PR: Allow plugins to hook into File > Open

spyder/api/plugins/new_api.py

@@ -19,7 +19,7 @@
 import os
 import os.path as osp
 import sys
-from typing import List, Union
+from typing import List, Optional, Union
 import warnings
 
 # Third party imports
@@ -298,6 +298,17 @@ class SpyderPluginV2(QObject, SpyderActionMixin, SpyderConfigurationObserver,
         The window state.
     """
 
+    sig_focused_plugin_changed = Signal(object)
+    """
+    This signal is emitted when the plugin with keyboard focus changes.
+
+    Parameters
+    ----------
+    plugin: Optional[SpyderDockablePlugin]
+        The plugin that currently has keyboard focus, or None if no dockable
+        plugin has focus.
+    """
+
     # ---- Private attributes
     # -------------------------------------------------------------------------
     # Define configuration name map for plugin to split configuration
@@ -972,6 +983,18 @@ class SpyderDockablePlugin(SpyderPluginV2):
     # the action to switch is called a second time.
     RAISE_AND_FOCUS = False
 
+    # List of file extensions which the plugin can open.
+    # If the user opens a file with one of these extensions, then the file
+    # will open in this plugin using the `open_file` function.
+    # Example: ['.ipynb'] for spyder-notebook
+    FILE_EXTENSIONS = []
+
+    # Whether the plugin can handle file actions.
+    # If set to true, then the `create_new_file`, `open_last_closed`,
+    # `save_file`, `save_file_as`, `save_copy_as`, `save_all` and `revert_file`
+    # functions will be called to handle the corresponding actions.
+    CAN_HANDLE_FILE_ACTIONS = False
+
     # ---- API: Available signals
     # -------------------------------------------------------------------------
     sig_focus_changed = Signal()
@@ -1053,6 +1076,135 @@ def __init__(self, parent, configuration):
         widget.sig_update_ancestor_requested.connect(
             self.sig_update_ancestor_requested)
 
+    # ---- API: Optional methods to override
+    # -------------------------------------------------------------------------
+    def create_new_file(self) -> None:
+        """
+        Create a new file inside the plugin.
+
+        This function will be called if the user create a new file using
+        the `File > New` menu item or the "New file" button in the toolbar,
+        and `CAN_HANDLE_FILE_ACTIONS` is set to `True`.
+        """
+        raise NotImplementedError
+
+    def open_file(self, filename: str):
+        """
+        Open file inside plugin.
+
+        This method will be called if the user wants to open a file with one
+        of the file name extensions listed in `FILE_EXTENSIONS`, so you need
+        to define that variable too.
+
+        Parameters
+        ----------
+        filename: str
+            The name of the file to be opened.
+        """
+        raise NotImplementedError
+
+    def open_last_closed_file(self) -> None:
+        """
+        Open the last closed file again.
+
+        This function will be called if the `File > Open last closed` menu item
+        is selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS`
+        is set to `True`.
+        """
+        raise NotImplementedError
+
+    def save_file(self) -> None:
+        """
+        Save the current file.
+
+        This function will be called if the user saves the current file using
+        the `File > Save` menu item or the "Save file" button in the toolbar,
+        the plugin has focus, and `CAN_HANDLE_FILE_ACTIONS` is set to `True`.
+        """
+        raise NotImplementedError
+
+    def save_file_as(self) -> None:
+        """
+        Save the current file under a different name.
+
+        This function will be called if the `File > Save as` menu item is
+        selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS` is
+        set to `True`.
+        """
+        raise NotImplementedError
+
+    def save_copy_as(self) -> None:
+        """
+        Save a copy of the current file under a different name.
+
+        This function will be called if the `File > Save copy as` menu item is
+        selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS` is
+        set to `True`.
+        """
+        raise NotImplementedError
+
+    def save_all(self) -> None:
+        """
+        Save all files that are opened in the plugin.
+
+        This function will be called if the user saves all files using the
+        `File > Save all` menu item or the "Save all" button in the toolbar,
+        the plugin has focus, and `CAN_HANDLE_FILE_ACTIONS` is set to `True`.
+        """
+        raise NotImplementedError
+
+    def revert_file(self) -> None:
+        """
+        Revert the current file to the version stored on disk.
+
+        This function will be called if the `File > Revert` menu item is
+        selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS` is
+        set to `True`.
+        """
+        raise NotImplementedError
+
+    def close_file(self) -> None:
+        """
+        Close the current file.
+
+        This function will be called if the `File > Close` menu item is
+        selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS` is
+        set to `True`.
+        """
+        raise NotImplementedError
+
+    def close_all(self) -> None:
+        """
+        Close all opened files.
+
+        This function will be called if the `File > Close all` menu item is
+        selected while the plugin has focus and `CAN_HANDLE_FILE_ACTIONS` is
+        set to `True`.
+        """
+        raise NotImplementedError
+
+    def get_current_filename(self) -> Optional[str]:
+        """
+        Return file name of the file that is currently displayed.
+
+        This is meant for plugins like the Editor or Notebook plugin which
+        editor display files. Return `None` if no file is displayed or if this
+        does not display files.
+
+        This function is used in the `Open file` action to initialize the
+        "Open file" dialog.
+        """
+        return None
+
+    def current_file_is_temporary(self) -> bool:
+        """
+        Return whether currently displayed file is a temporary file.
+
+        This function should only be called if a file is displayed, that is,
+        if `self.get_current_filename()` does not return `None`.
+        """
+        return False
+
     # ---- API: available methods
     # -------------------------------------------------------------------------
     def before_long_process(self, message):

spyder/api/widgets/menus.py

@@ -370,7 +370,6 @@ def _add_section(self, section, before_section=None):
                     self._sections.remove(after_section)
 
                 idx = self._sections.index(section)
-                idx = idx if (idx == 0) else (idx - 1)
                 self._sections.insert(idx, after_section)
 
     def _set_icons(self):

spyder/app/mainwindow.py

@@ -151,6 +151,17 @@ class MainWindow(QMainWindow, SpyderMainWindowMixin, SpyderShortcutsMixin):
         The window state.
     """
 
+    sig_focused_plugin_changed = Signal(object)
+    """
+    This signal is emitted when the another plugin received keyboard focus.
+
+    Parameters
+    ----------
+    plugin: Optional[SpyderDockablePlugin]
+        The plugin that currently has keyboard focus, or None if no dockable
+        plugin has focus.
+    """
+
     def __init__(self, splash=None, options=None):
         QMainWindow.__init__(self)
         qapp = QApplication.instance()
@@ -275,6 +286,7 @@ def signal_handler(signum, frame=None):
 
         # To keep track of the last focused widget
         self.last_focused_widget = None
+        self.last_focused_plugin = None
         self.previous_focused_widget = None
 
         # Server to open external files on a single instance
@@ -419,6 +431,8 @@ def register_plugin(self, plugin_name, external=False, omit_conf=False):
         self.sig_resized.connect(plugin.sig_mainwindow_resized)
         self.sig_window_state_changed.connect(
             plugin.sig_mainwindow_state_changed)
+        self.sig_focused_plugin_changed.connect(
+            plugin.sig_focused_plugin_changed)
 
         # Register plugin
         plugin._register(omit_conf=omit_conf)
@@ -1063,14 +1077,43 @@ def set_splash(self, message):
         QApplication.processEvents()
 
     def change_last_focused_widget(self, old, now):
-        """To keep track of to the last focused widget"""
+        """
+        Keep track of widget and plugin that has keyboard focus.
+
+        This function is connected to the `focusChanged` signal. It keeps
+        track of the widget and plugin that currently has keyboard focus, so
+        that we can give focus to the last focused widget when restoring it
+        after minimization. It also emits `sig_focused_plugin_changed` if the
+        plugin with focus has changed.
+
+        Parameters
+        ----------
+        old : Optional[QWidget]
+            Widget that used to have keyboard focus.
+        now : Optional[QWidget]
+            Widget that currently has keyboard focus.
+        """
         if (now is None and QApplication.activeWindow() is not None):
             QApplication.activeWindow().setFocus()
             self.last_focused_widget = QApplication.focusWidget()
         elif now is not None:
             self.last_focused_widget = now
 
-        self.previous_focused_widget =  old
+        self.previous_focused_widget = old
+
+        if self.last_focused_widget:
+            for plugin_name, plugin in self.get_dockable_plugins():
+                if self.is_plugin_available(plugin_name):
+                    plugin_widget = plugin.get_widget()
+                    if plugin_widget.isAncestorOf(self.last_focused_widget):
+                        focused_plugin = plugin
+                        break
+            else:
+                focused_plugin = None
+
+            if focused_plugin != self.last_focused_plugin:
+                self.last_focused_plugin = focused_plugin
+                self.sig_focused_plugin_changed.emit(focused_plugin)
 
     def closing(self, cancelable=False, close_immediately=False):
         """Exit tasks"""
@@ -1164,27 +1207,6 @@ def redirect_internalshell_stdio(self, state):
             else:
                 console.restore_stds()
 
-    def open_file(self, fname, external=False):
-        """
-        Open filename with the appropriate application
-        Redirect to the right widget (txt -> editor, spydata -> workspace, ...)
-        or open file outside Spyder (if extension is not supported)
-        """
-        fname = to_text_string(fname)
-        ext = osp.splitext(fname)[1]
-        editor = self.get_plugin(Plugins.Editor, error=False)
-        variableexplorer = self.get_plugin(
-            Plugins.VariableExplorer, error=False)
-
-        if encoding.is_text_file(fname):
-            if editor:
-                editor.load(fname)
-        elif variableexplorer is not None and ext in IMPORT_EXT:
-            variableexplorer.get_widget().import_data(fname)
-        elif not external:
-            fname = file_uri(fname)
-            start_file(fname)
-
     def get_initial_working_directory(self):
         """Return the initial working directory."""
         return self.INITIAL_CWD
@@ -1209,8 +1231,9 @@ def open_external_file(self, fname):
         if sys.platform == 'darwin' and 'bin/spyder' in fname:
             return
 
-        if osp.isfile(fpath):
-            self.open_file(fpath, external=True)
+        application = self.get_plugin(Plugins.Application, error=False)
+        if osp.isfile(fpath) and application:
+            application.open_file_in_plugin(fpath)
         elif osp.isdir(fpath):
             QMessageBox.warning(
                 self, _("Error"),

spyder/app/tests/test_mainwindow.py

@@ -3001,6 +3001,7 @@ def test_pylint_follows_file(qtbot, tmpdir, main_window):
         timeout=SHELL_TIMEOUT)
 
     pylint_plugin = main_window.get_plugin(Plugins.Pylint)
+    application_plugin = main_window.get_plugin(Plugins.Application)
 
     # Show pylint plugin
     pylint_plugin.dockwidget.show()
@@ -3014,7 +3015,7 @@ def test_pylint_follows_file(qtbot, tmpdir, main_window):
         fh = basedir.join('{}.py'.format(idx))
         fname = str(fh)
         fh.write('print("Hello world!")')
-        main_window.open_file(fh)
+        application_plugin.open_file_in_plugin(fname)
         qtbot.wait(200)
         assert fname == pylint_plugin.get_filename()
 
@@ -3029,7 +3030,7 @@ def test_pylint_follows_file(qtbot, tmpdir, main_window):
         fh = basedir.join('{}.py'.format(idx))
         fh.write('print("Hello world!")')
         fname = str(fh)
-        main_window.open_file(fh)
+        application_plugin.open_file_in_plugin(fname)
         qtbot.wait(200)
         assert fname == pylint_plugin.get_filename()