Documentation patch from Amanda Yilmaz (services/clipboard/typeregistry.py)

services/clipboard/typeregistry.py

@@ -4,36 +4,114 @@ import urlparse
 import posixpath
 
 class FileType:
+    """Generic base class for all classes representing clipboard item formats.
+
+    XXX This class's name is misleading; it represents a clipboard item
+    format and not a file type per se.  Perhaps it should be renamed to
+    ClipboardItemFormat?
+    """
+    
     def __init__(self, formats):
+        """Initializer for this class (and all subclasses).
+        
+        formats -- A dictionary of key-value pairs where the keys are MIME type
+            strings and the data values are the clipboard data in each
+            respective format.  A reference to this dictionary is stored within
+            the object for possible use later.
+        
+        This initializer is invoked when the clipboard item format object is
+        instantiated by the TypeRegistry class's get_type method.
+        
+        """
         self._formats = formats
 
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        This base-class implementation raises a NotImplementedError exception.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         raise NotImplementedError
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        This base-class implementation raises a NotImplementedError exception.
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         raise NotImplementedError
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        This base-class implementation raises a NotImplementedError exception.
+        
+        returns A string containing the item preview.
+        """
         raise NotImplementedError
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        This base-class implementation raises a NotImplementedError exception.
+        
+        returns A string containing the activity identifier. 
+        """
         raise NotImplementedError
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This base-class implementation currently raises a
+        NotImplementedError exception, but could (and should) be rewritten to
+        handle this functionality for *all* subclasses, since the code is
+        identical for all or most subclasses anyway.
+       
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         raise NotImplementedError
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class TextFileType(FileType):
+    """Represents the text clipboard item format.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
 
     _types = set(['text/plain', 'UTF8_STRING', 'STRING'])
 
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Text snippet')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-text'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        For the text file format, this returns a text string containing up to
+        49 characters of the actual item's text.
+        
+        returns A preview string containing up to 49 characters of the item's
+            text.
+        """
         for format, data in self._formats.iteritems():
             if format in TextFileType._types:
                 text = data.get_data()
@@ -45,43 +123,122 @@ class TextFileType(FileType):
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return 'org.laptop.AbiWordActivity'
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class ImageFileType(FileType):
+    """Represents the "image" clipboard item format.
+    
+    This clipboard item format represents *any* image format, including JPEG,
+    GIF, PNG and TIFF formats.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
 
     _types = set(['image/jpeg', 'image/gif', 'image/png', 'image/tiff'])
 
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Image')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-image'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return ''
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class UriFileType(FileType):
+    """Represents the URI clipboard item format.
+    
+    Not to be confused with the multiple-URI UriListFileType class.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['_NETSCAPE_URL'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Web Page')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-link'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        For the URI clipboard item format, this is the URI itself.
+        
+        returns A string containing the item preview, in this case the URI itself.
+        """
         for format, data in self._formats.iteritems():
             if format in UriFileType._types:
                 string = data.get_data()
@@ -91,119 +248,352 @@ class UriFileType(FileType):
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return ''
 
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class PdfFileType(FileType):
+    """Represents the PDF clipboard item format.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/pdf', 'application/x-pdf'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('PDF file')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-text'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return 'org.laptop.sugar.Xbook'
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class MsWordFileType(FileType):
+    """Represents the MS Word clipboard item format (*cringe*).
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/msword'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('MS Word file')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-text'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return 'org.laptop.AbiWordActivity'
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+       
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class RtfFileType(TextFileType):
+    """Represents the RTF clipboard item format (a subclass of TextFileType).
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/rtf', 'text/rtf'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('RTF file')
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class AbiwordFileType(TextFileType):
+    """Represents the AbiWord clipboard item format.
+   
+    (XXX This class's name is misleading; it represents a clipboard item format,
+    not a file type per se.)
+    (XXX AbiWord format is a full word processing format, like the OO Text and MS Word
+    formats, and should not be a subclass of TextFileType!  Otherwise the OO Text and
+    MS Word format types should also be made subclasses of TextFileType.)
+    """
     
     _types = set(['application/x-abiword'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Abiword file')
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class SqueakProjectFileType(FileType):
+    """Represents the Squeak Project clipboard item format.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/x-squeak-project'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Squeak project')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-squeak-project'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return 'org.vpri.EtoysActivity'
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class OOTextFileType(FileType):
+    """Represents the OpenDocument Text (OpenOffice.org Writer) clipboard item format.
+    
+    Note to the uninitiated: OpenDocument Text is a full word processing format,
+    not a simple text file.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/vnd.oasis.opendocument.text'])
     
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('OpenOffice text file')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:object-text'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return 'org.laptop.AbiWordActivity'
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class UriListFileType(FileType):
+    """Represents the URI-list clipboard item format.
+   
+    Not to be confused with the single-URI UriFileType class.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['text/uri-list'])
 
     def _is_image(self):
+        """Determines whether this URI list represents an image.
+        
+        Called by the get_name and get_icon methods.  For this URI list to be
+        considered to represent an image, it must fulfil two criteria: (1) it
+        must have only one URI in it, and (2) the URI must end with an extension
+        indicating an image type (currently ".jpg", ".jpeg", ".gif", ".png", or
+        ".svg").
+        
+        returns True if there is one URI in the list and it represents an image,
+            False otherwise.
+        """
         uris = self._formats['text/uri-list'].get_data().split('\n')
         if len(uris) == 1:
             uri = urlparse.urlparse(uris[0])
@@ -216,66 +606,188 @@ class UriListFileType(FileType):
         return False
 
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         if self._is_image():
             return _('Image')
         else:
             return _('File')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         if self._is_image():
             return 'theme:object-image'
         else:
             return 'theme:stock-missing'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return ''
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class XoFileType(FileType):
+    """Represents the "xo" (OLPC package) clipboard item format.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     
     _types = set(['application/vnd.olpc-x-sugar'])
 
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Activity package')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:stock-missing'
 
     def get_preview(self):
+        """Returns an appropriate preview of the clipboard item data for this item format.
+        
+        XXX Currently returns an empty string.
+        
+        returns A string containing the item preview.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        returns A string containing the activity identifier. 
+        """
         return ''
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        XXX This subclass method is unnecessary; a single base class method
+        in the FileType class would be sufficient to handle all or most
+        subclasses, since the code is identical for all or most subclasses
+        anyway.
+        
+        returns True if this class handles the given MIME type, False otherwise.
+        """
         return mime_type in cls._types
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class UnknownFileType(FileType):
+    """Represents an unknown clipboard item format.
+    
+    XXX This class's name is misleading; it represents a clipboard item format
+    and not a file type per se.
+    """
     def get_name(self):
+        """Returns a localized human-readable name for this clipboard item format.
+        
+        Since this clipboard item format is unknown, the format name will be
+        simply "Object" or something to that effect.
+        
+        returns A localized string containing the clipboard item format name.
+        """
         return _('Object')
 
     def get_icon(self):
+        """XXX Returns a "tag" to be used to get an icon for this clipboard item format (I think).
+        
+        returns XXX A string "tag" to be used to get the icon for this clipboard
+            item format (I think).
+        """
         return 'theme:stock-missing'
 
     def get_preview(self):
+        """Returns a "preview" for this clipboard item format.
+        
+        Since this clipboard item format is unknown, there can be no preview for
+        it, so the "preview" will be an empty string.
+        
+        returns An empty string, since there can be no preview for an unknown
+            clipboard item format.
+        """
         return ''
 
     def get_activity(self):
+        """Returns the activity identifier associated with this clipboard item format.
+        
+        Since this clipboard item format is unknown, there can be no activity
+        associated with it, so the activity identifier will be an empty string.
+        
+        returns A string containing the activity identifier (an empty string in
+            this case).
+        """
         return ''
         
     def matches_mime_type(cls, mime_type):
+        """Class method to determine whether this class handles a given MIME type.
+        
+        mime_type -- A string containing the MIME type.
+        
+        Always returns true, since UnknownFileType is the clipboard item format
+        class of last resort and must be used if no other class handles the
+        given MIME type.
+        
+        returns True if this class handles the given MIME type (always true in
+            this case).
+        """
         return true
+        
     matches_mime_type = classmethod(matches_mime_type)
 
+    
 class TypeRegistry:
+    """Represents a registry of all clipboard item formats.
+    
+    There will be one single global instantiation of this object, accessible via
+    the global typeregistry.get_instance method.
+    """
     def __init__(self):
+        """Initializes the registry.
+        """
         self._types = []
         self._types.append(PdfFileType)
         self._types.append(MsWordFileType)
@@ -290,6 +802,26 @@ class TypeRegistry:
         self._types.append(XoFileType)
     
     def get_type(self, formats):
+        """Returns a matching clipboard item format object for the passed-in clipboard data.
+        
+        formats -- A dictionary of key-value pairs where the keys are MIME type
+            strings and the data values are the clipboard data in each
+            respective format.
+        
+        A reference to the given clipboard data format dictionary is stored
+        within the returned object for possible use later.
+        
+        XXX The order of the clipboard item formats in the TypeRegistry object's
+        internal list matters.  For example, if clipboard item data is available
+        in both MS Word and OO Text formats, the MS Word type will currently be
+        matched first, and therefore an MsWordFileType object will be returned.
+        Is this really what is desired?  The ordering should definitely be given
+        some thought.
+        
+        returns A clipboard item format object of a type matching one of the
+            MIME type keys in the formats dictionary, or an UnknownFileType
+            object if none of the other types is appropriate.
+        """
         for file_type in self._types:
             for format, data in formats.iteritems():
                 if file_type.matches_mime_type(format):
@@ -299,6 +831,14 @@ class TypeRegistry:
     
 _type_registry = None
 def get_instance():
+    """Returns the global clipboard item format registry object (global method).
+    
+    Returns a reference to the global clipboard item format registry object,
+    instantiating it first if necessary.
+    
+    returns A TypeRegistry object representing the global clipboard item format
+        registry.
+    """
     global _type_registry
     if not _type_registry:
         _type_registry = TypeRegistry()