PR: Use Spyder prefs to set light/dark notebook theme

spyder_notebook/notebookplugin.py

@@ -145,7 +145,7 @@ def _handle_switcher_selection(self, item, mode, search_text):
         corresponds to this plugin, then ignore it. Otherwise, switch to
         selected item in notebook plugin and hide the switcher.
         """
-        if item.get_section() != self.get_title():
+        if item.get_section() != self.get_name():
             return
 
         client = item.get_data()

spyder_notebook/server/main.py

@@ -4,18 +4,29 @@
 """Entry point for server rendering notebooks for Spyder."""
 
 import os
-from notebook.app import aliases, JupyterNotebookApp, NotebookBaseHandler
+from notebook.app import (
+    aliases, flags, JupyterNotebookApp, NotebookBaseHandler)
 from tornado import web
-from traitlets import default, Unicode
+from traitlets import default, Bool, Unicode
 
 HERE = os.path.dirname(__file__)
 
 aliases['info-file'] = 'SpyderNotebookApp.info_file_cmdline'
 
+flags['dark'] = (
+    {'SpyderNotebookApp': {'dark_theme': True}},
+    'Use dark theme when rendering notebooks'
+)
+
 
 class SpyderNotebookHandler(NotebookBaseHandler):
     """A notebook page handler for Spyder."""
 
+    def get_page_config(self):
+        page_config = super().get_page_config()
+        page_config['darkTheme'] = self.extensionapp.dark_theme
+        return page_config
+
     @web.authenticated
     def get(self, path=None):
         """Get the notebook page."""
@@ -30,7 +41,15 @@ class SpyderNotebookApp(JupyterNotebookApp):
     name = 'spyder_notebook'
     file_url_prefix = "/spyder-notebooks"
 
+    flags = dict(flags)
     aliases = dict(aliases)
+
+    dark_theme = Bool(
+        False, config=True,
+        help='Whether to use dark theme when rendering notebooks')
+
+    flags = flags
+
     info_file_cmdline = Unicode(
         '', config=True,
         help='Name of file in Jupyter runtime dir with connection info')

spyder_notebook/server/packages/application-extension/src/index.ts

@@ -9,6 +9,10 @@ import {
   JupyterFrontEndPlugin
 } from '@jupyterlab/application';
 
+import { IThemeManager } from '@jupyterlab/apputils';
+
+import { PageConfig } from '@jupyterlab/coreutils';
+
 import { IDocumentManager } from '@jupyterlab/docmanager';
 
 import { IMainMenu } from '@jupyterlab/mainmenu';
@@ -80,12 +84,33 @@ const menus: JupyterFrontEndPlugin<void> = {
   }
 };
 
+/**
+ * A plugin to sync the notebook theme with the Spyder preferences
+ *
+ * On startup, read the `darkTheme` option from `PageConfig` and then set the
+ * notebook theme accordingly. This option is set in `SpyderNotebookHandler`.
+ */
+const theme: JupyterFrontEndPlugin<void> = {
+  id: '@spyder-notebook/application-extension:theme',
+  requires: [IThemeManager],
+  autoStart: true,
+  activate: (app: JupyterFrontEnd, themeManager: IThemeManager) => {
+    const darkTheme = PageConfig.getOption('darkTheme');
+    if (darkTheme == 'true') {
+      themeManager.setTheme('JupyterLab Dark');
+    } else {
+      themeManager.setTheme('JupyterLab Light');
+    }
+  }
+};
+
 /**
  * Export the plugins as default.
  */
 const plugins: JupyterFrontEndPlugin<any>[] = [
   menus,
-  opener
+  opener,
+  theme
 ];
 
 export default plugins;

spyder_notebook/utils/servermanager.py

@@ -210,8 +210,9 @@ def start_server(self, filename, interpreter):
                      f'--notebook-dir={nbdir}',
                      '--ServerApp.password=',
                      f'--KernelSpecManager.kernel_spec_class={KERNELSPEC}']
+        if self.dark_theme:
+            arguments.append('--dark')
 
-        # TODO: Add support for dark theme
         logger.debug('Arguments: %s', repr(arguments))
 
         if DEV:

spyder_notebook/utils/tests/test_servermanager.py

@@ -74,14 +74,14 @@ def test_get_server_with_server(
         mock_start.assert_not_called()
 
 
-@pytest.mark.parametrize('under_home', [True, False])
-def test_start_server(mocker, under_home):
+@pytest.mark.parametrize(('dark', 'under_home'),
+                         [(True, True), (False, True), (False, False)])
+def test_start_server(mocker, dark, under_home):
     """
     Test that .start_server() starts a process with the correct arguments,
     that it stores the server process in `.servers`; and that it calls
     ._check_server_running().
     """
-    dark = 'not used'
     serverManager = ServerManager(dark)
     mock_check = mocker.patch.object(serverManager, '_check_server_started')
     mock_QProcess = mocker.patch(
@@ -100,6 +100,7 @@ def test_start_server(mocker, under_home):
     mock_QProcess.return_value.start.assert_called_once()
     args = mock_QProcess.return_value.start.call_args[0]
     assert '--notebook-dir={}'.format(nbdir) in args[1]
+    assert ('--dark' in args[1]) == dark
     assert len(serverManager.servers) == 1
     assert serverManager.servers[0].process == mock_QProcess.return_value
     assert serverManager.servers[0].notebook_dir == nbdir