run_key_action_for_mode(): Keep track of `in_mode` in `state`

Instead of letting the Objective-C code keep track of `in_mode` by
passing it around in `CKeyActionResult`, keep track of it in a `State`
struct.

Derive `Clone` on `HeadphoneButton` to resolve this error:

    error[E0277]: the trait bound `parser::HeadphoneButton: std::clone::Clone` is not satisfied
       --> src/cocoa_bridge.rs:273:38
        |
    273 |         state.in_mode = Some(trigger.to_vec());
        |                                      ^^^^^^ the trait `std::clone::Clone` is not implemented for `parser::HeadphoneButton`

2 files changed, 12 insertions, 3 deletions

diff --git a/src/cocoa_bridge.rs b/src/cocoa_bridge.rs
index a864e13..11dc1c9 100644
--- a/src/cocoa_bridge.rs
+++ b/src/cocoa_bridge.rs
@@ -110,6 +110,7 @@ pub extern "C" fn state_free(ptr: *mut State) {
 
 #[no_mangle]
 pub extern "C" fn c_run_key_action(
+    state: *mut State,
     trigger: Trigger,
     mode: *const Trigger,
 ) -> *const CKeyActionResult {
@@ -133,7 +134,12 @@ pub extern "C" fn c_run_key_action(
     };
     println!("Mode after unsafe (118): {:?}", mode);
 
-    let result = run_key_action_for_mode(trigger, mode);
+    let mut state = unsafe {
+        assert!(!state.is_null());
+        &mut *state
+    };
+
+    let result = run_key_action_for_mode(&mut state, trigger, mode);
     let result = match result {
         Some(k) => {
             let action = k.action.map_or_else(
@@ -200,6 +206,7 @@ pub extern "C" fn c_run_key_action(
 
 #[no_mangle]
 pub extern "C" fn run_key_action_for_mode<'a>(
+    state: &mut State,
     trigger: &'a [HeadphoneButton],
     in_mode: Option<&[HeadphoneButton]>
 ) -> Option<KeyActionResult<'a>> {
@@ -217,7 +224,7 @@ mode <play><up> {
     let map = map_group.maps.get(trigger);
     let mode = map_group.modes.get(trigger);
 
-    if let Some(in_mode) = in_mode {
+    if let Some(ref mut in_mode) = state.in_mode {
         if let Some(mode) = map_group.modes.get(in_mode) {
             if let Some(map) = mode.get(trigger) {
                 return match map.kind {
@@ -263,6 +270,8 @@ mode <play><up> {
     }
 
     if let Some(mode) = mode {
+        state.in_mode = Some(trigger.to_vec());
+
         return Some(
             KeyActionResult::new(ActionKind::Mode)
                 .in_mode(trigger)
diff --git a/src/parser.rs b/src/parser.rs
index 1d9aa56..ea96740 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -14,7 +14,7 @@ use combine::parser::repeat::take_until;
 use combine::stream::state::{SourcePosition, State};
 
 #[repr(C)]
-#[derive(Debug, Hash, Eq, PartialEq)]
+#[derive(Clone, Debug, Hash, Eq, PartialEq)]
 pub enum HeadphoneButton {
     Play,
     Up,