help: Fall back to plain text when Qt WebEngine is not available

spyder/app/mainwindow.py

@@ -40,6 +40,9 @@
 from spyder import requirements
 requirements.check_qt()
 
+# Local imports
+from spyder.app.utils import HAVE_WEBENGINE
+
 #==============================================================================
 # Third-party imports
 #==============================================================================
@@ -748,7 +751,7 @@ def setup(self):
                     # https://github.com/spyder-ide/spyder/pull/
                     # 22196#issuecomment-2189377043
                     if PluginClass.REQUIRE_WEB_WIDGETS and (
-                        not WEBENGINE or
+                        not HAVE_WEBENGINE or
                         self._cli_options.no_web_widgets
                     ):
                         continue

spyder/app/utils.py

@@ -41,6 +41,12 @@
 except Exception:
     QQuickWindow = QSGRendererInterface = None
 
+try:
+    import qtpy.QtWebEngineWidgets
+except ImportError:
+    HAVE_WEBENGINE = False
+else:
+    HAVE_WEBENGINE = True
 
 root_logger = logging.getLogger()
 FILTER_NAMES = os.environ.get('SPYDER_FILTER_LOG', "").split(',')

spyder/plugins/help/plugin.py

@@ -50,7 +50,7 @@ class Help(SpyderDockablePlugin):
     CONF_FILE = False
     LOG_PATH = get_conf_path(CONF_SECTION)
     DISABLE_ACTIONS_WHEN_HIDDEN = False
-    REQUIRE_WEB_WIDGETS = True
+    REQUIRE_WEB_WIDGETS = False
     CAN_HANDLE_SEARCH_ACTIONS = True
 
     # Signals

spyder/plugins/help/widgets.py

@@ -27,6 +27,7 @@
 from spyder.api.widgets.comboboxes import SpyderComboBox
 from spyder.api.widgets.main_widget import PluginMainWidget
 from spyder.api.widgets.mixins import SpyderWidgetMixin
+from spyder.app.utils import HAVE_WEBENGINE
 from spyder.config.base import get_module_source_path
 from spyder.plugins.help.utils.sphinxify import (CSS_PATH, generate_context,
                                                  loading, usage, warning)
@@ -308,16 +309,18 @@ def __init__(self, name=None, plugin=None, parent=None):
         self.docstring = True  # TODO: What is this used for?
 
         # Widgets
-        self._sphinx_thread = SphinxThread(
-            None,
-            html_text_no_doc=warning(self.no_docs, css_path=self.css_path),
-            css_path=self.css_path,
-        )
         self.shell = None
         self.internal_console = None
         self.internal_shell = None
         self.plain_text = PlainText(self)
-        self.rich_text = RichText(self)
+
+        if HAVE_WEBENGINE:
+            self._sphinx_thread = SphinxThread(
+                None,
+                html_text_no_doc=warning(self.no_docs, css_path=self.css_path),
+                css_path=self.css_path,
+            )
+            self.rich_text = RichText(self)
 
         self.source_label = QLabel(_("Source"))
         self.source_label.ID = HelpWidgetToolbarItems.SourceLabel
@@ -347,20 +350,22 @@ def __init__(self, name=None, plugin=None, parent=None):
 
         # Layout
         self.stacked_widget = QStackedWidget()
-        self.stacked_widget.addWidget(self.rich_text)
+        if HAVE_WEBENGINE:
+            self.stacked_widget.addWidget(self.rich_text)
         self.stacked_widget.addWidget(self.plain_text)
 
         layout = QVBoxLayout()
         layout.addWidget(self.stacked_widget)
         self.setLayout(layout)
 
         # Signals
-        self._sphinx_thread.html_ready.connect(
-            self._on_sphinx_thread_html_ready)
-        self._sphinx_thread.error_msg.connect(
-            self._on_sphinx_thread_error_msg)
         self.object_combo.valid.connect(self.force_refresh)
-        self.rich_text.sig_link_clicked.connect(self.handle_link_clicks)
+        if HAVE_WEBENGINE:
+            self._sphinx_thread.html_ready.connect(
+                self._on_sphinx_thread_html_ready)
+            self._sphinx_thread.error_msg.connect(
+                self._on_sphinx_thread_error_msg)
+            self.rich_text.sig_link_clicked.connect(self.handle_link_clicks)
         self.source_combo.currentIndexChanged.connect(
             lambda x: self.source_changed())
         self.sig_render_started.connect(self.start_spinner)
@@ -404,18 +409,21 @@ def setup(self):
             toggled=True,
             option='show_source'
         )
+
         self.rich_text_action = self.create_action(
             name=HelpWidgetActions.ToggleRichMode,
             text=_("Rich Text"),
             toggled=True,
-            initial=self.get_conf('rich_mode'),
+            initial=self.get_conf('rich_mode') and HAVE_WEBENGINE,
             option='rich_mode'
         )
+        self.rich_text_action.setEnabled(HAVE_WEBENGINE)
+
         self.plain_text_action = self.create_action(
             name=HelpWidgetActions.TogglePlainMode,
             text=_("Plain Text"),
             toggled=True,
-            initial=self.get_conf('plain_mode'),
+            initial=self.get_conf('plain_mode') or not HAVE_WEBENGINE,
             option='plain_mode'
         )
         self.locked_action = self.create_action(
@@ -486,7 +494,10 @@ def setup(self):
             )
 
         self.source_changed()
-        self.switch_to_rich_text()
+        if self.get_conf("rich_mode") and HAVE_WEBENGINE:
+            self.switch_to_rich_text()
+        else:
+            self.switch_to_plain_text()
         self.show_intro_message()
 
         # Signals
@@ -526,16 +537,18 @@ def on_automatic_import_update(self, value):
 
     @on_conf_change(option='rich_mode')
     def on_rich_mode_update(self, value):
-        if value:
+        if value and HAVE_WEBENGINE:
             # Plain Text OFF / Rich text ON
             self.docstring = not value
             self.stacked_widget.setCurrentWidget(self.rich_text)
             self.get_action(HelpWidgetActions.ToggleShowSource).setChecked(
                 False)
+            self.get_action(HelpWidgetActions.ToggleRichMode).setChecked(True)
         else:
             # Plain Text ON / Rich text OFF
             self.docstring = value
             self.stacked_widget.setCurrentWidget(self.plain_text)
+            self.get_action(HelpWidgetActions.TogglePlainMode).setChecked(True)
 
         if self._should_display_welcome_page():
             self.show_intro_message()
@@ -666,23 +679,23 @@ def restore_text(self):
             cb = self._last_editor_cb
 
         if cb is None:
-            if self.get_conf('plain_mode'):
+            if self.get_conf('plain_mode') or not HAVE_WEBENGINE:
                 self.switch_to_plain_text()
             else:
                 self.switch_to_rich_text()
         else:
             func = cb[0]
             args = cb[1:]
             func(*args)
-            if func.__self__ is self.rich_text:
+            if HAVE_WEBENGINE and func.__self__ is self.rich_text:
                 self.switch_to_rich_text()
             else:
                 self.switch_to_plain_text()
 
     @property
     def find_widget(self):
         """Show find widget."""
-        if self.get_conf('plain_mode'):
+        if self.get_conf('plain_mode') or not HAVE_WEBENGINE:
             return self.plain_text.find_widget
         else:
             return self.rich_text.find_widget
@@ -792,7 +805,7 @@ def show_intro_message(self):
             shortcut_editor = shortcut_editor.replace('Ctrl', 'Cmd')
             shortcut_console = shortcut_console.replace('Ctrl', 'Cmd')
 
-        if self.get_conf('rich_mode'):
+        if self.get_conf('rich_mode') and HAVE_WEBENGINE:
             title = _("Usage")
             tutorial_message = _("New to Spyder? Read our")
             tutorial = _("tutorial")
@@ -811,9 +824,10 @@ def show_intro_message(self):
                                           css_path=self.css_path),
                                     QUrl.fromLocalFile(self.css_path))
         else:
-            install_sphinx = "\n\n%s" % _("Please consider installing Sphinx "
-                                          "to get documentation rendered in "
-                                          "rich text.")
+            # TOOD plain text fallback
+            install_sphinx = "\n\n%s" % _("Please consider installing "
+                                          "Qt WebEngine to get documentation "
+                                          "rendered in rich text.")
             if shortcut_editor == shortcut_console:
                 intro_message = (intro_message_eq + intro_message_common) % (
                     shortcut_editor, "\n\n", prefs)
@@ -838,10 +852,13 @@ def show_rich_text(self, text, collapse=False, img_path=''):
             Path to folder with additional images needed to correctly
             display the rich text help. Default is ''.
         """
-        self.switch_to_rich_text()
-        context = generate_context(collapse=collapse, img_path=img_path,
-                                   css_path=self.css_path)
-        self.render_sphinx_doc(text, context)
+        if HAVE_WEBENGINE:
+            self.switch_to_rich_text()
+            context = generate_context(collapse=collapse, img_path=img_path,
+                                       css_path=self.css_path)
+            self.render_sphinx_doc(text, context)
+        else:
+            self.show_plain_text(text)
 
     def show_plain_text(self, text):
         """
@@ -971,7 +988,7 @@ def set_editor_doc(self, help_data, force_refresh=False):
         self._last_editor_doc = help_data
         self.object_edit.setText(help_data['obj_text'])
 
-        if self.get_conf('rich_mode'):
+        if self.get_conf('rich_mode') and HAVE_WEBENGINE:
             self.render_sphinx_doc(help_data)
         else:
             self.set_plain_text(help_data, is_code=False)
@@ -1058,7 +1075,7 @@ def show_help(self, obj_text, ignore_unknown=False):
 
         is_code = False
 
-        if self.get_conf('rich_mode'):
+        if self.get_conf('rich_mode') and HAVE_WEBENGINE:
             self.render_sphinx_doc(doc, css_path=self.css_path)
             return doc is not None
         elif self.docstring:
@@ -1090,7 +1107,8 @@ def set_rich_text_font(self, font, fixed_font):
         fixed_font: QFont
             The current rich text font to use.
         """
-        self.rich_text.set_font(font, fixed_font=fixed_font)
+        if HAVE_WEBENGINE:
+            self.rich_text.set_font(font, fixed_font=fixed_font)
 
     def set_plain_text_font(self, font, color_scheme=None):
         """

spyder/plugins/ipythonconsole/tests/conftest.py

@@ -29,6 +29,7 @@
 from spyder.plugins.debugger.plugin import Debugger
 from spyder.plugins.help.utils.sphinxify import CSS_PATH
 from spyder.plugins.ipythonconsole.plugin import IPythonConsole
+import spyder.plugins.ipythonconsole.widgets.main_widget
 from spyder.utils.conda import get_list_conda_envs
 
 
@@ -90,19 +91,14 @@ def get_conda_test_env():
 # ---- Fixtures
 # =============================================================================
 @pytest.fixture
-def ipyconsole(qtbot, request, tmpdir):
+def ipyconsole(qtbot, request, tmpdir, monkeypatch):
     """IPython console fixture."""
     configuration = CONF
-    no_web_widgets = request.node.get_closest_marker('no_web_widgets')
 
     class MainWindowMock(QMainWindow):
 
         def __init__(self):
             # This avoids using the cli options passed to pytest
-            sys_argv = [sys.argv[0]]
-            self._cli_options = get_options(sys_argv)[0]
-            if no_web_widgets:
-                self._cli_options.no_web_widgets = True
             super().__init__()
 
         def __getattr__(self, attr):
@@ -190,6 +186,14 @@ def __getattr__(self, attr):
     # Conf css_path in the Appeareance plugin
     configuration.set('appearance', 'css_path', CSS_PATH)
 
+    no_web_widgets = request.node.get_closest_marker("no_web_widgets")
+    monkeypatch.setattr(
+        spyder.plugins.ipythonconsole.widgets.main_widget,
+        "HAVE_WEBENGINE",
+        not no_web_widgets,
+        raising=True,
+    )
+
     # Create the console and a new client and set environment
     os.environ['IPYCONSOLE_TESTING'] = 'True'
     window = MainWindowMock()

spyder/plugins/ipythonconsole/widgets/main_widget.py

@@ -36,6 +36,7 @@
 from spyder.api.config.decorators import on_conf_change
 from spyder.api.translations import _
 from spyder.api.widgets.main_widget import PluginMainWidget
+from spyder.app.utils import HAVE_WEBENGINE
 from spyder.config.base import get_home_dir, running_under_pytest
 from spyder.plugins.application.api import ApplicationActions
 from spyder.plugins.ipythonconsole.api import (
@@ -310,11 +311,7 @@ def __init__(self, name=None, plugin=None, parent=None):
         self._last_time_for_restart_dialog = None
 
         # Disable infowidget if requested by the user
-        self.enable_infowidget = True
-        if plugin:
-            cli_options = plugin.get_command_line_options()
-            if cli_options.no_web_widgets or not WEBENGINE:
-                self.enable_infowidget = False
+        self.enable_infowidget = HAVE_WEBENGINE
 
         # Attrs for testing
         self._testing = bool(os.environ.get('IPYCONSOLE_TESTING'))