 * Set a Preference
 * Setting Multiple Preferences
 * Class Selection Button

Default preferences
The Alice installer has a pre-defined set of preferences for the “look and feel” of the Alice environment. We say these are **default preferences.** The default preferences are shown. By default, almost all preference options are disabled (indicated by the lack of a check mark for preference items in the menu). However, the first two Gallery preference items are enabled (indicated by a check mark at the beginning of the item in the menu).



**Default preference settings**  With the default preference settings, Alice starts with the Code editor displaying only one tab, as shown. The tab is editor space for creating code in //myFirstMethod,// a method belonging to the scene. After code has been created and the user clicks on the **Run** button, the scene will be displayed in a popup window (the **runtime window** ) and the code in //myFirstMethod//is executed.

//**myFirstMethod**//**tabbed editor panel in Mode I**

**Set a preference**

To set a preference, click on **Window** in the Menu bar and select **Preferences**. Next, click on one of the preferences in the menu. The illustration below shows the **Include Type Decoration** setting has been selected. A preference is enabled when a check mark is displayed immediately to the left of the menu item. Any preference menu items that are NOT checked are disabled. **Click menu item to set a preference**

**Setting multiple preferences**  Any combination of preferences may be set.A recommended set of preferences is shown below for those who wish to focus on object-oriented programming concepts with an intention to prepare for a production level language, such as Java.

**A selection of multiple preferences** Different preference settings result in a different look and feel for the Alice environment. For example, the settings shown in the previous illustration will result in the display shown below. Two tabs are automatically displayed in the Code Editor as well as a class selection button. **Class selection button and two tabs in Code editor**

**Class selection button** The class selection button shown has a yellow tile labeled **Scene** and a black “down-arrow” image indicating that a click on this button will pull down a menu. When clicked, a menu displays a list of classes currently used in this world. In this example, the list of classes includes: //Program, Scene, Biped,// and //Alien//. Alice projects will typically have //Program// and //Scene// classes. However, other classes in the list will vary depending on objects in the scene. **The class selection menu** Selecting one of the classes in the menu causes a class tab to be displayed in the Code editor. A class tab displays an outline of the methods defined in that class. The figure below illustrates a class tab for //Alien//.

**A class tab in the Code editor** Methods listed on a class tab are subdivided into the same three groupings (procedures, functions, and properties) as are usually displayed on the Methods panel. In addition, a fourth group, named constructors, is also displayed. A **constructor** is a special kind of method that contains instructions for creating a new object as defined by this class.

**Method categories on a class panel** A Methods panel is normally displayed in the lower left corner of the Code editor window. But, when a class tab is selected in the Code editor, the Methods panel is replaced with a diagram showing where this class fits in the hierarchy of classes in this virtual world. The figure below shows the hierarchy of classes in this example.

**Hierarchy of classes in this world**