Selection Appearance

When the user selects an item, provide visual feedback to enable the user to distinguish it from items that are not selected. Selection appearance generally depends on the object and the context in which the selection appears.

Display an object with selection appearance as the user performs a selection operation. For example, display selection appearance when the user presses the mouse button to select an object.

Note
For more information about selection techniques, see Chapter 4, "Input Basics."

It is best to display the selection appearance only for the scope, area, or level (window or pane) that is active. This helps the user recognize which selection currently applies and the extent of the scope of that selection. Therefore, avoid displaying selections in inactive windows or panes, or at nested levels.

However, in other contexts, it may still be appropriate to display selection appearance simultaneously in multiple contexts. For example, when the user selects an object and then selects a menu item to apply to that object, selection appearance is always displayed for both the object and the menu item because it is clear where the user is directing the input. In cases where you need to show simultaneous selection, but with the secondary selection distinguished from the active selection, you can draw an outline in the selection highlight color around the secondary selection or use some similar variant of the standard selection highlight technique.