Java™ How To Program (Early Objects), Tenth Edition

Setting Up the File Menu

Lines 38–76 set up the File menu and attach it to the menu bar. The File menu contains an About... menu item that displays a message dialog when the menu item is selected and an Exit menu item that can be selected to terminate the application. Line 38 creates a JMenu and passes to the constructor the string "File" as the name of the menu. Line 39 uses JMenu method setMnemonic (inherited from class AbstractButton) to indicate that F is the mnemonic for this menu. Pressing the Alt key and the letter F opens the menu, just as clicking the menu name with the mouse would. In the GUI, the mnemonic character in the menu’s name is displayed with an underline. (See the screen captures in Fig. 22.6.)

Look-and-Feel Observation ...