text: # -*- coding: utf-8 -*-
  #
  # Copyright © Spyder Project Contributors
  # Licensed under the terms of the MIT License
  # (see spyder/__init__.py for details)
  
  """
  Spyder, the Scientific Python Development Environment
  =====================================================
  
  Developed and maintained by the Spyder Project
  Contributors
  
  Copyright © Spyder Project Contributors
  Licensed under the terms of the MIT License
  (see spyder/__init__.py for details)
  """
  
  # =============================================================================
  # Stdlib imports
  # =============================================================================
  from __future__ import print_function
  from collections import OrderedDict
  from enum import Enum
  import errno
  import gc
  import logging
  import os
  import os.path as osp
  import shutil
  import signal
  import socket
  import glob
  import sys
  import threading
  import traceback
  
  #==============================================================================
  # Check requirements before proceeding
  #==============================================================================
  from spyder import requirements
  requirements.check_path()
  requirements.check_qt()
  requirements.check_spyder_kernels()
  
  #==============================================================================
  # Third-party imports
  #==============================================================================
  from qtpy.compat import from_qvariant
  from qtpy.QtCore import (QCoreApplication, Qt, QTimer, Signal, Slot,
                           qInstallMessageHandler)
  from qtpy.QtGui import QColor, QKeySequence
  from qtpy.QtWidgets import (QAction, QApplication, QMainWindow, QMenu,
                              QMessageBox, QShortcut, QStyleFactory, QCheckBox)
  
  # Avoid a "Cannot mix incompatible Qt library" error on Windows platforms
  from qtpy import QtSvg  # analysis:ignore
  
  # Avoid a bug in Qt: https://bugreports.qt.io/browse/QTBUG-46720
  from qtpy import QtWebEngineWidgets  # analysis:ignore
  
  from qtawesome.iconic_font import FontError
  
  #==============================================================================
  # Local imports
  # NOTE: Move (if possible) import's of widgets and plugins exactly where they
  # are needed in MainWindow to speed up perceived startup time (i.e. the time
  # from clicking the Spyder icon to showing the splash screen).
  #==============================================================================
  from spyder import __version__
  from spyder import dependencies
  from spyder.app.utils import (
      create_application, create_splash_screen, create_window,
      delete_lsp_log_files, qt_message_handler, set_links_color, setup_logging,
      set_opengl_implementation)
  from spyder.api.plugin_registration.registry import PLUGIN_REGISTRY
  from spyder.config.base import (_, DEV, get_conf_path, get_debug_level,
                                  get_home_dir, get_module_source_path,
                                  is_pynsist, running_in_mac_app,
                                  running_under_pytest, STDERR)
  from spyder.config.gui import is_dark_font_color
  from spyder.config.main import OPEN_FILES_PORT
  from spyder.config.manager import CONF
  from spyder.config.utils import IMPORT_EXT, is_gtk_desktop
  from spyder.otherplugins import get_spyderplugins_mods
  from spyder.py3compat import configparser as cp, PY3, to_text_string
  from spyder.utils import encoding, programs
  from spyder.utils.icon_manager import ima
  from spyder.utils.misc import (select_port, getcwd_or_home,
                                 get_python_executable)
  from spyder.utils.palette import QStylePalette
  from spyder.utils.qthelpers import (create_action, add_actions, file_uri,
                                      qapplication, start_file)
  from spyder.utils.stylesheet import APP_STYLESHEET
  from spyder.app.find_plugins import find_external_plugins, find_internal_plugins
  
  # Spyder API Imports
  from spyder.api.exceptions import SpyderAPIError
  from spyder.api.plugins import (
      Plugins, SpyderPlugin, SpyderPluginV2, SpyderDockablePlugin,
      SpyderPluginWidget)
  
  #==============================================================================
  # Windows only local imports
  #==============================================================================
  set_attached_console_visible = None
  is_attached_console_visible = None
  set_windows_appusermodelid = None
  if os.name == 'nt':
      from spyder.utils.windows import (set_attached_console_visible,
                                        set_windows_appusermodelid)
  
  #==============================================================================
  # Constants
  #==============================================================================
  # Module logger
  logger = logging.getLogger(__name__)
  
  # Keeping a reference to the original sys.exit before patching it
  ORIGINAL_SYS_EXIT = sys.exit
  
  # Get the cwd before initializing WorkingDirectory, which sets it to the one
  # used in the last session
  CWD = getcwd_or_home()
  
  #==============================================================================
  # Install Qt messaage handler
  #==============================================================================
  qInstallMessageHandler(qt_message_handler)
  
  #==============================================================================
  # Main Window
  #==============================================================================
  class MainWindow(QMainWindow):
      """Spyder main window"""
      DOCKOPTIONS = (
          QMainWindow.AllowTabbedDocks | QMainWindow.AllowNestedDocks |
          QMainWindow.AnimatedDocks
      )
      SPYDER_PATH = get_conf_path('path')
      SPYDER_NOT_ACTIVE_PATH = get_conf_path('not_active_path')
      DEFAULT_LAYOUTS = 4
  
      # Signals
      restore_scrollbar_position = Signal()
      sig_setup_finished = Signal()
      all_actions_defined = Signal()
      # type: (OrderedDict, OrderedDict)
      sig_pythonpath_changed = Signal(object, object)
      sig_main_interpreter_changed = Signal()
      sig_open_external_file = Signal(str)
      sig_resized = Signal("QResizeEvent")
      sig_moved = Signal("QMoveEvent")
      sig_layout_setup_ready = Signal(object)  # Related to default layouts
  
      # --- Plugin handling methods
      # ------------------------------------------------------------------------
      def get_plugin(self, plugin_name, error=True):
          """
          Return a plugin instance by providing the plugin class.
          """
          if plugin_name in PLUGIN_REGISTRY:
              return PLUGIN_REGISTRY.get_plugin(plugin_name)
  
          if error:
              raise SpyderAPIError(f'Plugin "{plugin_name}" not found!')
  
          return None
  
      def get_dockable_plugins(self):
          """Get a list of all dockable plugins."""
          dockable_plugins = []
          for plugin_name in PLUGIN_REGISTRY:
              plugin = PLUGIN_REGISTRY.get_plugin(plugin_name)
              if isinstance(plugin, (SpyderDockablePlugin, SpyderPluginWidget)):
                  dockable_plugins.append((plugin_name, plugin))
          return dockable_plugins
  
      def is_plugin_enabled(self, plugin_name):
          """Determine if a given plugin is going to be loaded."""
          return PLUGIN_REGISTRY.is_plugin_enabled(plugin_name)
  
      def show_status_message(self, message, timeout):
          """
          Show a status message in Spyder Main Window.
          """
          status_bar = self.statusBar()
          if status_bar.isVisible():
              status_bar.showMessage(message, timeout)
  
      def show_plugin_compatibility_message(self, message):
          """
          Show a compatibility message.
          """
          messageBox = QMessageBox(self)
          messageBox.setWindowModality(Qt.NonModal)
          messageBox.setAttribute(Qt.WA_DeleteOnClose)
          messageBox.setWindowTitle(_('Compatibility Check'))
          messageBox.setText(message)
          messageBox.setStandardButtons(QMessageBox.Ok)
          messageBox.show()
  
      def add_plugin(self, plugin, external=False):
          """
          Add plugin to plugins dictionary.
          """
          self._PLUGINS[plugin.NAME] = plugin
          if external:
              self._EXTERNAL_PLUGINS[plugin.NAME] = plugin
          else:
              self._INTERNAL_PLUGINS[plugin.NAME] = plugin
  
      def register_plugin(self, plugin_name, external=False, omit_conf=False):
          """
          Register a plugin in Spyder Main Window.
          """
          plugin = PLUGIN_REGISTRY.get_plugin(plugin_name)
  
          self.set_splash(_("Loading {}...").format(plugin.get_name()))
          logger.info("Loading {}...".format(plugin.NAME))
  
          if plugin_name in [Plugins.Breakpoints,
                             Plugins.Profiler,
                             Plugins.Pylint]:
              self.thirdparty_plugins.append(plugin)
  
          # Check plugin compatibility
          is_compatible, message = plugin.check_compatibility()
          plugin.is_compatible = is_compatible
          plugin.get_description()
  
          if not is_compatible:
              self.show_compatibility_message(message)
              return
  
          # Connect Plugin Signals to main window methods
          plugin.sig_exception_occurred.connect(self.handle_exception)
          plugin.sig_free_memory_requested.connect(self.free_memory)
          plugin.sig_quit_requested.connect(self.close)
          plugin.sig_restart_requested.connect(self.restart)
          plugin.sig_redirect_stdio_requested.connect(
              self.redirect_internalshell_stdio)
          plugin.sig_status_message_requested.connect(self.show_status_message)
  
          if isinstance(plugin, SpyderDockablePlugin):
              plugin.sig_focus_changed.connect(self.plugin_focus_changed)
              plugin.sig_switch_to_plugin_requested.connect(
                  self.switch_to_plugin)
              plugin.sig_update_ancestor_requested.connect(
                  lambda: plugin.set_ancestor(self))
  
          # Connect Main window Signals to plugin signals
          self.sig_moved.connect(plugin.sig_mainwindow_moved)
          self.sig_resized.connect(plugin.sig_mainwindow_resized)
  
          # Register plugin
          plugin._register(omit_conf=omit_conf)
  
          if isinstance(plugin, SpyderDockablePlugin):
              # Add dockwidget
              self.add_dockwidget(plugin)
  
              # Update margins
              margin = 0
              if CONF.get('main', 'use_custom_margin'):
                  margin = CONF.get('main', 'custom_margin')
              plugin.update_margins(margin)
  
          self.add_plugin(plugin, external=external)
  
          if plugin_name == Plugins.Shortcuts:
              for action, context, action_name in self.shortcut_queue:
                  self.register_shortcut(action, context, action_name)
              self.shortcut_queue = []
  
          logger.info("Registering shortcuts for {}...".format(plugin.NAME))
          for action_name, action in plugin.get_actions().items():
              context = (getattr(action, 'shortcut_context', plugin.NAME)
                         or plugin.NAME)
  
              if getattr(action, 'register_shortcut', True):
                  if isinstance(action_name, Enum):
                      action_name = action_name.value
                  if Plugins.Shortcuts in PLUGIN_REGISTRY:
                      self.register_shortcut(action, context, action_name)
                  else:
                      self.shortcut_queue.append((action, context, action_name))
  
          if isinstance(plugin, SpyderDockablePlugin):
              try:
                  context = '_'
                  name = 'switch to {}'.format(plugin.CONF_SECTION)
                  shortcut = CONF.get_shortcut(context, name,
                                               plugin_name=plugin.CONF_SECTION)
              except (cp.NoSectionError, cp.NoOptionError):
                  shortcut = None
  
              sc = QShortcut(QKeySequence(), self,
                             lambda: self.switch_to_plugin(plugin))
              sc.setContext(Qt.ApplicationShortcut)
              plugin._shortcut = sc
  
              if Plugins.Shortcuts in PLUGIN_REGISTRY:
                  self.register_shortcut(sc, context, name)
                  self.register_shortcut(
                      plugin.toggle_view_action, context, name)
              else:
                  self.shortcut_queue.append((sc, context, name))
                  self.shortcut_queue.append(
                      (plugin.toggle_view_action, context, name))
  
      def unregister_plugin(self, plugin):
          """
          Unregister a plugin from the Spyder Main Window.
          """
          logger.info("Unloading {}...".format(plugin.NAME))
  
          # Disconnect all slots
          signals = [
              plugin.sig_quit_requested,
              plugin.sig_redirect_stdio_requested,
              plugin.sig_status_message_requested,
          ]
  
          for sig in signals:
              try:
                  sig.disconnect()
              except TypeError:
                  pass
  
          # Unregister shortcuts for actions
          logger.info("Unregistering shortcuts for {}...".format(plugin.NAME))
          for action_name, action in plugin.get_actions().items():
              context = (getattr(action, 'shortcut_context', plugin.NAME)
                         or plugin.NAME)
              self.shortcuts.unregister_shortcut(action, context, action_name)
  
          # Unregister switch to shortcut
          shortcut = None
          try:
              context = '_'
              name = 'switch to {}'.format(plugin.CONF_SECTION)
              shortcut = CONF.get_shortcut(context, name,
                                           plugin_name=plugin.CONF_SECTION)
          except Exception:
              pass
  
          if shortcut is not None:
              self.shortcuts.unregister_shortcut(
                  plugin._shortcut,
                  context,
                  "Switch to {}".format(plugin.CONF_SECTION),
              )
  
          # Remove dockwidget
          logger.info("Removing {} dockwidget...".format(plugin.NAME))
          self.remove_dockwidget(plugin)
  
          plugin.unregister()
          plugin._unregister()
  
      def create_plugin_conf_widget(self, plugin):
          """
          Create configuration dialog box page widget.
          """
          config_dialog = self.prefs_dialog_instance
          if plugin.CONF_WIDGET_CLASS is not None and config_dialog is not None:
              conf_widget = plugin.CONF_WIDGET_CLASS(plugin, config_dialog)
              conf_widget.initialize()
              return conf_widget
  
      @property
      def last_plugin(self):
          """
          Get last plugin with focus if it is a dockable widget.
  
          If a non-dockable plugin has the focus this will return by default
          the Editor plugin.
          """
          # Needed to prevent errors with the old API at
          # spyder/plugins/base::_switch_to_plugin
          return self.layouts.get_last_plugin()
  
      def maximize_dockwidget(self, restore=False):
          """
          This is needed to prevent errors with the old API at
          spyder/plugins/base::_switch_to_plugin.
  
          See spyder-ide/spyder#15164
  
          Parameters
          ----------
          restore : bool, optional
              If the current dockwidget needs to be restored to its unmaximized
              state. The default is False.
          """
          self.layouts.maximize_dockwidget(restore=restore)
  
      def switch_to_plugin(self, plugin, force_focus=None):
          """
          Switch to this plugin.
  
          Notes
          -----
          This operation unmaximizes the current plugin (if any), raises
          this plugin to view (if it's hidden) and gives it focus (if
          possible).
          """
          last_plugin = self.last_plugin
          try:
              # New API
              if (last_plugin is not None
                      and last_plugin.get_widget().is_maximized
                      and last_plugin is not plugin):
                  self.layouts.maximize_dockwidget()
          except AttributeError:
              # Old API
              if (last_plugin is not None and self.last_plugin._ismaximized
                      and last_plugin is not plugin):
                  self.layouts.maximize_dockwidget()
  
          try:
              # New API
              if not plugin.toggle_view_action.isChecked():
                  plugin.toggle_view_action.setChecked(True)
                  plugin.get_widget().is_visible = False
          except AttributeError:
              # Old API
              if not plugin._toggle_view_action.isChecked():
                  plugin._toggle_view_action.setChecked(True)
                  plugin._widget._is_visible = False
  
          plugin.change_visibility(True, force_focus=force_focus)
  
      def remove_dockwidget(self, plugin):
          """
          Remove a plugin QDockWidget from the main window.
          """
          self.removeDockWidget(plugin.dockwidget)
          try:
              self.widgetlist.remove(plugin)
          except ValueError:
              pass
  
      def tabify_plugins(self, first, second):
          """Tabify plugin dockwigdets."""
          self.tabifyDockWidget(first.dockwidget, second.dockwidget)
  
      def tabify_plugin(self, plugin, default=None):
          """
          Tabify the plugin using the list of possible TABIFY options.
  
          Only do this if the dockwidget does not have more dockwidgets
          in the same position and if the plugin is using the New API.
          """
          def tabify_helper(plugin, next_to_plugins):
              for next_to_plugin in next_to_plugins:
                  try:
                      self.tabify_plugins(next_to_plugin, plugin)
                      break
                  except SpyderAPIError as err:
                      logger.error(err)
  
          # If TABIFY not defined use the [default]
          tabify = getattr(plugin, 'TABIFY', [default])
          if not isinstance(tabify, list):
              next_to_plugins = [tabify]
          else:
              next_to_plugins = tabify
  
          # Check if TABIFY is not a list with None as unique value or a default
          # list
          if tabify in [[None], []]:
              return False
  
          # Get the actual plugins from the names
          next_to_plugins = [self.get_plugin(p) for p in next_to_plugins]
  
          # First time plugin starts
          if plugin.get_conf('first_time', True):
              if (isinstance(plugin, SpyderDockablePlugin)
                      and plugin.NAME != Plugins.Console):
                  logger.info(
                      "Tabify {} dockwidget for the first time...".format(
                          plugin.NAME))
                  tabify_helper(plugin, next_to_plugins)
  
              plugin.set_conf('enable', True)
              plugin.set_conf('first_time', False)
          else:
              # This is needed to ensure new plugins are placed correctly
              # without the need for a layout reset.
              logger.info("Tabify {} dockwidget...".format(plugin.NAME))
              # Check if plugin has no other dockwidgets in the same position
              if not bool(self.tabifiedDockWidgets(plugin.dockwidget)):
                  tabify_helper(plugin, next_to_plugins)
  
          return True
  
      def handle_exception(self, error_data):
          """
          This method will call the handle exception method of the Console
          plugin. It is provided as a signal on the Plugin API for convenience,
          so that plugin do not need to explicitly call the Console plugin.
  
          Parameters
          ----------
          error_data: dict
              The dictionary containing error data. The expected keys are:
              >>> error_data= {
                  "text": str,
                  "is_traceback": bool,
                  "repo": str,
                  "title": str,
                  "label": str,
                  "steps": str,
              }
  
          Notes
          -----
          The `is_traceback` key indicates if `text` contains plain text or a
          Python error traceback.
  
          The `title` and `repo` keys indicate how the error data should
          customize the report dialog and Github error submission.
  
          The `label` and `steps` keys allow customizing the content of the
          error dialog.
          """
          if self.console:
              self.console.handle_exception(error_data)
  
      def __init__(self, splash=None, options=None):
          QMainWindow.__init__(self)
          qapp = QApplication.instance()
  
          if running_under_pytest():
              self._proxy_style = None
          else:
              from spyder.utils.qthelpers import SpyderProxyStyle
              # None is needed, see: https://bugreports.qt.io/browse/PYSIDE-922
              self._proxy_style = SpyderProxyStyle(None)
  
          # Enabling scaling for high dpi
          qapp.setAttribute(Qt.AA_UseHighDpiPixmaps)
  
          self.default_style = str(qapp.style().objectName())
  
          self.init_workdir = options.working_directory
          self.profile = options.profile
          self.multithreaded = options.multithreaded
          self.new_instance = options.new_instance
          if options.project is not None and not running_in_mac_app():
              self.open_project = osp.normpath(osp.join(CWD, options.project))
          else:
              self.open_project = None
          self.window_title = options.window_title
  
          logger.info("Start of MainWindow constructor")
  
          def signal_handler(signum, frame=None):
              """Handler for signals."""
              sys.stdout.write('Handling signal: %s\n' % signum)
              sys.stdout.flush()
              QApplication.quit()
  
          if os.name == "nt":
              try:
                  import win32api
                  win32api.SetConsoleCtrlHandler(signal_handler, True)
              except ImportError:
                  pass
          else:
              signal.signal(signal.SIGTERM, signal_handler)
              if not DEV:
                  # Make spyder quit when presing ctrl+C in the console
                  # In DEV Ctrl+C doesn't quit, because it helps to
                  # capture the traceback when spyder freezes
                  signal.signal(signal.SIGINT, signal_handler)
  
          # Use a custom Qt stylesheet
          if sys.platform == 'darwin':
              spy_path = get_module_source_path('spyder')
              img_path = osp.join(spy_path, 'images')
              mac_style = open(osp.join(spy_path, 'app', 'mac_stylesheet.qss')).read()
              mac_style = mac_style.replace('$IMAGE_PATH', img_path)
              self.setStyleSheet(mac_style)
  
          # Shortcut management data
          self.shortcut_data = []
          self.shortcut_queue = []
  
          # Handle Spyder path
          self.path = ()
          self.not_active_path = ()
          self.project_path = ()
  
          # New API
          self._APPLICATION_TOOLBARS = OrderedDict()
          self._STATUS_WIDGETS = OrderedDict()
          self._PLUGINS = OrderedDict()
          self._EXTERNAL_PLUGINS = OrderedDict()
          self._INTERNAL_PLUGINS = OrderedDict()
          # Mapping of new plugin identifiers vs old attributtes
          # names given for plugins or to prevent collisions with other
          # attributes, i.e layout (Qt) vs layout (SpyderPluginV2)
          self._INTERNAL_PLUGINS_MAPPING = {
              'console': Plugins.Console,
              'maininterpreter': Plugins.MainInterpreter,
              'outlineexplorer': Plugins.OutlineExplorer,
              'variableexplorer': Plugins.VariableExplorer,
              'ipyconsole': Plugins.IPythonConsole,
              'workingdirectory': Plugins.WorkingDirectory,
              'projects': Plugins.Projects,
              'findinfiles': Plugins.Find,
              'layouts': Plugins.Layout,
              }
  
          self.thirdparty_plugins = []
  
          # File switcher
          self.switcher = None
  
          # Preferences
          self.prefs_dialog_size = None
          self.prefs_dialog_instance = None
  
          # Actions
          self.undo_action = None
          self.redo_action = None
          self.copy_action = None
          self.cut_action = None
          self.paste_action = None
          self.selectall_action = None
  
          # Menu bars
          self.edit_menu = None
          self.edit_menu_actions = []
          self.search_menu = None
          self.search_menu_actions = []
          self.source_menu = None
          self.source_menu_actions = []
          self.run_menu = None
          self.run_menu_actions = []
          self.debug_menu = None
          self.debug_menu_actions = []
  
          # TODO: Move to corresponding Plugins
          self.main_toolbar = None
          self.main_toolbar_actions = []
          self.file_toolbar = None
          self.file_toolbar_actions = []
          self.run_toolbar = None
          self.run_toolbar_actions = []
          self.debug_toolbar = None
          self.debug_toolbar_actions = []
  
          self.menus = []
  
          if running_under_pytest():
              # Show errors in internal console when testing.
              CONF.set('main', 'show_internal_errors', False)
  
          self.CURSORBLINK_OSDEFAULT = QApplication.cursorFlashTime()
  
          if set_windows_appusermodelid != None:
              res = set_windows_appusermodelid()
              logger.info("appusermodelid: %s", res)
  
          # Setting QTimer if running in travis
          test_app = os.environ.get('TEST_CI_APP')
          if test_app is not None:
              app = qapplication()
              timer_shutdown_time = 30000
              self.timer_shutdown = QTimer(self)
              self.timer_shutdown.timeout.connect(app.quit)
              self.timer_shutdown.start(timer_shutdown_time)
  
          # Showing splash screen
          self.splash = splash
          if CONF.get('main', 'current_version', '') != __version__:
              CONF.set('main', 'current_version', __version__)
              # Execute here the actions to be performed only once after
              # each update (there is nothing there for now, but it could
              # be useful some day...)
  
          # List of satellite widgets (registered in add_dockwidget):
          self.widgetlist = []
  
          # Flags used if closing() is called by the exit() shell command
          self.already_closed = False
          self.is_starting_up = True
          self.is_setting_up = True
  
          self.floating_dockwidgets = []
          self.window_size = None
          self.window_position = None
  
          # To keep track of the last focused widget
          self.last_focused_widget = None
          self.previous_focused_widget = None
  
          # Keep track of dpi message
          self.show_dpi_message = True
  
          # Server to open external files on a single instance
          # This is needed in order to handle socket creation problems.
          # See spyder-ide/spyder#4132.
          if os.name == 'nt':
              try:
                  self.open_files_server = socket.socket(socket.AF_INET,
                                                         socket.SOCK_STREAM,
                                                         socket.IPPROTO_TCP)
              except OSError:
                  self.open_files_server = None
                  QMessageBox.warning(None, "Spyder",
                           _("An error occurred while creating a socket needed "
                             "by Spyder. Please, try to run as an Administrator "
                             "from cmd.exe the following command and then "
                             "restart your computer: <br><br><span "
                             "style=\'color: {color}\'><b>netsh winsock reset "
                             "</b></span><br>").format(
                                 color=QStylePalette.COLOR_BACKGROUND_4))
          else:
              self.open_files_server = socket.socket(socket.AF_INET,
                                                     socket.SOCK_STREAM,
                                                     socket.IPPROTO_TCP)
  
          # Apply main window settings
          self.apply_settings()
  
          # To set all dockwidgets tabs to be on top (in case we want to do it
          # in the future)
          # self.setTabPosition(Qt.AllDockWidgetAreas, QTabWidget.North)
  
          logger.info("End of MainWindow constructor")
  
      # --- Window setup
      def _update_shortcuts_in_panes_menu(self, show=True):
          """
          Display the shortcut for the "Switch to plugin..." on the toggle view
          action of the plugins displayed in the Help/Panes menu.
  
          Notes
          -----
          SpyderDockablePlugins provide two actions that function as a single
          action. The `Switch to Plugin...` action has an assignable shortcut
          via the shortcut preferences. The `Plugin toggle View` in the `View`
          application menu, uses a custom `Toggle view action` that displays the
          shortcut assigned to the `Switch to Plugin...` action, but is not
          triggered by that shortcut.
          """
          for plugin_name in PLUGIN_REGISTRY:
              plugin = PLUGIN_REGISTRY.get_plugin(plugin_name)
              if isinstance(plugin, SpyderDockablePlugin):
                  try:
                      # New API
                      action = plugin.toggle_view_action
                  except AttributeError:
                      # Old API
                      action = plugin._toggle_view_action
  
                  if show:
                      section = plugin.CONF_SECTION
                      try:
                          context = '_'
                          name = 'switch to {}'.format(section)
                          shortcut = CONF.get_shortcut(
                              context, name, plugin_name=section)
                      except (cp.NoSectionError, cp.NoOptionError):
                          shortcut = QKeySequence()
                  else:
                      shortcut = QKeySequence()
  
                  action.setShortcut(shortcut)
  
      def setup(self):
          """Setup main window."""
          PLUGIN_REGISTRY.sig_plugin_ready.connect(
              lambda plugin_name, omit_conf: self.register_plugin(
                  plugin_name, omit_conf=omit_conf))
  
          # TODO: Remove circular dependency between help and ipython console
          # and remove this import. Help plugin should take care of it
          from spyder.plugins.help.utils.sphinxify import CSS_PATH, DARK_CSS_PATH
          logger.info("*** Start of MainWindow setup ***")
          logger.info("Updating PYTHONPATH")
          path_dict = self.get_spyder_pythonpath_dict()
          self.update_python_path(path_dict)
  
          logger.info("Applying theme configuration...")
          ui_theme = CONF.get('appearance', 'ui_theme')
          color_scheme = CONF.get('appearance', 'selected')
  
          if ui_theme == 'dark':
              if not running_under_pytest():
                  # Set style proxy to fix combobox popup on mac and qdark
                  qapp = QApplication.instance()
                  qapp.setStyle(self._proxy_style)
              dark_qss = str(APP_STYLESHEET)
              self.setStyleSheet(dark_qss)
              self.statusBar().setStyleSheet(dark_qss)
              css_path = DARK_CSS_PATH
  
          elif ui_theme == 'light':
              if not running_under_pytest():
                  # Set style proxy to fix combobox popup on mac and qdark
                  qapp = QApplication.instance()
                  qapp.setStyle(self._proxy_style)
              light_qss = str(APP_STYLESHEET)
              self.setStyleSheet(light_qss)
              self.statusBar().setStyleSheet(light_qss)
              css_path = CSS_PATH
  
          elif ui_theme == 'automatic':
              if not is_dark_font_color(color_scheme):
                  if not running_under_pytest():
                      # Set style proxy to fix combobox popup on mac and qdark
                      qapp = QApplication.instance()
                      qapp.setStyle(self._proxy_style)
                  dark_qss = str(APP_STYLESHEET)
                  self.setStyleSheet(dark_qss)
                  self.statusBar().setStyleSheet(dark_qss)
                  css_path = DARK_CSS_PATH
              else:
                  light_qss = str(APP_STYLESHEET)
                  self.setStyleSheet(light_qss)
                  self.statusBar().setStyleSheet(light_qss)
                  css_path = CSS_PATH
  
          # Set css_path as a configuration to be used by the plugins
          CONF.set('appearance', 'css_path', css_path)
  
          # Status bar
          status = self.statusBar()
          status.setObjectName("StatusBar")
          status.showMessage(_("Welcome to Spyder!"), 5000)
  
          # Switcher instance
          logger.info("Loading switcher...")
          self.create_switcher()
  
          message = _(
              "Spyder Internal Console\n\n"
              "This console is used to report application\n"
              "internal errors and to inspect Spyder\n"
              "internals with the following commands:\n"
              "  spy.app, spy.window, dir(spy)\n\n"
              "Please don't use it to run your code\n\n"
          )
          CONF.set('internal_console', 'message', message)
          CONF.set('internal_console', 'multithreaded', self.multithreaded)
          CONF.set('internal_console', 'profile', self.profile)
          CONF.set('internal_console', 'commands', [])
          CONF.set('internal_console', 'namespace', {})
          CONF.set('internal_console', 'show_internal_errors', True)
  
          # Working directory initialization
          CONF.set('workingdir', 'init_workdir', self.init_workdir)
  
          # Load and register internal and external plugins
          external_plugins = find_external_plugins()
          internal_plugins = find_internal_plugins()
          all_plugins = external_plugins.copy()
          all_plugins.update(internal_plugins.copy())
  
          # Determine 'enable' config for the plugins that have it
          enabled_plugins = {}
          for plugin in all_plugins.values():
              plugin_name = plugin.NAME
              plugin_main_attribute_name = (
                  self._INTERNAL_PLUGINS_MAPPING[plugin_name]
                  if plugin_name in self._INTERNAL_PLUGINS_MAPPING
                  else plugin_name)
              try:
                  if CONF.get(plugin_main_attribute_name, "enable"):
                      enabled_plugins[plugin_name] = plugin
                      PLUGIN_REGISTRY.set_plugin_enabled(plugin_name)
              except (cp.NoOptionError, cp.NoSectionError):
                  enabled_plugins[plugin_name] = plugin
                  PLUGIN_REGISTRY.set_plugin_enabled(plugin_name)
  
          # Instantiate internal Spyder 5 plugins
          for plugin_name in internal_plugins:
              if plugin_name in enabled_plugins:
                  PluginClass = internal_plugins[plugin_name]
                  if issubclass(PluginClass, SpyderPluginV2):
                      PLUGIN_REGISTRY.register_plugin(self, PluginClass,
                                                      external=False)
  
          # Instantiate internal Spyder 4 plugins
          for plugin_name in internal_plugins:
              if plugin_name in enabled_plugins:
                  PluginClass = internal_plugins[plugin_name]
                  if issubclass(PluginClass, SpyderPlugin):
                      if plugin_name == Plugins.IPythonConsole:
                          plugin_instance = PLUGIN_REGISTRY.register_plugin(
                              self, PluginClass, external=False)
                          plugin_instance.sig_exception_occurred.connect(
                              self.handle_exception)
                      else:
                          plugin_instance = PLUGIN_REGISTRY.register_plugin(
                              self, PluginClass, external=False)
                      self.preferences.register_plugin_preferences(
                          plugin_instance)
  
          # Instantiate external Spyder 5 plugins
          for plugin_name in external_plugins:
              if plugin_name in enabled_plugins:
                  PluginClass = external_plugins[plugin_name]
                  try:
                      plugin_instance = PLUGIN_REGISTRY.register_plugin(
                          self, PluginClass, external=True)
  
                      if not running_under_pytest():
                          # These attributes come from spyder.app.find_plugins
                          module = PluginClass._spyder_module_name
                          package_name = PluginClass._spyder_package_name
                          version = PluginClass._spyder_version
                          description = plugin_instance.get_description()
                          dependencies.add(module, package_name, description,
                                           version, None,
                                           kind=dependencies.PLUGIN)
                  except Exception as error:
                      print("%s: %s" % (PluginClass, str(error)), file=STDERR)
                      traceback.print_exc(file=STDERR)
  
          self.set_splash(_("Loading old third-party plugins..."))
          for mod in get_spyderplugins_mods():
              try:
                  plugin = PLUGIN_REGISTRY.register_plugin(self, mod,
                                                           external=True)
                  if plugin.check_compatibility()[0]:
                      if hasattr(plugin, 'CONFIGWIDGET_CLASS'):
                          self.preferences.register_plugin_preferences(plugin)
  
                      if not hasattr(plugin, 'COMPLETION_PROVIDER_NAME'):
                          self.thirdparty_plugins.append(plugin)
  
                      # Add to dependencies dialog
                      module = mod.__name__
                      name = module.replace('_', '-')
                      if plugin.DESCRIPTION:
                          description = plugin.DESCRIPTION
                      else:
                          description = plugin.get_plugin_title()
  
                      dependencies.add(module, name, description,
                                       '', None, kind=dependencies.PLUGIN)
              except TypeError:
                  # Fixes spyder-ide/spyder#13977
                  pass
              except Exception as error:
                  print("%s: %s" % (mod, str(error)), file=STDERR)
                  traceback.print_exc(file=STDERR)
  
          # Set window title
          self.set_window_title()
  
          # Menus
          # TODO: Remove when all menus are migrated to use the Main Menu Plugin
          logger.info("Creating Menus...")
          from spyder.plugins.mainmenu.api import (
              ApplicationMenus, ToolsMenuSections, FileMenuSections)
          mainmenu = self.mainmenu
          self.edit_menu = mainmenu.get_application_menu("edit_menu")
          self.search_menu = mainmenu.get_application_menu("search_menu")
          self.source_menu = mainmenu.get_application_menu("source_menu")
          self.source_menu.aboutToShow.connect(self.update_source_menu)
          self.run_menu = mainmenu.get_application_menu("run_menu")
          self.debug_menu = mainmenu.get_application_menu("debug_menu")
  
          # Switcher shortcuts
          self.file_switcher_action = create_action(
                                      self,
                                      _('File switcher...'),
                                      icon=ima.icon('filelist'),
                                      tip=_('Fast switch between files'),
                                      triggered=self.open_switcher,
                                      context=Qt.ApplicationShortcut)
          self.register_shortcut(self.file_switcher_action, context="_",
                                 name="File switcher")
          self.symbol_finder_action = create_action(
                                      self, _('Symbol finder...'),
                                      icon=ima.icon('symbol_find'),
                                      tip=_('Fast symbol search in file'),
                                      triggered=self.open_symbolfinder,
                                      context=Qt.ApplicationShortcut)
          self.register_shortcut(self.symbol_finder_action, context="_",
                                 name="symbol finder", add_shortcut_to_tip=True)
  
          def create_edit_action(text, tr_text, icon):
              textseq = text.split(' ')
              method_name = textseq[0].lower()+"".join(textseq[1:])
              action = create_action(self, tr_text,
                                     icon=icon,
                                     triggered=self.global_callback,
                                     data=method_name,
                                     context=Qt.WidgetShortcut)
              self.register_shortcut(action, "Editor", text)
              return action
  
          self.undo_action = create_edit_action('Undo', _('Undo'),
                                                ima.icon('undo'))
          self.redo_action = create_edit_action('Redo', _('Redo'),
                                                ima.icon('redo'))
          self.copy_action = create_edit_action('Copy', _('Copy'),
                                                ima.icon('editcopy'))
          self.cut_action = create_edit_action('Cut', _('Cut'),
                                               ima.icon('editcut'))
          self.paste_action = create_edit_action('Paste', _('Paste'),
                                                 ima.icon('editpaste'))
          self.selectall_action = create_edit_action("Select All",
                                                     _("Select All"),
                                                     ima.icon('selectall'))
  
          self.edit_menu_actions += [self.undo_action, self.redo_action,
                                     None, self.cut_action, self.copy_action,
                                     self.paste_action, self.selectall_action,
                                     None] + self.editor.edit_menu_actions
          switcher_actions = [
              self.file_switcher_action,
              self.symbol_finder_action
          ]
          for switcher_action in switcher_actions:
              mainmenu.add_item_to_application_menu(
                      switcher_action,
                      menu_id=ApplicationMenus.File,
                      section=FileMenuSections.Switcher,
                      before_section=FileMenuSections.Restart)
          self.set_splash("")
  
          # Toolbars
          # TODO: Remove after finishing the migration
          logger.info("Creating toolbars...")
          toolbar = self.toolbar
          self.file_toolbar = toolbar.get_application_toolbar("file_toolbar")
          self.run_toolbar = toolbar.get_application_toolbar("run_toolbar")
          self.debug_toolbar = toolbar.get_application_toolbar("debug_toolbar")
          self.main_toolbar = toolbar.get_application_toolbar("main_toolbar")
  
          # Tools + External Tools (some of this depends on the Application
          # plugin)
          logger.info("Creating Tools menu...")
  
          spyder_path_action = create_action(
              self,
              _("PYTHONPATH manager"),
              None, icon=ima.icon('pythonpath'),
              triggered=self.show_path_manager,
              tip=_("PYTHONPATH manager"),
              menurole=QAction.ApplicationSpecificRole)
          from spyder.plugins.application.plugin import (
              ApplicationActions, WinUserEnvDialog)
          winenv_action = None
          if WinUserEnvDialog:
              winenv_action = self.application.get_action(
                  ApplicationActions.SpyderWindowsEnvVariables)
          mainmenu.add_item_to_application_menu(
              spyder_path_action,
              menu_id=ApplicationMenus.Tools,
              section=ToolsMenuSections.Tools,
              before=winenv_action
          )
          if get_debug_level() >= 3:
              self.menu_lsp_logs = QMenu(_("LSP logs"))
              self.menu_lsp_logs.aboutToShow.connect(self.update_lsp_logs)
              mainmenu.add_item_to_application_menu(
                  self.menu_lsp_logs,
                  menu_id=ApplicationMenus.Tools)
  
          # Main toolbar
          from spyder.plugins.toolbar.api import (
              ApplicationToolbars, MainToolbarSections)
          self.toolbar.add_item_to_application_toolbar(
              spyder_path_action,
              toolbar_id=ApplicationToolbars.Main,
              section=MainToolbarSections.ApplicationSection
          )
  
          self.set_splash(_("Setting up main window..."))
  
          # TODO: Migrate to use the MainMenu Plugin instead of list of actions
          # Filling out menu/toolbar entries:
          add_actions(self.edit_menu, self.edit_menu_actions)
          add_actions(self.search_menu, self.search_menu_actions)
          add_actions(self.source_menu, self.source_menu_actions)
          add_actions(self.run_menu, self.run_menu_actions)
          add_actions(self.debug_menu, self.debug_menu_actions)
  
          # Emitting the signal notifying plugins that main window menu and
          # toolbar actions are all defined:
          self.all_actions_defined.emit()
  
      def __getattr__(self, attr):
          """
          Redefinition of __getattr__ to enable access to plugins.
  
          Loaded plugins can be accessed as attributes of the mainwindow
          as before, e.g self.console or self.main.console, preserving the
          same accessor as before.
          """
          # Mapping of new plugin identifiers vs old attributtes
          # names given for plugins
          if attr in self._INTERNAL_PLUGINS_MAPPING.keys():
              return self.get_plugin(self._INTERNAL_PLUGINS_MAPPING[attr])
          try:
              return self.get_plugin(attr)
          except SpyderAPIError:
              pass
          return super().__getattr__(attr)
  
      def update_lsp_logs(self):
          """Create an action for each lsp log file."""
          self.menu_lsp_logs.clear()
          lsp_logs = []
          files = glob.glob(osp.join(get_conf_path('lsp_logs'), '*.log'))
          for f in files:
              action = create_action(self, f, triggered=self.editor.load)
              action.setData(f)
              lsp_logs.append(action)
          add_actions(self.menu_lsp_logs, lsp_logs)
  
      def pre_visible_setup(self):
          """
          Actions to be performed before the main window is visible.
  
          The actions here are related with setting up the main window.
          """
          logger.info("Setting up window...")
          # Create external plugins before loading the layout to include them in
          # the window restore state after restarts.
          for plugin, plugin_instance in self._EXTERNAL_PLUGINS.items():
              self.tabify_plugin(plugin_instance, Plugins.Console)
              if isinstance(plugin_instance, SpyderDockablePlugin):
                  plugin_instance.get_widget().toggle_view(False)
  
          for plugin_name in PLUGIN_REGISTRY:
              plugin_instance = PLUGIN_REGISTRY.get_plugin(plugin_name)
              try:
                  plugin_instance.before_mainwindow_visible()
              except AttributeError:
                  pass
  
          if self.splash is not None:
              self.splash.hide()
  
          # Menu about to show
          for child in self.menuBar().children():
              if isinstance(child, QMenu):
                  try:
                      child.aboutToShow.connect(self.update_edit_menu)
                      child.aboutToShow.connect(self.update_search_menu)
                  except TypeError:
                      pass
  
          # Register custom layouts
          for plugin, plugin_instance in self._PLUGINS.items():
              if hasattr(plugin_instance, 'CUSTOM_LAYOUTS'):
                  if isinstance(plugin_instance.CUSTOM_LAYOUTS, list):
                      for custom_layout in plugin_instance.CUSTOM_LAYOUTS:
                          self.layouts.register_layout(
                              self, custom_layout)
                  else:
                      logger.info(
                          'Unable to load custom layouts for {}. '
                          'Expecting a list of layout classes but got {}'
                          .format(plugin, plugin_instance.CUSTOM_LAYOUTS)
                      )
          self.layouts.update_layout_menu_actions()
  
          logger.info("*** End of MainWindow setup ***")
          self.is_starting_up = False
  
  
      def post_visible_setup(self):
          """
          Actions to be performed only after the main window's `show` method
          is triggered.
          """
          # Process pending events and hide splash before loading the
          # previous session.
          QApplication.processEvents()
          if self.splash is not None:
              self.splash.hide()
  
          # Call on_mainwindow_visible for all plugins.
          for plugin_name in PLUGIN_REGISTRY:
              plugin = PLUGIN_REGISTRY.get_plugin(plugin_name)
              try:
                  plugin.on_mainwindow_visible()
                  QApplication.processEvents()
              except AttributeError:
                  pass
  
          self.restore_scrollbar_position.emit()
  
          logger.info('Deleting previous Spyder instance LSP logs...')
          delete_lsp_log_files()
  
          # Workaround for spyder-ide/spyder#880.
          # QDockWidget objects are not painted if restored as floating
          # windows, so we must dock them before showing the mainwindow,
          # then set them again as floating windows here.
          for widget in self.floating_dockwidgets:
              widget.setFloating(True)
  
          # Server to maintain just one Spyder instance and open files in it if
          # the user tries to start other instances with
          # $ spyder foo.py
          if (CONF.get('main', 'single_instance') and not self.new_instance
                  and self.open_files_server):
              t = threading.Thread(target=self.start_open_files_server)
              t.setDaemon(True)
              t.start()
  
              # Connect the window to the signal emitted by the previous server
              # when it gets a client connected to it
              self.sig_open_external_file.connect(self.open_external_file)
  
          # Hide Internal Console so that people don't use it instead of
          # the External or IPython ones
          if self.console.dockwidget.isVisible() and DEV is None:
              self.console.toggle_view_action.setChecked(False)
              self.console.dockwidget.hide()
  
          # Show Help and Consoles by default
          plugins_to_show = [self.ipyconsole]
          if self.help is not None:
              plugins_to_show.append(self.help)
          for plugin in plugins_to_show:
              if plugin.dockwidget.isVisible():
                  plugin.dockwidget.raise_()
  
          # Update plugins toggle actions to show the "Switch to" plugin shortcut
          self._update_shortcuts_in_panes_menu()
  
          # Load project, if any.
          # TODO: Remove this reference to projects once we can send the command
          # line options to the plugins.
          if self.open_project:
              if not running_in_mac_app():
                  self.projects.open_project(
                      self.open_project, workdir=self.init_workdir
                  )
          else:
              # Load last project if a project was active when Spyder
              # was closed
              self.projects.reopen_last_project()
  
              # If no project is active, load last session
              if self.projects.get_active_project() is None:
                  self.editor.setup_open_files(close_previous_files=False)
  
          # Raise the menuBar to the top of the main window widget's stack
          # Fixes spyder-ide/spyder#3887.
          self.menuBar().raise_()
  
          # Handle DPI scale and window changes to show a restart message.
          # Don't activate this functionality on macOS because it's being
          # triggered in the wrong situations.
          # See spyder-ide/spyder#11846
          if not sys.platform == 'darwin':
              window = self.window().windowHandle()
              window.screenChanged.connect(self.handle_new_screen)
              screen = self.window().windowHandle().screen()
              self.current_dpi = screen.logicalDotsPerInch()
              screen.logicalDotsPerInchChanged.connect(
                  self.show_dpi_change_message)
  
          # To avoid regressions. We shouldn't have loaded the modules
          # below at this point.
          if DEV is not None:
              assert 'pandas' not in sys.modules
              assert 'matplotlib' not in sys.modules
  
          # Notify that the setup of the mainwindow was finished
          self.is_setting_up = False
          self.sig_setup_finished.emit()
  
      def handle_new_screen(self, new_screen):
          """Connect DPI signals for new screen."""
          if new_screen is not None:
              new_screen_dpi = new_screen.logicalDotsPerInch()
              if self.current_dpi != new_screen_dpi:
                  self.show_dpi_change_message(new_screen_dpi)
              else:
                  new_screen.logicalDotsPerInchChanged.connect(
                      self.show_dpi_change_message)
  
      def handle_dpi_change_response(self, result, dpi):
          """Handle dpi change message dialog result."""
          if self.dpi_change_dismiss_box.isChecked():
              self.show_dpi_message = False
              self.dpi_change_dismiss_box = None
          if result == 0:  # Restart button was clicked
              # Activate HDPI auto-scaling option since is needed for a
              # proper display when using OS scaling
              CONF.set('main', 'normal_screen_resolution', False)
              CONF.set('main', 'high_dpi_scaling', True)
              CONF.set('main', 'high_dpi_custom_scale_factor', False)
              self.restart()
          else:
              # Update current dpi for future checks
              self.current_dpi = dpi
  
      def show_dpi_change_message(self, dpi):
          """Show message to restart Spyder since the DPI scale changed."""
          if not self.show_dpi_message:
              return
  
          if self.current_dpi != dpi:
              # Check the window state to not show the message if the window
              # is in fullscreen mode.
              window = self.window().windowHandle()
              if (window.windowState() == Qt.WindowFullScreen and
                      sys.platform == 'darwin'):
                  return
  
              self.dpi_change_dismiss_box = QCheckBox(
                  _("Hide this message during the current session"),
                  self
              )
  
              msgbox = QMessageBox(self)
              msgbox.setIcon(QMessageBox.Warning)
              msgbox.setText(
                  _
                  ("A monitor scale change was detected. <br><br>"
                   "We recommend restarting Spyder to ensure that it's properly "
                   "displayed. If you don't want to do that, please be sure to "
                   "activate the option<br><br><tt>Enable auto high DPI scaling"
                   "</tt><br><br>in <tt>Preferences > Application > "
                   "Interface</tt>, in case Spyder is not displayed "
                   "correctly.<br><br>"
                   "Do you want to restart Spyder?"))
              msgbox.addButton(_('Restart now'), QMessageBox.NoRole)
              dismiss_button = msgbox.addButton(
                  _('Dismiss'), QMessageBox.NoRole)
              msgbox.setCheckBox(self.dpi_change_dismiss_box)
              msgbox.setDefaultButton(dismiss_button)
              msgbox.finished.connect(
                  lambda result: self.handle_dpi_change_response(result, dpi))
              msgbox.open()
  
      def set_window_title(self):
          """Set window title."""
          if DEV is not None:
              title = u"Spyder %s (Python %s.%s)" % (__version__,
                                                     sys.version_info[0],
                                                     sys.version_info[1])
          elif running_in_mac_app() or is_pynsist():
              title = "Spyder"
          else:
              title = u"Spyder (Python %s.%s)" % (sys.version_info[0],
                                                  sys.version_info[1])
  
          if get_debug_level():
              title += u" [DEBUG MODE %d]" % get_debug_level()
  
          if self.window_title is not None:
              title += u' -- ' + to_text_string(self.window_title)
  
          # TODO: Remove self.projects reference once there's an API for setting
          # window title.
          if self.projects is not None:
              path = self.projects.get_active_project_path()
              if path:
                  path = path.replace(get_home_dir(), u'~')
                  title = u'{0} - {1}'.format(path, title)
  
          self.base_title = title
          self.setWindowTitle(self.base_title)
  
      # TODO: To be removed after all actions are moved to their corresponding
      # plugins
      def register_shortcut(self, qaction_or_qshortcut, context, name,
                            add_shortcut_to_tip=True, plugin_name=None):
          self.shortcuts.register_shortcut(
              qaction_or_qshortcut,
              context,
              name,
              add_shortcut_to_tip=add_shortcut_to_tip,
              plugin_name=plugin_name,
          )
  
      # --- Other
      def update_source_menu(self):
          """Update source menu options that vary dynamically."""
          # This is necessary to avoid an error at startup.
          # Fixes spyder-ide/spyder#14901
          try:
              self.editor.refresh_formatter_name()
          except AttributeError:
              pass
  
      def free_memory(self):
          """Free memory after event."""
          gc.collect()
  
      def plugin_focus_changed(self):
          """Focus has changed from one plugin to another"""
          self.update_edit_menu()
          self.update_search_menu()
  
      def show_shortcuts(self, menu):
          """Show action shortcuts in menu."""
          menu_actions = menu.actions()
          for action in menu_actions:
              if getattr(action, '_shown_shortcut', False):
                  # This is a SpyderAction
                  if action._shown_shortcut is not None:
                      action.setShortcut(action._shown_shortcut)
              elif action.menu() is not None:
                  # This is submenu, so we need to call this again
                  self.show_shortcuts(action.menu())
              else:
                  # We don't need to do anything for other elements
                  continue
  
      def hide_shortcuts(self, menu):
          """Hide action shortcuts in menu."""
          menu_actions = menu.actions()
          for action in menu_actions:
              if getattr(action, '_shown_shortcut', False):
                  # This is a SpyderAction
                  if action._shown_shortcut is not None:
                      action.setShortcut(QKeySequence())
              elif action.menu() is not None:
                  # This is submenu, so we need to call this again
                  self.hide_shortcuts(action.menu())
              else:
                  # We don't need to do anything for other elements
                  continue
  
      def hide_options_menus(self):
          """Hide options menu when menubar is pressed in macOS."""
          for plugin in self.widgetlist + self.thirdparty_plugins:
              if plugin.CONF_SECTION == 'editor':
                  editorstack = self.editor.get_current_editorstack()
                  editorstack.menu.hide()
              else:
                  try:
                      # New API
                      plugin.options_menu.hide()
                  except AttributeError:
                      # Old API
                      plugin._options_menu.hide()
  
      def get_focus_widget_properties(self):
          """Get properties of focus widget
          Returns tuple (widget, properties) where properties is a tuple of
          booleans: (is_console, not_readonly, readwrite_editor)"""
          from spyder.plugins.editor.widgets.base import TextEditBaseWidget
          from spyder.plugins.ipythonconsole.widgets import ControlWidget
          widget = QApplication.focusWidget()
  
          textedit_properties = None
          if isinstance(widget, (TextEditBaseWidget, ControlWidget)):
              console = isinstance(widget, ControlWidget)
              not_readonly = not widget.isReadOnly()
              readwrite_editor = not_readonly and not console
              textedit_properties = (console, not_readonly, readwrite_editor)
          return widget, textedit_properties
  
      def update_edit_menu(self):
          """Update edit menu"""
          widget, textedit_properties = self.get_focus_widget_properties()
          if textedit_properties is None: # widget is not an editor/console
              return
          # !!! Below this line, widget is expected to be a QPlainTextEdit
          #     instance
          console, not_readonly, readwrite_editor = textedit_properties
  
          # Editor has focus and there is no file opened in it
          if (not console and not_readonly and self.editor
                  and not self.editor.is_file_opened()):
              return
  
          # Disabling all actions to begin with
          for child in self.edit_menu.actions():
              child.setEnabled(False)
  
          self.selectall_action.setEnabled(True)
  
          # Undo, redo
          self.undo_action.setEnabled( readwrite_editor \
                                       and widget.document().isUndoAvailable() )
          self.redo_action.setEnabled( readwrite_editor \
                                       and widget.document().isRedoAvailable() )
  
          # Copy, cut, paste, delete
          has_selection = widget.has_selected_text()
          self.copy_action.setEnabled(has_selection)
          self.cut_action.setEnabled(has_selection and not_readonly)
          self.paste_action.setEnabled(not_readonly)
  
          # Comment, uncomment, indent, unindent...
          if not console and not_readonly:
              # This is the editor and current file is writable
              if self.editor:
                  for action in self.editor.edit_menu_actions:
                      action.setEnabled(True)
  
      def update_search_menu(self):
          """Update search menu"""
          # Disabling all actions except the last one
          # (which is Find in files) to begin with
          for child in self.search_menu.actions()[:-1]:
              child.setEnabled(False)
  
          widget, textedit_properties = self.get_focus_widget_properties()
          if textedit_properties is None: # widget is not an editor/console
              return
  
          # !!! Below this line, widget is expected to be a QPlainTextEdit
          #     instance
          console, not_readonly, readwrite_editor = textedit_properties
  
          # Find actions only trigger an effect in the Editor
          if not console:
              for action in self.search_menu.actions():
                  try:
                      action.setEnabled(True)
                  except RuntimeError:
                      pass
  
          # Disable the replace action for read-only files
          if len(self.search_menu_actions) > 3:
              self.search_menu_actions[3].setEnabled(readwrite_editor)
  
      def createPopupMenu(self):
          return self.application.get_application_context_menu(parent=self)
  
      def set_splash(self, message):
          """Set splash message"""
          if self.splash is None:
              return
          if message:
              logger.info(message)
          self.splash.show()
          self.splash.showMessage(message,
                                  int(Qt.AlignBottom | Qt.AlignCenter |
                                      Qt.AlignAbsolute),
                                  QColor(Qt.white))
          QApplication.processEvents()
  
      def closeEvent(self, event):
          """closeEvent reimplementation"""
          if self.closing(True):
              event.accept()
          else:
              event.ignore()
  
      def resizeEvent(self, event):
          """Reimplement Qt method"""
          if not self.isMaximized() and not self.layouts.get_fullscreen_flag():
              self.window_size = self.size()
          QMainWindow.resizeEvent(self, event)
  
          # To be used by the tour to be able to resize
          self.sig_resized.emit(event)
  
      def moveEvent(self, event):
          """Reimplement Qt method"""
          if not self.isMaximized() and not self.layouts.get_fullscreen_flag():
              self.window_position = self.pos()
          QMainWindow.moveEvent(self, event)
  
          # To be used by the tour to be able to move
          self.sig_moved.emit(event)
  
      def hideEvent(self, event):
          """Reimplement Qt method"""
          try:
              for plugin in (self.widgetlist + self.thirdparty_plugins):
                  # TODO: Remove old API
                  try:
                      # New API
                      if plugin.get_widget().isAncestorOf(
                              self.last_focused_widget):
                          plugin.change_visibility(True)
                  except AttributeError:
                      # Old API
                      if plugin.isAncestorOf(self.last_focused_widget):
                          plugin._visibility_changed(True)
  
              QMainWindow.hideEvent(self, event)
          except RuntimeError:
              QMainWindow.hideEvent(self, event)
  
      def change_last_focused_widget(self, old, now):
          """To keep track of to the last focused widget"""
          if (now is None and QApplication.activeWindow() is not None):
              QApplication.activeWindow().setFocus()
              self.last_focused_widget = QApplication.focusWidget()
          elif now is not None:
              self.last_focused_widget = now
  
          self.previous_focused_widget =  old
  
      def closing(self, cancelable=False):
          """Exit tasks"""
          if self.already_closed or self.is_starting_up:
              return True
  
          if cancelable and CONF.get('main', 'prompt_on_exit'):
              reply = QMessageBox.critical(self, 'Spyder',
                                           'Do you really want to exit?',
                                           QMessageBox.Yes, QMessageBox.No)
              if reply == QMessageBox.No:
                  return False
  
          if CONF.get('main', 'single_instance') and self.open_files_server:
              self.open_files_server.close()
  
          # Internal plugins
          for plugin in (self.widgetlist + self.thirdparty_plugins):
              # New API
              try:
                  if isinstance(plugin, SpyderDockablePlugin):
                      plugin.close_window()
                  if not plugin.on_close(cancelable):
                      return False
              except AttributeError:
                  pass
  
              # Old API
              try:
                  plugin._close_window()
                  if not plugin.closing_plugin(cancelable):
                      return False
              except AttributeError:
                  pass
  
          # New API: External plugins
          for plugin_name, plugin in self._EXTERNAL_PLUGINS.items():
              try:
                  if isinstance(plugin, SpyderDockablePlugin):
                      plugin.close_window()
  
                  if not plugin.on_close(cancelable):
                      return False
              except AttributeError as e:
                  logger.error(str(e))
  
          # Save window settings *after* closing all plugin windows, in order
          # to show them in their previous locations in the next session.
          # Fixes spyder-ide/spyder#12139
          prefix = 'window' + '/'
          self.layouts.save_current_window_settings(prefix)
  
          self.already_closed = True
          return True
  
      def add_dockwidget(self, plugin):
          """
          Add a plugin QDockWidget to the main window.
          """
          try:
              # New API
              if plugin.is_compatible:
                  dockwidget, location = plugin.create_dockwidget(self)
                  self.addDockWidget(location, dockwidget)
                  self.widgetlist.append(plugin)
          except AttributeError:
              # Old API
              if plugin._is_compatible:
                  dockwidget, location = plugin._create_dockwidget()
                  self.addDockWidget(location, dockwidget)
                  self.widgetlist.append(plugin)
  
      @Slot()
      def global_callback(self):
          """Global callback"""
          widget = QApplication.focusWidget()
          action = self.sender()
          callback = from_qvariant(action.data(), to_text_string)
          from spyder.plugins.editor.widgets.base import TextEditBaseWidget
          from spyder.plugins.ipythonconsole.widgets import ControlWidget
  
          if isinstance(widget, (TextEditBaseWidget, ControlWidget)):
              getattr(widget, callback)()
          else:
              return
  
      def redirect_internalshell_stdio(self, state):
          if state:
              self.console.redirect_stds()
          else:
              self.console.restore_stds()
  
      def open_external_console(self, fname, wdir, args, interact, debug, python,
                                python_args, systerm, post_mortem=False):
          """Open external console"""
          if systerm:
              # Running script in an external system terminal
              try:
                  if CONF.get('main_interpreter', 'default'):
                      executable = get_python_executable()
                  else:
                      executable = CONF.get('main_interpreter', 'executable')
                  programs.run_python_script_in_terminal(
                          fname, wdir, args, interact, debug, python_args,
                          executable)
              except NotImplementedError:
                  QMessageBox.critical(self, _("Run"),
                                       _("Running an external system terminal "
                                         "is not supported on platform %s."
                                         ) % os.name)
  
      def open_file(self, fname, external=False):
          """
          Open filename with the appropriate application
          Redirect to the right widget (txt -> editor, spydata -> workspace, ...)
          or open file outside Spyder (if extension is not supported)
          """
          fname = to_text_string(fname)
          ext = osp.splitext(fname)[1]
          if encoding.is_text_file(fname):
              self.editor.load(fname)
          elif self.variableexplorer is not None and ext in IMPORT_EXT:
              self.variableexplorer.import_data(fname)
          elif not external:
              fname = file_uri(fname)
              start_file(fname)
  
      def open_external_file(self, fname):
          """
          Open external files that can be handled either by the Editor or the
          variable explorer inside Spyder.
          """
          # Check that file exists
          fname = encoding.to_unicode_from_fs(fname)
          if osp.exists(osp.join(CWD, fname)):
              fpath = osp.join(CWD, fname)
          elif osp.exists(fname):
              fpath = fname
          else:
              return
  
          # Don't open script that starts Spyder at startup.
          # Fixes issue spyder-ide/spyder#14483
          if sys.platform == 'darwin' and 'bin/spyder' in fname:
              return
  
          if osp.isfile(fpath):
              self.open_file(fpath, external=True)
          elif osp.isdir(fpath):
              QMessageBox.warning(
                  self, _("Error"),
                  _('To open <code>{fpath}</code> as a project with Spyder, '
                    'please use <code>spyder -p "{fname}"</code>.')
                  .format(fpath=osp.normpath(fpath), fname=fname)
              )
  
      # --- Path Manager
      # ------------------------------------------------------------------------
      def load_python_path(self):
          """Load path stored in Spyder configuration folder."""
          if osp.isfile(self.SPYDER_PATH):
              with open(self.SPYDER_PATH, 'r', encoding='utf-8') as f:
                  path = f.read().splitlines()
              self.path = tuple(name for name in path if osp.isdir(name))
  
          if osp.isfile(self.SPYDER_NOT_ACTIVE_PATH):
              with open(self.SPYDER_NOT_ACTIVE_PATH, 'r',
                        encoding='utf-8') as f:
                  not_active_path = f.read().splitlines()
              self.not_active_path = tuple(name for name in not_active_path
                                           if osp.isdir(name))
  
      def save_python_path(self, new_path_dict):
          """
          Save path in Spyder configuration folder.
  
          `new_path_dict` is an OrderedDict that has the new paths as keys and
          the state as values. The state is `True` for active and `False` for
          inactive.
          """
          path = [p for p in new_path_dict]
          not_active_path = [p for p in new_path_dict if not new_path_dict[p]]
          try:
              encoding.writelines(path, self.SPYDER_PATH)
              encoding.writelines(not_active_path, self.SPYDER_NOT_ACTIVE_PATH)
          except EnvironmentError as e:
              logger.error(str(e))
          CONF.set('main', 'spyder_pythonpath', self.get_spyder_pythonpath())
  
      def get_spyder_pythonpath_dict(self):
          """
          Return Spyder PYTHONPATH.
  
          The returned ordered dictionary has the paths as keys and the state
          as values. The state is `True` for active and `False` for inactive.
  
          Example:
              OrderedDict([('/some/path, True), ('/some/other/path, False)])
          """
          self.load_python_path()
  
          path_dict = OrderedDict()
          for path in self.path:
              path_dict[path] = path not in self.not_active_path
  
          for path in self.project_path:
              path_dict[path] = True
  
          return path_dict
  
      def get_spyder_pythonpath(self):
          """
          Return Spyder PYTHONPATH.
          """
          path_dict = self.get_spyder_pythonpath_dict()
          path = [k for k, v in path_dict.items() if v]
          return path
  
      def update_python_path(self, new_path_dict):
          """Update python path on Spyder interpreter and kernels."""
          # Load previous path
          path_dict = self.get_spyder_pythonpath_dict()
  
          # Save path
          if path_dict != new_path_dict:
              # It doesn't include the project_path
              self.save_python_path(new_path_dict)
  
          # Load new path
          new_path_dict_p = self.get_spyder_pythonpath_dict()  # Includes project
  
          # Update Spyder interpreter
          for path in path_dict:
              while path in sys.path:
                  sys.path.remove(path)
  
          for path, active in reversed(new_path_dict_p.items()):
              if active:
                  sys.path.insert(1, path)
  
          # Any plugin that needs to do some work based on this signal should
          # connect to it on plugin registration
          self.sig_pythonpath_changed.emit(path_dict, new_path_dict_p)
  
      @Slot()
      def show_path_manager(self):
          """Show path manager dialog."""
          from spyder.widgets.pathmanager import PathManager
          read_only_path = tuple(self.projects.get_pythonpath())
          dialog = PathManager(self, self.path, read_only_path,
                               self.not_active_path, sync=True)
          self._path_manager = dialog
          dialog.sig_path_changed.connect(self.update_python_path)
          dialog.redirect_stdio.connect(self.redirect_internalshell_stdio)
          dialog.show()
  
      def pythonpath_changed(self):
          """Project's PYTHONPATH contribution has changed."""
          self.project_path = tuple(self.projects.get_pythonpath())
          path_dict = self.get_spyder_pythonpath_dict()
          self.update_python_path(path_dict)
  
      #---- Preferences
      def apply_settings(self):
          """Apply main window settings."""
          qapp = QApplication.instance()
  
          # Set 'gtk+' as the default theme in Gtk-based desktops
          # Fixes spyder-ide/spyder#2036.
          if is_gtk_desktop() and ('GTK+' in QStyleFactory.keys()):
              try:
                  qapp.setStyle('gtk+')
              except:
                  pass
  
          default = self.DOCKOPTIONS
          if CONF.get('main', 'vertical_tabs'):
              default = default|QMainWindow.VerticalTabs
          self.setDockOptions(default)
  
          self.apply_panes_settings()
  
          if CONF.get('main', 'use_custom_cursor_blinking'):
              qapp.setCursorFlashTime(
                  CONF.get('main', 'custom_cursor_blinking'))
          else:
              qapp.setCursorFlashTime(self.CURSORBLINK_OSDEFAULT)
  
      def apply_panes_settings(self):
          """Update dockwidgets features settings."""
          for plugin in (self.widgetlist + self.thirdparty_plugins):
              features = plugin.dockwidget.FEATURES
  
              plugin.dockwidget.setFeatures(features)
  
              try:
                  # New API
                  margin = 0
                  if CONF.get('main', 'use_custom_margin'):
                      margin = CONF.get('main', 'custom_margin')
                  plugin.update_margins(margin)
              except AttributeError:
                  # Old API
                  plugin._update_margins()
  
      @Slot()
      def show_preferences(self):
          """Edit Spyder preferences."""
          self.preferences.open_dialog(self.prefs_dialog_size)
  
      def set_prefs_size(self, size):
          """Save preferences dialog size."""
          self.prefs_dialog_size = size
  
      # -- Open files server
      def start_open_files_server(self):
          self.open_files_server.setsockopt(socket.SOL_SOCKET,
                                            socket.SO_REUSEADDR, 1)
          port = select_port(default_port=OPEN_FILES_PORT)
          CONF.set('main', 'open_files_port', port)
          self.open_files_server.bind(('127.0.0.1', port))
          self.open_files_server.listen(20)
          while 1:  # 1 is faster than True
              try:
                  req, dummy = self.open_files_server.accept()
              except socket.error as e:
                  # See spyder-ide/spyder#1275 for details on why errno EINTR is
                  # silently ignored here.
                  eintr = errno.WSAEINTR if os.name == 'nt' else errno.EINTR
                  # To avoid a traceback after closing on Windows
                  if e.args[0] == eintr:
                      continue
                  # handle a connection abort on close error
                  enotsock = (errno.WSAENOTSOCK if os.name == 'nt'
                              else errno.ENOTSOCK)
                  if e.args[0] in [errno.ECONNABORTED, enotsock]:
                      return
                  raise
              fname = req.recv(1024)
              fname = fname.decode('utf-8')
              self.sig_open_external_file.emit(fname)
              req.sendall(b' ')
  
      # ---- Quit and restart, and reset spyder defaults
      @Slot()
      def reset_spyder(self):
          """
          Quit and reset Spyder and then Restart application.
          """
          answer = QMessageBox.warning(self, _("Warning"),
               _("Spyder will restart and reset to default settings: <br><br>"
                 "Do you want to continue?"),
               QMessageBox.Yes | QMessageBox.No)
          if answer == QMessageBox.Yes:
              self.restart(reset=True)
  
      @Slot()
      def restart(self, reset=False):
          """Wrapper to handle plugins request to restart Spyder."""
          self.application.restart(reset=reset)
  
      # ---- Global Switcher
      def open_switcher(self, symbol=False):
          """Open switcher dialog box."""
          if self.switcher is not None and self.switcher.isVisible():
              self.switcher.clear()
              self.switcher.hide()
              return
          if symbol:
              self.switcher.set_search_text('@')
          else:
              self.switcher.set_search_text('')
              self.switcher.setup()
          self.switcher.show()
  
          # Note: The +6 pixel on the top makes it look better
          # FIXME: Why is this using the toolbars menu? A: To not be on top of
          # the toolbars.
          # Probably toolbars should be taken into account for this 'delta' only
          # when are visible
          delta_top = (self.toolbar.toolbars_menu.geometry().height() +
                       self.menuBar().geometry().height() + 6)
  
          self.switcher.set_position(delta_top)
  
      def open_symbolfinder(self):
          """Open symbol list management dialog box."""
          self.open_switcher(symbol=True)
  
      def create_switcher(self):
          """Create switcher dialog instance."""
          if self.switcher is None:
              from spyder.widgets.switcher import Switcher
              self.switcher = Switcher(self)
  
          return self.switcher
  
      # --- For OpenGL
      def _test_setting_opengl(self, option):
          """Get the current OpenGL implementation in use"""
          if option == 'software':
              return QCoreApplication.testAttribute(Qt.AA_UseSoftwareOpenGL)
          elif option == 'desktop':
              return QCoreApplication.testAttribute(Qt.AA_UseDesktopOpenGL)
          elif option == 'gles':
              return QCoreApplication.testAttribute(Qt.AA_UseOpenGLES)
  
  
  #==============================================================================
  # Main
  #==============================================================================
  def main(options, args):
      """Main function"""
      # **** For Pytest ****
      if running_under_pytest():
          if CONF.get('main', 'opengl') != 'automatic':
              option = CONF.get('main', 'opengl')
              set_opengl_implementation(option)
  
          app = create_application()
          window = create_window(MainWindow, app, None, options, None)
          return window
  
      # **** Handle hide_console option ****
      if options.show_console:
          print("(Deprecated) --show console does nothing, now the default "
                " behavior is to show the console, use --hide-console if you "
                "want to hide it")
  
      if set_attached_console_visible is not None:
          set_attached_console_visible(not options.hide_console
                                       or options.reset_config_files
                                       or options.reset_to_defaults
                                       or options.optimize
                                       or bool(get_debug_level()))
  
      # **** Set OpenGL implementation to use ****
      # This attribute must be set before creating the application.
      # See spyder-ide/spyder#11227
      if options.opengl_implementation:
          option = options.opengl_implementation
          set_opengl_implementation(option)
      else:
          if CONF.get('main', 'opengl') != 'automatic':
              option = CONF.get('main', 'opengl')
              set_opengl_implementation(option)
  
      # **** Set high DPI scaling ****
      # This attribute must be set before creating the application.
      if hasattr(Qt, 'AA_EnableHighDpiScaling'):
          QCoreApplication.setAttribute(Qt.AA_EnableHighDpiScaling,
                                        CONF.get('main', 'high_dpi_scaling'))
  
      # **** Set debugging info ****
      setup_logging(options)
  
      # **** Create the application ****
      app = create_application()
  
      # **** Create splash screen ****
      splash = create_splash_screen()
      if splash is not None:
          splash.show()
          splash.showMessage(
              _("Initializing..."),
              int(Qt.AlignBottom | Qt.AlignCenter | Qt.AlignAbsolute),
              QColor(Qt.white)
          )
          QApplication.processEvents()
  
      if options.reset_to_defaults:
          # Reset Spyder settings to defaults
          CONF.reset_to_defaults()
          return
      elif options.optimize:
          # Optimize the whole Spyder's source code directory
          import spyder
          programs.run_python_script(module="compileall",
                                     args=[spyder.__path__[0]], p_args=['-O'])
          return
  
      # **** Read faulthandler log file ****
      faulthandler_file = get_conf_path('faulthandler.log')
      previous_crash = ''
      if osp.exists(faulthandler_file):
          with open(faulthandler_file, 'r') as f:
              previous_crash = f.read()
  
          # Remove file to not pick it up for next time.
          try:
              dst = get_conf_path('faulthandler.log.old')
              shutil.move(faulthandler_file, dst)
          except Exception:
              pass
      CONF.set('main', 'previous_crash', previous_crash)
  
      # **** Set color for links ****
      set_links_color(app)
  
      # **** Create main window ****
      mainwindow = None
      try:
          if PY3 and options.report_segfault:
              import faulthandler
              with open(faulthandler_file, 'w') as f:
                  faulthandler.enable(file=f)
                  mainwindow = create_window(
                      MainWindow, app, splash, options, args
                  )
          else:
              mainwindow = create_window(MainWindow, app, splash, options, args)
      except FontError:
          QMessageBox.information(None, "Spyder",
                  "Spyder was unable to load the <i>Spyder 3</i> "
                  "icon theme. That's why it's going to fallback to the "
                  "theme used in Spyder 2.<br><br>"
                  "For that, please close this window and start Spyder again.")
          CONF.set('appearance', 'icon_theme', 'spyder 2')
      if mainwindow is None:
          # An exception occurred
          if splash is not None:
              splash.hide()
          return
  
      ORIGINAL_SYS_EXIT()
  
  
  if __name__ == "__main__":
      main()
  