feat(core): add cursor hint handling in RenderMiddleware

espanso/src/engine/process/middleware/render.rs

@@ -17,10 +17,16 @@
  * along with espanso.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-use log::{debug, error};
+use log::{error};
 
 use super::super::Middleware;
-use crate::engine::{event::{Event, text::{TextInjectRequest, TextInjectMode}, matches::MatchSelectedEvent, render::RenderedEvent}, process::{MatchFilter, MatchSelector, Renderer, RendererError}};
+use crate::engine::{
+  event::{
+    render::RenderedEvent,
+    Event,
+  },
+  process::{Renderer, RendererError},
+};
 
 pub struct RenderMiddleware<'a> {
   renderer: &'a dyn Renderer<'a>,
@@ -33,23 +39,28 @@ impl<'a> RenderMiddleware<'a> {
 }
 
 impl<'a> Middleware for RenderMiddleware<'a> {
+  fn name(&self) -> &'static str {
+    "render"
+  }
+
   fn next(&self, event: Event, _: &mut dyn FnMut(Event)) -> Event {
     if let Event::RenderingRequested(m_event) = event {
       match self.renderer.render(m_event.match_id, m_event.trigger_args) {
         Ok(body) => {
+          let (body, cursor_hint_back_count) = process_cursor_hint(body);
+
           return Event::Rendered(RenderedEvent {
             trigger: m_event.trigger,
             body,
-          })
+            cursor_hint_back_count,
+          });
         }
         Err(err) => {
           match err.downcast_ref::<RendererError>() {
-            Some(RendererError::Aborted) => {
-              return Event::NOOP
-            }
+            Some(RendererError::Aborted) => return Event::NOOP,
             _ => {
               error!("error during rendering: {}", err);
-              return Event::ProcessingError("An error has occurred during rendering, please examine the logs or contact support.".to_string())
+              return Event::ProcessingError("An error has occurred during rendering, please examine the logs or contact support.".to_string());
             }
           }
         }
@@ -61,3 +72,23 @@ impl<'a> Middleware for RenderMiddleware<'a> {
 }
 
 // TODO: test
+fn process_cursor_hint(body: String) -> (String, Option<usize>) {
+  if let Some(index) = body.find("$|$") {
+    // Convert the byte index to a char index
+    let char_str = &body[0..index];
+    let char_index = char_str.chars().count();
+    let total_size = body.chars().count();
+
+    // Remove the $|$ placeholder
+    let body = body.replace("$|$", "");
+
+    // Calculate the amount of rewind moves needed (LEFT ARROW).
+    // Subtract also 3, equal to the number of chars of the placeholder "$|$"
+    let moves = total_size - char_index - 3;
+    (body, Some(moves))
+  } else {
+    (body, None)
+  }
+}
+
+// TODO: test