C H A P T E R 4

Menus

Figure 4-3 A hierarchical menu

Because submenus add complexity to the interface and are physically more difficult to use, you should use them only when you have more menus than fit in the menu bar or for closely related commands. Use only one level of submenus. If a submenu contains more than five items, consider giving it its own menu.

When you use submenus, include them in a menu with a logical relationship to the choices they contain; the submenu title should clearly represent the choices it contains. Hierarchical menus work best for providing submenus of attributes (rather than actions).

Menu Behavior

To choose an item in a menu, the user positions the pointer on the menu title and drags to the desired item. Each item is highlighted as it is selected. No action should actually happen until the user releases the mouse button. (See “Using the Mouse” (page 164).) By moving the pointer off a menu before releasing the mouse button, people can open and scan menus to find out what features are available, without having to actually perform an action. When a menu item has been activated, it blinks briefly.

It may be appropriate in some cases to provide dynamic menu items—commands that change when the user presses a modifier key. For example, if the user opens the File menu in the Finder and then presses the Option key, the Close Window command changes to Close All. The system appropriately sizes the menu to hold the widest item, including Option-enabled commands.

Apple Computer, Inc. June 2002

C H A P T E R 4

Menus

Scrolling Menus

A scrolling menu contains more items than are visible onscreen. Your application shouldn’t have any scrolling menus; they should exist only when a user adds many items to a customizable menu.

If a menu becomes too long to fit onscreen, a downward-pointing indicator at the bottom of the menu indicates that there are more items. When the user starts to scroll, an upward-pointing indicator appears at the top of the menu to show that some items are no longer visible in that direction. When the user drags past the last visible item, the menu scrolls to show the additional items. When the last item is shown, the downward-pointing indicator disappears. This behavior happens automatically if you use the standard system menu definition procedure (MDEF).

If the user drags back up to the top, the menu scrolls back down in the same manner. The next time the menu is opened, it appears in its original state (with the indicator at the bottom), unless the menu stores a setting, in which case the menu displays the last user-selected item.

Toggled Menu Items

A toggled menu item changes between two states each time a user chooses it. There are three types of toggled menu items:

■A group of two menu items that are opposite states; for example, Grid On and Grid Off. The state currently in effect has a checkmark next to it. If you have room in your menu, it’s a good idea to display both items (rather than changing the name depending on its state) so there’s less chance of confusion about each item’s effect.

■One menu item whose name changes to reflect the current state; for example, Show Ruler and Hide Ruler. Use this type if your menu doesn’t have room to show both states.

Use two verbs that express opposite actions. Make sure the command name is completely unambiguous. For example, Turn Grid On and Turn Grid Off is unambiguous. Choosing the command Use Grid, however, could turn the grid on (it describes what happens as a result of choosing the command) or off (it describes the current state).

50Menu Behavior

Apple Computer, Inc. June 2002

C H A P T E R 4

Menus

Figure 4-4 Avoid ambiguous toggled menu items

■A menu item that has a checkmark next to it when it is in effect; for example, a style attribute such as Bold. Don’t use this kind of toggled item to indicate the presence or absence of a feature like a grid or ruler. It’s unclear whether the checkmark means that the feature is in effect or whether choosing the command turns the feature on.

Also see “Using Special Characters and Text Styles in Menus” (page 65).

Sticky Menus

Standard Aqua system menus and submenus are sticky: When a user clicks the menu title, the menu stays open without the user having to continue holding down the mouse button. The user can then move the pointer to an item to select it. In Mac OS X, once a menu is opened with a click, it remains open until another action forces it to close. Such actions include

■moving the pointer to another menu title

■a click elsewhere

■a system-initiated alert

■a system-initiated application switch or quit

Apple Computer, Inc. June 2002