GTK_TREE_VIEW_COLUMN_FIXED
. The size of the column is clamped to
the min/max width for the column. Please note that the min/max width of the
column doesn't actually affect the "fixed_width" property of the widget, just
the actual size when displayed.gtkTreeViewColumnSetFixedWidth(object, fixed.width)
object
fixed.width
tree.column
to. Must be greater than 0.