vim: Add support for temporary normal mode (ctrl-o) within insert mode (#19454)

Support has been added for the ctrl-o command within insert mode. Ctrl-o
is used to partially enter normal mode for 1 motion to then return back
into insert mode.

Release Notes:

- vim: Added support for `ctrl-o` in insert mode to enter temporary
normal mode

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/vim/src/vim.rs

@@ -28,7 +28,7 @@ use gpui::{
     actions, impl_actions, Action, AppContext, Entity, EventEmitter, KeyContext, KeystrokeEvent,
     Render, Subscription, View, ViewContext, WeakView,
 };
-use insert::NormalBefore;
+use insert::{NormalBefore, TemporaryNormal};
 use language::{CursorShape, Point, Selection, SelectionGoal, TransactionId};
 pub use mode_indicator::ModeIndicator;
 use motion::Motion;
@@ -38,7 +38,7 @@ use serde::Deserialize;
 use serde_derive::Serialize;
 use settings::{update_settings_file, Settings, SettingsSources, SettingsStore};
 use state::{Mode, Operator, RecordedSelection, SearchState, VimGlobals};
-use std::{ops::Range, sync::Arc};
+use std::{mem, ops::Range, sync::Arc};
 use surrounds::SurroundsType;
 use ui::{IntoElement, VisualContext};
 use workspace::{self, Pane, Workspace};
@@ -147,6 +147,8 @@ impl editor::Addon for VimAddon {
 pub(crate) struct Vim {
     pub(crate) mode: Mode,
     pub last_mode: Mode,
+    pub temp_mode: bool,
+    pub exit_temporary_mode: bool,
 
     /// pre_count is the number before an operator is specified (3 in 3d2d)
     pre_count: Option<usize>,
@@ -197,6 +199,8 @@ impl Vim {
         cx.new_view(|cx| Vim {
             mode: Mode::Normal,
             last_mode: Mode::Normal,
+            temp_mode: false,
+            exit_temporary_mode: false,
             pre_count: None,
             post_count: None,
             operator_stack: Vec::new(),
@@ -353,6 +357,16 @@ impl Vim {
     /// Called whenever an keystroke is typed so vim can observe all actions
     /// and keystrokes accordingly.
     fn observe_keystrokes(&mut self, keystroke_event: &KeystrokeEvent, cx: &mut ViewContext<Self>) {
+        if self.exit_temporary_mode {
+            self.exit_temporary_mode = false;
+            // Don't switch to insert mode if the action is temporary_normal.
+            if let Some(action) = keystroke_event.action.as_ref() {
+                if action.as_any().downcast_ref::<TemporaryNormal>().is_some() {
+                    return;
+                }
+            }
+            self.switch_mode(Mode::Insert, false, cx)
+        }
         if let Some(action) = keystroke_event.action.as_ref() {
             // Keystroke is handled by the vim system, so continue forward
             if action.name().starts_with("vim::") {
@@ -438,6 +452,17 @@ impl Vim {
     }
 
     pub fn switch_mode(&mut self, mode: Mode, leave_selections: bool, cx: &mut ViewContext<Self>) {
+        if self.temp_mode && mode == Mode::Normal {
+            self.temp_mode = false;
+            self.switch_mode(Mode::Normal, leave_selections, cx);
+            self.switch_mode(Mode::Insert, false, cx);
+            return;
+        } else if self.temp_mode
+            && !matches!(mode, Mode::Visual | Mode::VisualLine | Mode::VisualBlock)
+        {
+            self.temp_mode = false;
+        }
+
         let last_mode = self.mode;
         let prior_mode = self.last_mode;
         let prior_tx = self.current_tx;
@@ -729,7 +754,7 @@ impl Vim {
         Vim::update_globals(cx, |globals, cx| {
             if !globals.dot_replaying {
                 globals.dot_recording = true;
-                globals.recorded_actions = Default::default();
+                globals.recording_actions = Default::default();
                 globals.recorded_count = None;
 
                 let selections = self.editor().map(|editor| {
@@ -784,6 +809,7 @@ impl Vim {
         if globals.dot_recording {
             globals.stop_recording_after_next_action = true;
         }
+        self.exit_temporary_mode = self.temp_mode;
     }
 
     /// Stops recording actions immediately rather than waiting until after the
@@ -798,11 +824,13 @@ impl Vim {
         let globals = Vim::globals(cx);
         if globals.dot_recording {
             globals
-                .recorded_actions
+                .recording_actions
                 .push(ReplayableAction::Action(action.boxed_clone()));
+            globals.recorded_actions = mem::take(&mut globals.recording_actions);
             globals.dot_recording = false;
             globals.stop_recording_after_next_action = false;
         }
+        self.exit_temporary_mode = self.temp_mode;
     }
 
     /// Explicitly record one action (equivalents to start_recording and stop_recording)