Enhancement 1984017 - Add Apply button to Manage Tags

There are two requests here.
1) Add apply button. Because the work is done after the dialog has closed,  Changing this is more work than I am willing to do.

2) Add toolbar / shortcut / context menu support for Manage categories. Done.

src/calibre/customize/builtins.py

@@ -1063,6 +1063,13 @@ class ActionMarkBooks(InterfaceActionBase):
     description = _('Temporarily mark books')
 
 
+class ActionManageCategories(InterfaceActionBase):
+    name = 'Manage categories'
+    author = 'Charles Haley'
+    actual_plugin = 'calibre.gui2.actions.manage_categories:ManageCategoriesAction'
+    description = _('Manage tag browser categories')
+
+
 class ActionVirtualLibrary(InterfaceActionBase):
     name = 'Virtual Library'
     actual_plugin = 'calibre.gui2.actions.virtual_library:VirtualLibraryAction'
@@ -1104,7 +1111,7 @@ plugins += [ActionAdd, ActionFetchAnnotations, ActionGenerateCatalog,
         ActionPluginUpdater, ActionPickRandom, ActionEditToC, ActionSortBy,
         ActionMarkBooks, ActionEmbed, ActionTemplateTester, ActionTagMapper, ActionAuthorMapper,
         ActionVirtualLibrary, ActionBrowseAnnotations, ActionTemplateFunctions, ActionAutoscrollBooks,
-        ActionFullTextSearch,]
+        ActionFullTextSearch, ActionManageCategories]
 
 # }}}
 

src/calibre/gui2/actions/manage_categories.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python
+
+
+__license__ = 'GPL v3'
+__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
+
+from qt.core import (QPoint)
+
+from calibre.gui2.actions import InterfaceAction
+
+
+class ManageCategoriesAction(InterfaceAction):
+
+    name = 'Manage categories'
+    action_spec = (_('Manage categories'), 'tags.png',
+                   _('Manage categories: authors, tags, series, etc.'), '')
+    action_type = 'current'
+    action_add_menu = True
+    dont_add_to = frozenset(['context-menu-device', 'menubar-device'])
+
+    def genesis(self):
+        self.menu = m = self.qaction.menu()
+        self.qaction.triggered.connect(self.show_menu)
+        m.aboutToShow.connect(self.about_to_show_menu)
+
+    # We want to show the menu when the toolbar button is clicked. Apparently
+    # the only way to do that is to scan the toolbar(s) for the action button
+    # then exec the associated menu. The search is done here to take adding and
+    # removing the action from toolbars into account.
+    def show_menu(self):
+        for x in self.gui.bars_manager.main_bars + self.gui.bars_manager.child_bars:
+            try:
+                w = x.widgetForAction(self.qaction)
+                # It seems that multiple copies of the action can exist, such as
+                # when the device-connected menu is changed while the device is
+                # connected. Use the one that has an actual position.
+                if w.pos().x() == 0:
+                    continue
+                # The w.height() assures that the menu opens below the button.
+                self.menu.exec(w.mapToGlobal(QPoint(0, w.height())))
+                break
+            except:
+                continue
+
+    def about_to_show_menu(self):
+        db = self.gui.current_db
+        self.gui.populate_manage_categories_menu(db, self.menu)
+
+    def location_selected(self, loc):
+        enabled = loc == 'library'
+        self.qaction.setEnabled(enabled)
+        for action in self.menu.actions():
+            action.setEnabled(enabled)

src/calibre/gui2/tag_browser/ui.py

@@ -30,8 +30,11 @@ class TagBrowserMixin:  # {{{
         pass
 
     def populate_tb_manage_menu(self, db):
+        self.populate_manage_categories_menu(db, self.alter_tb.manage_menu)
+
+    def populate_manage_categories_menu(self, db, menu):
         from calibre.db.categories import find_categories
-        m = self.alter_tb.manage_menu
+        m = menu
         m.clear()
         for text, func, args, cat_name in (
              (_('Authors'),