Changing Input value doesn't update cursor position #5811
Description
Changing the Input value doesn't update the cursor position, which can result in an 'invalid' cursor position when the new value is shorter.
Here's a quick example to demonstrate:
from textual.app import App, ComposeResult
from textual.geometry import clamp
from textual.widgets import Button, Input, Label
class ExampleApp(App):
def compose(self) -> ComposeResult:
yield Label("[b]Enter a number between 1-10:[/]")
yield Input(
"999999999999999999999",
type="integer",
select_on_focus=False,
)
yield Label("[dim]The input value will be clamped after being submitted.[/]")
yield Label("[dim]Notice that the cursor seems to disappear.[/]")
yield Button("Check cursor position", variant="warning")
def on_input_submitted(self, event: Input.Submitted) -> None:
clamped_value = clamp(int(event.value), 1, 10)
event.input.value = str(clamped_value)
def on_button_pressed(self) -> None:
cursor_position = self.query_one(Input).cursor_position
severity = "error" if cursor_position > 2 else "information"
self.notify(
str(cursor_position),
title="Cursor position",
severity=severity,
)
if __name__ == "__main__":
app = ExampleApp()
app.run()