Click events not generated in Ghostty terminal inside tmux (widget identity check fails)

[brendandebeasi]

Summary

When running a Textual app inside tmux with Ghostty terminal, single clicks don't work - users have to double-click to trigger click handlers. The issue appears to be in the Click event generation logic where get_widget_at() returns different widget instances between MouseDown and MouseUp events, causing the identity check (is) to fail.

Environment

• Textual version: 7.5.0
• Python version: 3.11.13
• Terminal: Ghostty
• Running inside: tmux
• OS: macOS (Darwin 25.2.0)

Observed Behavior

• Single clicks do not trigger on_click handlers
• Double-clicking works
• Keyboard navigation works fine
• Mouse hover/tracking works fine
• The same app works correctly outside of tmux
• Other TUI apps work fine in the same tmux+Ghostty setup

Root Cause Analysis

I traced the issue to app.py lines 3090-3092:

if (
    self.get_widget_at(event.x, event.y)[0]
    is self._mouse_down_widget
):
    click_event = events.Click.from_event(event)
    self.screen._forward_event(click_event)

The Click event is only generated when the widget at MouseUp position is the same object (is comparison) as the widget saved during MouseDown. In Ghostty+tmux, get_widget_at() appears to return different widget instances between the two calls, even when clicking on the same widget at the same position.

Debugging Evidence

I added logging and confirmed:

• MouseDown and MouseUp coordinates are identical (same x, y, screen_x, screen_y)
• Both calls to get_widget_at() return widgets with the same ID and type
• However, the is identity check fails

Workaround That Works

Adding an on_mouse_up handler to widgets works reliably:

def on_mouse_up(self, event: events.MouseUp) -> None:
    """Handle mouse up directly since Click events fail in Ghostty+tmux."""
    option_index = event.style.meta.get("option")
    if option_index is None:
        scroll_y = int(self.scroll_offset.y)
        option_index = event.y + scroll_y

    if option_index is not None and 0 <= option_index < self.option_count:
        option = self.get_option_at_index(option_index)
        if option and not option.disabled:
            self.highlighted = option_index
            # Handle selection...

Attempted Fixes (None Worked)

1. Generating Click events in App.on_event based on position matching instead of identity:

   async def on_event(self, event) -> None:
       if isinstance(event, MouseDown):
           self._last_mouse_down_pos = (event.screen_x, event.screen_y)
       elif isinstance(event, MouseUp):
           if self._last_mouse_down_pos == (event.screen_x, event.screen_y):
               widget, region = self.get_widget_at(event.screen_x, event.screen_y)
               click_event = Click(widget=widget, ...)
               widget.post_message(click_event)

2. Forwarding to screen: self.screen._forward_event(click_event)

3. Setting app_focus on first MouseDown

4. Generating Click after super().on_event() completes

None of these approaches made single-clicks work for widgets other than the one with the on_mouse_up workaround.

Questions

1. Why might get_widget_at() return different widget instances between MouseDown and MouseUp in Ghostty+tmux specifically?

2. Is the identity check (is) intentional, or could it be changed to compare widget IDs instead?

3. Is there a recommended way to handle this at the application level without modifying every widget?

4. Are there any known issues with tmux or specific terminal emulators affecting widget lookup?

Minimal Reproduction

I haven't created a minimal reproduction yet, but can do so if helpful. The issue occurs with any clickable widget (OptionList, Button, etc.) when running in Ghostty inside tmux.

[github-actions]

We found the following entries in the FAQ which you may find helpful:

• Why doesn't Textual look good on macOS?
• How do I center a widget in a screen?
• How can I set a translucent app background?

Feel free to close this issue if you found an answer in the FAQ. Otherwise, please give us a little time to review.

This project is developed and maintained by Will McGugan. Consider sponsoring Will's work on this project (and others).

This is an automated reply, generated by FAQtory

[TomJGooding]

Textual version: 0.75.0

Maybe try updating your Textual version for starters!!!

[brendandebeasi]

@TomJGooding :P that was a typo. Fixed

[TomJGooding]

I thought it might just be a typo, but it doesn't make sense if you "traced the issue to app.py lines 3090-3092" in the latest version?

[davep]

When running a Textual app inside tmux with Ghostty terminal, single clicks don't work - users have to double-click to trigger click handlers.

So.. run a ghostty terminal, then run tmux inside that, then run a Textual application inside that? I just tested with Ghostty 1.2.3 and tmux 3.6a, on macOS and I can single-click away on any of my Textual-based applications without an issue.

Is the identity check (is) intentional, or could it be changed to compare widget IDs instead?

A screen can contain lots of widgets with the same ID so I can't imagine the latter working too well. Consider:

from textual.app import App, ComposeResult
from textual.containers import Vertical
from textual.widgets import Button

class MultiIDApp(App[None]):

    def compose(self) -> ComposeResult:
        for _ in range(4):
            with Vertical():
                yield Button("Press me to see my ID", id="one-id")

    def on_button_pressed(self, event: Button.Pressed) -> None:
        self.notify(f"{event.control!r}")

if __name__ == "__main__":
    MultiIDApp().run()

I haven't created a minimal reproduction yet, but can do so if helpful. The issue occurs with any clickable widget (OptionList, Button, etc.) when running in Ghostty inside tmux.

I imagine it's more of a typo, but here you say that it happens when Ghostty is running inside tmux, which is the other way round. But assuming you mean tmux inside Ghostty, the code I post above would seem to be a minimal reproduction, yeah? In which case I can run that inside tmux which is running inside a Ghostty session and I can click on the buttons with a single click and I get the notifications just fine.

[brendandebeasi]

Hey all, I'm going to close this out. I realized my app build I was updating to troubleshoot was not being properly symlinked. So I was testing and testing fixes on an old binary of mine 🙃

Sorry y'all for the confusion here. This was my bad...

[github-actions]

I hope I solved your issue!

Consider sponsoring my work to continue to maintain and develop Textual.

• Will McGugan