SRAXGlobalShortcutMonitor: Avoid using NSEvent from the CGEventTap handler

NSEvent seems to depend on being used from the main thread, which is unncessary limiting for the monitor.

Refs #129

Author: Kentzo

Library/SRCommon.h

@@ -24,6 +24,9 @@ NS_SWIFT_NAME(CarbonModifierFlagsMask)
 static const UInt32 SRCarbonModifierFlagsMask = cmdKey | optionKey | shiftKey | controlKey;
 
 
+NS_SWIFT_NAME(CoreGraphicsModifierFlagsMask)
+static const CGEventFlags SRCoreGraphicsModifierFlagsMask = kCGEventFlagMaskCommand | kCGEventFlagMaskAlternate | kCGEventFlagMaskShift | kCGEventFlagMaskControl;
+
 /*!
  Dawable unicode characters for key codes that do not have appropriate constants in Carbon and Cocoa.
 
@@ -301,6 +304,26 @@ NS_INLINE UInt32 SRCocoaToCarbonFlags(NSEventModifierFlags aCocoaFlags)
     return carbonFlags;
 }
 
+NS_SWIFT_NAME(coreGraphicsToCocoaFlags(_:))
+NS_INLINE NSEventModifierFlags SRCoreGraphicsToCocoaFlags(CGEventFlags aCoreGraphicsFlags)
+{
+    NSEventModifierFlags cocoaFlags = 0;
+
+    if (aCoreGraphicsFlags & kCGEventFlagMaskCommand)
+        cocoaFlags |= NSEventModifierFlagCommand;
+
+    if (aCoreGraphicsFlags & kCGEventFlagMaskAlternate)
+        cocoaFlags |= NSEventModifierFlagOption;
+
+    if (aCoreGraphicsFlags & kCGEventFlagMaskControl)
+        cocoaFlags |= NSEventModifierFlagControl;
+
+    if (aCoreGraphicsFlags & kCGEventFlagMaskShift)
+        cocoaFlags |= NSEventModifierFlagShift;
+
+    return cocoaFlags;
+}
+
 
 /*!
  Return Bundle where resources can be found.

Library/SRShortcutAction.h

@@ -198,6 +198,10 @@ typedef NS_CLOSED_ENUM(NSUInteger, SRKeyEventType)
 
 @interface NSEvent (SRShortcutAction)
 
++ (SRKeyEventType)SR_keyEventTypeForEventType:(NSEventType)anEventType
+                                      keyCode:(unsigned short)aKeyCode
+                                modifierFlags:(NSEventModifierFlags)aModifierFlags;
+
 /*!
  Keyboard event type as recognized by the shortcut recorder.
 

Library/SRShortcutAction.m

@@ -368,11 +368,13 @@ - (void)observeValueForKeyPath:(NSString *)aKeyPath
 
 @implementation NSEvent (SRShortcutAction)
 
-- (SRKeyEventType)SR_keyEventType
++ (SRKeyEventType)SR_keyEventTypeForEventType:(NSEventType)anEventType
+                                      keyCode:(unsigned short)aKeyCode
+                                modifierFlags:(NSEventModifierFlags)aModifierFlags
 {
     SRKeyEventType eventType = SRKeyEventTypeDown;
 
-    switch (self.type)
+    switch (anEventType)
     {
         case NSEventTypeKeyDown:
             eventType = SRKeyEventTypeDown;
@@ -382,8 +384,8 @@ - (SRKeyEventType)SR_keyEventType
             break;
         case NSEventTypeFlagsChanged:
         {
-            __auto_type keyCode = self.keyCode;
-            __auto_type modifierFlags = self.modifierFlags;
+            __auto_type keyCode = aKeyCode;
+            __auto_type modifierFlags = aModifierFlags;
 
             if (keyCode == kVK_Command || keyCode == kVK_RightCommand)
                 eventType = modifierFlags & NSEventModifierFlagCommand ? SRKeyEventTypeDown : SRKeyEventTypeUp;
@@ -398,13 +400,18 @@ - (SRKeyEventType)SR_keyEventType
             break;
         }
         default:
-            [NSException raise:NSInternalInconsistencyException format:@"Expected a key event, got %lu", self.type];
+            [NSException raise:NSInternalInconsistencyException format:@"Expected a key event, got %lu", anEventType];
             break;
     }
 
     return eventType;
 }
 
+- (SRKeyEventType)SR_keyEventType
+{
+    return [self.class SR_keyEventTypeForEventType:self.type keyCode:self.keyCode modifierFlags:self.modifierFlags];
+}
+
 @end
 
 
@@ -1342,25 +1349,34 @@ - (CGEventRef)handleEvent:(CGEventRef)anEvent
     __block __auto_type result = anEvent;
 
     os_activity_initiate("-[SRAXGlobalShortcutMonitor handleEvent:]", OS_ACTIVITY_FLAG_DETACHED, ^{
-        __auto_type nsEvent = [NSEvent eventWithCGEvent:anEvent];
-        if (!nsEvent)
-        {
-            os_trace_error("#Error Unexpected event");
-            return;
-        }
-
-        __auto_type shortcut = [SRShortcut shortcutWithEvent:nsEvent ignoringCharacters:YES];
-        if (!shortcut)
+        __auto_type eventKeyCode = CGEventGetIntegerValueField(anEvent, kCGKeyboardEventKeycode);
+        __auto_type eventType = CGEventGetType(anEvent);
+        __auto_type cocoaModifierFlags = SRCoreGraphicsToCocoaFlags(CGEventGetFlags(anEvent));
+        NSEventType cocoaEventType;
+        switch (eventType)
         {
-            os_trace_error("#Error Not a keyboard event");
-            return;
+            case kCGEventKeyDown:
+                cocoaEventType = NSEventTypeKeyDown;
+                break;
+            case kCGEventKeyUp:
+                cocoaEventType = NSEventTypeKeyUp;
+                break;
+            case kCGEventFlagsChanged:
+                cocoaEventType = NSEventTypeFlagsChanged;
+                break;
+            default:
+                cocoaEventType = 0;
+                break;
         }
 
-        SRKeyEventType eventType = nsEvent.SR_keyEventType;
-        if (eventType == 0)
-            return;
-
-        __auto_type actions = [self enabledActionsForShortcut:shortcut keyEvent:eventType];
+        __auto_type shortcut = [SRShortcut shortcutWithCode:eventType != kCGEventFlagsChanged ? (SRKeyCode)eventKeyCode : SRKeyCodeNone
+                                              modifierFlags:cocoaModifierFlags
+                                                 characters:nil
+                                charactersIgnoringModifiers:nil];
+        __auto_type keyEventType = [NSEvent SR_keyEventTypeForEventType:cocoaEventType
+                                                                keyCode:(unsigned short)eventKeyCode
+                                                          modifierFlags:cocoaModifierFlags];
+        __auto_type actions = [self enabledActionsForShortcut:shortcut keyEvent:keyEventType];
         __block BOOL isHandled = NO;
         [actions enumerateObjectsWithOptions:NSEnumerationReverse
                                   usingBlock:^(SRShortcutAction *obj, NSUInteger idx, BOOL *stop)
@@ -1577,11 +1593,7 @@ - (BOOL)handleEvent:(NSEvent *)anEvent withTarget:(nullable id)aTarget
         return NO;
     }
 
-    SRKeyEventType eventType = anEvent.SR_keyEventType;
-    if (eventType == 0)
-        return NO;
-
-    __auto_type actions = [self enabledActionsForShortcut:shortcut keyEvent:eventType];
+    __auto_type actions = [self enabledActionsForShortcut:shortcut keyEvent:anEvent.SR_keyEventType];
     __block BOOL isHandled = NO;
     [actions enumerateObjectsWithOptions:NSEnumerationReverse
                               usingBlock:^(SRShortcutAction *obj, NSUInteger idx, BOOL *stop)