From 4e62e8ad7abf833a3d2cb7ddfe01161e91c648ad Mon Sep 17 00:00:00 2001
From: Teddy Wing
Date: Thu, 16 Aug 2018 06:32:51 +0200
Subject: HeadphoneKey: Detect 3 headphone button types

Using my previous `NSLog`s, the `usageId`s came out to be 205, 233, 234.
Converted these to hex and looked for corresponding constants in
`/System/Library/Frameworks/IOKit.framework/Versions/A/Headers/hid/IOHIDUsageTables.h`.

Use these constants to figure out which button was presed. Will have to
test other headphones. I'm worried the numbers may change for different
headphones.

Added a `KeyPress` enum that's a lot easier to understand than the
`upOrDown` `BOOL`, whose meaning I completely didn't get until I looked
at the `NSLog` output I had before.
---
 DomeKey/HeadphoneKey.h |  5 +++++
 DomeKey/HeadphoneKey.m | 17 +++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/DomeKey/HeadphoneKey.h b/DomeKey/HeadphoneKey.h
index 16e74b2..0d4e729 100644
--- a/DomeKey/HeadphoneKey.h
+++ b/DomeKey/HeadphoneKey.h
@@ -9,6 +9,11 @@
 #import <Foundation/Foundation.h>
 #import <DDHidLib/DDHidAppleMikey.h>
 
+typedef enum KeyPress : BOOL {
+    KeyPressDown = YES,
+    KeyPressUp = NO
+} KeyPress;
+
 @interface HeadphoneKey : NSObject {
     NSArray *_mikeys;
 }
diff --git a/DomeKey/HeadphoneKey.m b/DomeKey/HeadphoneKey.m
index c01d2c5..0593173 100644
--- a/DomeKey/HeadphoneKey.m
+++ b/DomeKey/HeadphoneKey.m
@@ -28,10 +28,19 @@
                   press:(unsigned)usageId
                upOrDown:(BOOL)upOrDown
 {
-    NSLog(@"Clicked");
-    NSLog(@"%d", usageId);
-    NSLog(@"%@", mikey);
-    NSLog(@"%d", upOrDown);
+    if (upOrDown == KeyPressUp) {
+        switch (usageId) {
+        case kHIDUsage_Csmr_PlayOrPause:
+            NSLog(@"Middle");
+            break;
+        case kHIDUsage_Csmr_VolumeIncrement:
+            NSLog(@"Top");
+            break;
+        case kHIDUsage_Csmr_VolumeDecrement:
+            NSLog(@"Bottom");
+            break;
+        }
+    }
 }
 
 @end
-- 
cgit v1.2.3