More work on CSS transformations

src/calibre/ebooks/css_transform_rules.py

@@ -4,13 +4,238 @@
 
 from __future__ import (unicode_literals, division, absolute_import,
                         print_function)
+from functools import partial
+import operator
 
+from cssutils.css import Property
 import regex
 
-REGEX_FLAGS = regex.VERSION1 | regex.UNICODE
+from calibre import force_unicode
+from calibre.ebooks import parse_css_length
+from calibre.ebooks.oeb.normalize_css import normalizers, safe_parser
+
+REGEX_FLAGS = regex.VERSION1 | regex.UNICODE | regex.IGNORECASE
 
 def compile_pat(pat):
     return regex.compile(pat, flags=REGEX_FLAGS)
 
-def parse_length(raw):
-    raise NotImplementedError('TODO: implement this')
+def all_properties(decl):
+    ' This is needed because CSSStyleDeclaration.getProperties(None, all=True) does not work and is slower than it needs to be. '
+    for item in decl.seq:
+        p = item.value
+        if isinstance(p, Property):
+            yield p
+
+class StyleDeclaration(object):
+
+    def __init__(self, css_declaration):
+        self.css_declaration = css_declaration
+        self.expanded_properties = {}
+        self.changed = False
+
+    def __iter__(self):
+        dec = self.css_declaration
+        for p in all_properties(dec):
+            if isinstance(p, Property):
+                n = normalizers.get(p.name)
+                if n is None:
+                    yield p, None
+                else:
+                    if p not in self.expanded_properties:
+                        self.expanded_properties[p] = [Property(k, v, p.literalpriority) for k, v in n(p.name, p.propertyValue).iteritems()]
+                    for ep in self.expanded_properties[p]:
+                        yield ep, p
+
+    def expand_property(self, parent_prop):
+        props = self.expanded_properties.pop(parent_prop, None)
+        if props is None:
+            return
+        dec = self.css_declaration
+        seq = dec._tempSeq()
+        for item in dec.seq:
+            if item.value is parent_prop:
+                for c in props:
+                    c.parent = dec
+                    seq.append(c, 'Property')
+            else:
+                seq.appendItem(item)
+        dec._setSeq(seq)
+
+    def remove_property(self, prop, parent_prop):
+        if parent_prop is not None:
+            self.expand_property(parent_prop)
+        dec = self.css_declaration
+        seq = dec._tempSeq()
+        for item in dec.seq:
+            if item.value is not prop:
+                seq.appendItem(item)
+        dec._setSeq(seq)
+        self.changed = True
+
+    def change_property(self, prop, parent_prop, val):
+        if parent_prop is not None:
+            self.expand_property(parent_prop)
+        prop.value = val
+        self.changed = True
+
+    def append_properties(self, props):
+        if props:
+            self.changed = True
+            for prop in props:
+                self.css_declaration.setProperty(Property(prop.name, prop.value, prop.literalpriority, self.css_declaration))
+
+    def __str__(self):
+        return force_unicode(self.css_declaration.cssText, 'utf-8')
+
+operator_map = {'==':'eq', '<=':'le', '<':'lt', '>=':'ge', '>':'gt', '-':'sub', '+': 'add', '*':'mul', '/':'truediv'}
+
+def unit_convert(value, unit, dpi=96.0, body_font_size=12):
+    result = None
+    if unit == 'px':
+        result = value * 72.0 / dpi
+    elif unit == 'in':
+        result = value * 72.0
+    elif unit == 'pt':
+        result = value
+    elif unit == 'pc':
+        result = value * 12.0
+    elif unit == 'mm':
+        result = value * 2.8346456693
+    elif unit == 'cm':
+        result = value * 28.346456693
+    elif unit == 'rem':
+        result = value * body_font_size
+    elif unit == 'q':
+        result = value * 0.708661417325
+    return result
+
+def parse_css_length_or_number(raw, default_unit='px'):
+    if isinstance(raw, (int, long, float)):
+        return raw, default_unit
+    try:
+        return float(raw), default_unit
+    except Exception:
+        return parse_css_length(raw)
+
+def numeric_match(value, unit, pts, op, raw):
+    try:
+        v, u = parse_css_length_or_number(raw)
+    except Exception:
+        return False
+    if v is None:
+        return False
+    if unit is None or u is None or unit == u:
+        return op(v, value)
+    if pts is None:
+        return False
+    p = unit_convert(v, u)
+    if p is None:
+        return False
+    return op(p, pts)
+
+def transform_number(val, op, raw):
+    try:
+        v, u = parse_css_length_or_number(raw)
+    except Exception:
+        return raw
+    if v is None:
+        return raw
+    v = op(v, val)
+    if int(v) == v:
+        v = int(v)
+    return str(v) + u
+
+class Rule(object):
+
+    def __init__(self, property='color', match_type='*', query='', action='remove', action_data=''):
+        self.property_name = property.lower()
+        self.action, self.action_data = action, action_data
+        if self.action == 'append':
+            decl = safe_parser().parseStyle(self.action_data)
+            self.appended_properties = list(all_properties(decl))
+        elif self.action in '+-/*':
+            self.action_operator = partial(transform_number, float(self.action_data), getattr(operator, operator_map[self.action]))
+        if match_type == 'is':
+            self.property_matches = lambda x: x.lower() == query
+        elif match_type == '*':
+            self.property_matches = lambda x: True
+        elif 'matches' in match_type:
+            q = compile_pat(query)
+            if match_type.startswith('not_'):
+                self.property_matches = lambda x: q.match(x) is None
+            else:
+                self.property_matches = lambda x: q.match(x) is not None
+        else:
+            value, unit = parse_css_length_or_number(query, default_unit=None)
+            op = getattr(operator, operator_map[match_type])
+            pts = unit_convert(value, unit)
+            self.property_matches = partial(numeric_match, value, unit, pts, op)
+
+    def process_declaration(self, declaration):
+        oval, declaration.changed = declaration.changed, False
+        for prop, parent_prop in declaration:
+            if prop.name == self.property_name and self.property_matches(prop.value):
+                if self.action == 'remove':
+                    declaration.remove_property(prop, parent_prop)
+                elif self.action == 'change':
+                    declaration.change_property(prop, parent_prop, self.action_data)
+                elif self.action == 'append':
+                    declaration.append_properties(self.appended_properties)
+                else:
+                    val = prop.value
+                    nval = self.action_operator(val)
+                    if val != nval:
+                        declaration.change_property(prop, parent_prop, nval)
+        changed = declaration.changed
+        declaration.changed = oval or changed
+        return changed
+
+def test():  # {{{
+    import unittest
+
+    class TestTransforms(unittest.TestCase):
+        longMessage = True
+        maxDiff = None
+        ae = unittest.TestCase.assertEqual
+
+        def test_matching(self):
+
+            def apply_rule(style, **rule):
+                r = Rule(**rule)
+                decl = StyleDeclaration(safe_parser().parseStyle(style))
+                r.process_declaration(decl)
+                return str(decl)
+
+            def m(match_type='*', query=''):
+                self.ae(ecss, apply_rule(css, property=prop, match_type=match_type, query=query))
+
+            prop = 'color'
+            css, ecss = 'color: red; margin: 0', 'margin: 0'
+            m('*')
+            m('is', 'red')
+            m('matches', 'R.d')
+            m('not_matches', 'blue')
+            ecss = css.replace('; ', ';\n')
+            m('is', 'blue')
+
+            prop = 'margin-top'
+            css, ecss = 'color: red; margin-top: 10', 'color: red'
+            m('*')
+            m('==', '10')
+            m('<=', '10')
+            m('>=', '10')
+            m('<', '11')
+            m('>', '9')
+            css, ecss = 'color: red; margin-top: 1mm', 'color: red'
+            m('==', '1')
+            m('==', '1mm')
+            m('==', '4q')
+            ecss = css.replace('; ', ';\n')
+            m('==', '1pt')
+
+    tests = unittest.defaultTestLoader.loadTestsFromTestCase(TestTransforms)
+    unittest.TextTestRunner(verbosity=4).run(tests)
+
+if __name__ == '__main__':
+    test()
+# }}}

src/calibre/gui2/css_transform_rules.py

@@ -10,7 +10,8 @@ from PyQt5.Qt import (
     QWidget, QVBoxLayout, QHBoxLayout, QLabel, QComboBox, QLineEdit, QListWidgetItem
 )
 
-from calibre.ebooks.css_transform_rules import compile_pat, parse_length
+from calibre.ebooks.css_transform_rules import compile_pat, parse_css_length_or_number
+from calibre.ebooks.oeb.normalize_css import SHORTHAND_DEFAULTS
 from calibre.gui2 import error_dialog, elided_text
 from calibre.gui2.tag_mapper import RuleEditDialog as RuleEditDialogBase, Rules as RulesBase
 
@@ -27,13 +28,15 @@ class RuleEdit(QWidget):  # {{{
     ))
 
     MATCH_TYPE_MAP = OrderedDict((
-        ('==', _('is')),
+        ('is', _('is')),
+        ('*', _('is any value')),
+        ('matches', _('matches pattern')),
+        ('not_matches', _('does not match pattern'))
+        ('==', _('is the same length as')),
         ('<', _('is less than')),
         ('>', _('is greater than')),
         ('<=', _('is less than or equal to')),
         ('>=', _('is greater than or equal to')),
-        ('matches', _('matches pattern')),
-        ('not_matches', _('does not match pattern'))
     ))
 
     def __init__(self, parent=None):
@@ -55,7 +58,9 @@ class RuleEdit(QWidget):  # {{{
                 self.preamble = w = QLabel(_('If the &property:'))
             elif clause == '{property}':
                 self.property = w = QLineEdit(self)
-                w.setToolTip(_('The name of a CSS property, for example: font-size\n'))
+                w.setToolTip(_('The name of a CSS property, for example: font-size\n'
+                               'Do not use shorthand properties, they will not work.\n'
+                               'For instance use margin-top, not margin.'))
             elif clause == '{match_type}':
                 self.match_type = w = QComboBox(self)
                 for action, text in self.MATCH_TYPE_MAP.iteritems():
@@ -97,17 +102,20 @@ class RuleEdit(QWidget):  # {{{
         self.action_data.setVisible(r['action'] != 'remove')
         tt = _('The CSS property value')
         mt = r['match_type']
+        self.query.setVisible(mt != '*')
         if 'matches' in mt:
             tt = _('A regular expression')
         elif mt in '< > <= >='.split():
             tt = _('Either a CSS length, such as 10pt or a unit less number. If a unitless'
-                   ' number is used it will compared with the CSS value using whatever unit'
-                   ' the value has.')
+                   ' number is used it will be compared with the CSS value using whatever unit'
+                   ' the value has. Note that comparison automatically converts units, except'
+                   ' for relative units like percentage or em, for which comparison fails'
+                   ' if the units are different.')
         self.query.setToolTip(tt)
         tt = ''
         ac = r['action']
         if ac == 'append':
-            tt = _('CSS properties for to add to the rule that contains the matching style. You'
+            tt = _('CSS properties to add to the rule that contains the matching style. You'
                    ' can specify more than one property, separated by semi-colons, for example:'
                    ' color:red; font-weight: bold')
         elif ac in '+=*/':
@@ -117,7 +125,7 @@ class RuleEdit(QWidget):  # {{{
     @property
     def rule(self):
         return {
-            'property':self.property.text().strip(),
+            'property':self.property.text().strip().lower(),
             'match_type': self.match_type.currentData(),
             'query': self.query.text().strip(),
             'action': self.action.currentData(),
@@ -138,11 +146,20 @@ class RuleEdit(QWidget):  # {{{
 
     def validate(self):
         rule = self.rule
-        if not rule['query']:
+        mt = rule['match_type']
+        if not rule['property']:
+            error_dialog(self, _('Property required'), _(
+                'You must specify a CSS property to match'), show=True)
+            return False
+        if rule['property'] in SHORTHAND_DEFAULTS:
+            error_dialog(self, _('Shorthand property not allowed'), _(
+                '{0} is a shorthand property. Use the full form of the property,'
+                ' for example, instead of font, use font-family, instead of margin, use margin-top, etc.'), show=True)
+            return False
+        if not rule['query'] and mt != '*':
             error_dialog(self, _('Query required'), _(
                 'You must specify a value for the CSS property to match'), show=True)
             return False
-        mt = rule['match_type']
         if 'matches' in mt:
             try:
                 compile_pat(rule['query'])
@@ -150,9 +167,11 @@ class RuleEdit(QWidget):  # {{{
                 error_dialog(self, _('Query invalid'), _(
                     '%s is not a valid regular expression') % rule['query'], show=True)
                 return False
-        elif mt in '< > <= >='.split():
+        elif mt in '< > <= >= =='.split():
             try:
-                parse_length(rule['query'])
+                num = parse_css_length_or_number(rule['query'])[0]
+                if num is None:
+                    raise Exception('not a number')
             except Exception:
                 error_dialog(self, _('Query invalid'), _(
                     '%s is not a valid length or number') % rule['query'], show=True)