The cover browser position option with the "auto" choice.

src/calibre/gui2/__init__.py

@@ -426,6 +426,7 @@ def create_defs():
     defs['show_links_in_tag_browser'] = False
     defs['show_notes_in_tag_browser'] = False
     defs['icons_on_right_in_tag_browser'] = True
+    defs['cover_browser_narrow_view_position'] = 'automatic'
 
     def migrate_tweak(tweak_name, pref_name):
         # If the tweak has been changed then leave the tweak in the file so

src/calibre/gui2/central.py

@@ -365,12 +365,26 @@ class CentralContainer(QWidget):
         self.top_handle = h(Qt.Orientation.Horizontal)
         self.bottom_handle = h(Qt.Orientation.Horizontal)
 
+    _last_cb_position = None
+
     @property
     def narrow_cb_on_top(self):
-        from calibre.gui2.ui import get_gui
+        from calibre.gui2 import gui_prefs
-        gui = get_gui()
+        prefs = gui_prefs()
-        ratio = self.width() / self.height() if gui is None else gui.width() / gui.height()
+        p = self._last_cb_position = prefs['cover_browser_narrow_view_position']
-        return ratio <= 1.4
+        if p == 'automatic':
+            from calibre.gui2.ui import get_gui
+            gui = get_gui()
+            ratio = self.width() / self.height() if gui is None else gui.width() / gui.height()
+            return ratio <= 1.4
+        return bool(self._last_cb_position == 'on_top')
+
+    @property
+    def cb_on_top_changed(self):
+        from calibre.gui2 import gui_prefs
+        prefs = gui_prefs()
+        return (self._last_cb_position is None or
+                prefs['cover_browser_narrow_view_position'] != self._last_cb_position)
 
     @property
     def is_visible(self):
@@ -404,7 +418,7 @@ class CentralContainer(QWidget):
 
     def change_layout(self, gui, is_wide):
         layout = Layout.wide if is_wide else Layout.narrow
-        if layout is self.layout:
+        if layout is self.layout and not self.cb_on_top_changed:
             return False
         ss = self.serialized_settings()
         before = ss[self.layout.name + '_visibility']

src/calibre/gui2/preferences/look_feel.py

@@ -610,6 +610,10 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
         r('cover_flow_queue_length', config, restart_required=True)
         r('cover_browser_reflections', gprefs)
+        r('cover_browser_narrow_view_position', gprefs,
+                            choices=[(_('Automatic'), 'automatic'), # Automatic must be first
+                                     (_('On top'), 'on_top'),
+                                     (_('On right'), 'on_right')])
         r('cover_browser_title_template', db.prefs)
         fm = db.field_metadata
         r('cover_browser_subtitle_field', db.prefs, choices=[(_('No subtitle'), 'none')] + sorted(
@@ -836,6 +840,15 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.opt_gui_layout.addItem(_('Narrow'), 'narrow')
         self.opt_gui_layout.currentIndexChanged.connect(self.changed_signal)
         set_help_tips(self.opt_gui_layout, config.help('gui_layout'))
+        self.opt_gui_layout.currentIndexChanged.connect(self.gui_layout_changed)
+
+    def set_cover_browser_position_enabled(self, is_wide):
+        self.opt_cover_browser_narrow_view_position.setEnabled(not is_wide)
+        if is_wide:
+            self.opt_cover_browser_narrow_view_position.setCurrentIndex(0)
+
+    def gui_layout_changed(self, dex):
+        self.set_cover_browser_position_enabled(dex == 0) #0 == wide
 
     def initial_tab_changed(self):
         self.sections_view.setCurrentRow(self.tabWidget.currentIndex())
@@ -1044,6 +1057,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.tb_focus_label.setVisible(self.opt_tag_browser_allow_keyboard_focus.isChecked())
         self.update_color_palette_state()
         self.opt_gui_layout.setCurrentIndex(0 if self.gui.layout_container.is_wide else 1)
+        self.set_cover_browser_position_enabled(self.gui.layout_container.is_wide)
 
     def open_cg_cache(self):
         open_local_file(self.gui.grid_view.thumbnail_cache.location)

src/calibre/gui2/preferences/look_feel.ui

@@ -1846,7 +1846,7 @@ that don't have children.&lt;/p&gt;</string>
        <string>Cover &amp;browser</string>
       </attribute>
       <layout class="QGridLayout" name="gridLayout_11">
-       <item row="1" column="0">
+       <item row="0" column="1" colspan="2">
         <widget class="QCheckBox" name="opt_cb_fullscreen">
          <property name="text">
           <string>When showing in a separate window, show it &amp;fullscreen</string>
@@ -1860,11 +1860,11 @@ that don't have children.&lt;/p&gt;</string>
          </property>
         </widget>
        </item>
-       <item row="3" column="1" colspan="2">
+       <item row="7" column="1" colspan="2">
         <widget class="QSpinBox" name="opt_cover_flow_queue_length"/>
        </item>
-       <item row="3" column="0">
+       <item row="7" column="0">
-        <widget class="QLabel" name="label_6">
+        <widget class="QLabel" name="label_61">
          <property name="text">
           <string>&amp;Number of covers to show in browse mode (needs restart):</string>
          </property>
@@ -1873,7 +1873,7 @@ that don't have children.&lt;/p&gt;</string>
          </property>
         </widget>
        </item>
-       <item row="7" column="2">
+       <item row="8" column="2">
         <widget class="QPushButton" name="cover_browser_title_template_button">
          <property name="text">
           <string>Template &amp;editor</string>
@@ -1893,7 +1893,7 @@ that don't have children.&lt;/p&gt;</string>
          </property>
         </spacer>
        </item>
-       <item row="7" column="1">
+       <item row="8" column="1">
         <widget class="QLineEdit" name="opt_cover_browser_title_template">
          <property name="toolTip">
           <string>&lt;p&gt;The template used to generate the text below the covers. This template uses
@@ -1904,14 +1904,14 @@ empty template for no text.&lt;/p&gt;</string>
          </property>
         </widget>
        </item>
-       <item row="4" column="0" colspan="3">
+       <item row="4" column="0">
         <widget class="QCheckBox" name="opt_cover_browser_reflections">
          <property name="text">
           <string>Show &amp;reflections</string>
          </property>
         </widget>
        </item>
-       <item row="5" column="0" colspan="3">
+       <item row="4" column="1" colspan="2">
         <widget class="QCheckBox" name="opt_cb_preserve_aspect_ratio">
          <property name="toolTip">
           <string>Show covers in their original aspect ratio instead of resizing
@@ -1922,10 +1922,31 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="8" column="1" colspan="2">
+       <item row="6" column="0">
+        <widget class="QLabel" name="label_987">
+         <property name="text">
+          <string>Cover browser &amp;position in the narrow layout:</string>
+         </property>
+         <property name="toolTip">
+          <string>&lt;p&gt;This option controls the position of the cover browser when
+using the Narrow user interface layout. "Automatic" will place the cover browser
+on top or on the right of the book list depending on the aspect ratio of the
+calibre window. "On top" places it over the book list, and "On right" places it
+to the right of the book list. This option cannot be changed when using the
+Wide user interface layout.&lt;/p&gt;</string>
+         </property>
+         <property name="buddy">
+          <cstring>opt_cover_browser_narrow_view_position</cstring>
+         </property>
+        </widget>
+       </item>
+       <item row="6" column="1" colspan="2">
+        <widget class="QComboBox" name="opt_cover_browser_narrow_view_position"/>
+       </item>
+       <item row="9" column="1" colspan="2">
         <widget class="QComboBox" name="opt_cover_browser_subtitle_field"/>
        </item>
-       <item row="7" column="0">
+       <item row="8" column="0">
         <widget class="QLabel" name="label_23">
          <property name="text">
           <string>&amp;Template for caption:</string>
@@ -1935,7 +1956,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="8" column="0">
+       <item row="9" column="0">
         <widget class="QLabel" name="label_24">
          <property name="text">
           <string>Fie&amp;ld for sub-title:</string>
@@ -1945,7 +1966,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="2" column="0">
+       <item row="1" column="1" colspan="2">
         <widget class="QLabel" name="fs_help_msg">
          <property name="styleSheet">
           <string notr="true">margin-left: 1.5em</string>
@@ -1958,7 +1979,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="9" column="0">
+       <item row="10" column="0">
         <widget class="QLabel" name="label_26">
          <property name="text">
           <string>Show ne&amp;xt cover during auto scroll after:</string>
@@ -1968,7 +1989,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="9" column="1">
+       <item row="10" column="1">
         <widget class="QDoubleSpinBox" name="opt_books_autoscroll_time">
          <property name="suffix">
           <string> seconds</string>
@@ -1984,7 +2005,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="6" column="0" colspan="2">
+       <item row="5" column="0" colspan="2">
         <widget class="QCheckBox" name="opt_cb_double_click_to_activate">
          <property name="text">
           <string>&amp;Double click to view the central book, instead of single click</string>