The Label Areas

Presence

The label areas are shown if there is depth beyond what is needed for the window manager areas and the title area.  The space is divided up among the label areas, and each may be only partially shown.  Specifying the `naturalsize attribute causes all the label areas to be completely shown, of course (assuming the external constraints, like screen size, allow.)

Function

If a callback function has been set on the object, then when the left mouse button is pressed and released while the pointer is on a label area corresponding to a symbolic index, the function is called.  The path argument is that symbolic index and the data argument is the value picked from the underlying slotfiller by that index.

Arrangement

By default, the labels are arranged vertically, but the arrangement can be specified by the `geometry attribute.
Each label area corresponds to either
  • a symbolic index of the underlying slotfiller variable or
  • a blank area as specified in the `geometry attribute.  Rows containing only blank areas are not shown (i.e., have depth 0) unless `R is 1, and columns containing only blank areas are not shown (i.e., have width 0) unless `C is 1, and even then trailing columns with only blank areas are not shown.

Size

If there are no blank areas or horizontal repetitions specified by `geometry,
  • if `C is 0, all label areas in a column are the same width, which is by default determined by the longest label in the column;  but
  • if `C is 1, all columns have the same width, which is by default determined by the longest label in the object.

Because each label appears on a single line and all are in the same font, the virtual rows tend to be the same height, even when not forced to be by `R.

The size can be set using the attributes affecting overall size listed in the "Size, position, etc. on screen or in parent" page.

Color

The color is determined by the `bg attribute.  It is grey by default (more precisely, the value of s.GREY).


doc@aplusdev.org© Copyright 1995–2008 Morgan Stanley Dean Witter & Co. All rights reserved.