#Copyright ReportLab Europe Ltd. 2000-2004 #see license.txt for license details #history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/lib/styles.py __version__=''' $Id: styles.py 2385 2004-06-17 15:26:05Z rgbecker $ ''' from reportlab.lib.colors import white, black from reportlab.lib.enums import TA_LEFT, TA_CENTER ########################################################### # 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 not self.defaults.has_key('name'), "Class Defaults may not contain a 'name' attribute" assert not self.defaults.has_key('parent'), "Class Defaults may not contain a 'parent' attribute" if parent: assert parent.__class__ == self.__class__, "Parent style must have same class as new style" #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() #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 = 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) class ParagraphStyle(PropertySet): defaults = { 'fontName':'Times-Roman', 'fontSize':10, 'leading':12, 'leftIndent':0, 'rightIndent':0, 'firstLineIndent':0, 'alignment':TA_LEFT, 'spaceBefore':0, 'spaceAfter':0, 'bulletFontName':'Times-Roman', 'bulletFontSize':10, 'bulletIndent':0, 'textColor': black, 'backColor':None } 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 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 has_key(self, key): if self.byAlias.has_key(key): return 1 elif self.byName.has_key(key): return 1 else: return 0 def add(self, style, alias=None): key = style.name if self.byName.has_key(key): raise KeyError, "Style '%s' already defined in stylesheet" % key if self.byAlias.has_key(key): raise KeyError, "Style name '%s' is already an alias in stylesheet" % key if alias: if self.byName.has_key(alias): raise KeyError, "Style '%s' already defined in stylesheet" % alias if self.byAlias.has_key(alias): 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 = self.byName.items() styles.sort() alii = {} for (alias, style) in 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 = 'Times-Roman' 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='Times-Roman', fontSize=10, leading=12) ) stylesheet.add(ParagraphStyle(name='BodyText', parent=stylesheet['Normal'], spaceBefore=6) ) stylesheet.add(ParagraphStyle(name='Italic', parent=stylesheet['BodyText'], fontName = 'Times-Italic') ) stylesheet.add(ParagraphStyle(name='Heading1', parent=stylesheet['Normal'], fontName = 'Times-Bold', fontSize=18, leading=22, spaceAfter=6), alias='h1') stylesheet.add(ParagraphStyle(name='Title', parent=stylesheet['Normal'], fontName = 'Times-Bold', fontSize=18, leading=22, alignment=TA_CENTER, spaceAfter=6), alias='title') stylesheet.add(ParagraphStyle(name='Heading2', parent=stylesheet['Normal'], fontName = 'Times-Bold', fontSize=14, leading=18, spaceBefore=12, spaceAfter=6), alias='h2') stylesheet.add(ParagraphStyle(name='Heading3', parent=stylesheet['Normal'], fontName = 'Times-BoldItalic', fontSize=12, leading=14, spaceBefore=12, spaceAfter=6), alias='h3') 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='Times-BoldItalic'), alias='df') stylesheet.add(ParagraphStyle(name='Code', parent=stylesheet['Normal'], fontName='Courier', fontSize=8, leading=8.8, firstLineIndent=0, leftIndent=36)) return stylesheet