Module PackageVariable'

engine.SCons.Variables.PackageVariable

This file defines the option type for SCons implementing 'package
activation'.

To be used whenever a 'package' may be enabled/disabled and the
package path may be specified.

Usage example:

  Examples:
      x11=no   (disables X11 support)
      x11=yes  (will search for the package installation dir)
      x11=/usr/local/X11 (will check this path for existance)

  To replace autoconf's --with-xxx=yyy 

  opts = Variables()
  opts.Add(PackageVariable('x11',
                         'use X11 installed here (yes = search some places',
                         'yes'))
  ...
  if env['x11'] == True:
      dir = ... search X11 in some standard places ...
      env['x11'] = dir 
  if env['x11']:
      ... build with x11 ...

The input parameters describe a 'package list' option, thus they
are returned with the correct converter and validator appended. The
result is usable for input to opts.Add() .

A 'package list' option may either be 'all', 'none' or a list of
package names (seperated by space).