Fix liberation fonts not loading on windows

src/calibre/__init__.py

@@ -691,19 +691,27 @@ def remove_bracketed_text(src,
     return u''.join(buf)
 
 def load_builtin_fonts():
+    # On linux these are loaded by fontconfig which means that
+    # they are available to Qt as well, since Qt uses fontconfig
+    from calibre.utils.fonts import fontconfig
+    fontconfig
+
+    families = {u'Liberation Serif', u'Liberation Sans', u'Liberation Mono'}
+
     if iswindows or isosx:
         import glob
         from PyQt4.Qt import QFontDatabase
+        families = set()
         for f in glob.glob(P('fonts/liberation/*.ttf')):
-            QFontDatabase.addApplicationFont(f)
-    else:
-        # On linux these are loaded by fontconfig which means that
-        # they are available to Qt as well, since Qt uses fontconfig
-        from calibre.utils.fonts import fontconfig
-        fontconfig
-
-    return 'Liberation Serif', 'Liberation Sans', 'Liberation Mono'
+            with open(f, 'rb') as s:
+                # Windows requires font files to be executable for them to be
+                # loaded successfully, so we use the in memory loader
+                fid = QFontDatabase.addApplicationFontFromData(s.read())
+            if fid > -1:
+                families |= set(map(unicode,
+                    QFontDatabase.applicationFontFamilies(fid)))
 
+    return families
 
 def ipython(user_ns=None):
     from calibre.utils.ipython import ipython

src/calibre/gui2/font_family_chooser.py

@@ -99,7 +99,6 @@ class FontFamilyDelegate(QStyledItemDelegate):
         else:
             r.setLeft(r.left() + 4)
 
-        old = painter.font()
         painter.setFont(font)
         painter.drawText(r, Qt.AlignVCenter|Qt.AlignLeading|Qt.TextSingleLine, text)
 
@@ -113,8 +112,6 @@ class FontFamilyDelegate(QStyledItemDelegate):
                 r.setLeft(r.left() + w)
             painter.drawText(r, Qt.AlignVCenter|Qt.AlignLeading|Qt.TextSingleLine, sample)
 
-        painter.setFont(old)
-
 class FontFamilyChooser(QComboBox):
 
     def __init__(self, parent=None):

src/calibre/gui2/ui.py

@@ -191,10 +191,6 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, EmailMixin, # {{{
         self.content_server = None
         self.spare_servers = []
         self.must_restart_before_config = False
-        # Initialize fontconfig in a separate thread as this can be a lengthy
-        # process if run for the first time on this machine
-        from calibre.utils.fonts import fontconfig
-        self.fc = fontconfig
         self.listener = Listener(listener)
         self.check_messages_timer = QTimer()
         self.connect(self.check_messages_timer, SIGNAL('timeout()'),

src/calibre/utils/fonts/win_fonts.py

@@ -19,8 +19,8 @@ class WinFonts(object):
 
     def __init__(self, winfonts):
         self.w = winfonts
-        # Windows thinks the Liberation font files are not valid, so we use
-        # this hack to make them available
+        # Windows requires font files to be executable for them to be loaded,
+        # so instead we use this hack.
         self.app_font_families = {}
 
         for f in ('Serif', 'Sans', 'Mono'):
@@ -121,6 +121,10 @@ class WinFonts(object):
         return ans
 
     def add_system_font(self, path):
+        '''
+        WARNING: The file you are adding must have execute permissions or
+        windows will fail to add it. (ls -l in cygwin to check)
+        '''
         if isbytestring(path):
             path = path.decode(filesystem_encoding)
         path = os.path.abspath(path)