Application: gvSIG desktop » gvSIG scripting

"""CSSVariablesDeclaration

http://disruptive-innovations.com/zoo/cssvariables/#mozTocId496530

"""

__all__ = ['CSSVariablesDeclaration']

__docformat__ = 'restructuredtext'

__version__ = '$Id: cssstyledeclaration.py 1819 2009-08-01 20:52:43Z cthedot $'

from cssutils.prodparser import *

from cssutils.helper import normalize

from value import PropertyValue

import cssutils

import itertools

import xml.dom

class CSSVariablesDeclaration(cssutils.util._NewBase):

    """The CSSVariablesDeclaration interface represents a single block of

    variable declarations. 

    """

    def __init__(self, cssText=u'', parentRule=None, readonly=False):

        """

        :param cssText:

            Shortcut, sets CSSVariablesDeclaration.cssText

        :param parentRule:

            The CSS rule that contains this declaration block or

            None if this CSSVariablesDeclaration is not attached to a CSSRule.

        :param readonly:

            defaults to False

        Format::

            variableset

                : vardeclaration [ ';' S* vardeclaration ]* S*

                ;

            vardeclaration

                : varname ':' S* term

                ;

            varname

                : IDENT S*

                ;

        """

        super(CSSVariablesDeclaration, self).__init__()

        self._parentRule = parentRule

        self._vars = {}

        if cssText:

            self.cssText = cssText

        self._readonly = readonly

    def __repr__(self):

        return u"cssutils.css.%s(cssText=%r)" % (self.__class__.__name__,

                                                 self.cssText)

    def __str__(self):

        return u"<cssutils.css.%s object length=%r at 0x%x>" % (

                self.__class__.__name__,

                self.length,

                id(self))

    def __contains__(self, variableName):

        """Check if a variable is in variable declaration block.

        :param variableName:

            a string

        """

        return normalize(variableName) in self.keys()

    def __getitem__(self, variableName):

        """Retrieve the value of variable ``variableName`` from this 

        declaration.

        """

        return self.getVariableValue(variableName)

    def __setitem__(self, variableName, value):

        self.setVariable(variableName, value)

    def __delitem__(self, variableName):

        return self.removeVariable(variableName)

    def __iter__(self):

        """Iterator of names of set variables."""

        for name in self.keys():

            yield name

    def keys(self):

        """Analoguous to standard dict returns variable names which are set in

        this declaration."""

        return self._vars.keys()

    def _getCssText(self):

        """Return serialized property cssText."""

        return cssutils.ser.do_css_CSSVariablesDeclaration(self)

    def _setCssText(self, cssText):

        """Setting this attribute will result in the parsing of the new value

        and resetting of all the properties in the declaration block

        including the removal or addition of properties.

        :exceptions:

            - :exc:`~xml.dom.NoModificationAllowedErr`:

              Raised if this declaration is readonly or a property is readonly.

            - :exc:`~xml.dom.SyntaxErr`:

              Raised if the specified CSS string value has a syntax error and

              is unparsable.

        Format::

            variableset

            : vardeclaration [ ';' S* vardeclaration ]*

            ;

            vardeclaration

            : varname ':' S* term

            ;

            varname

            : IDENT S*

            ;

            expr

            : [ VARCALL | term ] [ operator [ VARCALL | term ] ]*

            ;

        """

        self._checkReadonly()

        vardeclaration = Sequence(

            PreDef.ident(),

            PreDef.char(u':', u':', toSeq=False, optional=True),

            #PreDef.S(toSeq=False, optional=True),

            Prod(name=u'term', match=lambda t, v: True,

                 toSeq=lambda t, tokens: (u'value', 

                                          PropertyValue(itertools.chain([t], 

                                                                        tokens), 

                                          parent=self)

                 )

            )

        )

        prods = Sequence(vardeclaration,                         

                         Sequence(PreDef.S(optional=True),

                                  PreDef.char(u';', u';', toSeq=False, optional=True),

                                  PreDef.S(optional=True),

                                  vardeclaration,

                                  minmax=lambda: (0, None)),

                         PreDef.S(optional=True),

                         PreDef.char(u';', u';', toSeq=False, optional=True)

                         )

        # parse

        wellformed, seq, store, notused = \

            ProdParser().parse(cssText, 

                               u'CSSVariableDeclaration',

                               prods,

                               emptyOk=True)

        if wellformed:

            newseq = self._tempSeq()

            newvars = {}

            # seq contains only name: value pairs plus comments etc

            nameitem = None

            for item in seq:

                if u'IDENT' == item.type:

                    nameitem = item

                elif u'value' == item.type:

                    nname = normalize(nameitem.value)

                    if nname in newvars:

                        # replace var with same name

                        for i, it in enumerate(newseq):

                            if normalize(it.value[0]) == nname:

                                newseq.replace(i,

                                               (nameitem.value, item.value),

                                               'var',

                                               nameitem.line, nameitem.col)

                    else: 

                        # saved non normalized name for reserialization

                        newseq.append((nameitem.value, item.value), 

                                      'var',

                                      nameitem.line, nameitem.col)

#                    newseq.append((nameitem.value, item.value), 

#                                  'var',

#                                  nameitem.line, nameitem.col)

                    newvars[nname] = item.value

                else:

                    newseq.appendItem(item)

            self._setSeq(newseq)

            self._vars = newvars

            self.wellformed = True

    cssText = property(_getCssText, _setCssText,

        doc=u"(DOM) A parsable textual representation of the declaration "

            u"block excluding the surrounding curly braces.")

    def _setParentRule(self, parentRule):

        self._parentRule = parentRule

    parentRule = property(lambda self: self._parentRule, _setParentRule,

                          doc=u"(DOM) The CSS rule that contains this"

                              u" declaration block or None if this block"

                              u" is not attached to a CSSRule.")

    def getVariableValue(self, variableName):

        """Used to retrieve the value of a variable if it has been explicitly

        set within this variable declaration block.

        :param variableName:

            The name of the variable.

        :returns:

            the value of the variable if it has been explicitly set in this

            variable declaration block. Returns the empty string if the

            variable has not been set.

        """

        try:

            return self._vars[normalize(variableName)].cssText

        except KeyError, e:

            return u''

    def removeVariable(self, variableName):

        """Used to remove a variable if it has been explicitly set within this

        variable declaration block.

        :param variableName:

            The name of the variable.

        :returns:

            the value of the variable if it has been explicitly set for this

            variable declaration block. Returns the empty string if the

            variable has not been set.

        :exceptions:

            - :exc:`~xml.dom.NoModificationAllowedErr`:

              Raised if this declaration is readonly is readonly.

        """

        normalname = variableName

        try:

            r = self._vars[normalname]

        except KeyError, e:

            return u''

        else: 

            self.seq._readonly = False

            if normalname in self._vars:

                for i, x in enumerate(self.seq):

                    if x.value[0] == variableName:

                        del self.seq[i]

            self.seq._readonly = True

            del self._vars[normalname]

        return r.cssText

    def setVariable(self, variableName, value):

        """Used to set a variable value within this variable declaration block.

        :param variableName:

            The name of the CSS variable. 

        :param value:

            The new value of the variable, may also be a PropertyValue object.

        :exceptions:

            - :exc:`~xml.dom.SyntaxErr`:

              Raised if the specified value has a syntax error and is

              unparsable.

            - :exc:`~xml.dom.NoModificationAllowedErr`:

              Raised if this declaration is readonly or the property is

              readonly.

        """

        self._checkReadonly()

        # check name

        wellformed, seq, store, unused = \

            ProdParser().parse(normalize(variableName),

                               u'variableName',

                               Sequence(PreDef.ident()))

        if not wellformed:

            self._log.error(u'Invalid variableName: %r: %r'

                            % (variableName, value))

        else:

            # check value

            if isinstance(value, PropertyValue):

                v = value 

            else:

                v = PropertyValue(cssText=value, parent=self)

            if not v.wellformed:

                self._log.error(u'Invalid variable value: %r: %r'

                                % (variableName, value))

            else:

                # update seq

                self.seq._readonly = False

                variableName = normalize(variableName)

                if variableName in self._vars:

                    for i, x in enumerate(self.seq):

                        if x.value[0] == variableName:

                            self.seq.replace(i, 

                                      [variableName, v], 

                                      x.type, 

                                      x.line,

                                      x.col)

                            break

                else:

                    self.seq.append([variableName, v], 'var')                

                self.seq._readonly = True

                self._vars[variableName] = v

    def item(self, index):

        """Used to retrieve the variables that have been explicitly set in

        this variable declaration block. The order of the variables

        retrieved using this method does not have to be the order in which

        they were set. This method can be used to iterate over all variables

        in this variable declaration block.

        :param index:

            of the variable name to retrieve, negative values behave like

            negative indexes on Python lists, so -1 is the last element

        :returns:

            The name of the variable at this ordinal position. The empty

            string if no variable exists at this position.

        """

        try:

            return self.keys()[index]

        except IndexError:

            return u''

    length = property(lambda self: len(self._vars),

        doc=u"The number of variables that have been explicitly set in this"

            u" variable declaration block. The range of valid indices is 0"

            u" to length-1 inclusive.")