A toolbar resides in the frame at the top of a window—below or integrated with the title bar—and provides convenient access to frequently used commands and features within an app window. The toolbars in Mail, for example, include the commands people use most often as they view, compose, and manage email.
For developer guidance, see NSToolbar.
The elements within a toolbar are considered toolbar items and consist of either image buttons or specific system controls that are optimized for use in the toolbar.
Consider using translucency when content flows beneath a toolbar. Translucency creates a sense of depth and context. A toolbar automatically adopts translucency when placed above a scroll view or when the window is configured as a full-size content view. For developer guidance, see NSFullSizeContentViewWindowMask. For related design guidance, see Translucency.
Avoid giving a toolbar item a persistent selected appearance. Clicking a toolbar item results in an immediate action—such as opening a new window, switching to a different view, displaying a menu, or inserting (or removing) an object—so it doesn’t make sense to imply that there is also a change in state. The exception to this is a segmented control that shows a persistent selected appearance within the context of the control, such as the view controls in a Finder window toolbar.
Accurately reflect the current state of a control that toggles between two states. Sometimes, a toolbar item toggles an app state on and off. This type of item must clearly communicate its state to the user. You can accomplish this by changing the item's color scheme and label. For example, Mail includes a toolbar item that toggles your accounts online and offline. When online, the item displays a blue icon and a Go Offline label. When offline, the item displays a gray icon and a Go Online label.
Make sure the meaning of each toolbar item is clear. People shouldn’t need to experiment or wait for a tooltip to figure out what an item does. Provide a simple, recognizable icon and a short, descriptive label.
Prefer system-provided icons in toolbar items because they’re familiar. Because system icons are template images, they automatically receive appropriate coloring and react to user interactions and vibrancy. See System Icons.
Prefer icons over text in toolbar items. In a customizable toolbar, labels appear beneath toolbar items when the user chooses to display them. Seeing control text above label text is unnecessarily repetitive.
If you must display text within a control, make sure it’s clear and concise. When describing an object, setting, or state, use a noun or noun phrase. When describing an action, use a verb or verb phrase. Use title-style capitalization.
Arrange toolbar items to support the main task people accomplish in your app. In general, use the leading end of the toolbar for commands that should have the highest visibility. “High visibility” can mean different things in different apps. In some apps, frequency of use should determine visibility. In other apps, it makes more sense to rank items by importance.
If appropriate, group related toolbar items. In some cases, you can define logical groups of toolbar items, such as one group for document manipulation tasks and another for text manipulation tasks. When you create a group, arrange its items according to importance or frequency of use. Use the same criteria to arrange groups themselves. The toolbar in Keynote includes several groups that are based on functionality, including one for presentation-level functions, one for playback functions, and one for object insertion.
Let people show or hide the toolbar. A user might want to hide the toolbar to minimize distractions or reveal more content. Be sure to provide commands for hiding and revealing the toolbar should in the View menu.
Consider automatically hiding the toolbar in full-screen mode to increase the focus on content. Although people usually rely on the presence of a toolbar, you can hide it in a full-screen window if it’s not needed to accomplish the focused task. For example, Preview hides the toolbar in a full-screen window because people are more likely to viewing content than annotating it. If you hide the toolbar in a full-screen window, reveal it (along with the menu bar) when the pointer moves to the top of the screen.
Toolbars are often customizable. In a customizable toolbar, the user can decide which items appear in the toolbar, and in many cases choose whether to show them as icons, text, or icons and text combined. Some toolbars let the user choose whether large or small toolbar items are displayed. Apps often let people hide the toolbar entirely, for increased focus on content.
In general, let people customize the toolbar. People have different workflows and should ideally be able to customize the toolbar’s contents and appearance to support their individual working styles.
Provide useful default toolbar items. Since not everyone customizes the toolbar, your default items should be commands that most people find useful. They should also educate new users about the key features of your app.
If you allow customization, add the Customize Toolbar menu item to the View menu. See View Menu.
Don’t add an app-specific contextual menu to the toolbar. A toolbar already has a contextual menu that’s used consistently across the system for customization. Additionally, title bars often let people Control-click to rename a document or reveal its path. If you require a set of commands that act on the selection, then either add a contextual menu in the content area of the window, or add an action pop-up button in the toolbar. For related guidance, see Contextual Menus and Action Pop-Up Buttons.
Consider letting people click nondestructive toolbar items when a window is inactive. Normally, clicking the toolbar of an inactive window brings the window to the front. In some cases, it may be useful to let the user invoke toolbar items without bringing the window to the front so they can stay focused on a task in a different window. The toolbar of the standard Fonts panel behaves this way.
Consider adding spring-loading support to toolbar items. On pressure-sensitive systems, such as systems with the Force Touch trackpad, spring loading lets a user activate a button or segmented control segment by dragging items over it and force clicking—pressing harder—without dropping the items. The user can then continue dragging the items, possibly to perform additional actions. In Calendar, for example, an event can be dragged over the day, week, month, or year segments in the toolbar. Force clicking a segment switches the calendar view without releasing the event. The event can then be dropped at the desired location in the new calendar view.