Release Overview
Version 6.0

Screen Layout Managers

Version 6.0 of ACUCOBOL-GT introduces a new concept to its screen programming capabilities. The concept is called a layout manager. The fundamentals of the new concept are included in Version 6.0, as well as a single example of a layout manager. Future versions may build upon this foundation to provide more functionality. The resize layout manager included in Version 6.0 helps simplify the programming for a vexing problem: how to manage the resizing of a window.

A layout manager is a piece of software that is tied to a particular window. This software manages the placement and sizes of controls in that window. Each layout manager imposes its own rules about how it will affect the size and placement of controls.

By default, a window does not have a layout manager attached to it. For such windows, the controls are placed and sized according to their normal properties (e.g., LINE, COLUMN, SIZE, and LINES). When a layout manager is attached to a window, the layout manager determines the size and placement, although it is free to use the normal control properties to help make these decisions. In addition, there is a new standard property for controls called "LAYOUT-DATA" that the control can use to provide additional information about itself to the layout manager. The precise meaning of LAYOUT-DATA varies from layout manager to layout manager.

Layout managers operate whenever a new control is placed in the window or the window is resized.

Version 6.0 contains a single layout manager called the resize manager. This manager does not attempt to lay out controls as they are being placed. Rather, it uses the size and position of the controls as specified by the program to automatically resize or reposition controls whenever the window gets resized. Controls use the LAYOUT-DATA property to inform the layout manager about which automatic actions should take place on them.

The layout manager facility and the resize layout manager are described in detail in section 4.8, "Layout Managers," of Book 2, ACUCOBOL-GT User Interface Programming.

© 1988-2003 Acucorp, Inc. All rights reserved.