Dogcows Code - chaz/openbox/blob - python/config.py

   1 # Openbox's config system. Please use the defined functions instead of
   2 # accessing the internal data structures directly, for the sake of us all.
   3
   4 def add(modulename, name, friendlyname, description, type, default,
   5         **keywords):
   6     """Add a variable to the configuration system.
   7
   8     Add a variable to the configuration system for a module.
   9     modulename - The name of the module, e.g. 'focus'
  10     name - The name of the variable, e.g. 'my_variable'
  11     friendlyname - The user-friendly name of the variable, e.g. 'My Variable'
  12     description - The detailed destription of the variable, e.g. 'Does Things'
  13     type - The type of the variable, one of:
  14              - 'boolean'
  15              - 'enum'
  16              - 'integer'
  17              - 'string'
  18              - 'file'
  19              - 'function'
  20              - 'object'
  21     default - The default value for the variable, e.g. 300
  22     keywords - Extra keyword=value pairs to further define the variable. These
  23                can be:
  24                  - For 'enum' types:
  25                      - options : A list of possible options for the variable.
  26                                  This *must* be set for all enum variables.
  27                  - For 'integer' types:
  28                      - min : The minimum value for the variable.
  29                      - max : The maximum value for the variable.
  30     """
  31     modulename = str(modulename).lower()
  32     name = str(name).lower()
  33     friendlyname = str(friendlyname)
  34     description = str(description)
  35     type = str(type).lower()
  36
  37     # make sure the sub-dicts exist
  38     try:
  39         _settings[modulename]
  40         try:
  41             _settings[modulename][name]
  42         except KeyError:
  43             _settings[modulename][name] = {}
  44     except KeyError:
  45         _settings[modulename] = {}
  46         _settings[modulename][name] = {}
  47
  48     # add the keywords first as they are used for the tests in set()
  49     for key,value in zip(keywords.keys(), keywords.values()):
  50         _settings[modulename][name][key] = value
  51
  52     _settings[modulename][name]['name'] = friendlyname
  53     _settings[modulename][name]['description'] = description
  54     _settings[modulename][name]['type'] = type
  55     _settings[modulename][name]['default'] = default
  56
  57     # put it through the tests
  58     try:
  59         set(modulename, name, default)
  60     except:
  61         del _settings[modulename][name]
  62         import sys
  63         raise sys.exc_info()[0], sys.exc_info()[1] # re-raise it
  64
  65 def set(modulename, name, value):
  66     """Set a variable's value.
  67
  68     Sets the value for a variable of the specified module.
  69     modulename - The name of the module, e.g. 'focus'
  70     name - The name of the variable, e.g. 'my_variable'
  71     value - The new value for the variable.
  72     """
  73     modulename = str(modulename).lower()
  74     name = str(name).lower()
  75
  76     # proper value checking for 'boolean's
  77     if _settings[modulename][name]['type'] == 'boolean':
  78         if not (value == 0 or value == 1):
  79             raise ValueError, 'Attempted to set ' + name + ' to a value of '+\
  80                   str(value) + ' but boolean variables can only contain 0 or'+\
  81                   ' 1.'
  82
  83     # proper value checking for 'enum's
  84     elif _settings[modulename][name]['type'] == 'enum':
  85         options = _settings[modulename][name]['options']
  86         if not value in options:
  87             raise ValueError, 'Attempted to set ' + name + ' to a value of '+\
  88                   str(value) + ' but this is not one of the possible values '+\
  89                   'for this enum variable. Possible values are: ' +\
  90                   str(options) + "."
  91
  92     # min/max checking for 'integer's
  93     elif _settings[modulename][name]['type'] == 'integer':
  94         try:
  95             min = _settings[modulename][name]['min']
  96             if value < min:
  97                 raise ValueError, 'Attempted to set ' + name + ' to a value '+\
  98                       ' of ' + str(value) + ' but it has a minimum value ' +\
  99                       ' of ' + str(min) + '.'
 100         except KeyError: pass
 101         try:
 102             max = _settings[modulename][name]['max']
 103             if value > max:
 104                 raise ValueError, 'Attempted to set ' + name + ' to a value '+\
 105                       ' of ' + str(value) + ' but it has a maximum value ' +\
 106                       ' of ' + str(min) + '.'
 107         except KeyError: pass
 108
 109     _settings[modulename][name]['value'] = value
 110
 111 def reset(modulename, name):
 112     """Reset a variable to its default value.
 113
 114     Resets the value for a variable in the specified module back to its
 115     original (default) value.
 116     modulename - The name of the module, e.g. 'focus'
 117     name - The name of the variable, e.g. 'my_variable'
 118     """
 119     modulename = str(modulename).lower()
 120     name = str(name).lower()
 121     _settings[modulename][name]['value'] = \
 122                                  _settings[modulename][name]['default']
 123
 124 def get(modulename, name):
 125     """Returns the value of a variable.
 126
 127     Returns the current value for a variable in the specified module.
 128     modulename - The name of the module, e.g. 'focus'
 129     name - The name of the variable, e.g. 'my variable'
 130     """
 131     modulename = str(modulename).lower()
 132     name = str(name).lower()
 133     return _settings[modulename][name]['value']
 134
 135 #---------------------------- Internals ---------------------------
 136
 137 """The main configuration dictionary, which holds sub-dictionaries for each
 138    module.
 139
 140    The format for entries in here like this (for a string):
 141    _settings['modulename']['varname']['name'] = 'Text Label'
 142    _settings['modulename']['varname']['description'] = 'Does this'
 143    _settings['modulename']['varname']['type'] = 'string'
 144    _settings['modulename']['varname']['default'] = 'Foo'
 145    _settings['modulename']['varname']['value'] = 'Foo'
 146                              # 'value' should always be initialized to the same
 147                              # value as the 'default' field!
 148
 149    Here's an example of an enum:
 150    _settings['modulename']['varname']['name'] = 'My Enum Variable'
 151    _settings['modulename']['varname']['description'] = 'Does Enum-like things.'
 152    _settings['modulename']['varname']['type'] = 'enum'
 153    _settings['modulename']['varname']['default'] = \
 154      _settings['modulename']['varname']['value'] = [ 'Blue', 'Green', 'Pink' ]
 155
 156    And Here's an example of an integer with bounds:
 157    _settings['modulename']['varname']['name'] = 'A Bounded Integer'
 158    _settings['modulename']['varname']['description'] = 'A fierce party animal!'
 159    _settings['modulename']['varname']['type'] = 'integer'
 160    _settings['modulename']['varname']['default'] = \
 161      _settings['modulename']['varname']['value'] = 0
 162    _settings['modulename']['varname']['min'] = 0
 163    _settings['modulename']['varname']['max'] = 49
 164
 165    Hopefully you get the idea.
 166    """
 167 _settings = {}
 168
 169 """Valid values for a variable's type."""
 170 _types = [ 'boolean', # Boolean types can only hold a value of 0 or 1.
 171
 172            'enum',    # Enum types hold a value from a list of possible values.
 173                       # An 'options' field *must* be provided for enums,
 174                       # containing a list of possible values for the variable.
 175
 176            'integer', # Integer types hold a single number, as well as a 'min'
 177                       # and 'max' property.
 178                       # If the 'min' or 'max' is ignore then bounds checking
 179                       # will not be performed in that direction.
 180
 181            'string',  # String types hold a text string.
 182
 183            'file',    # File types hold a file object.
 184
 185            'function',# Function types hold any callable object.
 186
 187            'object'   # Object types can hold any python object.
 188            ];
 189
 190 print "Loaded config.py"