nWindows Help can display only one secondary window at a time. If the user completes an action that requires Help to display a secondary window while one is already open, the new secondary window replaces the current one.A secondary window has the same characteristics as a standard window. It includes a Control menu, a title bar, minimize and maximize buttons, and window borders. Users can move, resize, minimize, or maximize secondary windows. If necessary, secondary windows can display horizontal and vertical scroll bars that users can use to view information displayed in the secondary window. Secondary windows do not include a menu bar or button bar or any other Help controls. Any custom controls or functionality in secondary windows must be defined by individual Help authors for each Help file.
A secondary window is completely independent of the main Help window It can be open even if the main Help window is closed. When open, a secondary window’s title appears in the Windows Task List. If a user minimizes a secondary window, it displays its own icon. Help uses the standard Windows Help question-mark icon unless the Help author specifies a custom icon using the ICON option in the [OPTIONS] section of the Help project file. (See Chapter 16, “The Help Project File,” for details.)
Any topic that you can display in the main Help window you can also display in a secondary window. Secondary windows can include any standard Windows Help feature, including text, graphics, jump hot spots, pop-up windows, macro hot spots, nonscrolling areas, or embedded windows.
Secondary windows appear on demand, usually when the user chooses a menu item, Help button, or hot spot. A macro in the Help project file or a WinHelp API call can also be used to display a secondary window. For information about using Help macros to display a secondary window, see Chapter 14, “Help Macros.” For information about how an application can send an API call to Help in order to display a secondary window, see Chapter 19, “The WinHelp API.”
Secondary window attributes are specified when a Help file is opened and remain in effect until the Help file is closed.
Despite their usefulness, secondary windows have the following limitations:
nWindows Help can display only one secondary window at a time. If the user completes an action that requires Help to display a secondary window while one is already open, the new secondary window replaces the current one.
nA single Help file can define only up to five secondary window types, which limits the number of different ways you can use secondary windows. For example, you cannot create a design that customizes the secondary window for every topic displayed in it; instead, you should design secondary windows for categories of information.
nYou cannot use all of the Help macros in secondary windows. Some macros are ignored when executed from a secondary window, and others are not recommended because they may create conflicts if executed from a secondary window. To find out whether a macro can be executed from a secondary window, check the macro’s Comments section in Chapter 15, “Help Macro Reference.”
nSecondary windows remain open if the user closes the main Windows Help window using the Control menu. The user must then close the secondary window using the secondary window’s Control menu or a custom control that you provide.
nSecondary window topics don’t appear in the history list nor are they recorded in the back list. So, if you place important information in a secondary window, the user will not be able to use the History or Back button to return to a previously viewed topic.
nThe keyword search feature in Windows Help displays all topics in the main Help window, even if that topic is normally displayed in a secondary window. You can assign keywords to secondary window topics, but when accessed from the Search dialog box, they will not appear in the secondary window.
nYou cannot use Help macros to change the on-top state of a secondary window without affecting the main Help window.