Improve font size rationalization (thanks to llasram). The new algorithm should be more consistent. However, the change means that some of you existing base font size settings may no longer be appropriate. So please check.

src/calibre/ebooks/lrf/pylrs/pylrs.py

@@ -553,54 +553,40 @@ class Book(Delegator):
             if isinstance(obj, Main):
                 main = obj
                 break
-        pages = [obj for obj in main.contents if isinstance(obj, Page)]
+
-        
-        text_blocks = []
-        for p in pages:
-            for obj in p.contents:
-                if isinstance(obj, TextBlock):
-                    text_blocks.append(obj)
-                elif isinstance(obj, Canvas):
-                    for o in obj.contents:
-                        if isinstance(o.content, TextBlock):
-                            text_blocks.append(o.content)
-            
-        text_styles = set([t.textStyle for t in text_blocks])
-        important_text_styles = []
-        for ts in text_styles:
-            temp = [len(tb.contents) for tb in text_blocks if tb.textStyle == ts]
-            avg_content_length = 0
-            if len(temp) > 0:
-                avg_content_length = sum(temp)/len(temp)
-            if avg_content_length > 4:
-                important_text_styles.append(ts)
-                
         fonts = {}
-        if not important_text_styles:
+        for text in main.get_all(lambda x: isinstance(x, Text)):
-            important_text_styles = text_styles
+            fs = base_font_size
-        
+            ancestor = text.parent
-        for ts in important_text_styles:
+            while ancestor:
-            fs = int(ts.attrs['fontsize'])
+                try:
-            if fonts.has_key(fs):
+                    fs = int(ancestor.attrs['fontsize'])
-                fonts[fs] += 1
+                    break
-            else:
+                except (AttributeError, KeyError):
-                fonts[fs] = 1
+                    pass
-        
+                try: 
+                    fs = int(ancestor.textSettings['fontsize'])
+                    break
+                except (AttributeError, KeyError):
+                    pass
+                try:
+                    fs = int(ancestor.textStyle.attrs['fontsize'])
+                    break
+                except (AttributeError, KeyError):
+                    pass
+                ancestor = ancestor.parent
+            length = len(text.text)
+            fonts[fs] = fonts.get(fs, 0) + length
         if not fonts:
             print 'WARNING: LRF seems to have no textual content. Cannot rationalize font sizes.'
             return
         
-        old_base_font_size = float(max(zip(fonts.keys(), fonts.values()), key=operator.itemgetter(1))[0])
+        old_base_font_size = float(max(fonts.items(), key=operator.itemgetter(1))[0])
-        
+        factor = base_font_size / old_base_font_size
-        factor = base_font_size/old_base_font_size
-        
         def rescale(old):
             return str(int(int(old) * factor))
-            
+
-        for ts in text_styles:
+        text_blocks = list(main.get_all(lambda x: isinstance(x, TextBlock)))
-            ts.attrs['fontsize'] = rescale(ts.attrs['fontsize'])
-            ts.attrs['baselineskip'] = rescale(ts.attrs['baselineskip'])
-        
         for tb in text_blocks:
             if tb.textSettings.has_key('fontsize'):
                 tb.textSettings['fontsize'] = rescale(tb.textSettings['fontsize'])
@@ -609,7 +595,12 @@ class Book(Delegator):
                     span.attrs['fontsize'] = rescale(span.attrs['fontsize'])
                 if span.attrs.has_key('baselineskip'):
                     span.attrs['baselineskip'] = rescale(span.attrs['baselineskip'])
-                
+
+        text_styles = set(tb.textStyle for tb in text_blocks)
+        for ts in text_styles:
+            ts.attrs['fontsize'] = rescale(ts.attrs['fontsize'])
+            ts.attrs['baselineskip'] = rescale(ts.attrs['baselineskip'])
+        
     
     def renderLrs(self, lrsFile, encoding="UTF-8"):
         if isinstance(lrsFile, basestring): 
@@ -1603,6 +1594,8 @@ class Paragraph(LrsContainer):
         LrsContainer.__init__(self, [Text, CR, DropCaps, CharButton,
                                      LrsSimpleChar1, basestring])
         if text is not None:
+            if isinstance(text, basestring):
+                text = Text(text)
             self.append(text)
         
     def CR(self):
@@ -1923,6 +1916,8 @@ class Span(LrsSimpleChar1, LrsContainer):
     def __init__(self, text=None, **attrs):
         LrsContainer.__init__(self, [LrsSimpleChar1, Text, basestring])
         if text is not None:
+            if isinstance(text, basestring):
+                text = Text(text)
             self.append(text)
 
         for attrname in attrs.keys():