Preferences: Standardize how tabs are created in config pages

- Now it's only necessary to call the create_tab method of
SpyderConfigPage to add tabs. Creating the tab widget and setting its
layout is done automatically by that method.
- This will allow us to easily control the properties of those tab
widgets in a single place.

spyder/plugins/application/confpage.py

@@ -18,8 +18,8 @@
 from qtpy.compat import from_qvariant
 from qtpy.QtCore import Qt
 from qtpy.QtWidgets import (QApplication, QButtonGroup, QGridLayout, QGroupBox,
-                            QHBoxLayout, QLabel, QMessageBox, QTabWidget,
-                            QVBoxLayout, QWidget)
+                            QHBoxLayout, QLabel, QMessageBox, QVBoxLayout,
+                            QWidget)
 
 from spyder.config.base import (_, DISABLED_LANGUAGES, LANGUAGE_CODES,
                                 is_conda_based_app, save_lang_conf)
@@ -236,21 +236,19 @@ def set_open_file(state):
 
         screen_resolution_layout.addLayout(screen_resolution_inner_layout)
         screen_resolution_group.setLayout(screen_resolution_layout)
+
         if sys.platform == "darwin" and not is_conda_based_app():
-            interface_tab = self.create_tab(screen_resolution_group,
-                                            interface_group, macOS_group)
+            self.create_tab(
+                _("Interface"),
+                [screen_resolution_group, interface_group, macOS_group]
+            )
         else:
-            interface_tab = self.create_tab(screen_resolution_group,
-                                            interface_group)
-
-        self.tabs = QTabWidget()
-        self.tabs.addTab(interface_tab, _("Interface"))
-        self.tabs.addTab(self.create_tab(advanced_widget),
-                         _("Advanced settings"))
+            self.create_tab(
+                _("Interface"),
+                [screen_resolution_group, interface_group]
+            )
 
-        vlayout = QVBoxLayout()
-        vlayout.addWidget(self.tabs)
-        self.setLayout(vlayout)
+        self.create_tab(_("Advanced settings"), advanced_widget)
 
     def apply_settings(self, options):
         if 'high_dpi_custom_scale_factors' in options:

spyder/plugins/editor/confpage.py

@@ -7,7 +7,7 @@
 """Editor config page."""
 
 from qtpy.QtWidgets import (QGridLayout, QGroupBox, QHBoxLayout, QLabel,
-                            QTabWidget, QVBoxLayout)
+                            QVBoxLayout)
 
 from spyder.api.config.decorators import on_conf_change
 from spyder.api.config.mixins import SpyderConfigurationObserver
@@ -333,27 +333,19 @@ def enable_tabwidth_spin(index):
         eol_group.setLayout(eol_layout)
 
         # --- Tabs ---
-        self.tabs = QTabWidget(self)
-        self.tabs.addTab(
-            self.create_tab(display_group, highlight_group, other_group),
-            _("Interface")
+        self.create_tab(
+            _("Interface"),
+            [display_group, highlight_group, other_group]
         )
 
-        self.tabs.addTab(
-            self.create_tab(automatic_group, indentation_group),
-            _("Source code")
-        )
+        self.create_tab(_("Source code"), [automatic_group, indentation_group])
 
-        self.tabs.addTab(
-            self.create_tab(templates_group, autosave_group, docstring_group,
-                            annotations_group, eol_group),
-            _("Advanced settings")
+        self.create_tab(
+            _("Advanced settings"),
+            [templates_group, autosave_group, docstring_group,
+             annotations_group, eol_group]
         )
 
-        vlayout = QVBoxLayout()
-        vlayout.addWidget(self.tabs)
-        self.setLayout(vlayout)
-
     @on_conf_change(
         option=('provider_configuration', 'lsp', 'values', 'format_on_save'),
         section='completions'

spyder/plugins/explorer/confpage.py

@@ -7,8 +7,8 @@
 """File explorer configuration page."""
 
 # Third party imports
-from qtpy.QtWidgets import (QTabWidget, QVBoxLayout, QWidget, QGroupBox,
-                            QLabel, QPushButton)
+from qtpy.QtWidgets import (QGroupBox, QLabel, QPushButton, QVBoxLayout,
+                            QWidget)
 
 # Local imports
 from spyder.api.preferences import PluginConfigPage
@@ -86,15 +86,8 @@ def setup_page(self):
         layout_file.addWidget(self.edit_file_associations)
         associations_widget.setLayout(layout_file)
 
-        self.tabs = QTabWidget()
-        self.tabs.addTab(self.create_tab(general_widget), _("General"))
-        self.tabs.addTab(self.create_tab(associations_widget),
-                         _("File associations"))
-
-        tab_layout = QVBoxLayout()
-        tab_layout.addWidget(self.tabs)
-
-        self.setLayout(tab_layout)
+        self.create_tab(_("General"), general_widget)
+        self.create_tab(_("File associations"), associations_widget)
 
         # Signals
         file_associations.sig_data_changed.connect(self.update_associations)

spyder/plugins/ipythonconsole/confpage.py

@@ -12,7 +12,7 @@
 # Third party imports
 from qtpy.QtCore import Qt
 from qtpy.QtWidgets import (QGridLayout, QGroupBox, QHBoxLayout, QLabel,
-                            QTabWidget, QVBoxLayout)
+                            QVBoxLayout)
 
 # Local imports
 from spyder.api.translations import _
@@ -368,29 +368,23 @@ def setup_page(self):
         windows_group.setLayout(windows_layout)
 
         # --- Tabs organization ---
-        self.tabs = QTabWidget(self)
-        self.tabs.addTab(
-            self.create_tab(display_group, confirmations_group, comp_group,
-                            source_code_group),
-            _("Interface")
+        self.create_tab(
+            _("Interface"),
+            [display_group, confirmations_group, comp_group, source_code_group]
         )
 
-        self.tabs.addTab(
-            self.create_tab(pylab_group, backend_group, inline_group),
-            _("Graphics")
+        self.create_tab(
+            _("Graphics"),
+            [pylab_group, backend_group, inline_group]
         )
 
-        self.tabs.addTab(
-            self.create_tab(run_lines_group, run_file_group),
-            _("Startup")
+        self.create_tab(
+            _("Startup"),
+            [run_lines_group, run_file_group]
         )
 
-        self.tabs.addTab(
-            self.create_tab(jedi_group, greedy_group, autocall_group,
-                            sympy_group, prompts_group, windows_group),
-            _("Advanced settings")
+        self.create_tab(
+            _("Advanced settings"),
+            [jedi_group, greedy_group, autocall_group, sympy_group,
+             prompts_group, windows_group]
         )
-
-        vlayout = QVBoxLayout()
-        vlayout.addWidget(self.tabs)
-        self.setLayout(vlayout)

spyder/plugins/preferences/widgets/config_widgets.py

@@ -889,16 +889,41 @@ def create_button(self, text, callback):
                 self.CONF_SECTION, opt))
         return btn
 
-    def create_tab(self, *widgets):
-        """Create simple tab widget page: widgets added in a vertical layout"""
-        widget = QWidget(self)
+    def create_tab(self, name, widgets):
+        """
+        Create a tab widget page.
+
+        Parameters
+        ----------
+        name: str
+            Name of the tab
+        widgets: list or QWidget
+            List of widgets to add to the tab. This can be also a single
+            widget.
+
+        Notes
+        -----
+        * Widgets are added in a vertical layout.
+        """
+        if self.tabs is None:
+            self.tabs = QTabWidget(self)
+
+            vlayout = QVBoxLayout()
+            vlayout.addWidget(self.tabs)
+            self.setLayout(vlayout)
+
+        if not isinstance(widgets, list):
+            widgets = [widgets]
+
+        tab = QWidget(self)
         layout = QVBoxLayout()
         layout.setContentsMargins(0, 0, 0, 0)
-        for widg in widgets:
-            layout.addWidget(widg)
+        for w in widgets:
+            layout.addWidget(w)
         layout.addStretch(1)
-        widget.setLayout(layout)
-        return widget
+        tab.setLayout(layout)
+
+        self.tabs.addTab(tab, name)
 
     def prompt_restart_required(self):
         """Prompt the user with a request to restart."""
@@ -922,24 +947,20 @@ def restart(self):
         """Restart Spyder."""
         self.main.restart(close_immediately=True)
 
-    def add_tab(self, Widget):
+    def _add_tab(self, Widget):
         widget = Widget(self)
+
         if self.tabs is None:
             # In case a preference page does not have any tabs, we need to
             # add a tab with the widgets that already exist and then add the
             # new tab.
-            self.tabs = QTabWidget()
             layout = self.layout()
-            main_widget = QWidget()
+            main_widget = QWidget(self)
             main_widget.setLayout(layout)
-            self.tabs.addTab(self.create_tab(main_widget),
-                             _('General'))
-            self.tabs.addTab(self.create_tab(widget),
-                             Widget.TITLE)
-            vlayout = QVBoxLayout()
-            vlayout.addWidget(self.tabs)
-            self.setLayout(vlayout)
+
+            self.create_tab(_('General'), main_widget)
+            self.create_tab(Widget.TITLE, widget)
         else:
-            self.tabs.addTab(self.create_tab(widget),
-                             Widget.TITLE)
+            self.create_tab(Widget.TITLE, widget)
+
         self.load_from_conf()

spyder/plugins/preferences/widgets/container.py

@@ -63,12 +63,12 @@ def _dialog_finished(result_code):
                     page = ConfigPage(plugin, dlg)
                     page.initialize()
                     for Tab in config_tabs.get(page_name, []):
-                        page.add_tab(Tab)
+                        page._add_tab(Tab)
                     dlg.add_page(page)
                 else:
                     page = plugin._create_configwidget(dlg, main_window)
                     for Tab in config_tabs.get(page_name, []):
-                        page.add_tab(Tab)
+                        page._add_tab(Tab)
                     dlg.add_page(page)
 
                 # Add separator after the last element of the most important

spyder/plugins/run/confpage.py

@@ -16,7 +16,7 @@
 from qtpy.QtCore import Qt
 from qtpy.QtWidgets import (QGroupBox, QLabel, QVBoxLayout, QComboBox,
                             QTableView, QAbstractItemView, QPushButton,
-                            QGridLayout, QHeaderView, QTabWidget, QWidget)
+                            QGridLayout, QHeaderView, QWidget)
 
 # Local imports
 from spyder.api.preferences import PluginConfigPage
@@ -239,13 +239,8 @@ def setup_page(self):
         executor_widget = QWidget()
         executor_widget.setLayout(vlayout)
 
-        self.tabs = QTabWidget()
-        self.tabs.addTab(self.create_tab(executor_widget), _("Run executors"))
-        self.tabs.addTab(
-            self.create_tab(run_widget), _("Editor interactions"))
-        main_layout = QVBoxLayout()
-        main_layout.addWidget(self.tabs)
-        self.setLayout(main_layout)
+        self.create_tab(_("Run executors"), executor_widget)
+        self.create_tab(_("Editor interactions"), run_widget)
 
     def executor_index_changed(self, index: int):
         # Save previous executor configuration