For more information about using standard controls and designing your own controls, see Chapter 13, "Visual Design."
Controls are graphic objects that represent the properties or operations of other objects. Some controls display and allow editing of particular values. Other controls start an associated command.
Each control has a unique appearance and operation designed for a specific form of interaction. The system also provides support for designing your own controls. When defining your own controls, follow the conventions consistent with those provided by the system-supplied controls.
Note
For more information about using standard controls and designing your own controls, see Chapter 13, "Visual Design."
Like most elements of the interface, controls provide feedback indicating when they have the input focus and when they are activated. For example, when the user interacts with controls using a mouse, each control indicates its selection upon the down transition of the mouse button, but does not activate until the user releases the button, unless the control supports auto-repeat.
Controls are generally interactive only when the pointer, actually the hot spot of the pointer, is over the control. If the user moves the pointer off the control while pressing a mouse button, the control no longer responds to the input device. If the user moves the pointer back onto the control, it once again responds to the input device. The hot zone, or boundary that defines whether a control responds to the pointer, depends on the type of control. For some controls, such as buttons, the hot zone coincides with the visible border of the control. For others, the hot zone may include the control's graphic and label (for example, check boxes) or some controls, such as scroll bars, as defined around the control's borders.
Many controls provide labels. Because labels help identify the purpose of a control, always label a control with which you want the user to directly interact. If a control does not have a label, you can provide a label using a static text field or a tooltip control. Define an access key for text labels to provide the user direct keyboard access to a control. Where possible, define consistent access keys for common commands.
Note
For more information about defining access keys, see Chapter 4, "Input Basics."
While controls provide specific interfaces for user interaction, you can also include pop-up menus for controls. This can provide an effective way to transfer the value the control represents or to provide access to context-sensitive Help information. The interface to pop-up menus for controls follows the standard conventions for pop-up menus, except that it does not affect the state of the control; that is, clicking the control with button 2 does not trigger the action associated with the control when the user clicks it with button 1. The only action is the display of the pop-up menu.
A pop-up menu for a control is contextual to what the control represents, rather than the control itself. Therefore, avoid commands such as Set, Unset, Check, or Uncheck. The exception is in a forms design or window layout context, where the commands on the pop-up menu can apply to the control itself.