helix-term: allow to backspace out-of the command prompt

[markus-oberhumer-forks]

This makes helix behave like vim and kakoune.

[the-mikedavis]

I forgot Kakoune had this behavior. Thanks!

[woojiq]

Maybe it would be better to introduce a config option for this? Many people are used to "old" behavior. I can't rename symbol now because I always hold backspace to clear prompt (I know ctrl-w exists)😓

[the-mikedavis]

It also tripped up my muscle memory for a while but for prompts like rename you can use C-w to delete the current line rather than trying to backspace precisely

[markus-oberhumer]

Well, basically this is a UX design issue, but I tend to agree that the default for the LSP-rename-prompt should be changed.

Please try this quick hack:

diff --git a/helix-term/src/commands/lsp.rs b/helix-term/src/commands/lsp.rs
index a3168dc2..55aa58df 100644
--- a/helix-term/src/commands/lsp.rs
+++ b/helix-term/src/commands/lsp.rs
@@ -1036,7 +1036,7 @@ fn create_rename_prompt(
         prefill: String,
         language_server_id: Option<usize>,
     ) -> Box<ui::Prompt> {
-        let prompt = ui::Prompt::new(
+        let mut prompt = ui::Prompt::new(
             "rename-to:".into(),
             None,
             ui::completers::none,
@@ -1070,6 +1070,7 @@ fn create_rename_prompt(
             },
         )
         .with_line(prefill, editor);
+        prompt.backspace_can_abort = false;

         Box::new(prompt)
     }
diff --git a/helix-term/src/ui/prompt.rs b/helix-term/src/ui/prompt.rs
index d46c1313..d681e183 100644
--- a/helix-term/src/ui/prompt.rs
+++ b/helix-term/src/ui/prompt.rs
@@ -36,6 +36,7 @@ pub struct Prompt {
     pub doc_fn: DocFn,
     next_char_handler: Option<PromptCharHandler>,
     language: Option<(&'static str, Arc<ArcSwap<syntax::Loader>>)>,
+    pub backspace_can_abort: bool,
 }

 #[derive(Clone, Copy, PartialEq, Eq)]
@@ -88,6 +89,7 @@ pub fn new(
             doc_fn: Box::new(|_| None),
             next_char_handler: None,
             language: None,
+            backspace_can_abort: true, // default: make helix behave like vim and kakoune
         }
     }

@@ -544,7 +546,7 @@ fn handle_event(&mut self, event: &Event, cx: &mut Context) -> EventResult {
                 (self.callback_fn)(cx, &self.line, PromptEvent::Update);
             }
             ctrl!('h') | key!(Backspace) | shift!(Backspace) => {
-                if self.line.is_empty() {
+                if self.backspace_can_abort && self.line.is_empty() {
                     (self.callback_fn)(cx, &self.line, PromptEvent::Abort);
                     return close_fn;
                 }

[mo8it]

This drove me crazy in the last days and I went into the source code just to find what caused it 😟

There are already two keybindings for aborting: ESC and CTRL+C. Why should we add this?

Of course, I get the argument of making the life of people migrating from other editors easier. But Vim/kakoune users will not be that surprised if backspace didn't abort. They see that nothing happens and just press ESC. But people hitting one backspace too much will need to repeat the whole operation…

Of course I am biased because I got used to the old behavior, but even just thinking about the UX, the new behavior is very limiting. People would need to use ESC or CTRL+C anyway if they want an "early" abort. For example, if your cursor is in the middle of the prompt and you want to abort, you can't just spam backspace, you have to use the other keybindings (or go to the end of the prompt and then spam backspace which would mean that Helix supported an inefficient way here instead of just letting people know of ESC or CTRL+C).

Please revert this or at least make it an option where the default is not aborting.

[archseer]

Hmm I also preferred the original behaviour since it seemed less surprising and it's really annoying when the prompt suddently closes when you backspace too far. I wasn't too opinonated though. If there's a clear preference I wouldn't be opposed to changing back

[markus-oberhumer]

Well, Vim and Kakoune set the precedent at least for the command : and find / prompts, and it obviously bothered me so much that I spent time writing and submitting this patch.

But then this indeed a UX design issue.

[the-mikedavis]

I'm not strongly opinionated on this either but I agree that the old behavior was less surprising. I think it would be fine to break with Vim and Kakoune here as @mo8it says we already have other ways of aborting. I definitely don't want inconsistency among the prompts though or a config option for a small behavior this.

[markus-oberhumer]

I definitely don't want inconsistency among the prompts though or a config option for a small behavior this.

Fully agree on this, so I'll let the project leaders decide. I can live with my private fork.