fix(core): handle AllModifiersRelease event on macOS to prevent modifier state getting out-of-sync with shortcuts. Fix #791

espanso/src/cli/worker/engine/funnel/detect.rs

@@ -37,12 +37,12 @@ impl<'a> funnel::Source<'a> for DetectSource {
     select.recv(&self.receiver)
   }
 
-  fn receive(&self, op: SelectedOperation) -> Event {
+  fn receive(&self, op: SelectedOperation) -> Option<Event> {
     let (input_event, source_id) = op
       .recv(&self.receiver)
       .expect("unable to select data from DetectSource receiver");
     match input_event {
-      InputEvent::Keyboard(keyboard_event) => Event {
+      InputEvent::Keyboard(keyboard_event) => Some(Event {
         source_id,
         etype: EventType::Keyboard(KeyboardEvent {
           key: convert_to_engine_key(keyboard_event.key),
@@ -50,20 +50,21 @@ impl<'a> funnel::Source<'a> for DetectSource {
           status: convert_to_engine_status(keyboard_event.status),
           variant: keyboard_event.variant.map(convert_to_engine_variant),
         }),
-      },
-      InputEvent::Mouse(mouse_event) => Event {
+      }),
+      InputEvent::Mouse(mouse_event) => Some(Event {
         source_id,
         etype: EventType::Mouse(MouseEvent {
           status: convert_to_engine_status(mouse_event.status),
           button: convert_to_engine_mouse_button(mouse_event.button),
         }),
-      },
-      InputEvent::HotKey(hotkey_event) => Event {
+      }),
+      InputEvent::HotKey(hotkey_event) => Some(Event {
         source_id,
         etype: EventType::HotKey(HotKeyEvent {
           hotkey_id: hotkey_event.hotkey_id,
         }),
-      },
+      }),
+      InputEvent::AllModifiersReleased => None,
     }
   }
 }

espanso/src/cli/worker/engine/funnel/exit.rs

@@ -45,13 +45,13 @@ impl<'a> funnel::Source<'a> for ExitSource<'a> {
     select.recv(&self.exit_signal)
   }
 
-  fn receive(&self, op: SelectedOperation) -> Event {
+  fn receive(&self, op: SelectedOperation) -> Option<Event> {
     let mode = op
       .recv(&self.exit_signal)
       .expect("unable to select data from ExitSource receiver");
-    Event {
+    Some(Event {
       source_id: self.sequencer.next_id(),
       etype: EventType::ExitRequested(mode),
-    }
+    })
   }
 }

espanso/src/cli/worker/engine/funnel/mod.rs

@@ -81,6 +81,8 @@ pub fn init_and_spawn(
               // Update the modifiers state
               if let Some((modifier, is_pressed)) = get_modifier_status(&event) {
                 modifier_state_store_clone.update_state(modifier, is_pressed);
+              } else if let InputEvent::AllModifiersReleased = &event {
+                modifier_state_store_clone.clear_state();
               }
 
               // Update the key state (if needed)

espanso/src/cli/worker/engine/funnel/modifier.rs

@@ -91,6 +91,13 @@ impl ModifierStateStore {
       }
     }
   }
+
+  pub fn clear_state(&self) {
+    let mut state = self.state.lock().expect("unable to obtain modifier state");
+    for (_, status) in &mut state.modifiers {
+      status.release();
+    }
+  }
 }
 
 struct ModifiersState {

espanso/src/cli/worker/engine/funnel/secure_input.rs

@@ -50,13 +50,13 @@ impl<'a> funnel::Source<'a> for SecureInputSource<'a> {
     }
   }
 
-  fn receive(&self, op: SelectedOperation) -> Event {
+  fn receive(&self, op: SelectedOperation) -> Option<Event> {
     if cfg!(target_os = "macos") {
       let si_event = op
         .recv(&self.receiver)
         .expect("unable to select data from SecureInputSource receiver");
 
-      Event {
+      Some(Event {
         source_id: self.sequencer.next_id(),
         etype: match si_event {
           SecureInputEvent::Disabled => EventType::SecureInputDisabled,
@@ -64,13 +64,12 @@ impl<'a> funnel::Source<'a> for SecureInputSource<'a> {
             EventType::SecureInputEnabled(SecureInputEnabledEvent { app_name, app_path })
           }
         },
-      }
+      })
     } else {
-      println!("noop");
-      Event {
+      Some(Event {
         source_id: self.sequencer.next_id(),
         etype: EventType::NOOP,
-      }
+      })
     }
   }
 }

espanso/src/cli/worker/engine/funnel/ui.rs

@@ -46,12 +46,12 @@ impl<'a> funnel::Source<'a> for UISource<'a> {
     select.recv(&self.ui_receiver)
   }
 
-  fn receive(&self, op: SelectedOperation) -> Event {
+  fn receive(&self, op: SelectedOperation) -> Option<Event> {
     let ui_event = op
       .recv(&self.ui_receiver)
       .expect("unable to select data from UISource receiver");
 
-    Event {
+    Some(Event {
       source_id: self.sequencer.next_id(),
       etype: match ui_event {
         UIEvent::TrayIconClick => EventType::TrayIconClicked,
@@ -60,6 +60,6 @@ impl<'a> funnel::Source<'a> for UISource<'a> {
         }
         UIEvent::Heartbeat => EventType::Heartbeat,
       },
-    }
+    })
   }
 }