Edit metadata dialog: Add an action to open the book's folder to the context menu of the formats list. Fixes #2083583 [[Enhancement] Action to open the Book folder when you right click the format in Edit metadata window](https://bugs.launchpad.net/calibre/+bug/2083583)

src/calibre/gui2/extra_files_watcher.py

@@ -5,7 +5,7 @@
 from time import monotonic
 from typing import NamedTuple, Tuple
 
-from qt.core import QObject, QTimer
+from qt.core import QObject, QTimer, pyqtSignal
 
 from calibre.db.constants import DATA_FILE_PATTERN
 
@@ -23,6 +23,7 @@ class ExtraFiles(NamedTuple):
 
 class ExtraFilesWatcher(QObject):
 
+    books_changed = pyqtSignal(object)
     WATCH_FOR = 300  # seconds
     TICK_INTERVAL = 1 # seconds
 
@@ -86,4 +87,6 @@ class ExtraFilesWatcher(QObject):
 
     def refresh_gui(self, book_ids):
         lv = self.gui.library_view
-        lv.model().refresh_ids(frozenset(book_ids), current_row=lv.currentIndex().row())
+        book_ids = frozenset(book_ids)
+        lv.model().refresh_ids(book_ids, current_row=lv.currentIndex().row())
+        self.books_changed.emit(book_ids)

src/calibre/gui2/metadata/basic_widgets.py

@@ -858,6 +858,7 @@ class FormatList(_FormatList):
     restore_fmt = pyqtSignal(object)
     view_fmt = pyqtSignal(object)
     edit_fmt = pyqtSignal(object)
+    open_book_folder = pyqtSignal()
 
     def __init__(self, parent):
         _FormatList.__init__(self, parent)
@@ -873,7 +874,6 @@ class FormatList(_FormatList):
         originals = [self.item(x).ext.upper() for x in range(self.count())]
         originals = [x for x in originals if x.startswith('ORIGINAL_')]
 
-        if item or originals:
         self.cm = cm = QMenu(self)
 
         if item:
@@ -893,6 +893,9 @@ class FormatList(_FormatList):
             action = OrigAction(fmt, cm)
             action.restore_fmt.connect(self.restore_fmt)
             cm.addAction(action)
+        ac = QAction(_('Open book folder'), cm)
+        ac.triggered.connect(self.open_book_folder)
+        cm.addAction(ac)
         cm.popup(event.globalPos())
         event.accept()
 
@@ -959,6 +962,7 @@ class FormatsManager(QWidget):
         self.formats.formats_dropped.connect(self.formats_dropped)
         self.formats.restore_fmt.connect(self.restore_fmt)
         self.formats.view_fmt.connect(self.show_format)
+        self.formats.open_book_folder.connect(self.open_book_folder)
         self.formats.edit_fmt.connect(self.edit_format)
         self.formats.delete_format.connect(self.remove_format)
         self.formats.itemDoubleClicked.connect(self.show_format)
@@ -1093,6 +1097,9 @@ class FormatsManager(QWidget):
     def show_format(self, item, *args):
         self.dialog.do_view_format(item.path, item.ext)
 
+    def open_book_folder(self, *a):
+        self.dialog.do_open_book_folder()
+
     def edit_format(self, item, *args):
         from calibre.gui2.widgets import BusyCursor
         with BusyCursor():

src/calibre/gui2/metadata/single.py

@@ -399,6 +399,10 @@ class MetadataSingleDialogBase(QDialog):
         else:
             self.view_format.emit(self.book_id, fmt)
 
+    def do_open_book_folder(self):
+        from calibre.gui2.ui import get_gui
+        get_gui().iactions['View'].view_folder_for_id(self.book_id)
+
     def do_edit_format(self, path, fmt):
         if self.was_data_edited:
             from calibre.gui2.tweak_book import tprefs
@@ -1330,11 +1334,15 @@ def edit_metadata(db, row_list, current_row, parent=None, view_slot=None, edit_s
     if cls not in editors:
         cls = 'default'
     d = editors[cls](db, parent, editing_multiple=editing_multiple)
+    if hasattr(parent, 'extra_files_watcher'):
+        conn = parent.extra_files_watcher.books_changed.connect(d.update_data_files_button)
     try:
         d.start(row_list, current_row, view_slot=view_slot, edit_slot=edit_slot,
                 set_current_callback=set_current_callback)
         return d.changed, d.rows_to_refresh
     finally:
+        if hasattr(parent, 'extra_files_watcher'):
+            parent.extra_files_watcher.disconnect(conn)
         # possible workaround for bug reports of occasional ghost edit metadata dialog on windows
         d.deleteLater()