Simulate keypress for system wide hotkeys

Question

I need to simulate keystrokes in OSX. Here\'s how I do it:

-(void)execute {
    CGEventSourceRef sourceRef =
    CGEventSourceCreate(kCGEventSourceStateHIDSy         


        

Answer 1

From the documentation for CGEventCreateKeyboardEvent:

All keystrokes needed to generate a character must be entered, including modifier keys. For example, to produce a 'Z', the SHIFT key must be down, the 'z' key must go down, and then the SHIFT and 'z' key must be released:

So, you can't just press and release space with the option modifier to trigger an option-space; you have to press option, press space, release space, release option.

As a side note, opt-space doesn't do anything by default; cmd-space is the Spotlight search hotkey, and cmd-opt-space is the Spotlight window hotkey.

So, this code will pop up the Spotlight search:

- (void)execute {
  CGEventSourceRef src = 
    CGEventSourceCreate(kCGEventSourceStateHIDSystemState);

  CGEventRef cmdd = CGEventCreateKeyboardEvent(src, 0x38, true);
  CGEventRef cmdu = CGEventCreateKeyboardEvent(src, 0x38, false);
  CGEventRef spcd = CGEventCreateKeyboardEvent(src, 0x31, true);
  CGEventRef spcu = CGEventCreateKeyboardEvent(src, 0x31, false);

  CGEventSetFlags(spcd, kCGEventFlagMaskCommand);
  CGEventSetFlags(spcu, kCGEventFlagMaskCommand);

  CGEventTapLocation loc = kCGHIDEventTap; // kCGSessionEventTap also works
  CGEventPost(loc, cmdd);
  CGEventPost(loc, spcd);
  CGEventPost(loc, spcu);
  CGEventPost(loc, cmdu);

  CFRelease(cmdd);
  CFRelease(cmdu);
  CFRelease(spcd);
  CFRelease(spcu);
  CFRelease(src);  
}