class KeyProcessor:
"""
Statemachine that receives :class:`KeyPress` instances and according to the
key bindings in the given :class:`KeyBindings`, calls the matching handlers.
::
p = KeyProcessor(key_bindings)
# Send keys into the processor.
p.feed(KeyPress(Keys.ControlX, '\x18'))
p.feed(KeyPress(Keys.ControlC, '\x03')
# Process all the keys in the queue.
p.process_keys()
# Now the ControlX-ControlC callback will be called if this sequence is
# registered in the key bindings.
:param key_bindings: `KeyBindingsBase` instance.
"""
def __init__(self, key_bindings: KeyBindingsBase) -> None:
self._bindings = key_bindings
self.before_key_press = Event(self)
self.after_key_press = Event(self)
self._keys_pressed = 0 # Monotonically increasing counter.
self.reset()
def reset(self) -> None:
self._previous_key_sequence: List[KeyPress] = []
self._previous_handler: Optional[Binding] = None
# The queue of keys not yet send to our _process generator/state machine.
self.input_queue: Deque[KeyPress] = deque()
# The key buffer that is matched in the generator state machine.
# (This is at at most the amount of keys that make up for one key binding.)
self.key_buffer: List[KeyPress] = []
#: Readline argument (for repetition of commands.)
#: https://www.gnu.org/software/bash/manual/html_node/Readline-Arguments.html
self.arg: Optional[str] = None
# Start the processor coroutine.
self._process_coroutine = self._process()
self._process_coroutine.send(None) # type: ignore
def _get_matches(self, key_presses: List[KeyPress]) -> List[Binding]:
"""
For a list of :class:`KeyPress` instances. Give the matching handlers
that would handle this.
"""
keys = tuple(k.key for k in key_presses)
# Try match, with mode flag
return [b for b in self._bindings.get_bindings_for_keys(keys) if b.filter()]
def _is_prefix_of_longer_match(self, key_presses: List[KeyPress]) -> bool:
"""
For a list of :class:`KeyPress` instances. Return True if there is any
handler that is bound to a suffix of this keys.
"""
keys = tuple(k.key for k in key_presses)
# Get the filters for all the key bindings that have a longer match.
# Note that we transform it into a `set`, because we don't care about
# the actual bindings and executing it more than once doesn't make
# sense. (Many key bindings share the same filter.)
filters = set(b.filter for b in self._bindings.get_bindings_starting_with_keys(keys))
# When any key binding is active, return True.
return any(f() for f in filters)
def _process(self) -> Generator[None, KeyPress, None]:
"""
Coroutine implementing the key match algorithm. Key strokes are sent
into this generator, and it calls the appropriate handlers.
"""
buffer = self.key_buffer
retry = False
while True:
flush = False
if retry:
retry = False
else:
key = yield
if key is _Flush:
flush = True
else:
buffer.append(key)
# If we have some key presses, check for matches.
if buffer:
matches = self._get_matches(buffer)
if flush:
is_prefix_of_longer_match = False
else:
is_prefix_of_longer_match = self._is_prefix_of_longer_match(buffer)
# When eager matches were found, give priority to them and also
# ignore all the longer matches.
eager_matches = [m for m in matches if m.eager()]
if eager_matches:
matches = eager_matches
is_prefix_of_longer_match = False
# Exact matches found, call handler.
if not is_prefix_of_longer_match and matches:
self._call_handler(matches[-1], key_sequence=buffer[:])
del buffer[:] # Keep reference.
# No match found.
elif not is_prefix_of_longer_match and not matches:
retry = True
found = False
# Loop over the input, try longest match first and shift.
for i in range(len(buffer), 0, -1):
matches = self._get_matches(buffer[:i])
if matches:
self._call_handler(matches[-1], key_sequence=buffer[:i])
del buffer[:i]
found = True
break
if not found:
del buffer[:1]
def feed(self, key_press: KeyPress, first: bool = False) -> None:
"""
Add a new :class:`KeyPress` to the input queue.
(Don't forget to call `process_keys` in order to process the queue.)
:param first: If true, insert before everything else.
"""
self._keys_pressed += 1
if first:
self.input_queue.appendleft(key_press)
else:
self.input_queue.append(key_press)
def feed_multiple(
self, key_presses: List[KeyPress], first: bool = False) -> None:
"""
:param first: If true, insert before everything else.
"""
self._keys_pressed += len(key_presses)
if first:
self.input_queue.extendleft(reversed(key_presses))
else:
self.input_queue.extend(key_presses)
def process_keys(self) -> None:
"""
Process all the keys in the `input_queue`.
(To be called after `feed`.)
Note: because of the `feed`/`process_keys` separation, it is
possible to call `feed` from inside a key binding.
This function keeps looping until the queue is empty.
"""
app = get_app()
def not_empty() -> bool:
# When the application result is set, stop processing keys. (E.g.
# if ENTER was received, followed by a few additional key strokes,
# leave the other keys in the queue.)
if app.is_done:
# But if there are still CPRResponse keys in the queue, these
# need to be processed.
return any(k for k in self.input_queue if k.key == Keys.CPRResponse)
else:
return bool(self.input_queue)
def get_next() -> KeyPress:
if app.is_done:
# Only process CPR responses. Everything else is typeahead.
cpr = [k for k in self.input_queue if k.key == Keys.CPRResponse][0]
self.input_queue.remove(cpr)
return cpr
else:
return self.input_queue.popleft()
keys_processed = False
is_flush = False
while not_empty():
keys_processed = True
# Process next key.
key_press = get_next()
is_flush = key_press is _Flush
is_cpr = key_press.key == Keys.CPRResponse
if not is_flush and not is_cpr:
self.before_key_press.fire()
try:
self._process_coroutine.send(key_press)
except Exception:
# If for some reason something goes wrong in the parser, (maybe
# an exception was raised) restart the processor for next time.
self.reset()
self.empty_queue()
app.invalidate()
raise
if not is_flush and not is_cpr:
self.after_key_press.fire()
if keys_processed:
# Invalidate user interface.
app.invalidate()
# Skip timeout if the last key was flush.
if not is_flush:
self._start_timeout()
def empty_queue(self) -> List[KeyPress]:
"""
Empty the input queue. Return the unprocessed input.
"""
key_presses = list(self.input_queue)
self.input_queue.clear()
# Filter out CPRs. We don't want to return these.
key_presses = [k for k in key_presses if k.key != Keys.CPRResponse]
return key_presses
def _call_handler(self, handler: Binding, key_sequence: List[KeyPress]) -> None:
app = get_app()
was_recording_emacs = app.emacs_state.is_recording
was_recording_vi = bool(app.vi_state.recording_register)
was_temporary_navigation_mode = app.vi_state.temporary_navigation_mode
arg = self.arg
self.arg = None
event = KeyPressEvent(
weakref.ref(self),
arg=arg,
key_sequence=key_sequence,
previous_key_sequence=self._previous_key_sequence,
is_repeat=(handler == self._previous_handler))
# Save the state of the current buffer.
if handler.save_before(event):
event.app.current_buffer.save_to_undo_stack()
# Call handler.
from prompt_toolkit.buffer import EditReadOnlyBuffer
try:
handler.call(event)
self._fix_vi_cursor_position(event)
except EditReadOnlyBuffer:
# When a key binding does an attempt to change a buffer which is
# read-only, we can ignore that. We sound a bell and go on.
app.output.bell()
if was_temporary_navigation_mode:
self._leave_vi_temp_navigation_mode(event)
self._previous_key_sequence = key_sequence
self._previous_handler = handler
# Record the key sequence in our macro. (Only if we're in macro mode
# before and after executing the key.)
if handler.record_in_macro():
if app.emacs_state.is_recording and was_recording_emacs:
recording = app.emacs_state.current_recording
if recording is not None: # Should always be true, given that
# `was_recording_emacs` is set.
recording.extend(key_sequence)
if app.vi_state.recording_register and was_recording_vi:
for k in key_sequence:
app.vi_state.current_recording += k.data
def _fix_vi_cursor_position(self, event: 'KeyPressEvent') -> None:
"""
After every command, make sure that if we are in Vi navigation mode, we
never put the cursor after the last character of a line. (Unless it's
an empty line.)
"""
app = event.app
buff = app.current_buffer
preferred_column = buff.preferred_column
if (vi_navigation_mode() and
buff.document.is_cursor_at_the_end_of_line and
len(buff.document.current_line) > 0):
buff.cursor_position -= 1
# Set the preferred_column for arrow up/down again.
# (This was cleared after changing the cursor position.)
buff.preferred_column = preferred_column
def _leave_vi_temp_navigation_mode(self, event: 'KeyPressEvent') -> None:
"""
If we're in Vi temporary navigation (normal) mode, return to
insert/replace mode after executing one action.
"""
app = event.app
if app.editing_mode == EditingMode.VI:
# Not waiting for a text object and no argument has been given.
if app.vi_state.operator_func is None and self.arg is None:
app.vi_state.temporary_navigation_mode = False
def _start_timeout(self) -> None:
"""
Start auto flush timeout. Similar to Vim's `timeoutlen` option.
Start a background thread with a timer. When this timeout expires and
no key was pressed in the meantime, we flush all data in the queue and
call the appropriate key binding handlers.
"""
timeout = get_app().timeoutlen
if timeout is None:
return
counter = self._keys_pressed
async def wait() -> None:
" Wait for timeout. "
await sleep(timeout)
if len(self.key_buffer) > 0 and counter == self._keys_pressed:
# (No keys pressed in the meantime.)
flush_keys()
def flush_keys() -> None:
" Flush keys. "
self.feed(_Flush)
self.process_keys()
# Automatically flush keys.
# (_daemon needs to be set, otherwise, this will hang the
# application for .5 seconds before exiting.)
ensure_future(wait())
class Application(object):
"""
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 on_abort: What to do when Control-C is pressed.
:param on_exit: What to do when Control-D is pressed.
: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.
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 a
: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:
: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()
"""
def __init__(self, layout=None,
style=None, include_default_pygments_style=True,
key_bindings=None, clipboard=None,
full_screen=False, color_depth=None,
mouse_support=False,
enable_page_navigation_bindings=None, # Can be None, True or False.
paste_mode=False,
editing_mode=EditingMode.EMACS,
erase_when_done=False,
reverse_vi_search_direction=False,
min_redraw_interval=None,
max_render_postpone_time=0,
on_reset=None, on_invalidate=None,
before_render=None, after_render=None,
# I/O.
input=None, output=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)
assert layout is None or isinstance(layout, Layout), 'Got layout: %r' % (layout, )
assert key_bindings is None or isinstance(key_bindings, KeyBindingsBase)
assert clipboard is None or isinstance(clipboard, Clipboard)
assert isinstance(full_screen, bool)
assert (color_depth is None or callable(color_depth) or
color_depth in ColorDepth._ALL), 'Got color_depth: %r' % (color_depth, )
assert isinstance(editing_mode, six.string_types)
assert style is None or isinstance(style, BaseStyle)
assert isinstance(erase_when_done, bool)
assert min_redraw_interval is None or isinstance(min_redraw_interval, (float, int))
assert max_render_postpone_time is None or isinstance(max_render_postpone_time, (float, int))
assert on_reset is None or callable(on_reset)
assert on_invalidate is None or callable(on_invalidate)
assert before_render is None or callable(before_render)
assert after_render is None or callable(after_render)
assert output is None or isinstance(output, Output)
assert input is None or isinstance(input, Input)
self.style = style
if layout is None:
layout = create_dummy_layout()
# 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 = 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
# 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.
self.output = output or get_default_output()
self.input = input or get_default_input()
# List of 'extra' functions to execute before a Application.run.
self.pre_run_callables = []
self._is_running = False
self.future = 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 = .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 = [] # Collection of 'invalidate' Event objects.
self._last_redraw_time = 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 = None
# Trigger initialize callback.
self.reset()
def _create_merged_style(self, include_default_pygments_style):
"""
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():
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):
"""
Active :class:`.ColorDepth`.
"""
depth = self._color_depth
if callable(depth):
depth = depth()
if depth is None:
depth = ColorDepth.default()
return depth
@property
def current_buffer(self):
"""
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):
"""
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):
"""
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.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):
"""
Thread safe way of sending a repaint trigger to the input event loop.
"""
# 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.on_invalidate.fire()
def redraw():
self._invalidated = False
self._redraw()
def schedule_redraw():
# Call redraw in the eventloop (thread safe).
# Usually with the high priority, in order to make the application
# feel responsive, but this can be tuned by changing the value of
# `max_render_postpone_time`.
if self.max_render_postpone_time:
_max_postpone_until = time.time() + self.max_render_postpone_time
else:
_max_postpone_until = None
call_from_executor(
redraw, _max_postpone_until=_max_postpone_until)
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:
def redraw_in_future():
time.sleep(self.min_redraw_interval - diff)
schedule_redraw()
run_in_executor(redraw_in_future)
else:
schedule_redraw()
else:
schedule_redraw()
@property
def invalidated(self):
" True when a redraw operation has been scheduled. "
return self._invalidated
def _redraw(self, render_as_done=False):
"""
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.
"""
# 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()
# Clear the 'rendered_ui_controls' list. (The `Window` class will
# populate this during the next rendering.)
self.rendered_user_controls = []
# Render
self.render_counter += 1
self.before_render.fire()
# NOTE: We want to make sure this Application is the active one, if
# we have a situation with multiple concurrent running apps.
# We had the case with pymux where `invalidate()` was called
# at the point where another Application was active. This
# would cause prompt_toolkit to render the wrong application
# to this output device.
with set_app(self):
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()
def _update_invalidate_events(self):
"""
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
# Gather all new events.
# (All controls are able to invalidate themselves.)
def gather_events():
for c in self.layout.find_all_controls():
for ev in c.get_invalidate_events():
yield ev
self._invalidate_events = list(gather_events())
# Attach invalidate event handler.
def invalidate(sender):
self.invalidate()
for ev in self._invalidate_events:
ev += invalidate
def _on_resize(self):
"""
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=None):
" Called during `run`. "
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[:]
def run_async(self, pre_run=None):
"""
Run asynchronous. Return a prompt_toolkit
:class:`~prompt_toolkit.eventloop.Future` object.
If you wish to run on top of asyncio, remember that a prompt_toolkit
`Future` needs to be converted to an asyncio `Future`. The cleanest way
is to call :meth:`~prompt_toolkit.eventloop.Future.to_asyncio_future`.
Also make sure to tell prompt_toolkit to use the asyncio event loop.
.. code:: python
from prompt_toolkit.eventloop import use_asyncio_event_loop
from asyncio import get_event_loop
use_asyncio_event_loop()
get_event_loop().run_until_complete(
application.run_async().to_asyncio_future())
"""
assert not self._is_running
def _run_async():
" Coroutine. "
loop = get_event_loop()
f = loop.create_future()
self.future = f # XXX: make sure to set this before calling '_redraw'.
# 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_counter = [0] # Non local.
# Reset.
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():
# 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:
f.set_exception(EOFError)
else:
# Increase this flush counter.
flush_counter[0] += 1
counter = flush_counter[0]
# Automatically flush keys.
# (_daemon needs to be set, otherwise, this will hang the
# application for .5 seconds before exiting.)
run_in_executor(
lambda: auto_flush_input(counter), _daemon=True)
def auto_flush_input(counter):
# Flush input after timeout.
# (Used for flushing the enter key.)
time.sleep(self.ttimeoutlen)
if flush_counter[0] == counter:
call_from_executor(flush_input)
def flush_input():
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.
with self.input.raw_mode():
with self.input.attach(read_from_input):
# Draw UI.
self._request_absolute_cursor_position()
self._redraw()
has_sigwinch = hasattr(signal, 'SIGWINCH') and in_main_thread()
if has_sigwinch:
previous_winch_handler = loop.add_signal_handler(
signal.SIGWINCH, self._on_resize)
# Wait for UI to finish.
try:
result = yield From(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
self._invalidate_events = []
# Wait for CPR responses.
if self.input.responds_to_cpr:
yield From(self.renderer.wait_for_cpr_responses())
if has_sigwinch:
loop.add_signal_handler(signal.SIGWINCH, previous_winch_handler)
# Wait for the run-in-terminals to terminate.
previous_run_in_terminal_f = self._running_in_terminal_f
if previous_run_in_terminal_f:
yield From(previous_run_in_terminal_f)
# Store unprocessed input as typeahead for next time.
store_typeahead(self.input, self.key_processor.empty_queue())
raise Return(result)
def _run_async2():
self._is_running = True
with set_app(self):
try:
f = From(_run_async())
result = yield f
finally:
assert not self._is_running
raise Return(result)
return ensure_future(_run_async2())
def run(self, pre_run=None, set_exception_handler=True, inputhook=None):
"""
A blocking 'run' call that waits until the UI is finished.
: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 inputhook: None or a callable that takes an `InputHookContext`.
"""
loop = get_event_loop()
def run():
f = self.run_async(pre_run=pre_run)
run_until_complete(f, inputhook=inputhook)
return f.result()
def handle_exception(context):
" 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))
def print_exception():
# 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 %s' % (context.get('exception'), ))
yield From(_do_wait_for_enter('Press ENTER to continue...'))
run_coroutine_in_terminal(print_exception)
if set_exception_handler:
# Run with patched exception handler.
previous_exc_handler = loop.get_exception_handler()
loop.set_exception_handler(handle_exception)
try:
return run()
finally:
loop.set_exception_handler(previous_exc_handler)
else:
run()
def cpr_not_supported_callback(self):
"""
Called when we don't receive the cursor position response in time.
"""
if not self.input.responds_to_cpr:
return # We know about this already.
def in_terminal():
self.output.write(
"WARNING: your terminal doesn't support cursor position requests (CPR).\r\n")
self.output.flush()
run_in_terminal(in_terminal)
def exit(self, result=None, exception=None, style=''):
"""
Exit application.
: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.done():
raise Exception('Return value already set.')
self.exit_style = style
if exception is not None:
self.future.set_exception(exception)
else:
self.future.set_result(result)
def _request_absolute_cursor_position(self):
"""
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()
def run_system_command(self, command, wait_for_enter=True,
display_before_text='',
wait_text='Press ENTER to continue...'):
"""
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.
"""
assert isinstance(wait_for_enter, bool)
def run():
# 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():
self.print_text(display_before_text)
p = Popen(command, shell=True,
stdin=input_fd, stdout=output_fd)
p.wait()
yield run_in_executor(run_command)
# Wait for the user to press enter.
if wait_for_enter:
yield From(_do_wait_for_enter(wait_text))
return run_coroutine_in_terminal(run)
def suspend_to_background(self, suspend_group=True):
"""
(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 hasattr(signal, 'SIGTSTP'):
def run():
# Send `SIGSTP` 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.SIGTSTP)
else:
os.kill(os.getpid(), signal.SIGTSTP)
run_in_terminal(run)
def print_text(self, text, style=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(self.output, text, style or self._merged_style, self.color_depth)
@property
def is_running(self):
" `True` when the application is currently active/running. "
return self._is_running
@property
def is_done(self):
return self.future and self.future.done()
def get_used_style_strings(self):
"""
Return a list of used style strings. This is helpful for debugging, and
for writing a new `Style`.
"""
return sorted([
re.sub(r'\s+', ' ', style_str).strip()
for style_str in self.renderer._attrs_for_style.keys()])
class InputProcessor(object):
"""
Statemachine that receives :class:`KeyPress` instances and according to the
key bindings in the given :class:`Registry`, calls the matching handlers.
::
p = InputProcessor(registry)
# Send keys into the processor.
p.feed(KeyPress(Keys.ControlX, '\x18'))
p.feed(KeyPress(Keys.ControlC, '\x03')
# Process all the keys in the queue.
p.process_keys()
# Now the ControlX-ControlC callback will be called if this sequence is
# registered in the registry.
:param registry: `Registry` instance.
:param cli_ref: weakref to `CommandLineInterface`.
"""
def __init__(self, registry, cli_ref):
assert isinstance(registry, Registry)
self._registry = registry
self._cli_ref = cli_ref
self.beforeKeyPress = Event(self)
self.afterKeyPress = Event(self)
# The queue of keys not yet send to our _process generator/state machine.
self.input_queue = deque()
# The key buffer that is matched in the generator state machine.
# (This is at at most the amount of keys that make up for one key binding.)
self.key_buffer = []
self.reset()
# print(' '.join(set(''.join(map(str, kb.keys)) for kb in registry.key_bindings if all(isinstance(X, unicode) for X in kb.keys))))
def reset(self):
self._previous_key_sequence = None
self._previous_handler = None
self._process_coroutine = self._process()
self._process_coroutine.send(None)
#: Readline argument (for repetition of commands.)
#: https://www.gnu.org/software/bash/manual/html_node/Readline-Arguments.html
self.arg = None
def _get_matches(self, key_presses):
"""
For a list of :class:`KeyPress` instances. Give the matching handlers
that would handle this.
"""
keys = tuple(k.key for k in key_presses)
cli = self._cli_ref()
# Try match, with mode flag
return [b for b in self._registry.get_bindings_for_keys(keys) if b.filter(cli)]
def _is_prefix_of_longer_match(self, key_presses):
"""
For a list of :class:`KeyPress` instances. Return True if there is any
handler that is bound to a suffix of this keys.
"""
keys = tuple(k.key for k in key_presses)
cli = self._cli_ref()
# Get the filters for all the key bindings that have a longer match.
# Note that we transform it into a `set`, because we don't care about
# the actual bindings and executing it more than once doesn't make
# sense. (Many key bindings share the same filter.)
filters = set(b.filter for b in self._registry.get_bindings_starting_with_keys(keys))
# When any key binding is active, return True.
return any(f(cli) for f in filters)
def _process(self):
"""
Coroutine implementing the key match algorithm. Key strokes are sent
into this generator, and it calls the appropriate handlers.
"""
buffer = self.key_buffer
retry = False
while True:
if retry:
retry = False
else:
buffer.append((yield))
# If we have some key presses, check for matches.
if buffer:
is_prefix_of_longer_match = self._is_prefix_of_longer_match(buffer)
matches = self._get_matches(buffer)
# When longer matches were found, but the current match is
# 'eager', ignore all the longer matches.
if matches and matches[-1].eager(self._cli_ref()):
is_prefix_of_longer_match = False
# Exact matches found, call handler.
if not is_prefix_of_longer_match and matches:
self._call_handler(matches[-1], key_sequence=buffer)
del buffer[:] # Keep reference.
# No match found.
elif not is_prefix_of_longer_match and not matches:
retry = True
found = False
# Loop over the input, try longest match first and shift.
for i in range(len(buffer), 0, -1):
matches = self._get_matches(buffer[:i])
if matches:
self._call_handler(matches[-1], key_sequence=buffer[:i])
del buffer[:i]
found = True
break
if not found:
del buffer[:1]
def feed(self, key_press):
"""
Add a new :class:`KeyPress` to the input queue.
(Don't forget to call `process_keys` in order to process the queue.)
"""
assert isinstance(key_press, KeyPress)
self.input_queue.append(key_press)
def process_keys(self):
"""
Process all the keys in the `input_queue`.
(To be called after `feed`.)
Note: because of the `feed`/`process_keys` separation, it is
possible to call `feed` from inside a key binding.
This function keeps looping until the queue is empty.
"""
while self.input_queue:
key_press = self.input_queue.popleft()
if key_press.key != Keys.CPRResponse:
self.beforeKeyPress.fire()
self._process_coroutine.send(key_press)
if key_press.key != Keys.CPRResponse:
self.afterKeyPress.fire()
# Invalidate user interface.
cli = self._cli_ref()
if cli:
cli.invalidate()
def _call_handler(self, handler, key_sequence=None):
arg = self.arg
self.arg = None
event = KeyPressEvent(
weakref.ref(self), arg=arg, key_sequence=key_sequence,
previous_key_sequence=self._previous_key_sequence,
is_repeat=(handler == self._previous_handler))
# Save the state of the current buffer.
cli = event.cli # Can be `None` (In unit-tests only.)
if handler.save_before(event) and cli:
cli.current_buffer.save_to_undo_stack()
# Call handler.
try:
handler.call(event)
self._fix_vi_cursor_position(event)
except EditReadOnlyBuffer:
# When a key binding does an attempt to change a buffer which is
# read-only, we can just silently ignore that.
pass
self._previous_key_sequence = key_sequence
self._previous_handler = handler
def _fix_vi_cursor_position(self, event):
"""
After every command, make sure that if we are in Vi navigation mode, we
never put the cursor after the last character of a line. (Unless it's
an empty line.)
"""
cli = self._cli_ref()
if cli:
buff = cli.current_buffer
preferred_column = buff.preferred_column
if (ViNavigationMode()(event.cli) and
buff.document.is_cursor_at_the_end_of_line and
len(buff.document.current_line) > 0):
buff.cursor_position -= 1
# Set the preferred_column for arrow up/down again.
# (This was cleared after changing the cursor position.)
buff.preferred_column = preferred_column
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 on_abort: What to do when Control-C is pressed.
:param on_exit: What to do when Control-D is pressed.
: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.
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 a
: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,
on_reset: Optional[ApplicationEventHandler] = None,
on_invalidate: Optional[ApplicationEventHandler] = None,
before_render: Optional[ApplicationEventHandler] = None,
after_render: Optional[ApplicationEventHandler] = None,
# I/O.
input: Optional[Input] = None,
output: Optional[Output] = 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
# 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,
self.input,
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:
"""
Active :class:`.ColorDepth`.
"""
depth = self._color_depth
if callable(depth):
return depth() or ColorDepth.default()
if depth is None:
return ColorDepth.default()
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: List[Task[None]] = []
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
# 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.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.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`).
if self.context is not None:
self.context.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 not in (None, 0):
async def auto_refresh(refresh_interval) -> 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():
for ev in c.get_invalidate_events():
yield ev
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`. "
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,
) -> _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.
"""
assert not self._is_running, "Application is already running."
async def _run_async() -> _AppResult:
" Coroutine. "
loop = get_event_loop()
f = loop.create_future()
self.future = f # XXX: make sure to set this before calling '_redraw'.
self.loop = loop
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.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:
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.
with self.input.raw_mode():
with self.input.attach(read_from_input):
# Draw UI.
self._request_absolute_cursor_position()
self._redraw()
self._start_auto_refresh_task()
has_sigwinch = hasattr(signal,
"SIGWINCH") and in_main_thread()
if has_sigwinch:
previous_winch_handler = signal.getsignal(
signal.SIGWINCH)
loop.add_signal_handler(signal.SIGWINCH,
self._on_resize)
# 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.input.responds_to_cpr:
await self.renderer.wait_for_cpr_responses()
if has_sigwinch:
loop.remove_signal_handler(signal.SIGWINCH)
signal.signal(signal.SIGWINCH,
previous_winch_handler)
# 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
async def _run_async2() -> _AppResult:
self._is_running = True
# 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 = get_event_loop()
if set_exception_handler:
previous_exc_handler = loop.get_exception_handler()
loop.set_exception_handler(self._handle_exception)
try:
with set_app(self):
try:
result = await _run_async()
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()
# Set the `_is_running` flag to `False`. Normally this
# happened already in the finally block in `run_async`
# above, but in case of exceptions, that's not always the
# case.
self._is_running = False
return result
finally:
if set_exception_handler:
loop.set_exception_handler(previous_exc_handler)
return await _run_async2()
def run(
self,
pre_run: Optional[Callable[[], None]] = None,
set_exception_handler: bool = True,
) -> _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.
: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.
"""
# 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))
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 %s" % (context.get("exception"), ))
await _do_wait_for_enter("Press ENTER to continue...")
ensure_future(in_term())
def create_background_task(
self, coroutine: Awaitable[None]) -> "asyncio.Task[None]":
"""
Start a background task (coroutine) for the running application.
If asyncio had nurseries like Trio, we would create a nursery in
`Application.run_async`, and run the given coroutine in that nursery.
"""
task = get_event_loop().create_task(coroutine)
self.background_tasks.append(task)
return task
async def cancel_and_wait_for_background_tasks(self) -> None:
"""
Cancel all background tasks, and wait for the cancellation to be done.
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()
for task in self.background_tasks:
try:
await task
except CancelledError:
pass
def cpr_not_supported_callback(self) -> None:
"""
Called when we don't receive the cursor position response in time.
"""
if not self.input.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.
: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 hasattr(signal, "SIGTSTP"):
def run() -> None:
# Send `SIGSTP` 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.SIGTSTP)
else:
os.kill(os.getpid(), signal.SIGTSTP)
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 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 on_abort: What to do when Control-C is pressed.
:param on_exit: What to do when Control-D is pressed.
: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.
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 a
: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()
"""
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] = .01,
on_reset: Optional[ApplicationEventHandler] = None,
on_invalidate: Optional[ApplicationEventHandler] = None,
before_render: Optional[ApplicationEventHandler] = None,
after_render: Optional[ApplicationEventHandler] = None,
# I/O.
input: Optional[Input] = None,
output: Optional[Output] = 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
# 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 = .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,
self.input,
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:
"""
Active :class:`.ColorDepth`.
"""
depth = self._color_depth
if callable(depth):
return depth() or ColorDepth.default()
if depth is None:
return ColorDepth.default()
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.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.
"""
# 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.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()
ensure_future(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`).
if self.context is not None:
self.context.run(run_in_context)
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():
for ev in c.get_invalidate_events():
yield ev
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`. "
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) -> _AppResult:
"""
Run asynchronous. Return a prompt_toolkit
:class:`~prompt_toolkit.eventloop.Future` object.
If you wish to run on top of asyncio, remember that a prompt_toolkit
`Future` needs to be converted to an asyncio `Future`. The cleanest way
is to call :meth:`~prompt_toolkit.eventloop.Future.to_asyncio_future`.
Also make sure to tell prompt_toolkit to use the asyncio event loop.
.. code:: python
from prompt_toolkit.eventloop import use_asyncio_event_loop
from asyncio import get_event_loop
use_asyncio_event_loop()
get_event_loop().run_until_complete(
application.run_async().to_asyncio_future())
"""
assert not self._is_running, 'Application is already running.'
async def _run_async() -> _AppResult:
" Coroutine. "
loop = get_event_loop()
f = loop.create_future()
self.future = f # XXX: make sure to set this before calling '_redraw'.
self.loop = loop
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_counter = 0
# Reset.
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_counter
# 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:
f.set_exception(EOFError)
else:
# Increase this flush counter.
flush_counter += 1
counter = flush_counter
# Automatically flush keys.
ensure_future(auto_flush_input(counter))
async def auto_flush_input(counter: int) -> None:
# Flush input after timeout.
# (Used for flushing the enter key.)
await sleep(self.ttimeoutlen)
if flush_counter == counter:
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.
with self.input.raw_mode():
with self.input.attach(read_from_input):
# Draw UI.
self._request_absolute_cursor_position()
self._redraw()
has_sigwinch = hasattr(signal, 'SIGWINCH') and in_main_thread()
if has_sigwinch:
previous_winch_handler = signal.getsignal(signal.SIGWINCH)
loop.add_signal_handler(signal.SIGWINCH, self._on_resize)
# 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.input.responds_to_cpr:
await self.renderer.wait_for_cpr_responses()
if has_sigwinch:
loop.remove_signal_handler(signal.SIGWINCH)
signal.signal(signal.SIGWINCH, previous_winch_handler)
# 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
async def _run_async2() -> _AppResult:
self._is_running = True
with set_app(self):
try:
result = await _run_async()
finally:
# Set the `_is_running` flag to `False`. Normally this
# happened already in the finally block in `run_async`
# above, but in case of exceptions, that's not always the
# case.
self._is_running = False
return result
return await _run_async2()
def run(self, pre_run: Optional[Callable[[], None]] = None,
set_exception_handler: bool = True) -> _AppResult:
"""
A blocking 'run' call that waits until the UI is finished.
: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.
"""
loop = get_event_loop()
def run() -> _AppResult:
f = ensure_future(self.run_async(pre_run=pre_run))
get_event_loop().run_until_complete(f)
return f.result()
def handle_exception(loop, context: Dict[str, Any]) -> None:
" 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 %s' % (context.get('exception'), ))
await _do_wait_for_enter('Press ENTER to continue...')
ensure_future(in_term())
if set_exception_handler:
# Run with patched exception handler.
previous_exc_handler = loop.get_exception_handler()
loop.set_exception_handler(handle_exception)
try:
return run()
finally:
loop.set_exception_handler(previous_exc_handler)
else:
return run()
def cpr_not_supported_callback(self) -> None:
"""
Called when we don't receive the cursor position response in time.
"""
if not self.input.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.
: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: str = '',
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 hasattr(signal, 'SIGTSTP'):
def run() -> None:
# Send `SIGSTP` 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.SIGTSTP)
else:
os.kill(os.getpid(), signal.SIGTSTP)
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 DataControl(UIControl):
def __init__(self, address, auth):
self._address = address
self._uri = "bolt://{}".format(self.address)
self._auth = auth
self._driver = None
self._running = False
self._invalidated = False
self._refresh_period = 1.0
self._refresh_thread = Thread(target=self.loop)
self._on_fresh_data = Event(self)
self._edition = self.work(
lambda tx: tx.run("CALL dbms.components").value("edition")[0])
@property
def edition(self):
return self._edition
def start(self):
self._running = True
self._refresh_thread.start()
def stop(self):
self._running = False
self._refresh_thread.join()
@property
def address(self):
return self._address
@property
def up(self):
return bool(self._driver)
def work(self, unit, on_error=None):
try:
if not self._driver:
self._driver = GraphDatabase.driver(self._uri,
auth=self._auth,
max_retry_time=1.0)
with self._driver.session(READ_ACCESS) as session:
return session.read_transaction(unit)
except (CypherError, ServiceUnavailable) as error:
self._driver = None
if callable(on_error):
on_error(error)
else:
raise
def loop(self):
while self._running:
self.work(self.fetch_data, self.on_fetch_error)
self._on_fresh_data.fire()
self._invalidated = False
for _ in range(int(10 * self._refresh_period)):
if self._running and not self._invalidated:
sleep(0.1)
else:
break
def invalidate(self):
self._invalidated = True
def exit(self):
self.stop()
if self._driver:
self._driver.close()
def get_invalidate_events(self):
"""
Return the Window invalidate events.
"""
yield self._on_fresh_data
def fetch_data(self, tx):
""" Retrieve data from database.
:return:
"""
def on_fetch_error(self, error):
""" Raised if an error occurs while fetching data.
:param error:
:return:
"""
def create_content(self, width, height):
""" Generate content.
class KeyProcessor(object):
"""
Statemachine that receives :class:`KeyPress` instances and according to the
key bindings in the given :class:`KeyBindings`, calls the matching handlers.
::
p = KeyProcessor(key_bindings)
# Send keys into the processor.
p.feed(KeyPress(Keys.ControlX, '\x18'))
p.feed(KeyPress(Keys.ControlC, '\x03')
# Process all the keys in the queue.
p.process_keys()
# Now the ControlX-ControlC callback will be called if this sequence is
# registered in the key bindings.
:param key_bindings: `KeyBindingsBase` instance.
"""
def __init__(self, key_bindings):
assert isinstance(key_bindings, KeyBindingsBase)
self._bindings = key_bindings
self.before_key_press = Event(self)
self.after_key_press = Event(self)
# Simple macro recording. (Like readline does.)
self.record_macro = False
self.macro = []
self.reset()
def reset(self):
self._previous_key_sequence = []
self._previous_handler = None
# The queue of keys not yet send to our _process generator/state machine.
self.input_queue = deque()
# The key buffer that is matched in the generator state machine.
# (This is at at most the amount of keys that make up for one key binding.)
self.key_buffer = []
#: Readline argument (for repetition of commands.)
#: https://www.gnu.org/software/bash/manual/html_node/Readline-Arguments.html
self.arg = None
# Start the processor coroutine.
self._process_coroutine = self._process()
self._process_coroutine.send(None)
def start_macro(self):
" Start recording macro. "
self.record_macro = True
self.macro = []
def end_macro(self):
" End recording macro. "
self.record_macro = False
def call_macro(self):
self.feed_multiple(self.macro, first=True)
def _get_matches(self, key_presses):
"""
For a list of :class:`KeyPress` instances. Give the matching handlers
that would handle this.
"""
keys = tuple(k.key for k in key_presses)
# Try match, with mode flag
return [
b for b in self._bindings.get_bindings_for_keys(keys)
if b.filter()
]
def _is_prefix_of_longer_match(self, key_presses):
"""
For a list of :class:`KeyPress` instances. Return True if there is any
handler that is bound to a suffix of this keys.
"""
keys = tuple(k.key for k in key_presses)
# Get the filters for all the key bindings that have a longer match.
# Note that we transform it into a `set`, because we don't care about
# the actual bindings and executing it more than once doesn't make
# sense. (Many key bindings share the same filter.)
filters = set(
b.filter
for b in self._bindings.get_bindings_starting_with_keys(keys))
# When any key binding is active, return True.
return any(f() for f in filters)
def _process(self):
"""
Coroutine implementing the key match algorithm. Key strokes are sent
into this generator, and it calls the appropriate handlers.
"""
buffer = self.key_buffer
retry = False
while True:
if retry:
retry = False
else:
buffer.append((yield))
# If we have some key presses, check for matches.
if buffer:
is_prefix_of_longer_match = self._is_prefix_of_longer_match(
buffer)
matches = self._get_matches(buffer)
# When eager matches were found, give priority to them and also
# ignore all the longer matches.
eager_matches = [m for m in matches if m.eager()]
if eager_matches:
matches = eager_matches
is_prefix_of_longer_match = False
# Exact matches found, call handler.
if not is_prefix_of_longer_match and matches:
self._call_handler(matches[-1], key_sequence=buffer[:])
del buffer[:] # Keep reference.
# No match found.
elif not is_prefix_of_longer_match and not matches:
retry = True
found = False
# Loop over the input, try longest match first and shift.
for i in range(len(buffer), 0, -1):
matches = self._get_matches(buffer[:i])
if matches:
self._call_handler(matches[-1],
key_sequence=buffer[:i])
del buffer[:i]
found = True
break
if not found:
del buffer[:1]
def feed(self, key_press, first=False):
"""
Add a new :class:`KeyPress` to the input queue.
(Don't forget to call `process_keys` in order to process the queue.)
:param first: If true, insert before everything else.
"""
assert isinstance(key_press, KeyPress)
if first:
self.input_queue.appendleft(key_press)
else:
self.input_queue.append(key_press)
def feed_multiple(self, key_presses, first=False):
"""
:param first: If true, insert before everything else.
"""
if first:
self.input_queue.extendleft(reversed(key_presses))
else:
self.input_queue.extend(key_presses)
def process_keys(self):
"""
Process all the keys in the `input_queue`.
(To be called after `feed`.)
Note: because of the `feed`/`process_keys` separation, it is
possible to call `feed` from inside a key binding.
This function keeps looping until the queue is empty.
"""
app = get_app()
def not_empty():
# When the application result is set, stop processing keys. (E.g.
# if ENTER was received, followed by a few additional key strokes,
# leave the other keys in the queue.)
if app.is_done:
# But if there are still CPRResponse keys in the queue, these
# need to be processed.
return any(k for k in self.input_queue
if k.key == Keys.CPRResponse)
else:
return bool(self.input_queue)
def get_next():
if app.is_done:
# Only process CPR responses. Everything else is typeahead.
cpr = [
k for k in self.input_queue if k.key == Keys.CPRResponse
][0]
self.input_queue.remove(cpr)
return cpr
else:
return self.input_queue.popleft()
while not_empty():
# Process next key.
key_press = get_next()
if key_press.key != Keys.CPRResponse:
self.before_key_press.fire()
try:
self._process_coroutine.send(key_press)
except Exception:
# If for some reason something goes wrong in the parser, (maybe
# an exception was raised) restart the processor for next time.
self.reset()
self.flush()
app.invalidate()
raise
if key_press.key != Keys.CPRResponse:
self.after_key_press.fire()
# Invalidate user interface.
app.invalidate()
def flush(self):
"""
Flush the input queue. Return the inprocessed input.
"""
key_presses = list(self.input_queue)
self.input_queue.clear()
# Filter out CPRs. We don't want to return these.
key_presses = [k for k in key_presses if k.key != Keys.CPRResponse]
return key_presses
def _call_handler(self, handler, key_sequence=None):
was_recording = self.record_macro
arg = self.arg
self.arg = None
event = KeyPressEvent(
weakref.ref(self),
arg=arg,
key_sequence=key_sequence,
previous_key_sequence=self._previous_key_sequence,
is_repeat=(handler == self._previous_handler))
# Save the state of the current buffer.
if handler.save_before(event):
event.app.current_buffer.save_to_undo_stack()
# Call handler.
try:
handler.call(event)
self._fix_vi_cursor_position(event)
except EditReadOnlyBuffer:
# When a key binding does an attempt to change a buffer which is
# read-only, we can just silently ignore that.
pass
self._previous_key_sequence = key_sequence
self._previous_handler = handler
# Record the key sequence in our macro. (Only if we're in macro mode
# before and after executing the key.)
if self.record_macro and was_recording:
self.macro.extend(key_sequence)
def _fix_vi_cursor_position(self, event):
"""
After every command, make sure that if we are in Vi navigation mode, we
never put the cursor after the last character of a line. (Unless it's
an empty line.)
"""
app = get_app()
buff = app.current_buffer
preferred_column = buff.preferred_column
if (vi_navigation_mode() and buff.document.is_cursor_at_the_end_of_line
and len(buff.document.current_line) > 0):
buff.cursor_position -= 1
# Set the preferred_column for arrow up/down again.
# (This was cleared after changing the cursor position.)
buff.preferred_column = preferred_column