Edit book: When right clicking on a class in a HTML file, add an option to rename the class throughout the book

manual/edit.rst

@@ -824,6 +824,10 @@ You can also hold down the :kbd:`Ctrl` key and click on any filename inside a li
 to open that file in the editor automatically. Similarly, :kbd:`Ctrl` clicking
 a class name will take you to the first style rule that matches the tag and class.
 
+Right clicking a class name in an HTML file will allow you to rename the class,
+changing all occurrences of the class throughout the book and all its
+stylesheets.
+
 .. _editor_auto_complete:
 
 Auto-complete

src/calibre/ebooks/oeb/polish/css.py

@@ -5,6 +5,7 @@
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
+import re
 from collections import defaultdict
 from functools import partial
 from operator import itemgetter
@@ -463,3 +464,55 @@ def add_stylesheet_links(container, name, text):
         head.append(link)
     pretty_xml_tree(head)
     return serialize(root, 'text/html')
+
+
+def rename_class_in_rule_list(css_rules, old_name, new_name):
+    pat = re.compile(rf'\b{re.escape(old_name)}\b')
+    changed = False
+    for rule in css_rules:
+        if rule.type == rule.STYLE_RULE:
+            old = rule.selectorText
+            q = pat.sub(new_name, old)
+            if q != old:
+                changed = True
+                rule.selectorText = q
+        elif hasattr(rule, 'cssRules'):
+            if rename_class_in_rule_list(rule.cssRules, old_name, new_name):
+                changed = True
+    return changed
+
+
+def rename_class_in_doc(container, root, old_name, new_name):
+    changed = False
+    pat = re.compile(rf'\b{re.escape(old_name)}\b')
+    for elem in root.xpath('//*[@class]'):
+        old = elem.get('class')
+        if old:
+            new = pat.sub(new_name, old)
+            if new != old:
+                changed = True
+                elem.set('class', new)
+    for style in root.xpath('//*[local-name()="style"]'):
+        if style.get('type', 'text/css') == 'text/css' and style.text:
+            sheet = container.parse_css(style.text)
+            if rename_class_in_rule_list(sheet.cssRules, old_name, new_name):
+                changed = True
+                style.text = force_unicode(sheet.cssText, 'utf-8')
+    return changed
+
+
+def rename_class(container, old_name, new_name):
+    changed = False
+    if not old_name or old_name == new_name:
+        return changed
+    for sheet_name in container.manifest_items_of_type(lambda mt: mt in OEB_STYLES):
+        sheet = container.parsed(sheet_name)
+        if rename_class_in_rule_list(sheet.cssRules, old_name, new_name):
+            container.dirty(sheet_name)
+            changed = True
+    for doc_name in container.manifest_items_of_type(lambda mt: mt in OEB_DOCS):
+        doc = container.parsed(doc_name)
+        if rename_class_in_doc(container, doc, old_name, new_name):
+            container.dirty(doc_name)
+            changed = True
+    return changed

src/calibre/gui2/tweak_book/boss.py

@@ -25,7 +25,7 @@ from calibre.ebooks.oeb.polish.container import (
 from calibre.ebooks.oeb.polish.cover import (
     mark_as_cover, mark_as_titlepage, set_cover
 )
-from calibre.ebooks.oeb.polish.css import filter_css
+from calibre.ebooks.oeb.polish.css import filter_css, rename_class
 from calibre.ebooks.oeb.polish.main import SUPPORTED, tweak_polish
 from calibre.ebooks.oeb.polish.pretty import fix_all_html, pretty_all
 from calibre.ebooks.oeb.polish.replace import (
@@ -956,6 +956,22 @@ class Boss(QObject):
             else:
                 ed.action_triggered(action)
 
+    def rename_class(self, class_name):
+        self.commit_all_editors_to_container()
+        text, ok = QInputDialog.getText(self.gui, _('New class name'), _(
+            'Rename the class {} to?').format(class_name))
+        if ok:
+            self.add_savepoint(_('Before: Rename {}').format(class_name))
+            with BusyCursor():
+                changed = rename_class(current_container(), class_name, text.strip())
+            if changed:
+                self.apply_container_update_to_gui()
+                self.show_current_diff()
+            else:
+                self.rewind_savepoint()
+                return info_dialog(self.gui, _('No matches'), _(
+                    'No class {} found to change').format(class_name), show=True)
+
     def set_semantics(self):
         self.commit_all_editors_to_container()
         c = current_container()
@@ -1609,6 +1625,8 @@ class Boss(QObject):
             editor.link_clicked.connect(self.editor_link_clicked)
         if hasattr(editor, 'class_clicked'):
             editor.class_clicked.connect(self.editor_class_clicked)
+        if hasattr(editor, 'rename_class'):
+            editor.rename_class.connect(self.rename_class)
         if getattr(editor, 'syntax', None) == 'html':
             editor.smart_highlighting_updated.connect(self.gui.live_css.sync_to_editor)
         if hasattr(editor, 'set_request_completion'):

src/calibre/gui2/tweak_book/editor/widget.py

@@ -23,7 +23,8 @@ from calibre.gui2.tweak_book import (
     editors, tprefs, update_mark_text_action
 )
 from calibre.gui2.tweak_book.editor import (
-    CSS_PROPERTY, LINK_PROPERTY, SPELL_PROPERTY, TAG_NAME_PROPERTY
+    CLASS_ATTRIBUTE_PROPERTY, CSS_PROPERTY, LINK_PROPERTY, SPELL_PROPERTY,
+    TAG_NAME_PROPERTY
 )
 from calibre.gui2.tweak_book.editor.help import help_url
 from calibre.gui2.tweak_book.editor.text import TextEdit
@@ -142,6 +143,7 @@ class Editor(QMainWindow):
     word_ignored = pyqtSignal(object, object)
     link_clicked = pyqtSignal(object)
     class_clicked = pyqtSignal(object)
+    rename_class = pyqtSignal(object)
     smart_highlighting_updated = pyqtSignal()
 
     def __init__(self, syntax, parent=None):
@@ -579,6 +581,12 @@ class Editor(QMainWindow):
             href = self.editor.text_for_range(origc.block(), origr)
             m.addAction(_('Open %s') % href, partial(self.link_clicked.emit, href))
 
+        if origr is not None and origr.format.property(CLASS_ATTRIBUTE_PROPERTY):
+            cls = self.editor.class_for_position(pos)
+            if cls:
+                class_name = cls['class']
+                m.addAction(_('Rename the class {}').format(class_name), partial(self.rename_class.emit, class_name))
+
         if origr is not None and (origr.format.property(TAG_NAME_PROPERTY) or origr.format.property(CSS_PROPERTY)):
             word = self.editor.text_for_range(origc.block(), origr)
             item_type = 'tag_name' if origr.format.property(TAG_NAME_PROPERTY) else 'css_property'