input: Failure when reducing text string while editing

[katyo]

I remove some characters while user input so the length of edited text is reduced but cursor position stay some as before:

thread 'main' panicked at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ropey-1.6.1/src/rope.rs:345:41:
called `Result::unwrap()` on an `Err` value: Char index out of bounds: char index 2, Rope/RopeSlice char length 1
stack backtrace:
   0: rust_begin_unwind
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/std/src/panicking.rs:595:5
   1: core::panicking::panic_fmt
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/core/src/panicking.rs:67:14
   2: core::result::unwrap_failed
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/core/src/result.rs:1652:5
   3: core::result::Result<T,E>::unwrap
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/core/src/result.rs:1077:23
   4: ropey::rope::Rope::insert
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ropey-1.6.1/src/rope.rs:345:9
   5: <freya_hooks::rope_editor::RopeEditor as freya_hooks::text_editor::TextEditor>::insert
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/hooks/src/rope_editor.rs:50:9
   6: freya_hooks::text_editor::TextEditor::process_key
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/hooks/src/text_editor.rs:367:33
   7: freya_hooks::use_editable::UseEditable::process_event::{{closure}}
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/hooks/src/use_editable.rs:111:33
   8: dioxus_hooks::usestate::UseState<T>::with_mut
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dioxus-hooks-0.4.0/src/usestate.rs:248:9
   9: freya_hooks::use_editable::UseEditable::process_event
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/hooks/src/use_editable.rs:110:17
  10: freya_components::input::Input::{{closure}}
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/components/src/input.rs:110:17
  11: dioxus_core::scopes::ScopeState::listener::{{closure}}
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dioxus-core-0.4.2/src/scopes.rs:532:21
  12: dioxus_core::virtual_dom::VirtualDom::handle_event
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dioxus-core-0.4.2/src/virtual_dom.rs:422:37
  13: freya_renderer::app::App<State>::poll_vdom::{{closure}}
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/renderer/src/app.rs:181:33
  14: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/core/src/future/future.rs:125:9
  15: futures_util::future::future::FutureExt::poll_unpin
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/future/future/mod.rs:562:9
  16: freya_renderer::app::App<State>::poll_vdom
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/renderer/src/app.rs:191:23
  17: freya_renderer::event_loop::run_event_loop::{{closure}}
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/renderer/src/event_loop.rs:80:21
  18: winit::platform_impl::platform::sticky_exit_callback
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/platform_impl/linux/mod.rs:884:9
  19: winit::platform_impl::platform::x11::EventLoop<T>::run_return::single_iteration
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/platform_impl/linux/x11/mod.rs:348:21
  20: winit::platform_impl::platform::x11::EventLoop<T>::run_return
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/platform_impl/linux/x11/mod.rs:483:27
  21: winit::platform_impl::platform::x11::EventLoop<T>::run
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/platform_impl/linux/x11/mod.rs:498:25
  22: winit::platform_impl::platform::EventLoop<T>::run
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/platform_impl/linux/mod.rs:792:56
  23: winit::event_loop::EventLoop<T>::run
             at /home/kayo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.28.7/src/event_loop.rs:305:9
  24: freya_renderer::event_loop::run_event_loop
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/renderer/src/event_loop.rs:38:5
  25: freya_renderer::run_app
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/renderer/src/lib.rs:64:5
  26: freya::launch::launch_cfg
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/freya/src/launch.rs:214:5
  27: freya::launch::launch
             at /home/kayo/.cargo/git/checkouts/freya-aa88117f1f713ee2/6dda57e/crates/freya/src/launch.rs:33:5
  28: ex1::main
             at ./src/main.rs:9:5
  29: core::ops::function::FnOnce::call_once
             at /rustc/cc66ad468955717ab92600c770da8c1601a4ff33/library/core/src/ops/function.rs:250:5

I think we need sync cursor position with actual text string length before inserting or removing characters while editing to prevent such wrong behavior. Currently I'm not quite familiar with dioxus/freya architecture so I don't sure where the right place to do it.

[katyo]

I fixed it in #349. It works fine but I'm not sure that my solution is fully correct.

[marc2332]

Hey! Your fix makes sense but I can't seem to reproduce the error without your fix. What exactly did you do to trigger it?

[katyo]

My simplified example to reproduce error:

let text = use_state(cx, || "".to_string());

Input {
  value: text.get().clone(),
  onchange: |event: String| text.set(event.trim().to_string()),
}

In empty input press space next insert some non-space char and either press space again or backspace.

[marc2332]

Your fix indeed seems to fix it! Although now I see another issue, when you press space, it will move the cursor even though the text doesn't contain a space, I'll see what I can do about that

[katyo]

Looks like we need a way to precise control input which includes updating cursor position (and maybe text selection) simultaneously with updating contents.

[marc2332]

Looks like we need a way to precise control input which includes updating cursor position (and maybe text selection) simultaneously with updating contents.

No worries! I just pushed a fix in your PR, I think it works great, let me know what you think!

[katyo]

@marc2332 I tested your changes. Now it works as expected. Thank you so much! Have you future plans to add ability to control text cursor and selection?

Also I found some wrong behavior related to text selection. I will create new issue for that.

[marc2332]

Have you future plans to add ability to control text cursor and selection?

Of course! Many things can still be improved