Add disconnect button, thonny#2328

thonny/backend.py

@@ -17,6 +17,7 @@
 import thonny
 from thonny import report_time
 from thonny.common import (  # TODO: try to get rid of this
+    ALL_EXPLAINED_STATUS_CODE,
     IGNORED_FILES_AND_DIRS,
     PROCESS_ACK,
     BackendEvent,
@@ -103,9 +104,15 @@ def handle_connection_error(self, error=None):
         message = "Connection lost"
         if error:
             message += " -- " + str(error)
+        self._send_output(
+            "\n", "stderr"
+        )  # in case we were at prompt or another line without newline
         self._send_output("\n" + message + "\n", "stderr")
-        self._send_output("\n" + "Use Stop/Restart to reconnect." + "\n", "stderr")
-        sys.exit(1)
+        self._send_output(
+            "\n" + "Click ☐ at the bottom of the window or use Stop/Restart to reconnect." + "\n",
+            "stderr",
+        )
+        sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
     def _current_command_is_interrupted(self):
         return getattr(self._current_command, "interrupted", False)
@@ -300,7 +307,7 @@ def _handle_normal_command(self, cmd: CommandToBackend) -> None:
             except Exception as e:
                 logger.exception("Exception while handling %r", cmd.name)
                 self._report_internal_exception("Exception while handling %r" % cmd.name)
-                sys.exit(1)
+                sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
         if response is False:
             # Command doesn't want to send any response
@@ -785,7 +792,7 @@ def _try_load_paramiko(self):
                 " Install it from 'Tools => Manage plug-ins' or via your system package manager.",
                 file=sys.stderr,
             )
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
     def _connect(self):
         from paramiko import SSHException
@@ -805,7 +812,7 @@ def _connect(self):
             print("Re-check your host, authentication method, password or keys.", file=sys.stderr)
             delete_stored_ssh_password()
 
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
     def _create_remote_process(self, cmd_items: List[str], cwd: str, env: Dict) -> RemoteProcess:
         import shlex

thonny/common.py

@@ -23,6 +23,7 @@
 OBJECT_LINK_END = "[/object_link_for_thonny]"
 REMOTE_PATH_MARKER = " :: "
 PROCESS_ACK = "OK"
+ALL_EXPLAINED_STATUS_CODE = 193
 
 IGNORED_FILES_AND_DIRS = [
     "System Volume Information",

thonny/plugins/micropython/bare_metal_backend.py

@@ -19,6 +19,7 @@
 from thonny import report_time
 from thonny.backend import UploadDownloadMixin, convert_newlines_if_has_shebang
 from thonny.common import (
+    ALL_EXPLAINED_STATUS_CODE,
     PROCESS_ACK,
     BackendEvent,
     EOFCommand,
@@ -1742,7 +1743,7 @@ def launch_bare_metal_backend(backend_class: Callable[..., BareMetalMicroPythonB
     try:
         if args["port"] is None:
             print("\nPort not defined", file=sys.stderr)
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
         elif args["port"] == "webrepl":
             connection = WebReplConnection(args["url"], args["password"])
         else:
@@ -1763,7 +1764,7 @@ def launch_bare_metal_backend(backend_class: Callable[..., BareMetalMicroPythonB
         msg = BackendEvent(event_type="ProgramOutput", stream_name="stderr", data=text)
         sys.stdout.write(serialize_message(msg) + "\n")
         sys.stdout.flush()
-        sys.exit(1)
+        sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
 
 if __name__ == "__main__":

thonny/plugins/micropython/mp_front.py

@@ -301,6 +301,9 @@ def _augment_dist_info(cls, dist_info: DistInfo) -> DistInfo:
 
         return dist_info
 
+    def needs_disconnect_button(self):
+        return True
+
 
 class BareMetalMicroPythonProxy(MicroPythonProxy):
     def __init__(self, clean):
@@ -505,6 +508,9 @@ def _show_error(self, text):
 
     def disconnect(self):
         self.destroy()
+        self._show_error(
+            "\nDisconnected.\n\nClick ☐ at the bottom of the window or use Stop/Restart to reconnect."
+        )
 
     def get_node_label(self):
         if "CircuitPython" in self._welcome_text:

thonny/plugins/micropython/os_mp_backend.py

@@ -18,7 +18,7 @@
 import thonny
 from thonny import report_time
 from thonny.backend import SshMixin
-from thonny.common import PROCESS_ACK, BackendEvent, serialize_message
+from thonny.common import ALL_EXPLAINED_STATUS_CODE, PROCESS_ACK, BackendEvent, serialize_message
 from thonny.plugins.micropython.bare_metal_backend import LF, NORMAL_PROMPT
 from thonny.plugins.micropython.connection import MicroPythonConnection
 from thonny.plugins.micropython.mp_back import (
@@ -75,7 +75,7 @@ def __init__(self, args):
             msg = BackendEvent(event_type="ProgramOutput", stream_name="stderr", data=text)
             sys.stdout.write(serialize_message(msg) + "\n")
             sys.stdout.flush()
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
         MicroPythonBackend.__init__(self, None, args)
 

thonny/plugins/micropython/subprocess_connection.py

@@ -1,6 +1,7 @@
 import signal
 import sys
 
+from thonny.common import ALL_EXPLAINED_STATUS_CODE
 from thonny.plugins.micropython.connection import MicroPythonConnection
 
 
@@ -15,7 +16,7 @@ def __init__(self, executable, args=[]):
                 "ERROR: This back-end requires a Python package named 'ptyprocess'.\n"
                 + "Install it via system package manager or 'Tools => Manage plug-ins'."
             )
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
         super().__init__()
         cmd = [executable] + args

thonny/plugins/micropython/webrepl_connection.py

@@ -3,7 +3,7 @@
 from logging import DEBUG, getLogger
 from queue import Queue
 
-from ...common import execute_with_frontend_sys_path
+from ...common import ALL_EXPLAINED_STATUS_CODE, execute_with_frontend_sys_path
 from .connection import MicroPythonConnection
 
 logger = getLogger(__name__)
@@ -47,7 +47,7 @@ def _try_load_websockets(self):
                 "Can't import `websockets`. You can install it via 'Tools => Manage plug-ins'.",
                 file=sys.stderr,
             )
-            sys.exit(1)
+            sys.exit(ALL_EXPLAINED_STATUS_CODE)
 
     def _wrap_ws_main(self):
         import asyncio

thonny/running.py

@@ -46,6 +46,7 @@
     report_time,
 )
 from thonny.common import (
+    ALL_EXPLAINED_STATUS_CODE,
     PROCESS_ACK,
     BackendEvent,
     CommandToBackend,
@@ -657,7 +658,8 @@ def disconnect(self):
         proxy.disconnect()
 
     def disconnect_enabled(self):
-        return hasattr(self.get_backend_proxy(), "disconnect")
+        proxy = self.get_backend_proxy()
+        return proxy is not None and proxy.needs_disconnect_button()
 
     def ctrld(self):
         proxy = self.get_backend_proxy()
@@ -749,8 +751,11 @@ def _pull_backend_messages(self):
         self._send_thread_commands()
         self._send_postponed_commands()
 
-    def _handle_backend_termination(self, returncode: int) -> None:
-        err = f"Process ended with exit code {returncode}."
+    def _handle_backend_termination(self, returncode: Optional[int]) -> None:
+        if returncode is None or returncode == ALL_EXPLAINED_STATUS_CODE:
+            err = ""
+        else:
+            err = f"Process ended with exit code {returncode}."
 
         try:
             faults_file = os.path.join(get_thonny_user_dir(), "backend_faults.log")
@@ -896,6 +901,12 @@ def using_venv(self) -> bool:
             isinstance(self._proxy, (LocalCPythonProxy, SshCPythonProxy)) and self._proxy._in_venv
         )
 
+    def is_connected(self):
+        if self._proxy is None:
+            return False
+        else:
+            return self._proxy.is_connected()
+
 
 class BackendProxy(ABC):
     """Communicates with backend process.
@@ -949,7 +960,24 @@ def destroy(self, for_restart: bool = False):
         ...
 
     @abstractmethod
-    def is_connected(self): ...
+    def is_connected(self) -> bool:
+        """Returns True if the backend is operational.
+        Returns False if the connection is lost (or not created yet)
+        or the remote process has died (or not created yet).
+        """
+        ...
+
+    def disconnect(self):
+        """
+        Means different things for different backends.
+        For local CPython it does nothing (???).
+        For BareMetalMicroPython it means simply closing the serial connection.
+        For SSH back-ends it means closing the SSH connection.
+        """
+        pass
+
+    def needs_disconnect_button(self):
+        return False
 
     @abstractmethod
     def has_local_interpreter(self): ...

thonny/workbench.py

@@ -223,6 +223,7 @@ def __init__(self, parsed_args: Dict[str, Any]) -> None:
         self.bind("<FocusOut>", self._on_focus_out, True)
         self.bind("<FocusIn>", self._on_focus_in, True)
         self.bind("BackendRestart", self._on_backend_restart, True)
+        self.bind("BackendTerminated", self._on_backend_terminated, True)
 
         self._publish_commands()
         self.initializing = False
@@ -904,11 +905,38 @@ def _init_backend_switcher(self):
             menu_conf = get_style_configuration("Menu")
         self._backend_menu = tk.Menu(self._statusbar, tearoff=False, **menu_conf)
 
-        # Set up the button.
-        self._backend_button = CustomToolbutton(self._statusbar, text=get_menu_char())
+        # Set up the buttons
+        self._connection_button = CustomToolbutton(
+            self._statusbar, text="", command=self._toggle_connection
+        )
+        self._connection_button.grid(row=1, column=8, sticky="nes")
+
+        self._backend_button = CustomToolbutton(
+            self._statusbar, text=get_menu_char(), command=self._post_backend_menu
+        )
 
-        self._backend_button.grid(row=1, column=3, sticky="nes")
-        self._backend_button.configure(command=self._post_backend_menu)
+        self._backend_button.grid(row=1, column=9, sticky="nes")
+
+    def _update_connection_button(self):
+        if get_runner().is_connected():
+            # ▣☑☐🔲🔳☑️☹️🟢🔴🔵🟠🟡🟣🟤🟦🟧🟥🟨🟩🟪🟫🟬🟭🟮
+            self._connection_button.configure(text=" ☑ ")
+            should_be_visible = get_runner().disconnect_enabled()
+        else:
+            self._connection_button.configure(text=" ☐ ")
+            should_be_visible = True
+
+        if should_be_visible and not self._connection_button.winfo_ismapped():
+            self._connection_button.grid()
+        elif not should_be_visible and self._connection_button.winfo_ismapped():
+            self._connection_button.grid_remove()
+
+    def _toggle_connection(self):
+        if get_runner().is_connected():
+            get_runner().get_backend_proxy().disconnect()
+        else:
+            get_runner().restart_backend(clean=False, first=False, automatic=False)
+        self._update_connection_button()
 
     def _post_backend_menu(self):
         from thonny.plugins.micropython.uf2dialog import (
@@ -1016,6 +1044,10 @@ def _on_backend_restart(self, event):
         self._backend_conf_variable.set(value=switcher_value)
         self._last_active_backend_conf_variable_value = switcher_value
         self._backend_button.configure(text=desc + "  " + get_menu_char())
+        self._update_connection_button()
+
+    def _on_backend_terminated(self, event):
+        self._update_connection_button()
 
     def _init_theming(self) -> None:
         if self.get_option("view.ui_theme") == "Kind of Aqua":