NoWidget: No widget under screen coordinate (x, y) crash when clicking on the terminal after new screen was recently pushed

[mzebrak]

Textual version: 0.43.0 (observable since 0.42.0, I haven't noticed it on 0.41.0)

Minimal working example to reproduce

from textual import on
from textual.app import App, ComposeResult
from textual.screen import Screen
from textual.widgets import Label, Footer, Button


class SomeScreen(Screen):
    def compose(self) -> ComposeResult:
        for i in range(50):
            yield Label(f"Label {i}")

        yield Footer()


class NoWidgetCrashApp(App):
    def compose(self) -> ComposeResult:
        yield Label("Hello, world!")
        yield Button("Click me!")
        yield Footer()

    @on(Button.Pressed)
    def push_some_screen(self) -> None:
        self.push_screen(SomeScreen())


NoWidgetCrashApp().run()

Steps:
Just launch the app, then start spamming LMB on the "Click me!" Button. When you click in the right time - right after new screen was pushed - you'll get a crash.

Video

Screencast.from.11-29-2023.08.41.29.AM.webm

[willmcgugan]

Please paste the output of textual diagnose. A copy of the traceback would also be helpful.

[mzebrak]

Please paste the output of textual diagnose. A copy of the traceback would also be helpful.

Here you go:

Traceback

╭─────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/drivers/linux_d │
│ river.py:242 in _run_input_thread                                                                │
│                                                                                                  │
│   239 │   │   an exception                                                                       │
│   240 │   │   """                                                                                │
│   241 │   │   try:                                                                               │
│ ❱ 242 │   │   │   self.run_input_thread()                                                        │
│   243 │   │   except BaseException as error:                                                     │
│   244 │   │   │   import rich.traceback                                                          │
│   245                                                                                            │
│                                                                                                  │
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/drivers/linux_d │
│ river.py:281 in run_input_thread                                                                 │
│                                                                                                  │
│   278 │   │   │   │   │   if mask & EVENT_READ:                                                  │
│   279 │   │   │   │   │   │   unicode_data = decode(read(fileno, 1024))                          │
│   280 │   │   │   │   │   │   for event in feed(unicode_data):                                   │
│ ❱ 281 │   │   │   │   │   │   │   self.process_event(event)                                      │
│   282 │   │   finally:                                                                           │
│   283 │   │   │   selector.close()                                                               │
│   284                                                                                            │
│                                                                                                  │
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/driver.py:63 in │
│ process_event                                                                                    │
│                                                                                                  │
│    60 │   │   """                                                                                │
│    61 │   │   event._set_sender(self._app)                                                       │
│    62 │   │   if isinstance(event, events.MouseDown):                                            │
│ ❱  63 │   │   │   self._mouse_down_widget = self._app.get_widget_at(event.x, event.y)[0]         │
│    64 │   │   │   if event.button:                                                               │
│    65 │   │   │   │   self._down_buttons.append(event.button)                                    │
│    66 │   │   elif isinstance(event, events.MouseUp):                                            │
│                                                                                                  │
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/app.py:2606 in  │
│ get_widget_at                                                                                    │
│                                                                                                  │
│   2603 │   │   Returns:                                                                          │
│   2604 │   │   │   The widget and the widget's screen region.                                    │
│   2605 │   │   """                                                                               │
│ ❱ 2606 │   │   return self.screen.get_widget_at(x, y)                                            │
│   2607 │                                                                                         │
│   2608 │   def bell(self) -> None:                                                               │
│   2609 │   │   """Play the console 'bell'.                                                       │
│                                                                                                  │
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/screen.py:289   │
│ in get_widget_at                                                                                 │
│                                                                                                  │
│    286 │   │   Returns:                                                                          │
│    287 │   │   │   Widget and screen region.                                                     │
│    288 │   │   """                                                                               │
│ ❱  289 │   │   return self._compositor.get_widget_at(x, y)                                       │
│    290 │                                                                                         │
│    291 │   def get_widgets_at(self, x: int, y: int) -> Iterable[tuple[Widget, Region]]:          │
│    292 │   │   """Get all widgets under a given coordinate.                                      │
│                                                                                                  │
│ /home/mzebrak/.pyenv/versions/textual-tests/lib/python3.10/site-packages/textual/_compositor.py: │
│ 787 in get_widget_at                                                                             │
│                                                                                                  │
│    784 │   │   │   for widget, cropped_region, region in self.layers_visible[y]:                 │
│    785 │   │   │   │   if contains(cropped_region, x, y) and widget.visible:                     │
│    786 │   │   │   │   │   return widget, region                                                 │
│ ❱  787 │   │   raise errors.NoWidget(f"No widget under screen coordinate ({x}, {y})")            │
│    788 │                                                                                         │
│    789 │   def get_widgets_at(self, x: int, y: int) -> Iterable[tuple[Widget, Region]]:          │
│    790 │   │   """Get all widgets under a given coordinate.                                      │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
NoWidget: No widget under screen coordinate (8, 3)

Textual Diagnostics

Versions

Name	Value
Textual	0.43.0
Rich	13.5.1

Python

Name	Value
Version	3.10.6
Implementation	CPython
Compiler	GCC 11.3.0
Executable	/home/mzebrak/.pyenv/versions/3.10.6/envs/textual-tests/bin/python3.10

Operating System

Name	Value
System	Linux
Release	6.2.6-76060206-generic
Version	#202303130630167942497222.04~4a8cde1 SMP PREEMPT_DYNAMIC Tue M

Terminal

Name	Value
Terminal Application	Unknown
TERM	xterm-256color
COLORTERM	truecolor
FORCE_COLOR	Not set
NO_COLOR	Not set

Rich Console options

Name	Value
size	width=220, height=40
legacy_windows	False
min_width	1
max_width	220
is_terminal	True
encoding	utf-8
max_height	40
justify	None
overflow	None
no_wrap	False
highlight	None
markup	None
height	None

[willmcgugan]

Will have a hotfix shortly. Didn't manage to reproduce it here, but I can see how it could occur. Would appreciate a test when it is released.

[mzebrak]

Will have a hotfix shortly. Didn't manage to reproduce it here, but I can see how it could occur. Would appreciate a test when it is released.

Sure, just let me know.

[github-actions]

Don't forget to star the repository!

Follow @textualizeio for Textual updates.