HeadphoneKey: Play audio only with the `--audio` command line flag

Allow users to decide whether interface audio (mode activated &
deactivated) should play.

The flag value is in a `Config`, so to make it easier to pass both the
audio flag and the timeout config value to `HeadphoneKey`, rename
`initWithTimeout:` to `initWithConfig:`.

Only allocate a `Sounds` instance if `--audio` is passed, because
there's no reason to allocate memory for it otherwise.

Add a `_play_audio` flag as a static variable to make it accessible to
the `on_mode_change()` function, just like we did for `sounds_inst`.

In `on_mode_change()`, don't play any audio if `_play_audio` is on.

3 files changed, 15 insertions, 5 deletions

diff --git a/DomeKey/AppDelegate.m b/DomeKey/AppDelegate.m
index bcd4dd0..30bd898 100644
--- a/DomeKey/AppDelegate.m
+++ b/DomeKey/AppDelegate.m
@@ -21,7 +21,7 @@
 
 - (void)applicationDidFinishLaunching:(NSNotification *)notification
 {
-    _headphone_key = [[HeadphoneKey alloc] initWithTimeout:_config->timeout];
+    _headphone_key = [[HeadphoneKey alloc] initWithConfig:_config];
 }
 
 @end
diff --git a/DomeKey/HeadphoneKey.h b/DomeKey/HeadphoneKey.h
index fc500cd..1d12e10 100644
--- a/DomeKey/HeadphoneKey.h
+++ b/DomeKey/HeadphoneKey.h
@@ -27,7 +27,7 @@ static const Milliseconds TIMEOUT_DEFAULT = 500;
     Milliseconds _timeout;
 }
 
-- (instancetype)initWithTimeout:(Milliseconds)timeout;
+- (instancetype)initWithConfig:(Config *)config;
 - (void)handleDeadKey:(HeadphoneButton)button;
 - (void)runAction;
 
diff --git a/DomeKey/HeadphoneKey.m b/DomeKey/HeadphoneKey.m
index a176cbf..11046e7 100644
--- a/DomeKey/HeadphoneKey.m
+++ b/DomeKey/HeadphoneKey.m
@@ -9,6 +9,7 @@
 #import "HeadphoneKey.h"
 
 static const Sounds *sounds_inst;
+static BOOL _play_audio;
 
 @implementation HeadphoneKey
 
@@ -23,7 +24,7 @@ static const Sounds *sounds_inst;
         // default should always come from a `Config`, set in the Rust library.
         _timeout = TIMEOUT_DEFAULT;
 
-        sounds_inst = [[Sounds alloc] init];
+        _play_audio = NO;
 
         // TODO: Think about moving this logger higher up
         dome_key_logger_init();
@@ -39,11 +40,16 @@ static const Sounds *sounds_inst;
     return self;
 }
 
-- (instancetype)initWithTimeout:(Milliseconds)timeout
+- (instancetype)initWithConfig:(Config *)config
 {
     self = [self init];
     if (self) {
-        _timeout = timeout;
+        _timeout = config->timeout;
+        _play_audio = config->args.audio;
+
+        if (_play_audio) {
+            sounds_inst = [[Sounds alloc] init];
+        }
     }
     return self;
 }
@@ -112,6 +118,10 @@ static const Sounds *sounds_inst;
 }
 
 void on_mode_change(ModeChange mode_change) {
+    if (!_play_audio) {
+        return;
+    }
+
     switch (mode_change) {
     case ModeChange_Activated:
         [sounds_inst playModeActivated];