Enable Save action only if notebook is dirty

Enable the File > Save menu item and the Save button in the Spyder
toolbar only if there the current notebook is dirty (i.e., if there
is something to save).

Enable the Save All action only if any notebook is dirty. If the
user triggers this action, then only save notebooks that are dirty.

Author: jitseniesen

spyder_notebook/notebookplugin.py

@@ -84,6 +84,7 @@ def on_application_available(self) -> None:
         )
         widget = self.get_widget()
         widget.sig_new_recent_file.connect(application.add_recent_file)
+        widget.sig_enable_save_requested.connect(self._enable_save_actions)
 
     @on_plugin_available(plugin=Plugins.Preferences)
     def on_preferences_available(self):
@@ -106,6 +107,7 @@ def on_application_teardown(self) -> None:
         application = self.get_plugin(Plugins.Application)
         widget = self.get_widget()
         widget.sig_new_recent_file.disconnect(application.add_recent_file)
+        widget.sig_file_action_enabled.connect(self._enable_file_action)
 
     @on_plugin_teardown(plugin=Plugins.Preferences)
     def on_preferences_teardown(self):
@@ -261,3 +263,28 @@ def _handle_switcher_selection(self, item, mode, search_text):
         self.switch_to_plugin()
         switcher = self.get_plugin(Plugins.Switcher)
         switcher.hide()
+
+    def _enable_save_actions(
+            self,
+            save_enabled: bool,
+            save_all_enabled: bool
+        ) -> None:
+        """
+        Enable or disable file action for this plugin.
+        """
+        # Moving this import to the top of the file interferes with the
+        # async loop in Jupyter
+        from spyder.plugins.application.api import ApplicationActions
+
+        application = self.get_plugin(Plugins.Application, error=False)
+        if application:
+            application.enable_file_action(
+                ApplicationActions.SaveFile,
+                save_enabled,
+                self.NAME
+            )
+            application.enable_file_action(
+                ApplicationActions.SaveAll,
+                save_all_enabled,
+                self.NAME
+            )

spyder_notebook/widgets/main_widget.py

@@ -54,6 +54,19 @@ class NotebookMainWidgetRecentNotebooksMenuSections:
 
 class NotebookMainWidget(PluginMainWidget):
 
+    sig_enable_save_requested = Signal(bool, bool)
+    """
+    Request to enable or disable the Save and Save All actions.
+
+    Parameters
+    ----------
+    save_enabled: bool
+        True if the Save action should be enabled, False if it should disabled.
+    save_all_enabled: bool
+        True if the Save All action should be enabled, False if it should
+        disabled.
+    """
+
     sig_new_recent_file = Signal(str)
     """
     This signal is emitted when a file is opened or got a new name.
@@ -90,6 +103,9 @@ def __init__(self, name, plugin, parent):
             dark_theme=self.dark_theme
         )
         self.tabwidget.currentChanged.connect(self.refresh_plugin)
+        self.tabwidget.sig_refresh_save_actions_requested.connect(
+            self.refresh_save_actions
+        )
 
         # Widget layout
         layout = QVBoxLayout()
@@ -223,6 +239,7 @@ def open_previous_session(self):
             self.tabwidget.maybe_create_welcome_client()
             self.create_new_client()
             self.tabwidget.setCurrentIndex(0)  # bring welcome tab to top
+        self.refresh_save_actions()
 
     def open_notebook(self, filenames=None):
         """Open a notebook from file."""
@@ -255,7 +272,8 @@ def save_all(self) -> None:
         """
         for client_index in range(self.tabwidget.count()):
             client = self.tabwidget.widget(client_index)
-            self.tabwidget.save_notebook(client)
+            if self.tabwidget.can_save_client(client):
+                self.tabwidget.save_notebook(client)
 
     def save_as(self, close_after_save=True):
         """
@@ -272,6 +290,22 @@ def save_as(self, close_after_save=True):
         if old_filename != new_filename:
             self.sig_new_recent_file.emit(new_filename)
 
+    def refresh_save_actions(self):
+        """
+        Enable or disable 'Save' and 'Save All' actions.
+
+        The 'Save' action is enabled if the current notebook can be saved.
+        The 'Save all' action is enabled if any notebook can be saved.
+        """
+        current_index = self.tabwidget.currentIndex()
+        current_client = self.tabwidget.widget(current_index)
+        save_enabled = self.tabwidget.can_save_client(current_client)
+        save_all_enabled = any(
+            self.tabwidget.can_save_client(self.tabwidget.widget(index))
+            for index in range(self.tabwidget.count())
+        )
+        self.sig_enable_save_requested.emit(save_enabled, save_all_enabled)
+
     def close_notebook(self) -> None:
         """
         Close current notebook.

spyder_notebook/widgets/notebooktabwidget.py

@@ -14,7 +14,7 @@
 
 # Qt imports
 from qtpy.compat import getopenfilenames, getsavefilename
-from qtpy.QtCore import QEventLoop, QTimer
+from qtpy.QtCore import QEventLoop, QTimer, Signal
 from qtpy.QtWidgets import QMessageBox
 
 # Third-party imports
@@ -103,6 +103,11 @@ class NotebookTabWidget(Tabs, SpyderConfigurationAccessor):
         most recently closed one listed last.
     """
 
+    sig_refresh_save_actions_requested = Signal()
+    """
+    This signal is emitted when the save actions should be refreshed.
+    """
+
     def __init__(self, parent, server_manager, actions=None, menu=None,
                  corner_widgets=None, dark_theme=False):
         """
@@ -478,6 +483,25 @@ def is_welcome_client(client):
         """
         return client.get_filename() in [WELCOME, WELCOME_DARK]
 
+    @classmethod
+    def can_save_client(cls, client: NotebookClient) -> bool:
+        """
+        Return whether some client can be saved.
+
+        A client can be saved if it contains a notebook (i.e., it is not a
+        welcome client) and it is dirty.
+
+        Parameters
+        ----------
+        client : NotebookClient
+            Client under consideration.
+
+        Returns
+        -------
+        True if `client` can be saved, False otherwise.
+        """
+        return not cls.is_welcome_client(client) and client.dirty
+
     def add_tab(self, widget):
         """
         Add tab containing some notebook widget to the tabbed widget.
@@ -496,7 +520,8 @@ def handle_dirty_changed(self, new_value: bool) -> None:
         Handle signal that a notebook became dirty or not.
 
         Append a `*` to the filename of the notebook in the tab title if the
-        notebook is dirty.
+        notebook is dirty. Then signal that the save actions should be
+        refreshed.
 
         Parameters
         ----------
@@ -511,6 +536,7 @@ def handle_dirty_changed(self, new_value: bool) -> None:
             suffix = '*' if new_value else ''
             self.setTabText(index, notebook_client.get_short_name() + suffix)
             self.setTabToolTip(index, notebook_client.get_filename() + suffix)
+        self.sig_refresh_save_actions_requested.emit()
 
     def handle_server_started(self, process):
         """