From 4b2c386c951f427e6a69fbf8745f60e883e326cf Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 4 Feb 2021 13:21:12 +0530
Subject: [PATCH] Make logic to get preferred view format re-useable

---
 src/calibre/gui2/actions/view.py | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/calibre/gui2/actions/view.py b/src/calibre/gui2/actions/view.py
index a8dfd08caa..df402c1481 100644
--- a/src/calibre/gui2/actions/view.py
+++ b/src/calibre/gui2/actions/view.py
@@ -24,6 +24,16 @@ from calibre.utils.config import prefs, tweaks
 from polyglot.builtins import as_bytes, unicode_type
 
 
+def preferred_format(formats):
+    formats = tuple(x.upper() for x in formats if x)
+    fmt = formats[0]
+    for format in prefs['input_format_order']:
+        if format in formats:
+            fmt = format
+            break
+    return fmt
+
+
 class HistoryAction(QAction):
 
     view_historical = pyqtSignal(object)
@@ -303,19 +313,13 @@ class ViewAction(InterfaceAction):
                 self.update_history([], remove={id_})
                 continue
 
-            formats = db.formats(id_, index_is_id=True)
+            formats = db.new_api.formats(id_, verify_formats=True)
             if not formats:
                 error_dialog(self.gui, _('Cannot view'),
                     _('%s has no available formats.')%(title,), show=True)
                 continue
 
-            formats = formats.upper().split(',')
-
-            fmt = formats[0]
-            for format in prefs['input_format_order']:
-                if format in formats:
-                    fmt = format
-                    break
+            fmt = preferred_format(formats)
             views.append((id_, title))
             self.view_format_by_id(id_, fmt)