Provide an API for action chains and view manager to show and hide calibre panels. I did it as an Action because these are easy for the plugins to use. In fact, Action Chains requires no work.

src/calibre/customize/builtins.py

@@ -1077,6 +1077,13 @@ class ActionSavedSearches(InterfaceActionBase):
     description = _('Show a menu of saved searches')
 
 
+class ActionLayoutActions(InterfaceActionBase):
+    name = 'Layout actions'
+    author = 'Charles Haley'
+    actual_plugin = 'calibre.gui2.actions.layout_actions:LayoutActions'
+    description = _("Show a menu of actions to change calibre's layout")
+
+
 class ActionBooklistContextMenu(InterfaceActionBase):
     name = 'Booklist context menu'
     author = 'Charles Haley'
@@ -1125,7 +1132,8 @@ plugins += [ActionAdd, ActionFetchAnnotations, ActionGenerateCatalog,
         ActionPluginUpdater, ActionPickRandom, ActionEditToC, ActionSortBy,
         ActionMarkBooks, ActionEmbed, ActionTemplateTester, ActionTagMapper, ActionAuthorMapper,
         ActionVirtualLibrary, ActionBrowseAnnotations, ActionTemplateFunctions, ActionAutoscrollBooks,
-        ActionFullTextSearch, ActionManageCategories, ActionBooklistContextMenu, ActionSavedSearches]
+        ActionFullTextSearch, ActionManageCategories, ActionBooklistContextMenu, ActionSavedSearches,
+        ActionLayoutActions]
 
 # }}}
 

src/calibre/gui2/actions/layout_actions.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+# License: GPLv3 Copyright: 2022, Charles Haley
+#
+
+from functools import partial
+
+from qt.core import QIcon, QToolButton
+
+from calibre.gui2.actions import InterfaceAction
+
+
+class LayoutActions(InterfaceAction):
+
+    name = 'Layout Actions'
+    action_spec = (_('Layout Actions'), 'tags.png',
+                   _('Add/remove layout items: search bar, tag browser, etc.'), None)
+    action_type = 'current'
+    popup_type = QToolButton.ToolButtonPopupMode.InstantPopup
+    action_add_menu = True
+    dont_add_to = frozenset(['context-menu-device', 'menubar-device'])
+
+    # The button names used by change_item_by_name() come from gui2.init. They are
+    # 'sb' => Search Bar
+    # 'tb' => Tag Browser
+    # 'bd' => Book Details
+    # 'gv' => Grid View
+    # 'cb' => Cover Browser
+    # 'qv' => QuickView
+
+    def gui_layout_complete(self):
+        m = self.qaction.menu()
+        self.button_names = {}
+        m.addAction(_('Hide all'), self.hide_all)
+        for i,b in enumerate(self.gui.layout_buttons):
+            m.addSeparator()
+            self.button_names[self.gui.button_order[i]] = b
+            ic = QIcon.ic(b.icname)
+            m.addAction(ic, _('Show ') + b.label, partial(self.change_item, b, True))
+            m.addAction(ic, _('Hide ') + b.label, partial(self.change_item, b, False))
+
+    def change_item(self, button, show=True):
+        if button.isChecked() and not show:
+            button.click()
+        elif not button.isChecked() and show:
+            button.click()
+
+    def change_item_by_name(self, name, show=True):
+        self.change_item(self.button_names[name], show)
+
+    def hide_all(self):
+        for name in self.button_names:
+            self.change_item_by_name(name, show=False)

src/calibre/gui2/init.py

@@ -581,7 +581,7 @@ class LayoutMixin:  # {{{
             self.bd_splitter.addWidget(self.book_details)
             self.bd_splitter.setCollapsible(self.bd_splitter.other_index, False)
             self.centralwidget.layout().addWidget(self.bd_splitter)
-            button_order = ('sb', 'tb', 'bd', 'gv', 'cb', 'qv')
+            self.button_order = button_order = ('sb', 'tb', 'bd', 'gv', 'cb', 'qv')
         # }}}
         else:  # wide {{{
             self.bd_splitter = Splitter('book_details_splitter',
@@ -596,7 +596,7 @@ class LayoutMixin:  # {{{
             self.bd_splitter.setSizePolicy(QSizePolicy(QSizePolicy.Policy.Expanding,
                 QSizePolicy.Policy.Expanding))
             self.centralwidget.layout().addWidget(self.bd_splitter)
-            button_order = ('sb', 'tb', 'cb', 'gv', 'qv', 'bd')
+            self.button_order = button_order = ('sb', 'tb', 'cb', 'gv', 'qv', 'bd')
         # }}}
 
         # This must use the base method to find the plugin because it hasn't