Get mapping reloader to reload mappings for real

Previously I got the inter-process communication set up, but left the
work of actually reloading the mappings into memory for later. That
later is now.

Make `Mappings` solely responsible for loading and reloading mappings.
What used to be in `HeadphoneKey` for this has now been moved.

HeadphoneKey:
* Store a reference to a `Mappings` instance
* Load mappings using the `Mappings` API instead of calling
  `dome_key_state_load_map_group()` directly.
* Move the call to `observeReloadNotification` here from `main()`. Made
  more sense to me to have it with the other related mappings setup
  method calls.
* Move the `_state` variable into `Mappings`, since that's where it's
  used most. Get it from an accessor in the one spot we need it.

Mappings:
* Make `observeReloadNotification` an instance method. While not
  necessary, since I decided to call it in `HeadphoneKey` after
  initialising `_mappings` and calling `reloadMappings`, I figured it
  made sense to call the method on the instance.
* Make `reloadMappings` both an instance method and a class method. Made
  sense to call it on the instance since we instantiate `Mappings` just
  before calling it in `HeadphoneKey`. But we also need to be able to
  call it from `reload_mappings`, the C function, which has no knowledge
  of the `Mappings` instance. That's why we make it a class method also.
* Add a `_state` static variable. Not ideal. Would rather have an
  instance variable, but this value needs to be accessible from the
  `reload_mappings` C function, which doesn't have access to instance
  variables.

5 files changed, 44 insertions, 16 deletions

diff --git a/DomeKey/HeadphoneKey.h b/DomeKey/HeadphoneKey.h
index 1d12e10..4496785 100644
--- a/DomeKey/HeadphoneKey.h
+++ b/DomeKey/HeadphoneKey.h
@@ -9,6 +9,7 @@
 #import <Foundation/Foundation.h>
 #import <DDHidLib/DDHidAppleMikey.h>
 
+#import "Mappings.h"
 #import "Sounds.h"
 #import "dome_key_map.h"
 #import "log.h"
@@ -23,7 +24,7 @@ static const Milliseconds TIMEOUT_DEFAULT = 500;
 @interface HeadphoneKey : NSObject {
     NSArray *_mikeys;
     NSMutableArray *_key_buffer;
-    State *_state;
+    Mappings *_mappings;
     Milliseconds _timeout;
 }
 
diff --git a/DomeKey/HeadphoneKey.m b/DomeKey/HeadphoneKey.m
index aec9598..a16dbc0 100644
--- a/DomeKey/HeadphoneKey.m
+++ b/DomeKey/HeadphoneKey.m
@@ -18,7 +18,10 @@ static BOOL _play_audio;
     self = [super init];
     if (self) {
         _key_buffer = [[NSMutableArray alloc] initWithCapacity:5];
-        _state = dome_key_state_new();
+
+        _mappings = [[Mappings alloc] init];
+        [_mappings reloadMappings];
+        [_mappings observeReloadNotification];
 
         // Should never be used. We initialise it just in case, but the real
         // default should always come from a `Config`, set in the Rust library.
@@ -26,8 +29,6 @@ static BOOL _play_audio;
 
         _play_audio = NO;
 
-        dome_key_state_load_map_group(_state);
-
         _mikeys = [DDHidAppleMikey allMikeys];
         [_mikeys makeObjectsPerformSelector:@selector(setDelegate:)
             withObject:self];
@@ -52,11 +53,6 @@ static BOOL _play_audio;
     return self;
 }
 
-- (void)dealloc
-{
-    dome_key_state_free(_state);
-}
-
 - (void)ddhidAppleMikey:(DDHidAppleMikey *)mikey
                   press:(unsigned)usageId
                upOrDown:(BOOL)upOrDown
@@ -110,7 +106,7 @@ static BOOL _play_audio;
         .length = count
     };
 
-    dome_key_run_key_action(_state, trigger, on_mode_change);
+    dome_key_run_key_action([_mappings state], trigger, on_mode_change);
 
     [_key_buffer removeAllObjects];
 }
diff --git a/DomeKey/Mappings.h b/DomeKey/Mappings.h
index 136dc87..acd3546 100644
--- a/DomeKey/Mappings.h
+++ b/DomeKey/Mappings.h
@@ -9,9 +9,16 @@
 #import <Foundation/Foundation.h>
 #include <notify.h>
 
+#import "dome_key_map.h"
+
 @interface Mappings : NSObject
 
-+ (void)observeReloadNotification;
+- (State *)state;
+
+- (void)observeReloadNotification;
+
+- (void)reloadMappings;
++ (void)reloadMappings;
 + (uint32_t)dispatchReload;
 
 @end
diff --git a/DomeKey/Mappings.m b/DomeKey/Mappings.m
index 62098fe..f130ba6 100644
--- a/DomeKey/Mappings.m
+++ b/DomeKey/Mappings.m
@@ -12,9 +12,21 @@
 
 static const CFStringRef CFNOTIFICATION_NAME_RELOAD = CFSTR(NOTIFICATION_NAME_RELOAD);
 
+static State *_state;
+
 @implementation Mappings
 
-+ (void)observeReloadNotification
+- (void)dealloc
+{
+    dome_key_state_free(_state);
+}
+
+- (State *)state
+{
+    return _state;
+}
+
+- (void)observeReloadNotification
 {
     CFNotificationCenterRef center = CFNotificationCenterGetDarwinNotifyCenter();
 
@@ -39,15 +51,29 @@ void reload_mappings(
 ) {
     if (CFStringCompare(name, CFNOTIFICATION_NAME_RELOAD, 0) ==
             kCFCompareEqualTo) {
-        // Reload mappings
-        NSLog(@"TODO: reload mappings");
+        // TODO: Mappings reloaded message
+
+        [Mappings reloadMappings];
     }
 }
 
+- (void)reloadMappings
+{
+    [Mappings reloadMappings];
+}
+
++ (void)reloadMappings
+{
+    dome_key_state_free(_state);
+    _state = dome_key_state_new();
+    dome_key_state_load_map_group(_state);
+}
+
 + (uint32_t)dispatchReload
 {
     uint32_t status = notify_post(NOTIFICATION_NAME_RELOAD);
     if (status != 0) {
+        // TODO: print to stderr
         // Notification failed
         NSLog(@"Reload notification failed");
     }
diff --git a/DomeKey/main.m b/DomeKey/main.m
index 0b33a55..7c2f1c7 100644
--- a/DomeKey/main.m
+++ b/DomeKey/main.m
@@ -50,8 +50,6 @@ int main(int argc, const char * argv[]) {
             // insert code here...
             NSLog(@"Hello, World!");
 
-            [Mappings observeReloadNotification];
-
             [NSApp run];
         }
     } else if (config->args.version) {