add DJVU sub-menu item to book context and document menu configuration

Author: kfix

README.md

@@ -6,9 +6,10 @@ Files can be converted through a GUI menu and optionally as FileType hook for au
 ![GUI menu](/screenshot_menu.png?raw=true)
 ![Job log](/screenshot_job.png?raw=true)
 
-DjVU files are best for rendering large image-based documents (100+ pg. black-and-white-scaned archive-books) on markup-ebook readers with sub-300MiB memory and sub-2GiB storage capacities.  
-The community-made Kindle readers kindlepdfviewer & koreader support DjVu files and can deliver noticable speed increase over PDF originals of such documents.  
-Some massive 1000+ page books can only be read unsplit on these devices in DjVu format.  
+DjVU format is ideal for reading large black & white scanned Google Books on E-Readers with >300MB RAM and >2GB flash.
+Big 100+ page books scanned into PDF format usually slow these devices' built-in software to a halt.
+
+To read DJVU files on the Kindle, I suggest koreader/koreader.
 
 PDF is still better for vector/markup based "ebooks" so this plugin will not try to convert documents it detects having less than 1 raster image per page.  
 
@@ -26,6 +27,8 @@ Installation
 ```calibre-debug -R djvumaker install_deps``` 
 3. (Re)start Calibre and start converting your PDF books!  
 
+4. [Optional] go to Preferences -> Interface::Toolbars so you can place the DJVU menu where you see fit.
+
 Under the Hood
 ---
 There are a few implementations of DjVU tools in the wild, but the fastest and most robust free one is the DjVuLibre suite and its Ghostscript plugin "GsDjvu".  

gui.py

@@ -17,7 +17,7 @@ class ConvertToDJVUAction(InterfaceAction):
     action_spec = (_('Convert to DJVU'), 'mimetypes/djvu.png', _('engage the djvumaker plugin on this book'), None)
     #  (label, icon_path, tooltip, keyboard shortcut)
 
-    action_type = 'current'
+    action_type = 'global'
 
     #don't auto-add the button to any menus' top-level
     dont_add_to = frozenset(['toolbar', 'toolbar-device', 'context-menu',
@@ -27,12 +27,15 @@ class ConvertToDJVUAction(InterfaceAction):
     def genesis(self):
 	self.qaction.triggered.connect(self.convert_book)
 
-    def gui_layout_complete(self):
-	#append my top-level DJVU action to the built-in conversion menus
-	#https://github.com/kovidgoyal/calibre/blob/master/src/calibre/gui2/actions/convert.py
+    #def gui_layout_complete(self):
+    def initialization_complete(self):
+	# append my top-level DJVU action to the built-in conversion menus
+	# https://github.com/kovidgoyal/calibre/blob/master/src/calibre/gui2/actions/convert.py
+	# https://github.com/kovidgoyal/calibre/blob/master/src/calibre/gui2/__init__.py#L26
 	cb = self.gui.iactions['Convert Books']
         cm = partial(cb.create_menu_action, cb.qaction.menu()) 
 	cm('convert-djvu-cvtm', _('Convert to DJVU'), icon=self.qaction.icon(), triggered=self.convert_book)
+	cb.qaction.setMenu(cb.qaction.menu())
 
     def location_selected(self, loc):
         # Currently values for loc are: ``library, main, card and cardb``.