More work on edit book plugin interface

src/calibre/customize/__init__.py

@@ -743,6 +743,8 @@ class ViewerPlugin(Plugin):  # {{{
 # }}}
 
 class EditBookToolPlugin(Plugin):  # {{{
-    pass
+
+    minimum_calibre_version = (1, 45, 0)
+
 # }}}
 

src/calibre/gui2/tweak_book/boss.py

@@ -70,9 +70,14 @@ def in_thread_job(func):
             return func(*args, **kwargs)
     return ans
 
+_boss = None
+def get_boss():
+    return _boss
+
 class Boss(QObject):
 
     def __init__(self, parent, notify=None):
+        global _boss
         QObject.__init__(self, parent)
         self.global_undo = GlobalUndoHistory()
         self.container_count = 0
@@ -82,6 +87,7 @@ class Boss(QObject):
         self.doing_terminal_save = False
         self.ignore_preview_to_editor_sync = False
         setup_cssutils_serialization()
+        _boss = self
 
     def __call__(self, gui):
         self.gui = gui

src/calibre/gui2/tweak_book/plugin.py

@@ -0,0 +1,41 @@
+#!/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.boss import get_boss
+
+class Tool(object):
+
+    #: Set this to a unique name it will be used as a key
+    name = None
+
+    #: If True the user can choose to place this tool in the plugins toolbar
+    allowed_in_toolbar = True
+
+    #: If True the user can choose to place this tool in the plugins menu
+    allowed_in_menu = True
+
+    @property
+    def boss(self):
+        ' The :class:`calibre.gui2.tweak_book.boss.Boss` object. Used to control the user interface. '
+        return get_boss()
+
+    @property
+    def gui(self):
+        ' The main window of the user interface '
+        return self.boss.gui
+
+    def create_action(self, for_toolbar=True):
+        '''
+        Create a QAction that will be added to either the plugins toolbar or
+        the plugins menu depending on ``for_toolbar``. For example::
+
+            def create_action(self, for_toolbar):
+                ac = QAction(
+        '''
+        raise NotImplementedError()
+