diff options
Diffstat (limited to 'src/prompt_toolkit/application')
| -rw-r--r-- | src/prompt_toolkit/application/__init__.py | 30 | ||||
| -rw-r--r-- | src/prompt_toolkit/application/application.py | 1521 | ||||
| -rw-r--r-- | src/prompt_toolkit/application/current.py | 197 | ||||
| -rw-r--r-- | src/prompt_toolkit/application/dummy.py | 51 | ||||
| -rw-r--r-- | src/prompt_toolkit/application/run_in_terminal.py | 117 |
5 files changed, 1916 insertions, 0 deletions
diff --git a/src/prompt_toolkit/application/__init__.py b/src/prompt_toolkit/application/__init__.py new file mode 100644 index 0000000..dc61ca7 --- /dev/null +++ b/src/prompt_toolkit/application/__init__.py @@ -0,0 +1,30 @@ +from .application import Application +from .current import ( + AppSession, + create_app_session, + create_app_session_from_tty, + get_app, + get_app_or_none, + get_app_session, + set_app, +) +from .dummy import DummyApplication +from .run_in_terminal import in_terminal, run_in_terminal + +__all__ = [ + # Application. + "Application", + # Current. + "AppSession", + "get_app_session", + "create_app_session", + "create_app_session_from_tty", + "get_app", + "get_app_or_none", + "set_app", + # Dummy. + "DummyApplication", + # Run_in_terminal + "in_terminal", + "run_in_terminal", +] diff --git a/src/prompt_toolkit/application/application.py b/src/prompt_toolkit/application/application.py new file mode 100644 index 0000000..0915a9e --- /dev/null +++ b/src/prompt_toolkit/application/application.py @@ -0,0 +1,1521 @@ +import asyncio +import os +import re +import signal +import sys +import threading +import time +from asyncio import ( + AbstractEventLoop, + Future, + Task, + ensure_future, + new_event_loop, + set_event_loop, + sleep, +) +from contextlib import ExitStack, contextmanager +from subprocess import Popen +from traceback import format_tb +from typing import ( + Any, + Awaitable, + Callable, + Coroutine, + Dict, + FrozenSet, + Generator, + Generic, + Hashable, + Iterable, + Iterator, + List, + Optional, + Set, + Tuple, + Type, + TypeVar, + Union, + cast, + overload, +) + +from prompt_toolkit.buffer import Buffer +from prompt_toolkit.cache import SimpleCache +from prompt_toolkit.clipboard import Clipboard, InMemoryClipboard +from prompt_toolkit.cursor_shapes import AnyCursorShapeConfig, to_cursor_shape_config +from prompt_toolkit.data_structures import Size +from prompt_toolkit.enums import EditingMode +from prompt_toolkit.eventloop import ( + get_traceback_from_context, + run_in_executor_with_context, +) +from prompt_toolkit.eventloop.utils import call_soon_threadsafe, get_event_loop +from prompt_toolkit.filters import Condition, Filter, FilterOrBool, to_filter +from prompt_toolkit.formatted_text import AnyFormattedText +from prompt_toolkit.input.base import Input +from prompt_toolkit.input.typeahead import get_typeahead, store_typeahead +from prompt_toolkit.key_binding.bindings.page_navigation import ( + load_page_navigation_bindings, +) +from prompt_toolkit.key_binding.defaults import load_key_bindings +from prompt_toolkit.key_binding.emacs_state import EmacsState +from prompt_toolkit.key_binding.key_bindings import ( + Binding, + ConditionalKeyBindings, + GlobalOnlyKeyBindings, + KeyBindings, + KeyBindingsBase, + KeysTuple, + merge_key_bindings, +) +from prompt_toolkit.key_binding.key_processor import KeyPressEvent, KeyProcessor +from prompt_toolkit.key_binding.vi_state import ViState +from prompt_toolkit.keys import Keys +from prompt_toolkit.layout.containers import Container, Window +from prompt_toolkit.layout.controls import BufferControl, UIControl +from prompt_toolkit.layout.dummy import create_dummy_layout +from prompt_toolkit.layout.layout import Layout, walk +from prompt_toolkit.output import ColorDepth, Output +from prompt_toolkit.renderer import Renderer, print_formatted_text +from prompt_toolkit.search import SearchState +from prompt_toolkit.styles import ( + BaseStyle, + DummyStyle, + DummyStyleTransformation, + DynamicStyle, + StyleTransformation, + default_pygments_style, + default_ui_style, + merge_styles, +) +from prompt_toolkit.utils import Event, in_main_thread + +from .current import get_app_session, set_app +from .run_in_terminal import in_terminal, run_in_terminal + +try: + import contextvars +except ImportError: + import prompt_toolkit.eventloop.dummy_contextvars as contextvars # type: ignore + + +__all__ = [ + "Application", +] + + +E = KeyPressEvent +_AppResult = TypeVar("_AppResult") +ApplicationEventHandler = Callable[["Application[_AppResult]"], None] + +_SIGWINCH = getattr(signal, "SIGWINCH", None) +_SIGTSTP = getattr(signal, "SIGTSTP", None) + + +class Application(Generic[_AppResult]): + """ + The main Application class! + This glues everything together. + + :param layout: A :class:`~prompt_toolkit.layout.Layout` instance. + :param key_bindings: + :class:`~prompt_toolkit.key_binding.KeyBindingsBase` instance for + the key bindings. + :param clipboard: :class:`~prompt_toolkit.clipboard.Clipboard` to use. + :param full_screen: When True, run the application on the alternate screen buffer. + :param color_depth: Any :class:`~.ColorDepth` value, a callable that + returns a :class:`~.ColorDepth` or `None` for default. + :param erase_when_done: (bool) Clear the application output when it finishes. + :param reverse_vi_search_direction: Normally, in Vi mode, a '/' searches + forward and a '?' searches backward. In Readline mode, this is usually + reversed. + :param min_redraw_interval: Number of seconds to wait between redraws. Use + this for applications where `invalidate` is called a lot. This could cause + a lot of terminal output, which some terminals are not able to process. + + `None` means that every `invalidate` will be scheduled right away + (which is usually fine). + + When one `invalidate` is called, but a scheduled redraw of a previous + `invalidate` call has not been executed yet, nothing will happen in any + case. + + :param max_render_postpone_time: When there is high CPU (a lot of other + scheduled calls), postpone the rendering max x seconds. '0' means: + don't postpone. '.5' means: try to draw at least twice a second. + + :param refresh_interval: Automatically invalidate the UI every so many + seconds. When `None` (the default), only invalidate when `invalidate` + has been called. + + :param terminal_size_polling_interval: Poll the terminal size every so many + seconds. Useful if the applications runs in a thread other then then + main thread where SIGWINCH can't be handled, or on Windows. + + Filters: + + :param mouse_support: (:class:`~prompt_toolkit.filters.Filter` or + boolean). When True, enable mouse support. + :param paste_mode: :class:`~prompt_toolkit.filters.Filter` or boolean. + :param editing_mode: :class:`~prompt_toolkit.enums.EditingMode`. + + :param enable_page_navigation_bindings: When `True`, enable the page + navigation key bindings. These include both Emacs and Vi bindings like + page-up, page-down and so on to scroll through pages. Mostly useful for + creating an editor or other full screen applications. Probably, you + don't want this for the implementation of a REPL. By default, this is + enabled if `full_screen` is set. + + Callbacks (all of these should accept an + :class:`~prompt_toolkit.application.Application` object as input.) + + :param on_reset: Called during reset. + :param on_invalidate: Called when the UI has been invalidated. + :param before_render: Called right before rendering. + :param after_render: Called right after rendering. + + I/O: + (Note that the preferred way to change the input/output is by creating an + `AppSession` with the required input/output objects. If you need multiple + applications running at the same time, you have to create a separate + `AppSession` using a `with create_app_session():` block. + + :param input: :class:`~prompt_toolkit.input.Input` instance. + :param output: :class:`~prompt_toolkit.output.Output` instance. (Probably + Vt100_Output or Win32Output.) + + Usage: + + app = Application(...) + app.run() + + # Or + await app.run_async() + """ + + def __init__( + self, + layout: Optional[Layout] = None, + style: Optional[BaseStyle] = None, + include_default_pygments_style: FilterOrBool = True, + style_transformation: Optional[StyleTransformation] = None, + key_bindings: Optional[KeyBindingsBase] = None, + clipboard: Optional[Clipboard] = None, + full_screen: bool = False, + color_depth: Union[ + ColorDepth, Callable[[], Union[ColorDepth, None]], None + ] = None, + mouse_support: FilterOrBool = False, + enable_page_navigation_bindings: Optional[ + FilterOrBool + ] = None, # Can be None, True or False. + paste_mode: FilterOrBool = False, + editing_mode: EditingMode = EditingMode.EMACS, + erase_when_done: bool = False, + reverse_vi_search_direction: FilterOrBool = False, + min_redraw_interval: Union[float, int, None] = None, + max_render_postpone_time: Union[float, int, None] = 0.01, + refresh_interval: Optional[float] = None, + terminal_size_polling_interval: Optional[float] = 0.5, + cursor: AnyCursorShapeConfig = None, + on_reset: Optional["ApplicationEventHandler[_AppResult]"] = None, + on_invalidate: Optional["ApplicationEventHandler[_AppResult]"] = None, + before_render: Optional["ApplicationEventHandler[_AppResult]"] = None, + after_render: Optional["ApplicationEventHandler[_AppResult]"] = None, + # I/O. + input: Optional[Input] = None, + output: Optional[Output] = None, + ) -> None: + + # If `enable_page_navigation_bindings` is not specified, enable it in + # case of full screen applications only. This can be overridden by the user. + if enable_page_navigation_bindings is None: + enable_page_navigation_bindings = Condition(lambda: self.full_screen) + + paste_mode = to_filter(paste_mode) + mouse_support = to_filter(mouse_support) + reverse_vi_search_direction = to_filter(reverse_vi_search_direction) + enable_page_navigation_bindings = to_filter(enable_page_navigation_bindings) + include_default_pygments_style = to_filter(include_default_pygments_style) + + if layout is None: + layout = create_dummy_layout() + + if style_transformation is None: + style_transformation = DummyStyleTransformation() + + self.style = style + self.style_transformation = style_transformation + + # Key bindings. + self.key_bindings = key_bindings + self._default_bindings = load_key_bindings() + self._page_navigation_bindings = load_page_navigation_bindings() + + self.layout = layout + self.clipboard = clipboard or InMemoryClipboard() + self.full_screen: bool = full_screen + self._color_depth = color_depth + self.mouse_support = mouse_support + + self.paste_mode = paste_mode + self.editing_mode = editing_mode + self.erase_when_done = erase_when_done + self.reverse_vi_search_direction = reverse_vi_search_direction + self.enable_page_navigation_bindings = enable_page_navigation_bindings + self.min_redraw_interval = min_redraw_interval + self.max_render_postpone_time = max_render_postpone_time + self.refresh_interval = refresh_interval + self.terminal_size_polling_interval = terminal_size_polling_interval + + self.cursor = to_cursor_shape_config(cursor) + + # Events. + self.on_invalidate = Event(self, on_invalidate) + self.on_reset = Event(self, on_reset) + self.before_render = Event(self, before_render) + self.after_render = Event(self, after_render) + + # I/O. + session = get_app_session() + self.output = output or session.output + self.input = input or session.input + + # List of 'extra' functions to execute before a Application.run. + self.pre_run_callables: List[Callable[[], None]] = [] + + self._is_running = False + self.future: Optional[Future[_AppResult]] = None + self.loop: Optional[AbstractEventLoop] = None + self.context: Optional[contextvars.Context] = None + + #: Quoted insert. This flag is set if we go into quoted insert mode. + self.quoted_insert = False + + #: Vi state. (For Vi key bindings.) + self.vi_state = ViState() + self.emacs_state = EmacsState() + + #: When to flush the input (For flushing escape keys.) This is important + #: on terminals that use vt100 input. We can't distinguish the escape + #: key from for instance the left-arrow key, if we don't know what follows + #: after "\x1b". This little timer will consider "\x1b" to be escape if + #: nothing did follow in this time span. + #: This seems to work like the `ttimeoutlen` option in Vim. + self.ttimeoutlen = 0.5 # Seconds. + + #: Like Vim's `timeoutlen` option. This can be `None` or a float. For + #: instance, suppose that we have a key binding AB and a second key + #: binding A. If the uses presses A and then waits, we don't handle + #: this binding yet (unless it was marked 'eager'), because we don't + #: know what will follow. This timeout is the maximum amount of time + #: that we wait until we call the handlers anyway. Pass `None` to + #: disable this timeout. + self.timeoutlen = 1.0 + + #: The `Renderer` instance. + # Make sure that the same stdout is used, when a custom renderer has been passed. + self._merged_style = self._create_merged_style(include_default_pygments_style) + + self.renderer = Renderer( + self._merged_style, + self.output, + full_screen=full_screen, + mouse_support=mouse_support, + cpr_not_supported_callback=self.cpr_not_supported_callback, + ) + + #: Render counter. This one is increased every time the UI is rendered. + #: It can be used as a key for caching certain information during one + #: rendering. + self.render_counter = 0 + + # Invalidate flag. When 'True', a repaint has been scheduled. + self._invalidated = False + self._invalidate_events: List[ + Event[object] + ] = [] # Collection of 'invalidate' Event objects. + self._last_redraw_time = 0.0 # Unix timestamp of last redraw. Used when + # `min_redraw_interval` is given. + + #: The `InputProcessor` instance. + self.key_processor = KeyProcessor(_CombinedRegistry(self)) + + # If `run_in_terminal` was called. This will point to a `Future` what will be + # set at the point when the previous run finishes. + self._running_in_terminal = False + self._running_in_terminal_f: Optional[Future[None]] = None + + # Trigger initialize callback. + self.reset() + + def _create_merged_style(self, include_default_pygments_style: Filter) -> BaseStyle: + """ + Create a `Style` object that merges the default UI style, the default + pygments style, and the custom user style. + """ + dummy_style = DummyStyle() + pygments_style = default_pygments_style() + + @DynamicStyle + def conditional_pygments_style() -> BaseStyle: + if include_default_pygments_style(): + return pygments_style + else: + return dummy_style + + return merge_styles( + [ + default_ui_style(), + conditional_pygments_style, + DynamicStyle(lambda: self.style), + ] + ) + + @property + def color_depth(self) -> ColorDepth: + """ + The active :class:`.ColorDepth`. + + The current value is determined as follows: + + - If a color depth was given explicitly to this application, use that + value. + - Otherwise, fall back to the color depth that is reported by the + :class:`.Output` implementation. If the :class:`.Output` class was + created using `output.defaults.create_output`, then this value is + coming from the $PROMPT_TOOLKIT_COLOR_DEPTH environment variable. + """ + depth = self._color_depth + + if callable(depth): + depth = depth() + + if depth is None: + depth = self.output.get_default_color_depth() + + return depth + + @property + def current_buffer(self) -> Buffer: + """ + The currently focused :class:`~.Buffer`. + + (This returns a dummy :class:`.Buffer` when none of the actual buffers + has the focus. In this case, it's really not practical to check for + `None` values or catch exceptions every time.) + """ + return self.layout.current_buffer or Buffer( + name="dummy-buffer" + ) # Dummy buffer. + + @property + def current_search_state(self) -> SearchState: + """ + Return the current :class:`.SearchState`. (The one for the focused + :class:`.BufferControl`.) + """ + ui_control = self.layout.current_control + if isinstance(ui_control, BufferControl): + return ui_control.search_state + else: + return SearchState() # Dummy search state. (Don't return None!) + + def reset(self) -> None: + """ + Reset everything, for reading the next input. + """ + # Notice that we don't reset the buffers. (This happens just before + # returning, and when we have multiple buffers, we clearly want the + # content in the other buffers to remain unchanged between several + # calls of `run`. (And the same is true for the focus stack.) + + self.exit_style = "" + + self._background_tasks: Set[Task[None]] = set() + + self.renderer.reset() + self.key_processor.reset() + self.layout.reset() + self.vi_state.reset() + self.emacs_state.reset() + + # Trigger reset event. + self.on_reset.fire() + + # Make sure that we have a 'focusable' widget focused. + # (The `Layout` class can't determine this.) + layout = self.layout + + if not layout.current_control.is_focusable(): + for w in layout.find_all_windows(): + if w.content.is_focusable(): + layout.current_window = w + break + + def invalidate(self) -> None: + """ + Thread safe way of sending a repaint trigger to the input event loop. + """ + if not self._is_running: + # Don't schedule a redraw if we're not running. + # Otherwise, `get_event_loop()` in `call_soon_threadsafe` can fail. + # See: https://github.com/dbcli/mycli/issues/797 + return + + # `invalidate()` called if we don't have a loop yet (not running?), or + # after the event loop was closed. + if self.loop is None or self.loop.is_closed(): + return + + # Never schedule a second redraw, when a previous one has not yet been + # executed. (This should protect against other threads calling + # 'invalidate' many times, resulting in 100% CPU.) + if self._invalidated: + return + else: + self._invalidated = True + + # Trigger event. + self.loop.call_soon_threadsafe(self.on_invalidate.fire) + + def redraw() -> None: + self._invalidated = False + self._redraw() + + def schedule_redraw() -> None: + call_soon_threadsafe( + redraw, max_postpone_time=self.max_render_postpone_time, loop=self.loop + ) + + if self.min_redraw_interval: + # When a minimum redraw interval is set, wait minimum this amount + # of time between redraws. + diff = time.time() - self._last_redraw_time + if diff < self.min_redraw_interval: + + async def redraw_in_future() -> None: + await sleep(cast(float, self.min_redraw_interval) - diff) + schedule_redraw() + + self.loop.call_soon_threadsafe( + lambda: self.create_background_task(redraw_in_future()) + ) + else: + schedule_redraw() + else: + schedule_redraw() + + @property + def invalidated(self) -> bool: + "True when a redraw operation has been scheduled." + return self._invalidated + + def _redraw(self, render_as_done: bool = False) -> None: + """ + Render the command line again. (Not thread safe!) (From other threads, + or if unsure, use :meth:`.Application.invalidate`.) + + :param render_as_done: make sure to put the cursor after the UI. + """ + + def run_in_context() -> None: + # Only draw when no sub application was started. + if self._is_running and not self._running_in_terminal: + if self.min_redraw_interval: + self._last_redraw_time = time.time() + + # Render + self.render_counter += 1 + self.before_render.fire() + + if render_as_done: + if self.erase_when_done: + self.renderer.erase() + else: + # Draw in 'done' state and reset renderer. + self.renderer.render(self, self.layout, is_done=render_as_done) + else: + self.renderer.render(self, self.layout) + + self.layout.update_parents_relations() + + # Fire render event. + self.after_render.fire() + + self._update_invalidate_events() + + # NOTE: We want to make sure this Application is the active one. The + # invalidate function is often called from a context where this + # application is not the active one. (Like the + # `PromptSession._auto_refresh_context`). + # We copy the context in case the context was already active, to + # prevent RuntimeErrors. (The rendering is not supposed to change + # any context variables.) + if self.context is not None: + self.context.copy().run(run_in_context) + + def _start_auto_refresh_task(self) -> None: + """ + Start a while/true loop in the background for automatic invalidation of + the UI. + """ + if self.refresh_interval is not None and self.refresh_interval != 0: + + async def auto_refresh(refresh_interval: float) -> None: + while True: + await sleep(refresh_interval) + self.invalidate() + + self.create_background_task(auto_refresh(self.refresh_interval)) + + def _update_invalidate_events(self) -> None: + """ + Make sure to attach 'invalidate' handlers to all invalidate events in + the UI. + """ + # Remove all the original event handlers. (Components can be removed + # from the UI.) + for ev in self._invalidate_events: + ev -= self._invalidate_handler + + # Gather all new events. + # (All controls are able to invalidate themselves.) + def gather_events() -> Iterable[Event[object]]: + for c in self.layout.find_all_controls(): + yield from c.get_invalidate_events() + + self._invalidate_events = list(gather_events()) + + for ev in self._invalidate_events: + ev += self._invalidate_handler + + def _invalidate_handler(self, sender: object) -> None: + """ + Handler for invalidate events coming from UIControls. + + (This handles the difference in signature between event handler and + `self.invalidate`. It also needs to be a method -not a nested + function-, so that we can remove it again .) + """ + self.invalidate() + + def _on_resize(self) -> None: + """ + When the window size changes, we erase the current output and request + again the cursor position. When the CPR answer arrives, the output is + drawn again. + """ + # Erase, request position (when cursor is at the start position) + # and redraw again. -- The order is important. + self.renderer.erase(leave_alternate_screen=False) + self._request_absolute_cursor_position() + self._redraw() + + def _pre_run(self, pre_run: Optional[Callable[[], None]] = None) -> None: + """ + Called during `run`. + + `self.future` should be set to the new future at the point where this + is called in order to avoid data races. `pre_run` can be used to set a + `threading.Event` to synchronize with UI termination code, running in + another thread that would call `Application.exit`. (See the progress + bar code for an example.) + """ + if pre_run: + pre_run() + + # Process registered "pre_run_callables" and clear list. + for c in self.pre_run_callables: + c() + del self.pre_run_callables[:] + + async def run_async( + self, + pre_run: Optional[Callable[[], None]] = None, + set_exception_handler: bool = True, + handle_sigint: bool = True, + slow_callback_duration: float = 0.5, + ) -> _AppResult: + """ + Run the prompt_toolkit :class:`~prompt_toolkit.application.Application` + until :meth:`~prompt_toolkit.application.Application.exit` has been + called. Return the value that was passed to + :meth:`~prompt_toolkit.application.Application.exit`. + + This is the main entry point for a prompt_toolkit + :class:`~prompt_toolkit.application.Application` and usually the only + place where the event loop is actually running. + + :param pre_run: Optional callable, which is called right after the + "reset" of the application. + :param set_exception_handler: When set, in case of an exception, go out + of the alternate screen and hide the application, display the + exception, and wait for the user to press ENTER. + :param handle_sigint: Handle SIGINT signal if possible. This will call + the `<sigint>` key binding when a SIGINT is received. (This only + works in the main thread.) + :param slow_callback_duration: Display warnings if code scheduled in + the asyncio event loop takes more time than this. The asyncio + default of `0.1` is sometimes not sufficient on a slow system, + because exceptionally, the drawing of the app, which happens in the + event loop, can take a bit longer from time to time. + """ + assert not self._is_running, "Application is already running." + + if not in_main_thread() or sys.platform == "win32": + # Handling signals in other threads is not supported. + # Also on Windows, `add_signal_handler(signal.SIGINT, ...)` raises + # `NotImplementedError`. + # See: https://github.com/prompt-toolkit/python-prompt-toolkit/issues/1553 + handle_sigint = False + + async def _run_async(f: "asyncio.Future[_AppResult]") -> _AppResult: + self.context = contextvars.copy_context() + + # Counter for cancelling 'flush' timeouts. Every time when a key is + # pressed, we start a 'flush' timer for flushing our escape key. But + # when any subsequent input is received, a new timer is started and + # the current timer will be ignored. + flush_task: Optional[asyncio.Task[None]] = None + + # Reset. + # (`self.future` needs to be set when `pre_run` is called.) + self.reset() + self._pre_run(pre_run) + + # Feed type ahead input first. + self.key_processor.feed_multiple(get_typeahead(self.input)) + self.key_processor.process_keys() + + def read_from_input() -> None: + nonlocal flush_task + + # Ignore when we aren't running anymore. This callback will + # removed from the loop next time. (It could be that it was + # still in the 'tasks' list of the loop.) + # Except: if we need to process incoming CPRs. + if not self._is_running and not self.renderer.waiting_for_cpr: + return + + # Get keys from the input object. + keys = self.input.read_keys() + + # Feed to key processor. + self.key_processor.feed_multiple(keys) + self.key_processor.process_keys() + + # Quit when the input stream was closed. + if self.input.closed: + if not f.done(): + f.set_exception(EOFError) + else: + # Automatically flush keys. + if flush_task: + flush_task.cancel() + flush_task = self.create_background_task(auto_flush_input()) + + async def auto_flush_input() -> None: + # Flush input after timeout. + # (Used for flushing the enter key.) + # This sleep can be cancelled, in that case we won't flush yet. + await sleep(self.ttimeoutlen) + flush_input() + + def flush_input() -> None: + if not self.is_done: + # Get keys, and feed to key processor. + keys = self.input.flush_keys() + self.key_processor.feed_multiple(keys) + self.key_processor.process_keys() + + if self.input.closed: + f.set_exception(EOFError) + + # Enter raw mode, attach input and attach WINCH event handler. + with self.input.raw_mode(), self.input.attach( + read_from_input + ), attach_winch_signal_handler(self._on_resize): + + # Draw UI. + self._request_absolute_cursor_position() + self._redraw() + self._start_auto_refresh_task() + + self.create_background_task(self._poll_output_size()) + + # Wait for UI to finish. + try: + result = await f + finally: + # In any case, when the application finishes. + # (Successful, or because of an error.) + try: + self._redraw(render_as_done=True) + finally: + # _redraw has a good chance to fail if it calls widgets + # with bad code. Make sure to reset the renderer + # anyway. + self.renderer.reset() + + # Unset `is_running`, this ensures that possibly + # scheduled draws won't paint during the following + # yield. + self._is_running = False + + # Detach event handlers for invalidate events. + # (Important when a UIControl is embedded in multiple + # applications, like ptterm in pymux. An invalidate + # should not trigger a repaint in terminated + # applications.) + for ev in self._invalidate_events: + ev -= self._invalidate_handler + self._invalidate_events = [] + + # Wait for CPR responses. + if self.output.responds_to_cpr: + await self.renderer.wait_for_cpr_responses() + + # Wait for the run-in-terminals to terminate. + previous_run_in_terminal_f = self._running_in_terminal_f + + if previous_run_in_terminal_f: + await previous_run_in_terminal_f + + # Store unprocessed input as typeahead for next time. + store_typeahead(self.input, self.key_processor.empty_queue()) + + return result + + @contextmanager + def get_loop() -> Iterator[AbstractEventLoop]: + loop = get_event_loop() + self.loop = loop + + try: + yield loop + finally: + self.loop = None + + @contextmanager + def set_is_running() -> Iterator[None]: + self._is_running = True + try: + yield + finally: + self._is_running = False + + @contextmanager + def set_handle_sigint(loop: AbstractEventLoop) -> Iterator[None]: + if handle_sigint: + loop.add_signal_handler( + signal.SIGINT, + lambda *_: loop.call_soon_threadsafe( + self.key_processor.send_sigint + ), + ) + try: + yield + finally: + loop.remove_signal_handler(signal.SIGINT) + else: + yield + + @contextmanager + def set_exception_handler_ctx(loop: AbstractEventLoop) -> Iterator[None]: + if set_exception_handler: + previous_exc_handler = loop.get_exception_handler() + loop.set_exception_handler(self._handle_exception) + try: + yield + finally: + loop.set_exception_handler(previous_exc_handler) + + else: + yield + + @contextmanager + def set_callback_duration(loop: AbstractEventLoop) -> Iterator[None]: + # Set slow_callback_duration. + original_slow_callback_duration = loop.slow_callback_duration + loop.slow_callback_duration = slow_callback_duration + try: + yield + finally: + # Reset slow_callback_duration. + loop.slow_callback_duration = original_slow_callback_duration + + @contextmanager + def create_future( + loop: AbstractEventLoop, + ) -> "Iterator[asyncio.Future[_AppResult]]": + f = loop.create_future() + self.future = f # XXX: make sure to set this before calling '_redraw'. + + try: + yield f + finally: + # Also remove the Future again. (This brings the + # application back to its initial state, where it also + # doesn't have a Future.) + self.future = None + + with ExitStack() as stack: + stack.enter_context(set_is_running()) + + # Make sure to set `_invalidated` to `False` to begin with, + # otherwise we're not going to paint anything. This can happen if + # this application had run before on a different event loop, and a + # paint was scheduled using `call_soon_threadsafe` with + # `max_postpone_time`. + self._invalidated = False + + loop = stack.enter_context(get_loop()) + + stack.enter_context(set_handle_sigint(loop)) + stack.enter_context(set_exception_handler_ctx(loop)) + stack.enter_context(set_callback_duration(loop)) + stack.enter_context(set_app(self)) + stack.enter_context(self._enable_breakpointhook()) + + f = stack.enter_context(create_future(loop)) + + try: + return await _run_async(f) + finally: + # Wait for the background tasks to be done. This needs to + # go in the finally! If `_run_async` raises + # `KeyboardInterrupt`, we still want to wait for the + # background tasks. + await self.cancel_and_wait_for_background_tasks() + + # The `ExitStack` above is defined in typeshed in a way that it can + # swallow exceptions. Without next line, mypy would think that there's + # a possibility we don't return here. See: + # https://github.com/python/mypy/issues/7726 + assert False, "unreachable" + + def run( + self, + pre_run: Optional[Callable[[], None]] = None, + set_exception_handler: bool = True, + handle_sigint: bool = True, + in_thread: bool = False, + ) -> _AppResult: + """ + A blocking 'run' call that waits until the UI is finished. + + This will start the current asyncio event loop. If no loop is set for + the current thread, then it will create a new loop. If a new loop was + created, this won't close the new loop (if `in_thread=False`). + + :param pre_run: Optional callable, which is called right after the + "reset" of the application. + :param set_exception_handler: When set, in case of an exception, go out + of the alternate screen and hide the application, display the + exception, and wait for the user to press ENTER. + :param in_thread: When true, run the application in a background + thread, and block the current thread until the application + terminates. This is useful if we need to be sure the application + won't use the current event loop (asyncio does not support nested + event loops). A new event loop will be created in this background + thread, and that loop will also be closed when the background + thread terminates. When this is used, it's especially important to + make sure that all asyncio background tasks are managed through + `get_appp().create_background_task()`, so that unfinished tasks are + properly cancelled before the event loop is closed. This is used + for instance in ptpython. + :param handle_sigint: Handle SIGINT signal. Call the key binding for + `Keys.SIGINT`. (This only works in the main thread.) + """ + if in_thread: + result: _AppResult + exception: Optional[BaseException] = None + + def run_in_thread() -> None: + nonlocal result, exception + try: + result = self.run( + pre_run=pre_run, + set_exception_handler=set_exception_handler, + # Signal handling only works in the main thread. + handle_sigint=False, + ) + except BaseException as e: + exception = e + finally: + # Make sure to close the event loop in this thread. Running + # the application creates a new loop (because we're in + # another thread), but it doesn't get closed automatically + # (also not by the garbage collector). + loop = get_event_loop() + loop.run_until_complete(loop.shutdown_asyncgens()) + loop.close() + + thread = threading.Thread(target=run_in_thread) + thread.start() + thread.join() + + if exception is not None: + raise exception + return result + + # We don't create a new event loop by default, because we want to be + # sure that when this is called multiple times, each call of `run()` + # goes through the same event loop. This way, users can schedule + # background-tasks that keep running across multiple prompts. + try: + loop = get_event_loop() + except RuntimeError: + # Possibly we are not running in the main thread, where no event + # loop is set by default. Or somebody called `asyncio.run()` + # before, which closes the existing event loop. We can create a new + # loop. + loop = new_event_loop() + set_event_loop(loop) + + return loop.run_until_complete( + self.run_async( + pre_run=pre_run, + set_exception_handler=set_exception_handler, + handle_sigint=handle_sigint, + ) + ) + + def _handle_exception( + self, loop: AbstractEventLoop, context: Dict[str, Any] + ) -> None: + """ + Handler for event loop exceptions. + This will print the exception, using run_in_terminal. + """ + # For Python 2: we have to get traceback at this point, because + # we're still in the 'except:' block of the event loop where the + # traceback is still available. Moving this code in the + # 'print_exception' coroutine will loose the exception. + tb = get_traceback_from_context(context) + formatted_tb = "".join(format_tb(tb)) + + async def in_term() -> None: + async with in_terminal(): + # Print output. Similar to 'loop.default_exception_handler', + # but don't use logger. (This works better on Python 2.) + print("\nUnhandled exception in event loop:") + print(formatted_tb) + print("Exception {}".format(context.get("exception"))) + + await _do_wait_for_enter("Press ENTER to continue...") + + ensure_future(in_term()) + + @contextmanager + def _enable_breakpointhook(self) -> Generator[None, None, None]: + """ + Install our custom breakpointhook for the duration of this context + manager. (We will only install the hook if no other custom hook was + set.) + """ + if sys.version_info >= (3, 7) and sys.breakpointhook == sys.__breakpointhook__: + sys.breakpointhook = self._breakpointhook + + try: + yield + finally: + sys.breakpointhook = sys.__breakpointhook__ + else: + yield + + def _breakpointhook(self, *a: object, **kw: object) -> None: + """ + Breakpointhook which uses PDB, but ensures that the application is + hidden and input echoing is restored during each debugger dispatch. + """ + app = self + # Inline import on purpose. We don't want to import pdb, if not needed. + import pdb + from types import FrameType + + TraceDispatch = Callable[[FrameType, str, Any], Any] + + class CustomPdb(pdb.Pdb): + def trace_dispatch( + self, frame: FrameType, event: str, arg: Any + ) -> TraceDispatch: + # Hide application. + app.renderer.erase() + + # Detach input and dispatch to debugger. + with app.input.detach(): + with app.input.cooked_mode(): + return super().trace_dispatch(frame, event, arg) + + # Note: we don't render the application again here, because + # there's a good chance that there's a breakpoint on the next + # line. This paint/erase cycle would move the PDB prompt back + # to the middle of the screen. + + frame = sys._getframe().f_back + CustomPdb(stdout=sys.__stdout__).set_trace(frame) + + def create_background_task( + self, coroutine: Coroutine[Any, Any, None] + ) -> "asyncio.Task[None]": + """ + Start a background task (coroutine) for the running application. When + the `Application` terminates, unfinished background tasks will be + cancelled. + + Given that we still support Python versions before 3.11, we can't use + task groups (and exception groups), because of that, these background + tasks are not allowed to raise exceptions. If they do, we'll call the + default exception handler from the event loop. + + If at some point, we have Python 3.11 as the minimum supported Python + version, then we can use a `TaskGroup` (with the lifetime of + `Application.run_async()`, and run run the background tasks in there. + + This is not threadsafe. + """ + loop = self.loop or get_event_loop() + task: asyncio.Task[None] = loop.create_task(coroutine) + self._background_tasks.add(task) + + task.add_done_callback(self._on_background_task_done) + return task + + def _on_background_task_done(self, task: "asyncio.Task[None]") -> None: + """ + Called when a background task completes. Remove it from + `_background_tasks`, and handle exceptions if any. + """ + self._background_tasks.discard(task) + + if task.cancelled(): + return + + exc = task.exception() + if exc is not None: + get_event_loop().call_exception_handler( + { + "message": f"prompt_toolkit.Application background task {task!r} " + "raised an unexpected exception.", + "exception": exc, + "task": task, + } + ) + + async def cancel_and_wait_for_background_tasks(self) -> None: + """ + Cancel all background tasks, and wait for the cancellation to complete. + If any of the background tasks raised an exception, this will also + propagate the exception. + + (If we had nurseries like Trio, this would be the `__aexit__` of a + nursery.) + """ + for task in self._background_tasks: + task.cancel() + + # Wait until the cancellation of the background tasks completes. + # `asyncio.wait()` does not propagate exceptions raised within any of + # these tasks, which is what we want. Otherwise, we can't distinguish + # between a `CancelledError` raised in this task because it got + # cancelled, and a `CancelledError` raised on this `await` checkpoint, + # because *we* got cancelled during the teardown of the application. + # (If we get cancelled here, then it's important to not suppress the + # `CancelledError`, and have it propagate.) + # NOTE: Currently, if we get cancelled at this point then we can't wait + # for the cancellation to complete (in the future, we should be + # using anyio or Python's 3.11 TaskGroup.) + # Also, if we had exception groups, we could propagate an + # `ExceptionGroup` if something went wrong here. Right now, we + # don't propagate exceptions, but have them printed in + # `_on_background_task_done`. + if len(self._background_tasks) > 0: + await asyncio.wait( + self._background_tasks, timeout=None, return_when=asyncio.ALL_COMPLETED + ) + + async def _poll_output_size(self) -> None: + """ + Coroutine for polling the terminal dimensions. + + Useful for situations where `attach_winch_signal_handler` is not sufficient: + - If we are not running in the main thread. + - On Windows. + """ + size: Optional[Size] = None + interval = self.terminal_size_polling_interval + + if interval is None: + return + + while True: + await asyncio.sleep(interval) + new_size = self.output.get_size() + + if size is not None and new_size != size: + self._on_resize() + size = new_size + + def cpr_not_supported_callback(self) -> None: + """ + Called when we don't receive the cursor position response in time. + """ + if not self.output.responds_to_cpr: + return # We know about this already. + + def in_terminal() -> None: + self.output.write( + "WARNING: your terminal doesn't support cursor position requests (CPR).\r\n" + ) + self.output.flush() + + run_in_terminal(in_terminal) + + @overload + def exit(self) -> None: + "Exit without arguments." + + @overload + def exit(self, *, result: _AppResult, style: str = "") -> None: + "Exit with `_AppResult`." + + @overload + def exit( + self, *, exception: Union[BaseException, Type[BaseException]], style: str = "" + ) -> None: + "Exit with exception." + + def exit( + self, + result: Optional[_AppResult] = None, + exception: Optional[Union[BaseException, Type[BaseException]]] = None, + style: str = "", + ) -> None: + """ + Exit application. + + .. note:: + + If `Application.exit` is called before `Application.run()` is + called, then the `Application` won't exit (because the + `Application.future` doesn't correspond to the current run). Use a + `pre_run` hook and an event to synchronize the closing if there's a + chance this can happen. + + :param result: Set this result for the application. + :param exception: Set this exception as the result for an application. For + a prompt, this is often `EOFError` or `KeyboardInterrupt`. + :param style: Apply this style on the whole content when quitting, + often this is 'class:exiting' for a prompt. (Used when + `erase_when_done` is not set.) + """ + assert result is None or exception is None + + if self.future is None: + raise Exception("Application is not running. Application.exit() failed.") + + if self.future.done(): + raise Exception("Return value already set. Application.exit() failed.") + + self.exit_style = style + + if exception is not None: + self.future.set_exception(exception) + else: + self.future.set_result(cast(_AppResult, result)) + + def _request_absolute_cursor_position(self) -> None: + """ + Send CPR request. + """ + # Note: only do this if the input queue is not empty, and a return + # value has not been set. Otherwise, we won't be able to read the + # response anyway. + if not self.key_processor.input_queue and not self.is_done: + self.renderer.request_absolute_cursor_position() + + async def run_system_command( + self, + command: str, + wait_for_enter: bool = True, + display_before_text: AnyFormattedText = "", + wait_text: str = "Press ENTER to continue...", + ) -> None: + """ + Run system command (While hiding the prompt. When finished, all the + output will scroll above the prompt.) + + :param command: Shell command to be executed. + :param wait_for_enter: FWait for the user to press enter, when the + command is finished. + :param display_before_text: If given, text to be displayed before the + command executes. + :return: A `Future` object. + """ + async with in_terminal(): + # Try to use the same input/output file descriptors as the one, + # used to run this application. + try: + input_fd = self.input.fileno() + except AttributeError: + input_fd = sys.stdin.fileno() + try: + output_fd = self.output.fileno() + except AttributeError: + output_fd = sys.stdout.fileno() + + # Run sub process. + def run_command() -> None: + self.print_text(display_before_text) + p = Popen(command, shell=True, stdin=input_fd, stdout=output_fd) + p.wait() + + await run_in_executor_with_context(run_command) + + # Wait for the user to press enter. + if wait_for_enter: + await _do_wait_for_enter(wait_text) + + def suspend_to_background(self, suspend_group: bool = True) -> None: + """ + (Not thread safe -- to be called from inside the key bindings.) + Suspend process. + + :param suspend_group: When true, suspend the whole process group. + (This is the default, and probably what you want.) + """ + # Only suspend when the operating system supports it. + # (Not on Windows.) + if _SIGTSTP is not None: + + def run() -> None: + signal = cast(int, _SIGTSTP) + # Send `SIGTSTP` to own process. + # This will cause it to suspend. + + # Usually we want the whole process group to be suspended. This + # handles the case when input is piped from another process. + if suspend_group: + os.kill(0, signal) + else: + os.kill(os.getpid(), signal) + + run_in_terminal(run) + + def print_text( + self, text: AnyFormattedText, style: Optional[BaseStyle] = None + ) -> None: + """ + Print a list of (style_str, text) tuples to the output. + (When the UI is running, this method has to be called through + `run_in_terminal`, otherwise it will destroy the UI.) + + :param text: List of ``(style_str, text)`` tuples. + :param style: Style class to use. Defaults to the active style in the CLI. + """ + print_formatted_text( + output=self.output, + formatted_text=text, + style=style or self._merged_style, + color_depth=self.color_depth, + style_transformation=self.style_transformation, + ) + + @property + def is_running(self) -> bool: + "`True` when the application is currently active/running." + return self._is_running + + @property + def is_done(self) -> bool: + if self.future: + return self.future.done() + return False + + def get_used_style_strings(self) -> List[str]: + """ + Return a list of used style strings. This is helpful for debugging, and + for writing a new `Style`. + """ + attrs_for_style = self.renderer._attrs_for_style + + if attrs_for_style: + return sorted( + re.sub(r"\s+", " ", style_str).strip() + for style_str in attrs_for_style.keys() + ) + + return [] + + +class _CombinedRegistry(KeyBindingsBase): + """ + The `KeyBindings` of key bindings for a `Application`. + This merges the global key bindings with the one of the current user + control. + """ + + def __init__(self, app: Application[_AppResult]) -> None: + self.app = app + self._cache: SimpleCache[ + Tuple[Window, FrozenSet[UIControl]], KeyBindingsBase + ] = SimpleCache() + + @property + def _version(self) -> Hashable: + """Not needed - this object is not going to be wrapped in another + KeyBindings object.""" + raise NotImplementedError + + @property + def bindings(self) -> List[Binding]: + """Not needed - this object is not going to be wrapped in another + KeyBindings object.""" + raise NotImplementedError + + def _create_key_bindings( + self, current_window: Window, other_controls: List[UIControl] + ) -> KeyBindingsBase: + """ + Create a `KeyBindings` object that merges the `KeyBindings` from the + `UIControl` with all the parent controls and the global key bindings. + """ + key_bindings = [] + collected_containers = set() + + # Collect key bindings from currently focused control and all parent + # controls. Don't include key bindings of container parent controls. + container: Container = current_window + while True: + collected_containers.add(container) + kb = container.get_key_bindings() + if kb is not None: + key_bindings.append(kb) + + if container.is_modal(): + break + + parent = self.app.layout.get_parent(container) + if parent is None: + break + else: + container = parent + + # Include global bindings (starting at the top-model container). + for c in walk(container): + if c not in collected_containers: + kb = c.get_key_bindings() + if kb is not None: + key_bindings.append(GlobalOnlyKeyBindings(kb)) + + # Add App key bindings + if self.app.key_bindings: + key_bindings.append(self.app.key_bindings) + + # Add mouse bindings. + key_bindings.append( + ConditionalKeyBindings( + self.app._page_navigation_bindings, + self.app.enable_page_navigation_bindings, + ) + ) + key_bindings.append(self.app._default_bindings) + + # Reverse this list. The current control's key bindings should come + # last. They need priority. + key_bindings = key_bindings[::-1] + + return merge_key_bindings(key_bindings) + + @property + def _key_bindings(self) -> KeyBindingsBase: + current_window = self.app.layout.current_window + other_controls = list(self.app.layout.find_all_controls()) + key = current_window, frozenset(other_controls) + + return self._cache.get( + key, lambda: self._create_key_bindings(current_window, other_controls) + ) + + def get_bindings_for_keys(self, keys: KeysTuple) -> List[Binding]: + return self._key_bindings.get_bindings_for_keys(keys) + + def get_bindings_starting_with_keys(self, keys: KeysTuple) -> List[Binding]: + return self._key_bindings.get_bindings_starting_with_keys(keys) + + +async def _do_wait_for_enter(wait_text: AnyFormattedText) -> None: + """ + Create a sub application to wait for the enter key press. + This has two advantages over using 'input'/'raw_input': + - This will share the same input/output I/O. + - This doesn't block the event loop. + """ + from prompt_toolkit.shortcuts import PromptSession + + key_bindings = KeyBindings() + + @key_bindings.add("enter") + def _ok(event: E) -> None: + event.app.exit() + + @key_bindings.add(Keys.Any) + def _ignore(event: E) -> None: + "Disallow typing." + pass + + session: PromptSession[None] = PromptSession( + message=wait_text, key_bindings=key_bindings + ) + try: + await session.app.run_async() + except KeyboardInterrupt: + pass # Control-c pressed. Don't propagate this error. + + +@contextmanager +def attach_winch_signal_handler( + handler: Callable[[], None] +) -> Generator[None, None, None]: + """ + Attach the given callback as a WINCH signal handler within the context + manager. Restore the original signal handler when done. + + The `Application.run` method will register SIGWINCH, so that it will + properly repaint when the terminal window resizes. However, using + `run_in_terminal`, we can temporarily send an application to the + background, and run an other app in between, which will then overwrite the + SIGWINCH. This is why it's important to restore the handler when the app + terminates. + """ + # The tricky part here is that signals are registered in the Unix event + # loop with a wakeup fd, but another application could have registered + # signals using signal.signal directly. For now, the implementation is + # hard-coded for the `asyncio.unix_events._UnixSelectorEventLoop`. + + # No WINCH? Then don't do anything. + sigwinch = getattr(signal, "SIGWINCH", None) + if sigwinch is None or not in_main_thread(): + yield + return + + # Keep track of the previous handler. + # (Only UnixSelectorEventloop has `_signal_handlers`.) + loop = get_event_loop() + previous_winch_handler = getattr(loop, "_signal_handlers", {}).get(sigwinch) + + try: + loop.add_signal_handler(sigwinch, handler) + yield + finally: + # Restore the previous signal handler. + loop.remove_signal_handler(sigwinch) + if previous_winch_handler is not None: + loop.add_signal_handler( + sigwinch, + previous_winch_handler._callback, + *previous_winch_handler._args, + ) diff --git a/src/prompt_toolkit/application/current.py b/src/prompt_toolkit/application/current.py new file mode 100644 index 0000000..ae69bfd --- /dev/null +++ b/src/prompt_toolkit/application/current.py @@ -0,0 +1,197 @@ +import sys +from contextlib import contextmanager +from typing import TYPE_CHECKING, Any, Generator, Optional + +try: + from contextvars import ContextVar +except ImportError: + from prompt_toolkit.eventloop.dummy_contextvars import ContextVar # type: ignore + +if TYPE_CHECKING: + from prompt_toolkit.input.base import Input + from prompt_toolkit.output.base import Output + + from .application import Application + +__all__ = [ + "AppSession", + "get_app_session", + "get_app", + "get_app_or_none", + "set_app", + "create_app_session", + "create_app_session_from_tty", +] + + +class AppSession: + """ + An AppSession is an interactive session, usually connected to one terminal. + Within one such session, interaction with many applications can happen, one + after the other. + + The input/output device is not supposed to change during one session. + + Warning: Always use the `create_app_session` function to create an + instance, so that it gets activated correctly. + + :param input: Use this as a default input for all applications + running in this session, unless an input is passed to the `Application` + explicitely. + :param output: Use this as a default output. + """ + + def __init__( + self, input: Optional["Input"] = None, output: Optional["Output"] = None + ) -> None: + + self._input = input + self._output = output + + # The application will be set dynamically by the `set_app` context + # manager. This is called in the application itself. + self.app: Optional["Application[Any]"] = None + + def __repr__(self) -> str: + return f"AppSession(app={self.app!r})" + + @property + def input(self) -> "Input": + if self._input is None: + from prompt_toolkit.input.defaults import create_input + + self._input = create_input() + return self._input + + @property + def output(self) -> "Output": + if self._output is None: + from prompt_toolkit.output.defaults import create_output + + self._output = create_output() + return self._output + + +_current_app_session: ContextVar["AppSession"] = ContextVar( + "_current_app_session", default=AppSession() +) + + +def get_app_session() -> AppSession: + return _current_app_session.get() + + +def get_app() -> "Application[Any]": + """ + Get the current active (running) Application. + An :class:`.Application` is active during the + :meth:`.Application.run_async` call. + + We assume that there can only be one :class:`.Application` active at the + same time. There is only one terminal window, with only one stdin and + stdout. This makes the code significantly easier than passing around the + :class:`.Application` everywhere. + + If no :class:`.Application` is running, then return by default a + :class:`.DummyApplication`. For practical reasons, we prefer to not raise + an exception. This way, we don't have to check all over the place whether + an actual `Application` was returned. + + (For applications like pymux where we can have more than one `Application`, + we'll use a work-around to handle that.) + """ + session = _current_app_session.get() + if session.app is not None: + return session.app + + from .dummy import DummyApplication + + return DummyApplication() + + +def get_app_or_none() -> Optional["Application[Any]"]: + """ + Get the current active (running) Application, or return `None` if no + application is running. + """ + session = _current_app_session.get() + return session.app + + +@contextmanager +def set_app(app: "Application[Any]") -> Generator[None, None, None]: + """ + Context manager that sets the given :class:`.Application` active in an + `AppSession`. + + This should only be called by the `Application` itself. + The application will automatically be active while its running. If you want + the application to be active in other threads/coroutines, where that's not + the case, use `contextvars.copy_context()`, or use `Application.context` to + run it in the appropriate context. + """ + session = _current_app_session.get() + + previous_app = session.app + session.app = app + try: + yield + finally: + session.app = previous_app + + +@contextmanager +def create_app_session( + input: Optional["Input"] = None, output: Optional["Output"] = None +) -> Generator[AppSession, None, None]: + """ + Create a separate AppSession. + + This is useful if there can be multiple individual `AppSession`s going on. + Like in the case of an Telnet/SSH server. This functionality uses + contextvars and requires at least Python 3.7. + """ + if sys.version_info <= (3, 6): + raise RuntimeError("Application sessions require Python 3.7.") + + # If no input/output is specified, fall back to the current input/output, + # whatever that is. + if input is None: + input = get_app_session().input + if output is None: + output = get_app_session().output + + # Create new `AppSession` and activate. + session = AppSession(input=input, output=output) + + token = _current_app_session.set(session) + try: + yield session + finally: + _current_app_session.reset(token) + + +@contextmanager +def create_app_session_from_tty() -> Generator[AppSession, None, None]: + """ + Create `AppSession` that always prefers the TTY input/output. + + Even if `sys.stdin` and `sys.stdout` are connected to input/output pipes, + this will still use the terminal for interaction (because `sys.stderr` is + still connected to the terminal). + + Usage:: + + from prompt_toolkit.shortcuts import prompt + + with create_app_session_from_tty(): + prompt('>') + """ + from prompt_toolkit.input.defaults import create_input + from prompt_toolkit.output.defaults import create_output + + input = create_input(always_prefer_tty=True) + output = create_output(always_prefer_tty=True) + + with create_app_session(input=input, output=output) as app_session: + yield app_session diff --git a/src/prompt_toolkit/application/dummy.py b/src/prompt_toolkit/application/dummy.py new file mode 100644 index 0000000..4e5e4aa --- /dev/null +++ b/src/prompt_toolkit/application/dummy.py @@ -0,0 +1,51 @@ +from typing import Callable, Optional + +from prompt_toolkit.formatted_text import AnyFormattedText +from prompt_toolkit.input import DummyInput +from prompt_toolkit.output import DummyOutput + +from .application import Application + +__all__ = [ + "DummyApplication", +] + + +class DummyApplication(Application[None]): + """ + When no :class:`.Application` is running, + :func:`.get_app` will run an instance of this :class:`.DummyApplication` instead. + """ + + def __init__(self) -> None: + super().__init__(output=DummyOutput(), input=DummyInput()) + + def run( + self, + pre_run: Optional[Callable[[], None]] = None, + set_exception_handler: bool = True, + handle_sigint: bool = True, + in_thread: bool = False, + ) -> None: + raise NotImplementedError("A DummyApplication is not supposed to run.") + + async def run_async( + self, + pre_run: Optional[Callable[[], None]] = None, + set_exception_handler: bool = True, + handle_sigint: bool = True, + slow_callback_duration: float = 0.5, + ) -> None: + raise NotImplementedError("A DummyApplication is not supposed to run.") + + async def run_system_command( + self, + command: str, + wait_for_enter: bool = True, + display_before_text: AnyFormattedText = "", + wait_text: str = "", + ) -> None: + raise NotImplementedError + + def suspend_to_background(self, suspend_group: bool = True) -> None: + raise NotImplementedError diff --git a/src/prompt_toolkit/application/run_in_terminal.py b/src/prompt_toolkit/application/run_in_terminal.py new file mode 100644 index 0000000..d5ef8aa --- /dev/null +++ b/src/prompt_toolkit/application/run_in_terminal.py @@ -0,0 +1,117 @@ +""" +Tools for running functions on the terminal above the current application or prompt. +""" +import sys +from asyncio import Future, ensure_future +from typing import AsyncGenerator, Awaitable, Callable, TypeVar + +from prompt_toolkit.eventloop import run_in_executor_with_context + +from .current import get_app_or_none + +if sys.version_info >= (3, 7): + from contextlib import asynccontextmanager +else: + from prompt_toolkit.eventloop.async_context_manager import asynccontextmanager + + +__all__ = [ + "run_in_terminal", + "in_terminal", +] + +_T = TypeVar("_T") + + +def run_in_terminal( + func: Callable[[], _T], render_cli_done: bool = False, in_executor: bool = False +) -> Awaitable[_T]: + """ + Run function on the terminal above the current application or prompt. + + What this does is first hiding the prompt, then running this callable + (which can safely output to the terminal), and then again rendering the + prompt which causes the output of this function to scroll above the + prompt. + + ``func`` is supposed to be a synchronous function. If you need an + asynchronous version of this function, use the ``in_terminal`` context + manager directly. + + :param func: The callable to execute. + :param render_cli_done: When True, render the interface in the + 'Done' state first, then execute the function. If False, + erase the interface first. + :param in_executor: When True, run in executor. (Use this for long + blocking functions, when you don't want to block the event loop.) + + :returns: A `Future`. + """ + + async def run() -> _T: + async with in_terminal(render_cli_done=render_cli_done): + if in_executor: + return await run_in_executor_with_context(func) + else: + return func() + + return ensure_future(run()) + + +@asynccontextmanager +async def in_terminal(render_cli_done: bool = False) -> AsyncGenerator[None, None]: + """ + Asynchronous context manager that suspends the current application and runs + the body in the terminal. + + .. code:: + + async def f(): + async with in_terminal(): + call_some_function() + await call_some_async_function() + """ + app = get_app_or_none() + if app is None or not app._is_running: + yield + return + + # When a previous `run_in_terminal` call was in progress. Wait for that + # to finish, before starting this one. Chain to previous call. + previous_run_in_terminal_f = app._running_in_terminal_f + new_run_in_terminal_f: Future[None] = Future() + app._running_in_terminal_f = new_run_in_terminal_f + + # Wait for the previous `run_in_terminal` to finish. + if previous_run_in_terminal_f is not None: + await previous_run_in_terminal_f + + # Wait for all CPRs to arrive. We don't want to detach the input until + # all cursor position responses have been arrived. Otherwise, the tty + # will echo its input and can show stuff like ^[[39;1R. + if app.output.responds_to_cpr: + await app.renderer.wait_for_cpr_responses() + + # Draw interface in 'done' state, or erase. + if render_cli_done: + app._redraw(render_as_done=True) + else: + app.renderer.erase() + + # Disable rendering. + app._running_in_terminal = True + + # Detach input. + try: + with app.input.detach(): + with app.input.cooked_mode(): + yield + finally: + # Redraw interface again. + try: + app._running_in_terminal = False + app.renderer.reset() + app._request_absolute_cursor_position() + app._redraw() + finally: + new_run_in_terminal_f.set_result(None) |