2057 Allow Resetting GUI to Default Layout

docs/release_notes/next/dev-2057-reset_gui_to_default_layout

@@ -0,0 +1 @@
+#2057: Updated the code to allow resetting the GUI to the default layout, including floating windows, through both the View menu and the right-click menu.

docs/release_notes/next/feature-1619-lock_sidebar_for_spectrum_viewer_window

@@ -0,0 +1 @@
+#1619: Updated the code to prevent the sidebar from minimising at all.

mantidimaging/gui/windows/main/test/view_test.py

@@ -504,3 +504,51 @@ def test_live_viewer_asks_for_data_dir_no_path(self, mock_show_live_viewer, mock
         self.view.live_view_choose_directory()
 
         mock_show_live_viewer.assert_not_called()
+
+    @mock.patch("mantidimaging.gui.windows.main.view.QMessageBox")
+    def test_reset_layout_no_stacks_shows_error(self, mock_qmb: mock.Mock):
+        # Make get_all_stacks return empty
+        self.view.get_all_stacks = mock.Mock(return_value=[])  # type: ignore[method-assign]
+
+        self.view.reset_layout()
+
+        mock_qmb.critical.assert_called_once_with(self.view, "Error", "No stacks detected.")
+
+    def test_reset_layout_recreates_stacks(self):
+        # Fake stacks to recreate
+        fake_stacks = [mock.Mock(), mock.Mock(), mock.Mock()]
+        self.view.get_all_stacks = mock.Mock(return_value=fake_stacks)
+        self.view.create_new_stack = mock.Mock()
+
+        # Mock existing stack_visualisers
+        old1, old2 = mock.Mock(), mock.Mock()
+        self.presenter.stack_visualisers = {"a": old1, "b": old2}
+
+        self.view.reset_layout()
+
+        # Close created stack visualisers
+        old1.close.assert_called_once()
+        old2.close.assert_called_once()
+
+        # stack_visualisers cleared
+        self.assertEqual(self.presenter.stack_visualisers, {})
+
+        # create_new_stack called for each new stack
+        self.assertEqual(self.view.create_new_stack.call_count, len(fake_stacks))
+        for stack in fake_stacks:
+            self.view.create_new_stack.assert_any_call(stack)
+
+    @mock.patch("mantidimaging.gui.windows.main.view.QMessageBox")
+    def test_reset_layout_handles_exceptions(self, mock_qmb: mock.Mock):
+        # Force an exception inside reset_layout
+        self.view.get_all_stacks = mock.Mock(side_effect=AttributeError("fail"))  # type: ignore[method-assign]
+
+        self.view.reset_layout()
+
+        # Ensure critical error dialog is shown
+        mock_qmb.critical.assert_called_once()
+        args = mock_qmb.critical.call_args[0]
+        self.assertIn(
+            "Reset Layout could not completely reset the stacks",
+            args[2],
+        )

mantidimaging/gui/windows/main/view.py

@@ -79,6 +79,7 @@ class MainWindowView(BaseMainWindowView):
     menuWorkflow: QMenu
     menuImage: QMenu
     menuHelp: QMenu
+    menuView: QMenu
     menuTreeView: QMenu | None = None
 
     actionRecon: QAction
@@ -118,6 +119,8 @@ class MainWindowView(BaseMainWindowView):
     def __init__(self, open_dialogs: bool = True):
         super().__init__(None, "gui/ui/main_window.ui")
 
+        self.menuView = self.menuBar().addMenu("View")
+
         self.setWindowTitle("Mantid Imaging")
 
         self.presenter = MainWindowPresenter(self)
@@ -252,6 +255,18 @@ def setup_shortcuts(self) -> None:
 
         self.model_changed.connect(self.update_shortcuts)
 
+        self.actionResetLayout = QAction("Reset Layout", self)
+        self.actionResetLayout.setShortcut("Ctrl+Shift+R")
+        self.actionResetLayout.triggered.connect(self.reset_layout)
+
+        # Add Reset Layout action
+        self.actionResetLayout = QAction("Reset Layout", self)
+        self.actionResetLayout.setShortcut("Ctrl+Shift+R")
+        self.actionResetLayout.triggered.connect(self.reset_layout)
+
+        # Add to View menu (menuView always exists now)
+        self.menuView.addAction(self.actionResetLayout)
+
     def populate_image_menu(self) -> None:
         self.menuImage.clear()
         current_stack = self.current_showing_stack()
@@ -813,3 +828,25 @@ def show_stack_properties_dialog(self, stack_id: uuid.UUID, origin_dataset: Data
         assert stack is not None
         stack_properties_dialog = StackPropertiesDialog(self, stack, origin_dataset, stack_data_type)
         stack_properties_dialog.show()
+
+    def reset_layout(self):
+        """Close and reopen all stacks, showing critical GUI errors for unsuccessful actions."""
+        try:
+            # Close all open stack windows
+            for vis in list(self.presenter.stack_visualisers.values()):
+                vis.close()
+            self.presenter.stack_visualisers.clear()
+
+            # Get all stacks
+            stacks = self.get_all_stacks()
+            if not stacks:
+                QMessageBox.critical(self, "Error", "No stacks detected.")
+                return
+
+            # Recreate all stacks
+            for stack in stacks:
+                self.create_new_stack(stack)
+
+        except (AttributeError, RuntimeError, TypeError) as unexpected_error:
+            QMessageBox.critical(self, "Error",
+                                 f"Reset Layout could not completely reset the stacks.\n\nDetails: {unexpected_error}")

mantidimaging/gui/windows/stack_visualiser/view.py

@@ -61,7 +61,8 @@ def __init__(self, parent: MainWindowView, images: ImageStack):
                          ("Create sinograms from stack", lambda: self.presenter.notify(SVNotification.SWAP_AXES)),
                          ("Set ROI", self.set_roi), ("Copy ROI to clipboard", self.copy_roi_to_clipboard), ("", None),
                          ("Change window name", self.change_window_name_clicked),
-                         ("Goto projection", self.goto_projection), ("Goto angle", self.goto_angle)]
+                         ("Goto projection", self.goto_projection), ("Goto angle", self.goto_angle),
+                         ("Reset main window layout", self._main_window.reset_layout)]
         self._context_actions = self.build_context_menu()
 
         self.image_view = MIImageView(self)