Overview of Floating Windows

ACUCOBOL-GT includes a class of graphical windows called floating windows. When run under a graphical environment, floating windows correspond to the graphical windows that are native to the host environment. On character-based systems, floating windows are emulated with text-mode elements and are managed directly by the ACUCOBOL-GT runtime system.

The primary characteristics of a floating window are:

1. It is either modal or modeless (see below)
2. It pops up over its parent window (usually the main application window) and is always displayed over the parent window wherever they intersect
3. It can be moved independently of the parent window and is able to leave the area described by the parent window. The user can move it directly with the mouse, without any program interaction
4. It belongs to the parent window. If the parent window is minimized, it is too. (Independent windows do not belong to parent windows; independent windows are considered siblings of parent windows. They can be minimized or maximized without controlling the parent window.)
5. It may have a system menu associated with it that allows the user to select some basic operations on the window, such as moving or closing it

The main application window is treated as a special-case floating window that has no parent window.

Floating windows may be either modal or modeless. A modal window is a window that the user cannot leave until it is dealt with and closed. When a modal window is active, all other windows are disabled.

A modeless window is one that allows the user to switch among windows while allowing each modeless window to remain open and available. When a modeless window is active, the user can activate another window using the host system's techniques for doing so (for example, by clicking on the window with the mouse).

The names modal and modeless are derived from the idea that a modal window enters a new mode in the program (for example, selecting a file to open), while a modeless window does not (since the user can continue working on tasks in other windows).

Floating windows are modal by default. The MODAL phrase may be included as commentary. Inclusion of the MODELESS phrase makes a window modeless.