Current File : //usr/lib/calibre/calibre/ebooks/oeb/transforms/page_margin.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'
import numbers
from collections import Counter
from calibre.ebooks.oeb.base import barename, XPath
from polyglot.builtins import iteritems
class RemoveAdobeMargins:
'''
Remove margins specified in Adobe's page templates.
'''
def __call__(self, oeb, log, opts):
self.oeb, self.opts, self.log = oeb, opts, log
for item in self.oeb.manifest:
if item.media_type in {
'application/vnd.adobe-page-template+xml', 'application/vnd.adobe.page-template+xml',
'application/adobe-page-template+xml', 'application/adobe.page-template+xml',
} and hasattr(item.data, 'xpath'):
self.log('Removing page margins specified in the'
' Adobe page template')
for elem in item.data.xpath(
'//*[@margin-bottom or @margin-top '
'or @margin-left or @margin-right]'):
for margin in ('left', 'right', 'top', 'bottom'):
attr = 'margin-'+margin
elem.attrib.pop(attr, None)
class NegativeTextIndent(Exception):
pass
class RemoveFakeMargins:
'''
Remove left and right margins from paragraph/divs if the same margin is specified
on almost all the elements at that level.
Must be called only after CSS flattening
'''
def __call__(self, oeb, log, opts):
if not opts.remove_fake_margins:
return
self.oeb, self.log, self.opts = oeb, log, opts
stylesheet = None
self.levels = {}
self.stats = {}
self.selector_map = {}
stylesheet = self.oeb.manifest.main_stylesheet
if stylesheet is None:
return
self.log('Removing fake margins...')
stylesheet = stylesheet.data
from css_parser.css import CSSRule
for rule in stylesheet.cssRules.rulesOfType(CSSRule.STYLE_RULE):
self.selector_map[rule.selectorList.selectorText] = rule.style
self.find_levels()
for level in self.levels:
try:
self.process_level(level)
except NegativeTextIndent:
self.log.debug('Negative text indent detected at level '
' %s, ignoring this level'%level)
def get_margins(self, elem):
cls = elem.get('class', None)
if cls:
style = self.selector_map.get('.'+cls, None)
if style:
try:
ti = style['text-indent']
except:
pass
else:
if ((hasattr(ti, 'startswith') and ti.startswith('-')) or
isinstance(ti, numbers.Number) and ti < 0):
raise NegativeTextIndent()
return style.marginLeft, style.marginRight, style
return '', '', None
def process_level(self, level):
elems = self.levels[level]
self.stats[level+'_left'] = Counter()
self.stats[level+'_right'] = Counter()
for elem in elems:
lm, rm = self.get_margins(elem)[:2]
self.stats[level+'_left'][lm] += 1
self.stats[level+'_right'][rm] += 1
self.log.debug(level, ' left margin stats:', self.stats[level+'_left'])
self.log.debug(level, ' right margin stats:', self.stats[level+'_right'])
remove_left = self.analyze_stats(self.stats[level+'_left'])
remove_right = self.analyze_stats(self.stats[level+'_right'])
if remove_left:
mcl = self.stats[level+'_left'].most_common(1)[0][0]
self.log('Removing level %s left margin of:'%level, mcl)
if remove_right:
mcr = self.stats[level+'_right'].most_common(1)[0][0]
self.log('Removing level %s right margin of:'%level, mcr)
if remove_left or remove_right:
for elem in elems:
lm, rm, style = self.get_margins(elem)
if remove_left and lm == mcl:
style.removeProperty('margin-left')
if remove_right and rm == mcr:
style.removeProperty('margin-right')
def find_levels(self):
def level_of(elem, body):
ans = 1
while elem.getparent() is not body:
ans += 1
elem = elem.getparent()
return ans
paras = XPath('descendant::h:p|descendant::h:div')
for item in self.oeb.spine:
body = XPath('//h:body')(item.data)
if not body:
continue
body = body[0]
for p in paras(body):
level = level_of(p, body)
level = '%s_%d'%(barename(p.tag), level)
if level not in self.levels:
self.levels[level] = []
self.levels[level].append(p)
remove = set()
for k, v in iteritems(self.levels):
num = len(v)
self.log.debug('Found %d items of level:'%num, k)
level = int(k.split('_')[-1])
tag = k.split('_')[0]
if tag == 'p' and num < 25:
remove.add(k)
if tag == 'div':
if level > 2 and num < 25:
remove.add(k)
elif level < 3:
# Check each level < 3 element and only keep those
# that have many child paras
for elem in list(v):
children = len(paras(elem))
if children < 5:
v.remove(elem)
for k in remove:
self.levels.pop(k)
self.log.debug('Ignoring level', k)
def analyze_stats(self, stats):
if not stats:
return False
mc = stats.most_common(1)
if len(mc) > 1:
return False
mc = mc[0]
most_common, most_common_count = mc
if not most_common or most_common == '0':
return False
total = sum(stats.values())
# True if greater than 95% of elements have the same margin
return most_common_count/total > 0.95
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