1 files changed, 151 insertions, 0 deletions
diff --git a/MASShortcut+UserDefaults.m b/MASShortcut+UserDefaults.m
new file mode 100644
index 0000000..af3b5af
--- /dev/null
+++ b/MASShortcut+UserDefaults.m
@@ -0,0 +1,151 @@
+#import "MASShortcut+UserDefaults.h"
+
+@interface MASShortcutHotKey : NSObject
+
+@property (nonatomic, readonly) NSString *userDefaultsKey;
+@property (nonatomic, readonly) void (^handler)();
+@property (nonatomic, readonly) EventHotKeyRef carbonHotKey;
+@property (nonatomic, readonly) UInt32 carbonHotKeyID;
+
+- (id)initWithUserDefaultsKey:(NSString *)userDefaultsKey handler:(void (^)())handler;
+
++ (void)uninstallEventHandler;
+
+@end
+
+#pragma mark -
+
+@implementation MASShortcut (UserDefaults)
+
++ (NSMutableDictionary *)registeredHotKeys
+{
+    static NSMutableDictionary *shared = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        shared = [NSMutableDictionary dictionary];
+    });
+    return shared;
+}
+
++ (void)registerGlobalShortcutWithUserDefaultsKey:(NSString *)userDefaultsKey handler:(void (^)())handler;
+{
+    MASShortcutHotKey *hotKey = [[MASShortcutHotKey alloc] initWithUserDefaultsKey:userDefaultsKey handler:handler];
+    [[self registeredHotKeys] setObject:hotKey forKey:userDefaultsKey];
+}
+
++ (void)unregisterGlobalShortcutWithUserDefaultsKey:(NSString *)userDefaultsKey
+{
+    NSMutableDictionary *registeredHotKeys = [self registeredHotKeys];
+    [registeredHotKeys removeObjectForKey:userDefaultsKey];
+    if (registeredHotKeys.count == 0) {
+        [MASShortcutHotKey uninstallEventHandler];
+    }
+}
+
+@end
+
+#pragma mark -
+
+@implementation MASShortcutHotKey
+
+- (id)initWithUserDefaultsKey:(NSString *)userDefaultsKey handler:(void (^)())handler
+{
+    self = [super init];
+    if (self) {
+        _userDefaultsKey = userDefaultsKey.copy;
+        _handler = [handler copy];
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(userDefaultsDidChange:)
+                                                     name:NSUserDefaultsDidChangeNotification object:[NSUserDefaults standardUserDefaults]];
+        [self installHotKeyFromUserDefaults];
+    }
+    return self;
+}
+
+- (void)dealloc
+{
+    [[NSNotificationCenter defaultCenter] removeObserver:self name:NSUserDefaultsDidChangeNotification object:[NSUserDefaults standardUserDefaults]];
+    [self uninstallExisitingHotKey];
+}
+
+#pragma mark -
+
+- (void)userDefaultsDidChange:(NSNotification *)note
+{
+    [self uninstallExisitingHotKey];
+    [self installHotKeyFromUserDefaults];
+}
+
+#pragma mark - Carbon events
+
+static EventHandlerRef sEventHandler = NULL;
+
++ (BOOL)installCommonEventHandler
+{
+    if (sEventHandler == NULL) {
+        EventTypeSpec hotKeyPressedSpec = { .eventClass = kEventClassKeyboard, .eventKind = kEventHotKeyPressed };
+        OSStatus status = InstallEventHandler(GetEventDispatcherTarget(), CarbonCallback, 1, &hotKeyPressedSpec, NULL, &sEventHandler);
+        if (status != noErr) {
+            sEventHandler = NULL;
+            return NO;
+        }
+    }
+    return YES;
+}
+
++ (void)uninstallEventHandler
+{
+    if (sEventHandler) {
+        RemoveEventHandler(sEventHandler);
+        sEventHandler = NULL;
+    }
+}
+
+#pragma mark -
+
+- (void)uninstallExisitingHotKey
+{
+    if (_carbonHotKey) {
+        UnregisterEventHotKey(_carbonHotKey);
+        _carbonHotKey = NULL;
+    }
+}
+
+FourCharCode const kMASShortcutSignature = 'MASS';
+
+- (void)installHotKeyFromUserDefaults
+{
+    NSData *data = [[NSUserDefaults standardUserDefaults] dataForKey:_userDefaultsKey];
+    MASShortcut *shortcut = [MASShortcut shortcutWithData:data];
+    if ((shortcut == nil) || ![[self class] installCommonEventHandler]) return;
+
+    static UInt32 sCarbonHotKeyID = 0;
+    _carbonHotKeyID = ++ sCarbonHotKeyID;
+	EventHotKeyID hotKeyID = { .signature = kMASShortcutSignature, .id = _carbonHotKeyID };
+    if (RegisterEventHotKey(shortcut.carbonKeyCode, shortcut.carbonFlags, hotKeyID, GetEventDispatcherTarget(), kEventHotKeyExclusive, &_carbonHotKey) != noErr) {
+        _carbonHotKey = NULL;
+    }
+}
+
+static OSStatus CarbonCallback(EventHandlerCallRef inHandlerCallRef, EventRef inEvent, void *inUserData)
+{
+	if (GetEventClass(inEvent) != kEventClassKeyboard) return noErr;
+
+	EventHotKeyID hotKeyID;
+	OSStatus status = GetEventParameter(inEvent, kEventParamDirectObject, typeEventHotKeyID, NULL, sizeof(hotKeyID), NULL, &hotKeyID);
+	if (status != noErr) return status;
+
+	if (hotKeyID.signature != kMASShortcutSignature) return noErr;
+
+    [[MASShortcut registeredHotKeys] enumerateKeysAndObjectsUsingBlock:^(id key, MASShortcutHotKey *hotKey, BOOL *stop) {
+        if (hotKeyID.id == hotKey.carbonHotKeyID) {
+            if (hotKey.handler) {
+                hotKey.handler();
+            }
+            *stop = YES;
+        }
+    }];
+
+	return noErr;
+}
+
+@end
+\ No newline at end of file