Load all syntax related code on demand

src/calibre/gui2/tweak_book/editor/smart/css.py

@@ -26,6 +26,6 @@ def find_rule(raw, rule_address):
             rules = getattr(r, 'rules', ())
     return ans
 
-class CSSSmarts(NullSmarts):
+class Smarts(NullSmarts):
     pass
 

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

@@ -269,7 +269,7 @@ def set_style_property(tag, property_name, value, editor):
         d.setProperty(property_name, value)
         c.insertText('"%s"' % css(d))
 
-class HTMLSmarts(NullSmarts):
+class Smarts(NullSmarts):
 
     def __init__(self, *args, **kwargs):
         NullSmarts.__init__(self, *args, **kwargs)

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

@@ -306,7 +306,7 @@ def create_formats(highlighter):
     return formats
 
 
-class CSSHighlighter(SyntaxHighlighter):
+class Highlighter(SyntaxHighlighter):
 
     state_map = state_map
     create_formats_func = create_formats

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

@@ -543,7 +543,7 @@ def create_formats(highlighter, add_css=True):
     return formats
 
 
-class HTMLHighlighter(SyntaxHighlighter):
+class Highlighter(SyntaxHighlighter):
 
     state_map = state_map
     create_formats_func = create_formats
@@ -553,7 +553,7 @@ class HTMLHighlighter(SyntaxHighlighter):
     def tag_ok_for_spell(self, name):
         return HTMLUserData.tag_ok_for_spell(name)
 
-class XMLHighlighter(HTMLHighlighter):
+class XMLHighlighter(Highlighter):
 
     state_map = xml_state_map
     spell_attributes = ('opf:file-as',)
@@ -576,7 +576,7 @@ def profile():
     raw = open(sys.argv[-2], 'rb').read().decode('utf-8')
     doc = QTextDocument()
     doc.setPlainText(raw)
-    h = HTMLHighlighter()
+    h = Highlighter()
     theme = get_theme(tprefs['editor_theme'])
     h.apply_theme(theme)
     h.set_document(doc)

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

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__ = 'GPL v3'
+__copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
+
+from calibre.gui2.tweak_book.editor.syntax.html import XMLHighlighter as Highlighter  # noqa

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

@@ -23,11 +23,7 @@ from calibre.gui2.tweak_book.editor import (
     SYNTAX_PROPERTY, SPELL_PROPERTY, SPELL_LOCALE_PROPERTY, store_locale, LINK_PROPERTY)
 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
-from calibre.gui2.tweak_book.editor.syntax.css import CSSHighlighter
 from calibre.gui2.tweak_book.editor.smart import NullSmarts
-from calibre.gui2.tweak_book.editor.smart.html import HTMLSmarts
-from calibre.gui2.tweak_book.editor.smart.css import CSSSmarts
 from calibre.spell.break_iterator import index_of
 from calibre.utils.icu import safe_chr, string_length, capitalize, upper, lower, swapcase
 from calibre.utils.titlecase import titlecase
@@ -35,13 +31,11 @@ from calibre.utils.titlecase import titlecase
 PARAGRAPH_SEPARATOR = '\u2029'
 
 def get_highlighter(syntax):
-    ans = {'html':HTMLHighlighter, 'css':CSSHighlighter, 'xml':XMLHighlighter}.get(syntax, SyntaxHighlighter)
+    # Load these highlighters only on demand
-    if ans is SyntaxHighlighter:
+    try:
-        # Load these highlighters only on demand
+        ans = importlib.import_module('calibre.gui2.tweak_book.editor.syntax.' + syntax).Highlighter
-        try:
+    except (ImportError, AttributeError):
-            ans = importlib.import_module('calibre.gui2.tweak_book.editor.syntax.' + syntax).Highlighter
+        ans = SyntaxHighlighter
-        except (ImportError, AttributeError):
-            pass
     return ans
 
 _dff = None
@@ -216,8 +210,12 @@ class TextEdit(PlainTextEdit):
         self.highlighter = get_highlighter(syntax)()
         self.highlighter.apply_theme(self.theme)
         self.highlighter.set_document(self.document(), doc_name=doc_name)
-        sclass = {'html':HTMLSmarts, 'xml':HTMLSmarts, 'css':CSSSmarts}.get(syntax, None)
+        smartsname = {'xml':'html'}.get(syntax, syntax)
-        if sclass is not None:
+        try:
+            sclass = importlib.import_module('calibre.gui2.tweak_book.editor.smart.' + smartsname).Smarts
+        except (ImportError, AttributeError):
+            pass
+        else:
             self.smarts = sclass(self)
         self.setPlainText(unicodedata.normalize('NFC', unicode(text)))
         if process_template and QPlainTextEdit.find(self, '%CURSOR%'):