#see license.txt for license details

#history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/lib/styles.py

__version__='3.3.0'

__doc__='''Classes for ParagraphStyle and similar things.

A style is a collection of attributes, but with some extra features

to allow 'inheritance' from a parent, and to ensure nobody makes

changes after construction.

ParagraphStyle shows all the attributes available for formatting

paragraphs.

getSampleStyleSheet()  returns a stylesheet you can use for initial

development, with a few basic heading and text styles.

'''

__all__=(

        'PropertySet',

        'ParagraphStyle',

        'LineStyle',

        'ListStyle',

        'StyleSheet1',

        'getSampleStyleSheet',

        )

from reportlab.lib.colors import white, black

from reportlab.lib.enums import TA_LEFT, TA_CENTER

from reportlab.lib.fonts import tt2ps

from reportlab.rl_config import canvas_basefontname as _baseFontName, \

                                baseUnderlineProportion as _baseUnderlineProportion, \

                                spaceShrinkage

_baseFontNameB = tt2ps(_baseFontName,1,0)

_baseFontNameI = tt2ps(_baseFontName,0,1)

_baseFontNameBI = tt2ps(_baseFontName,1,1)

###########################################################

# This class provides an 'instance inheritance'

# mechanism for its descendants, simpler than acquisition

# but not as far-reaching

###########################################################

class PropertySet:

    defaults = {}

    def __init__(self, name, parent=None, **kw):

        """When initialized, it copies the class defaults;

        then takes a copy of the attributes of the parent

        if any.  All the work is done in init - styles

        should cost little to use at runtime."""

        # step one - validate the hell out of it

        assert 'name' not in self.defaults, "Class Defaults may not contain a 'name' attribute"

        assert 'parent' not in self.defaults, "Class Defaults may not contain a 'parent' attribute"

        if parent:

            assert parent.__class__ == self.__class__, "Parent style %s must have same class as new style %s" % (parent.__class__.__name__,self.__class__.__name__)

        #step two

        self.name = name

        self.parent = parent

        self.__dict__.update(self.defaults)

        #step two - copy from parent if any.  Try to be

        # very strict that only keys in class defaults are

        # allowed, so they cannot inherit

        self.refresh()

        self._setKwds(**kw)

    def _setKwds(self,**kw):

        #step three - copy keywords if any

        for key, value in kw.items():

             self.__dict__[key] = value

    def __repr__(self):

        return "<%s '%s'>" % (self.__class__.__name__, self.name)

    def refresh(self):

        """re-fetches attributes from the parent on demand;

        use if you have been hacking the styles.  This is

        used by __init__"""

        if self.parent:

            for key, value in self.parent.__dict__.items():

                if (key not in ['name','parent']):

                    self.__dict__[key] = value

    def listAttrs(self, indent=''):

        print(indent + 'name =', self.name)

        print(indent + 'parent =', self.parent)

        keylist = list(self.__dict__.keys())

        keylist.sort()

        keylist.remove('name')

        keylist.remove('parent')

        for key in keylist:

            value = self.__dict__.get(key, None)

            print(indent + '%s = %s' % (key, value))

    def clone(self, name, parent=None, **kwds):

        r = self.__class__(name,parent)

        r.__dict__ = self.__dict__.copy()

        r.name = name

        r.parent = parent is None and self or parent

        r._setKwds(**kwds)

        return r

class ParagraphStyle(PropertySet):

    defaults = {

        'fontName':_baseFontName,

        'fontSize':10,

        'leading':12,

        'leftIndent':0,

        'rightIndent':0,

        'firstLineIndent':0,

        'alignment':TA_LEFT,

        'spaceBefore':0,

        'spaceAfter':0,

        'bulletFontName':_baseFontName,

        'bulletFontSize':10,

        'bulletIndent':0,

        #'bulletColor':black,

        'textColor': black,

        'backColor':None,

        'wordWrap':None,        #None means do nothing special

                                #CJK use Chinese Line breaking

                                #LTR RTL use left to right / right to left

                                #with support from pyfribi2 if available

        'borderWidth': 0,

        'borderPadding': 0,

        'borderColor': None,

        'borderRadius': None,

        'allowWidows': 1,

        'allowOrphans': 0,

        'textTransform':None,   #uppercase lowercase (captitalize not yet) or None or absent

        'endDots':None,         #dots on the last line of left/right justified paras

                                #string or object with text and optional fontName, fontSize, textColor & backColor

                                #dy

        'splitLongWords':1,     #make best efforts to split long words

        'underlineProportion': _baseUnderlineProportion,    #set to non-zero to get proportional

        'bulletAnchor': 'start',    #where the bullet is anchored ie start, middle, end or numeric

        'justifyLastLine': 0,   #n allow justification on the last line for more than n words 0 means don't bother

        'justifyBreaks': 0,     #justify lines broken with <br/>

        'spaceShrinkage': spaceShrinkage,   #allow shrinkage of percentage of space to fit on line

        }

class LineStyle(PropertySet):

    defaults = {

        'width':1,

        'color': black

        }

    def prepareCanvas(self, canvas):

        """You can ask a LineStyle to set up the canvas for drawing

        the lines."""

        canvas.setLineWidth(1)

        #etc. etc.

class ListStyle(PropertySet):

    defaults = dict(

                leftIndent=18,

                rightIndent=0,

                bulletAlign='left',

                bulletType='1',

                bulletColor=black,

                bulletFontName='Helvetica',

                bulletFontSize=12,

                bulletOffsetY=0,

                bulletDedent='auto',

                bulletDir='ltr',

                bulletFormat=None,

                start=None,         #starting value for a list; if a list then the start sequence

                )

_stylesheet1_undefined = object()

class StyleSheet1:

    """

    This may or may not be used.  The idea is to:

    1. slightly simplify construction of stylesheets;

    2. enforce rules to validate styles when added

       (e.g. we may choose to disallow having both

       'heading1' and 'Heading1' - actual rules are

       open to discussion);

    3. allow aliases and alternate style lookup

       mechanisms

    4. Have a place to hang style-manipulation

       methods (save, load, maybe support a GUI

       editor)

    Access is via getitem, so they can be

    compatible with plain old dictionaries.

    """

    def __init__(self):

        self.byName = {}

        self.byAlias = {}

    def __getitem__(self, key):

        try:

            return self.byAlias[key]

        except KeyError:

            try:

                return self.byName[key]

            except KeyError:

                raise KeyError("Style '%s' not found in stylesheet" % key)

    def get(self,key,default=_stylesheet1_undefined):

        try:

            return self[key]

        except KeyError:

            if default!=_stylesheet1_undefined: return default

            raise

    def __contains__(self, key):

        return key in self.byAlias or key in self.byName

    def has_key(self,key):

        return key in self

    def add(self, style, alias=None):

        key = style.name

        if key in self.byName:

            raise KeyError("Style '%s' already defined in stylesheet" % key)

        if key in self.byAlias:

            raise KeyError("Style name '%s' is already an alias in stylesheet" % key)

        if alias:

            if alias in self.byName:

                raise KeyError("Style '%s' already defined in stylesheet" % alias)

            if alias in self.byAlias:

                raise KeyError("Alias name '%s' is already an alias in stylesheet" % alias)

        #passed all tests?  OK, add it

        self.byName[key] = style

        if alias:

            self.byAlias[alias] = style

    def list(self):

        styles = list(self.byName.items())

        styles.sort()

        alii = {}

        for (alias, style) in list(self.byAlias.items()):

            alii[style] = alias

        for (name, style) in styles:

            alias = alii.get(style, None)

            print(name, alias)

            style.listAttrs('    ')

            print()

def testStyles():

    pNormal = ParagraphStyle('Normal',None)

    pNormal.fontName = _baseFontName

    pNormal.fontSize = 12

    pNormal.leading = 14.4

    pNormal.listAttrs()

    print()

    pPre = ParagraphStyle('Literal', pNormal)

    pPre.fontName = 'Courier'

    pPre.listAttrs()

    return pNormal, pPre

def getSampleStyleSheet():

    """Returns a stylesheet object"""

    stylesheet = StyleSheet1()

    stylesheet.add(ParagraphStyle(name='Normal',

                                  fontName=_baseFontName,

                                  fontSize=10,

                                  leading=12)

                   )

    stylesheet.add(ParagraphStyle(name='BodyText',

                                  parent=stylesheet['Normal'],

                                  spaceBefore=6)

                   )

    stylesheet.add(ParagraphStyle(name='Italic',

                                  parent=stylesheet['BodyText'],

                                  fontName = _baseFontNameI)

                   )

    stylesheet.add(ParagraphStyle(name='Heading1',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameB,

                                  fontSize=18,

                                  leading=22,

                                  spaceAfter=6),

                   alias='h1')

    stylesheet.add(ParagraphStyle(name='Title',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameB,

                                  fontSize=18,

                                  leading=22,

                                  alignment=TA_CENTER,

                                  spaceAfter=6),

                   alias='title')

    stylesheet.add(ParagraphStyle(name='Heading2',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameB,

                                  fontSize=14,

                                  leading=18,

                                  spaceBefore=12,

                                  spaceAfter=6),

                   alias='h2')

    stylesheet.add(ParagraphStyle(name='Heading3',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameBI,

                                  fontSize=12,

                                  leading=14,

                                  spaceBefore=12,

                                  spaceAfter=6),

                   alias='h3')

    stylesheet.add(ParagraphStyle(name='Heading4',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameBI,

                                  fontSize=10,

                                  leading=12,

                                  spaceBefore=10,

                                  spaceAfter=4),

                   alias='h4')

    stylesheet.add(ParagraphStyle(name='Heading5',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameB,

                                  fontSize=9,

                                  leading=10.8,

                                  spaceBefore=8,

                                  spaceAfter=4),

                   alias='h5')

    stylesheet.add(ParagraphStyle(name='Heading6',

                                  parent=stylesheet['Normal'],

                                  fontName = _baseFontNameB,

                                  fontSize=7,

                                  leading=8.4,

                                  spaceBefore=6,

                                  spaceAfter=2),

                   alias='h6')

    stylesheet.add(ParagraphStyle(name='Bullet',

                                  parent=stylesheet['Normal'],

                                  firstLineIndent=0,

                                  spaceBefore=3),

                   alias='bu')

    stylesheet.add(ParagraphStyle(name='Definition',

                                  parent=stylesheet['Normal'],

                                  firstLineIndent=0,

                                  leftIndent=36,

                                  bulletIndent=0,

                                  spaceBefore=6,

                                  bulletFontName=_baseFontNameBI),

                   alias='df')

    stylesheet.add(ParagraphStyle(name='Code',

                                  parent=stylesheet['Normal'],

                                  fontName='Courier',

                                  fontSize=8,

                                  leading=8.8,

                                  firstLineIndent=0,

                                  leftIndent=36))

    stylesheet.add(ListStyle(name='UnorderedList',

                                parent=None,

                                leftIndent=18,

                                rightIndent=0,

                                bulletAlign='left',

                                bulletType='1',

                                bulletColor=black,

                                bulletFontName='Helvetica',

                                bulletFontSize=12,

                                bulletOffsetY=0,

                                bulletDedent='auto',

                                bulletDir='ltr',

                                bulletFormat=None,

                                #start='circle square blackstar sparkle disc diamond'.split(),

                                start=None,

                            ),

                   alias='ul')

    stylesheet.add(ListStyle(name='OrderedList',

                                parent=None,

                                leftIndent=18,

                                rightIndent=0,

                                bulletAlign='left',

                                bulletType='1',

                                bulletColor=black,

                                bulletFontName='Helvetica',

                                bulletFontSize=12,

                                bulletOffsetY=0,

                                bulletDedent='auto',

                                bulletDir='ltr',

                                bulletFormat=None,

                                #start='1 a A i I'.split(),

                                start=None,

                            ),

                   alias='ol')

    return stylesheet