Container Objects

All Windows Designer objects exist in an object ownership hierarchy, where larger objects own smaller objects. For example, a window often has an info box. Container objects and group objects, however, are special because containing other objects is their main purpose. For example, column boxes are container objects. Their main purpose is to contain columns.

Container objects and group objects make it easier to organize and maintain the layout of controls in a window. For example, you can draw a group border around a group of controls. You can also specify that a group object has vertical orientation; this causes the objects within the group (for example, text boxes with prompts) to appear neatly underneath each other.

USoft Developer automatically implements container objects. They include column boxes containing controls for each column in a base table. Group objects are specified by the developer. They can containing any selection of objects, and are often to make layout of user-defined controls in a dialog box easier.

There are small differences in behavior between container objects and group objects. You can delete a group object without also deleting its contained objects. Group objects automatically disappear if they have no contained objects left.

Default info windows have a Column Box object that contains Column objects. Column objects have a Header object to organize their prompt or label, and a Data object to display data stored in the base column (in the database). The length and height of the Header objects are calculated per group in horizontal and vertical orientation, per column if the group has vertical orientation, and per row in horizontal orientation. This gives you many layout possibilities.