Add a new tool to easily test templates. Go to Preferences->Toolbars to add the tool to one of the calibre toolbars. Fixes #1360550 [Shortcut to template editor](https://bugs.launchpad.net/calibre/+bug/1360550)

Merge branch 'master' of https://github.com/cbhaley/calibre

src/calibre/customize/builtins.py

@@ -834,6 +834,11 @@ class ActionQuickview(InterfaceActionBase):
     actual_plugin = 'calibre.gui2.actions.show_quickview:ShowQuickviewAction'
     description = _('Show a list of related books quickly')
 
+class ActionTemplateTester(InterfaceActionBase):
+    name = 'Template Tester'
+    actual_plugin = 'calibre.gui2.actions.show_template_tester:ShowTemplateTesterAction'
+    description = _('Show an editor for testing templates')
+
 class ActionSaveToDisk(InterfaceActionBase):
     name = 'Save To Disk'
     actual_plugin = 'calibre.gui2.actions.save_to_disk:SaveToDiskAction'
@@ -969,7 +974,7 @@ plugins += [ActionAdd, ActionFetchAnnotations, ActionGenerateCatalog,
         ActionAddToLibrary, ActionEditCollections, ActionMatchBooks, ActionChooseLibrary,
         ActionCopyToLibrary, ActionTweakEpub, ActionUnpackBook, ActionNextMatch, ActionStore,
         ActionPluginUpdater, ActionPickRandom, ActionEditToC, ActionSortBy,
-        ActionMarkBooks, ActionEmbed]
+        ActionMarkBooks, ActionEmbed, ActionTemplateTester]
 
 # }}}
 

src/calibre/gui2/actions/show_template_tester.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+
+__license__   = 'GPL v3'
+__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+
+from calibre.gui2.actions import InterfaceAction
+from calibre.gui2.dialogs.template_dialog import TemplateDialog
+from calibre.gui2 import error_dialog
+
+class ShowTemplateTesterAction(InterfaceAction):
+
+    name = 'Template tester'
+    action_spec = (_('Template tester'), 'debug.png', None, '')
+    dont_add_to = frozenset(['context-menu-device'])
+    action_type = 'current'
+
+    def genesis(self):
+        self.qaction.triggered.connect(self.show_template_editor)
+
+    def show_template_editor(self, *args):
+        view = self.gui.current_view()
+        if view is not self.gui.library_view:
+            return error_dialog(self.gui, _('No template tester available'),
+                _('Template tester is not available for books '
+                  'on the device.')).exec_()
+
+        rows = view.selectionModel().selectedRows()
+        if not rows:
+            return error_dialog(self.gui, _('No books selected'),
+                    _('A book must be selected'), show=True)
+        if len(rows) > 1:
+            return error_dialog(self.gui, _('Selected multiple books'),
+                    _('Only one book can be selected'), show=True)
+
+        index = rows[0]
+        if index.isValid():
+            db = view.model().db
+            t = TemplateDialog(self.gui, _('Enter a template to test'),
+                               mi=db.get_metadata(index.row(), index_is_id=False,
+                                                  get_cover=False))
+            t.setWindowTitle(_('Template tester'))
+            t.exec_()