9 Controls and Dialog Boxes

One of the most efficient ways to obtain structured information from the user is by presenting him with a dialog box in which he may enter text, select items from a list, check choices, etc. Lidskjalv enables the construction of such dialog boxes through the window pattern. Dialogs may be either modal or modeless. A modal dialog box will take over the entire control of the underlying window system, restricting the user only to interact with the dialog box until it is removed from the screen. A modeless dialog box, on the other hand, allows the user to choose also to interact with the other windows and menus on the screen while the dialog box is on the screen. Dialogs are constructed by a window, and either shown using either showModal or show.

Dialog boxes consists of the dialog box window and a number of control items in that window. Control items are either static text, editable text, buttons, check boxes, radio boxes or icons, along possibly with other graphics (e.g. figure items). The control items are used to specify the various options, that the user has to choose among in order to fill-in the requested information.

Program 18: screendump (Macintosh)