Windows Interface Components - Secondary Windows
Use pop-up windows to display additional information when an abbreviated form of the information is the main presentation. For example, you could use a pop-up window to display the full path for a field or control when an entire path cannot be presented and must be abbreviated. Pop-up windows are also used to provide context-sensitive Help information, as shown in Figure 9.23.
Figure 9.23 A context-sensitive Help pop-up window
More Information
For more information about using pop-up windows for Help information, see Chapter 13, "User Assistance."
ToolTips and balloon tips that provide the names for controls in toolbars are another example of pop-up windows used to display contextual information.
How pop-up windows appear depends on how they are used. Typically, the user points at an object, clicks an object or uses its keyboard equivalent, or clicks an explicit command.
If your application uses pointing as the technique for displaying a pop-up window, display the window after a time-out. The system automatically handles time-outs if you use the standard ToolTip controls. If you are providing your own implementation, you can use the current settings for ToolTip controls, which can be retrieved by creating a ToolTip and sending it a TTM_GETDELAYTIME message.
More Information
For more information about TTM_GETDELAYTIME, see the Microsoft Platform SDK on the MSDN Online Web site at http://msdn.microsoft.com/ui/guide/sdk.asp.
If your application uses clicking to display a pop-up window, change the pointer as feedback to the user indicating that the pop-up window exists and requires a click. From the keyboard, you can use the Select key (SPACEBAR) to open and close the window.
Fundamentals of Designing User Interaction
Design Specifications and Guidelines