Automatically track pseudo-pending text (#4077)

This change automatically tracks pending text for for commands which use
on-next-key callbacks. For example, `t` will await the next key event
and "t" will be shown in the bottom right-hand corner to show that we're
in a pending state.

Previously, the text for these on-next-key commands needed to be
hard-coded into the command definition which had some drawbacks:

* It was easy to forget to write and clear the pending text.
* If a command was remapped in a custom config, the pending text would
  still show the old key.

With this change, pending text is automatically tracked based on the
key events that lead to the command being executed. This works even
when the command is remapped in config and when the on-next-key
callback is nested under some key sequence (for example `mi`).

1 files changed, 10 insertions, 2 deletions

diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index e5dc3c95..97639ff2 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -33,6 +33,7 @@ use super::statusline;
 pub struct EditorView {
     pub keymaps: Keymaps,
     on_next_key: Option<Box<dyn FnOnce(&mut commands::Context, KeyEvent)>>,
+    pseudo_pending: Vec<KeyEvent>,
     last_insert: (commands::MappableCommand, Vec<InsertEvent>),
     pub(crate) completion: Option<Completion>,
     spinners: ProgressSpinners,
@@ -56,6 +57,7 @@ impl EditorView {
         Self {
             keymaps,
             on_next_key: None,
+            pseudo_pending: Vec::new(),
             last_insert: (commands::MappableCommand::normal_mode, Vec::new()),
             completion: None,
             spinners: ProgressSpinners::default(),
@@ -839,6 +841,7 @@ impl EditorView {
         event: KeyEvent,
     ) -> Option<KeymapResult> {
         let mut last_mode = mode;
+        self.pseudo_pending.extend(self.keymaps.pending());
         let key_result = self.keymaps.get(mode, event);
         cxt.editor.autoinfo = self.keymaps.sticky().map(|node| node.infobox());
 
@@ -1316,6 +1319,11 @@ impl Component for EditorView {
                 }
 
                 self.on_next_key = cx.on_next_key_callback.take();
+                match self.on_next_key {
+                    Some(_) => self.pseudo_pending.push(key),
+                    None => self.pseudo_pending.clear(),
+                }
+
                 // appease borrowck
                 let callback = cx.callback.take();
 
@@ -1416,8 +1424,8 @@ impl Component for EditorView {
             for key in self.keymaps.pending() {
                 disp.push_str(&key.key_sequence_format());
             }
-            if let Some(pseudo_pending) = &cx.editor.pseudo_pending {
-                disp.push_str(pseudo_pending.as_str())
+            for key in &self.pseudo_pending {
+                disp.push_str(&key.key_sequence_format());
             }
             let style = cx.editor.theme.get("ui.text");
             let macro_width = if cx.editor.macro_recording.is_some() {