Refactor boilerplate functionality into base class

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

@@ -26,3 +26,27 @@ class SyntaxHighlighter(QSyntaxHighlighter):
     def create_formats(self):
         pass
 
+    def highlightBlock(self, text):
+        try:
+            state = self.previousBlockState()
+            if state == -1:
+                state = 0
+            self.do_highlight(state, unicode(text))
+        except:
+            import traceback
+            traceback.print_exc()
+
+    def do_highlight(self, state, text):
+        state = self.state_class(state)
+
+        i = 0
+        while i < len(text):
+            fmt = self.state_map[state.parse](state, text, i, self.formats)
+            for num, f in fmt:
+                if f is not None:
+                    self.setFormat(i, num, f)
+                i += num
+
+        self.setCurrentBlockState(state.value)
+
+

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

@@ -251,6 +251,9 @@ for x in (State.SQ_VAL, State.DQ_VAL):
 
 class HTMLHighlighter(SyntaxHighlighter):
 
+    state_map = state_map
+    state_class = State
+
     def __init__(self, parent):
         SyntaxHighlighter.__init__(self, parent)
 
@@ -284,29 +287,6 @@ class HTMLHighlighter(SyntaxHighlighter):
         f = self.formats['title'] = QTextCharFormat()
         f.setFontWeight(QFont.Bold)
 
-    def highlightBlock(self, text):
-        try:
-            self.do_highlight(unicode(text))
-        except:
-            import traceback
-            traceback.print_exc()
-
-    def do_highlight(self, text):
-        state = self.previousBlockState()
-        if state == -1:
-            state = State.NORMAL
-        state = State(state)
-
-        i = 0
-        while i < len(text):
-            fmt = state_map[state.parse](state, text, i, self.formats)
-            for num, f in fmt:
-                if f is not None:
-                    self.setFormat(i, num, f)
-                i += num
-
-        self.setCurrentBlockState(state.value)
-
 if __name__ == '__main__':
     from calibre.gui2.tweak_book.editor.text import launch_editor
     launch_editor('''\