8.5.1 Building Widgets

In LUX, widgets are identified by widget identification numbers or widget IDs, which are small positive integer numbers. Widgets are part of a hierarchy with one or more top-level widgets, and zero or more other widgets that are dependent parts of widgets higher up in the hierarchy. For convenience, widget associations are referred to as if dependent widgets are the offspring of widgets that contain them.

Widget dependency is such that if a particular widget is destroyed (removed), then all of its children are removed, too. Top-level widgets stand out because they have no ancestors.

The following top-level widgets are currently available: xmmessage, xmprompt, xmtoplevel_board, and xmtoplevel_form. The last two can contain children.

In a bulletin board widget, child widgets can be placed at absolute positions, using xmposition. In a form widget, child widget placement is constrained by specifying widget attachments through xmattach. In both types of widgets, convenient placement can also be achieved by including child widgets in row or column widgets, using xmrows or xmcolumns.

See also: xmmessage, xmprompt, xmtoplevel_board, and xmtoplevel_form.