Edit Book: 2x speedup for inline spell checking. Useful if you are editing large HTML files (over 100KB in size).

Qt's text layout engine becomes very slow if we store arbitrary python
objects in QTextCharFormat classes. So refactor to not do that.

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

@@ -35,6 +35,7 @@ def editor_from_syntax(syntax, parent=None):
 
 SYNTAX_PROPERTY = QTextCharFormat.UserProperty
 SPELL_PROPERTY = SYNTAX_PROPERTY + 1
+SPELL_LOCALE_PROPERTY = SPELL_PROPERTY + 1
 
 class SyntaxTextCharFormat(QTextCharFormat):
 
@@ -47,4 +48,16 @@ class SyntaxTextCharFormat(QTextCharFormat):
             id(self), self.foreground().color().name(), self.fontItalic(), self.fontWeight() >= QFont.DemiBold)
     __str__ = __repr__
 
+class StoreLocale(object):
 
+    __slots__ = ('enabled',)
+
+    def __init__(self):
+        self.enabled = False
+
+    def __enter__(self):
+        self.enabled = True
+
+    def __exit__(self, *args):
+        self.enabled = False
+store_locale = StoreLocale()

src/calibre/gui2/tweak_book/editor/syntax/base.py

@@ -129,28 +129,32 @@ class SyntaxHighlighter(object):
         try:
             block = doc.findBlock(position)
             while block.isValid() and (block.position() < end_pos or force_next_highlight):
-                ud, new_ud = self.get_user_data(block)
+                formats, force_next_highlight = self.parse_single_block(block)
-                orig_state = ud.state
-                pblock = block.previous()
-                if pblock.isValid():
-                    start_state = pblock.userData()
-                    if start_state is None:
-                        start_state = self.user_data_factory().state
-                    else:
-                        start_state = start_state.state.copy()
-                else:
-                    start_state = self.user_data_factory().state
-                ud.clear(state=start_state)  # Ensure no stale user data lingers
-                formats = []
-                for i, num, fmt in run_loop(ud, self.state_map, self.formats, unicode(block.text())):
-                    if fmt is not None:
-                        formats.append((i, num, fmt))
                 self.apply_format_changes(doc, block, formats)
-                force_next_highlight = new_ud or ud.state != orig_state
                 block = block.next()
         finally:
             doc.contentsChange.connect(self.reformat_blocks)
 
+    def parse_single_block(self, block):
+        ud, new_ud = self.get_user_data(block)
+        orig_state = ud.state
+        pblock = block.previous()
+        if pblock.isValid():
+            start_state = pblock.userData()
+            if start_state is None:
+                start_state = self.user_data_factory().state
+            else:
+                start_state = start_state.state.copy()
+        else:
+            start_state = self.user_data_factory().state
+        ud.clear(state=start_state)  # Ensure no stale user data lingers
+        formats = []
+        for i, num, fmt in run_loop(ud, self.state_map, self.formats, unicode(block.text())):
+            if fmt is not None:
+                formats.append((i, num, fmt))
+        force_next_highlight = new_ud or ud.state != orig_state
+        return formats, force_next_highlight
+
     def reformat_block(self, block):
         if block.isValid():
             self.reformat_blocks(block.position(), 0, 1)

src/calibre/gui2/tweak_book/editor/syntax/html.py

@@ -16,7 +16,7 @@ from calibre.ebooks.oeb.polish.spell import html_spell_tags, xml_spell_tags
 from calibre.spell.dictionary import parse_lang_code
 from calibre.spell.break_iterator import split_into_words_and_positions
 from calibre.gui2.tweak_book import dictionaries, tprefs
-from calibre.gui2.tweak_book.editor import SyntaxTextCharFormat, SPELL_PROPERTY
+from calibre.gui2.tweak_book.editor import SyntaxTextCharFormat, SPELL_PROPERTY, SPELL_LOCALE_PROPERTY, store_locale
 from calibre.gui2.tweak_book.editor.syntax.base import SyntaxHighlighter, run_loop
 from calibre.gui2.tweak_book.editor.syntax.css import (
     create_formats as create_css_formats, state_map as css_state_map, CSSState, CSSUserData)
@@ -235,9 +235,12 @@ def check_spelling(text, tpos, tlen, fmt, locale, sfmt):
         if recognized:
             split_ans.append((length, fmt))
         else:
-            wsfmt = SyntaxTextCharFormat(sfmt)
+            if store_locale.enabled:
-            wsfmt.setProperty(SPELL_PROPERTY, (ctext[start:ppos], locale))
+                s = SyntaxTextCharFormat(sfmt)
-            split_ans.append((length, wsfmt))
+                s.setProperty(SPELL_LOCALE_PROPERTY, locale)
+                split_ans.append((length, s))
+            else:
+                split_ans.append((length, sfmt))
     if ppos < tlen:
         split_ans.append((tlen - ppos, fmt))
     return split_ans
@@ -486,6 +489,7 @@ def create_formats(highlighter, add_css=True):
     f.setFontWeight(QFont.Bold)
     if add_css:
         formats['css_sub_formats'] = create_css_formats(highlighter)
+    formats['spell'].setProperty(SPELL_PROPERTY, True)
     return formats
 
 

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

@@ -18,7 +18,7 @@ from PyQt4.Qt import (
 
 from calibre import prepare_string_for_xml, xml_entity_to_unicode
 from calibre.gui2.tweak_book import tprefs, TOP
-from calibre.gui2.tweak_book.editor import SYNTAX_PROPERTY, SPELL_PROPERTY
+from calibre.gui2.tweak_book.editor import SYNTAX_PROPERTY, SPELL_PROPERTY, SPELL_LOCALE_PROPERTY, store_locale
 from calibre.gui2.tweak_book.editor.themes import get_theme, theme_color, theme_format
 from calibre.gui2.tweak_book.editor.syntax.base import SyntaxHighlighter
 from calibre.gui2.tweak_book.editor.syntax.html import HTMLHighlighter, XMLHighlighter
@@ -427,7 +427,7 @@ class TextEdit(PlainTextEdit):
         block = c.block()
         while block.isValid():
             for r in block.layout().additionalFormats():
-                if r.format.property(SPELL_PROPERTY).toPyObject() is not None:
+                if r.format.property(SPELL_PROPERTY).toBool():
                     if not from_cursor or block.position() + r.start + r.length > c.position():
                         c.setPosition(block.position() + r.start)
                         c.setPosition(c.position() + r.length, c.KeepAnchor)
@@ -568,26 +568,42 @@ class TextEdit(PlainTextEdit):
                 return False
         return QPlainTextEdit.event(self, ev)
 
+    def text_for_range(self, block, r):
+        c = self.textCursor()
+        c.setPosition(block.position() + r.start)
+        c.setPosition(c.position() + r.length, c.KeepAnchor)
+        return unicode(c.selectedText())
+
+    def spellcheck_locale_for_cursor(self, c):
+        with store_locale:
+            formats = self.highlighter.parse_single_block(c.block())[0]
+        pos = c.positionInBlock()
+        for i, num, fmt in formats:
+            if i <= pos < i + num and fmt.property(SPELL_PROPERTY).toBool():
+                return fmt.property(SPELL_LOCALE_PROPERTY).toPyObject()
+
     def recheck_word(self, word, locale):
         c = self.textCursor()
         c.movePosition(c.Start)
         block = c.block()
         while block.isValid():
             for r in block.layout().additionalFormats():
-                x = r.format.property(SPELL_PROPERTY).toPyObject()
+                if r.format.property(SPELL_PROPERTY).toBool() and self.text_for_range(block, r) == word:
-                if x is not None and word == x[0]:
                     self.highlighter.reformat_block(block)
                     break
             block = block.next()
 
     # Tooltips {{{
-    def syntax_format_for_cursor(self, cursor):
+    def syntax_range_for_cursor(self, cursor):
         if cursor.isNull():
             return
         pos = cursor.positionInBlock()
         for r in cursor.block().layout().additionalFormats():
             if r.start <= pos < r.start + r.length and r.format.property(SYNTAX_PROPERTY).toBool():
-                return r.format
+                return r
+
+    def syntax_format_for_cursor(self, cursor):
+        return getattr(self.syntax_range_for_cursor(cursor), 'format', None)
 
     def show_tooltip(self, ev):
         c = self.cursorForPosition(ev.pos())

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

@@ -383,10 +383,10 @@ class Editor(QMainWindow):
         m = QMenu(self)
         a = m.addAction
         c = self.editor.cursorForPosition(pos)
-        fmt = self.editor.syntax_format_for_cursor(c)
+        r = self.editor.syntax_range_for_cursor(c)
-        spell = fmt.property(SPELL_PROPERTY).toPyObject() if fmt is not None else None
+        if r.format.property(SPELL_PROPERTY).toBool():
-        if spell is not None:
+            word = self.editor.text_for_range(c.block(), r)
-            word, locale = spell
+            locale = self.editor.spellcheck_locale_for_cursor(c)
             orig_pos = c.position()
             c.setPosition(orig_pos - utf16_length(word))
             found = False