I'd love to pre-define some global hotkeys in my little cocoa application, and my question is: should I worry about the keyboard layouts?
I mean for example, when I pre-define a global key combo like "Cmd+Opt+A", I can look up key code of 'A' and hard-code it in my program, but i'm not sure if it would be a problem when users using a different keyboard layout rather than mine. Aslo, is it OK to use kVK_ANSI_A etc in this situation? What's the best practice to handle this kind of problem?
Thanks!
Keycodes are designed to be universally. That is why they are used rather than just the letter "A". So yeah, it is safe to do so. Here is a very useful app on the mac app store for finding key codes. They keycode for "A" is 97. So you can register a hotkey using keycode = 97 and modifierFlags = NSCommandKeyMask | NSAlternateKeyMask;
Related
I would like to map:
CAPS-LOCK to Fn
Fn to Left-MOUSE
LSHIFT+3 to #
RSHIFT+3 to something else
etc.
I have searched exhaustively for any tool that offers complete freedom for remapping keyboard input, but cannot find one. (Windows has AutoHotkey).
I'm planning to write my own tool that parses a config file.
But how to actually dig in and do this?
Solving this problem will require a thorough understanding of the journey of a keystroke through the operating system, so as to intercept at the appropriate point.
I think I need to eat the event at a low-level, where it is still a virtual key code, then provide my own customised mapping system and inject an appropriate event further up the system.
But where (and how)?
Edit: I am detailing the results of my research in an answer below (which maybe should be migrated back into the question at some point).
I'm making this community wiki, please feel welcome to improve it.
Sub-Questions I've asked:
Make SHIFT+3 produce `#` not `£` on OSX by code
How to tap (hook) F7 through F12 and Power/Eject on a MacBook keyboard
How to tap/hook keyboard events in OSX and record which keyboard fires each event
-> https://github.com/Daij-Djan/DDHidLib
Trap each SHIFT key independently on OS X
In OSX, how to determine which keyboard generated an NSEvent?
I can intercept almost all keydown/keyup events at the bottom of the middle tier. Except for power, and also CAPSLOCK key-UP when it is transitioning from ON to OFF.
Pretty nasty!
Working at the bottom tier level, I can get all key up/down except for the PowerKey.
If it were not for that awkward 75% success rate for CapsLock I would have a good solution. It is vexing that handling a key in such a useful location massively escalates the required complexity.
I have found DDHidLib and am currently looking through it to figure out if it smoothes that problem.
Research
Googling "keyEventWithType CGEventTapCreate" seems like a good idea, as those are essential ingredients for Tapping the event and Re-Emitting it.
Yay! Modify keyDown output -- that code compiles, and with minor tweaking (CGEventMaskBit( kCGEventKeyDown ) | CGEventMaskBit( kCGEventFlagsChanged ),) I can pick up modifier keys also. I get different keycodes for LSHIFT and RSHIFT. Brilliant!
Problems with the above:
Tapping kCGEventKeyDown works for some function keys but not others. It looks as though Apple have only overloaded certain keys, and the overloaded ones seem to get caught at a lower level.
Power/Eject key doesn't get caught.
I don't see any way to disambiguate which device the keystroke is coming from.
How to tap (hook) F7 through F12 and Power/Eject on a MacBook keyboard
http://blog.tklee.org/2008/09/modifiers-across-keyboards.html
-> http://forums.macrumors.com/showthread.php?t=778484
-> https://github.com/maravillas/dual-keyboards
https://github.com/pkamb/PowerKey may provide some insight
-> https://github.com/pkamb/PowerKey/blob/master/PowerKey/PKPowerKeyEventListener.m
-> Apple Keyboard Media Key Event Handling -- Rogue Amoeba
... system wide shortcut for Mac OS X
-> http://snippets.aktagon.com/snippets/361-registering-global-hot-keys-with-cocoa-and-objective-c
Another problem is: LSHIFT-down RSHIFT-down&up LSHIFT-up. The RSHIFT events wouldn't get caught.
Looks like I need to dip down into IOKit
Using IOHIDManager to Get Modifier Key Events
-> https://github.com/candera/khordr/blob/master/src/c/keygrab/hid-scratch.c
kEventRawKeyDown in:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/
Developer/SDKs/MacOSX10.10.sdk/System/Library/
Frameworks//Carbon.framework/Frameworks/HIToolbox.framework/
Headers/CarbonEvents.h
Resources
3-tier:
Cocoa/AppKit is a higher-level wrapper
Quartz takes the events from IOKit routes them to apps
Note: NSEvent is built over Quartz Event
IOKit -- talks to the hardware
Top Tier (Cocoa/AppKit)
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/EventOverview/EventArchitecture/EventArchitecture.html -- this document is a must-see, and shows the above basic 3-tier architecture pic. However, it appears to only focus on the top tier (Cocoa/AppKit).
http://www.hcs.harvard.edu/~jrus/Site/Cocoa%20Text%20System.html <-- this article shows you 3 OSX config files that operate at an even higher level, letting you script your own mappings. This is documented here.
^ KeyBindingsEditor lets you make the above modifications.
Middle Tier (Quartz)
QuartzEventServicesRef
NSEvent -- specifically Creating Events
A couple of working code examples at this level. However, they all perform the same basic trick of receiving one virtual key code and emitting another. So you could use this technique for example to swap 'a' and 'z'.
Intercept keyboard input in OSX -- leads to Quartz Event Taps
Modify NSEvent to send a different key than the one that was pressed -- Dave De Long provide a working example, also using QET.
https://gist.github.com/wewearglasses/8313195 <-- "Global keyboard hook for OSX" -- another short working demo using QET.
Ukelele lets you choose which Unicode gets associated with a particular key, or Modifier+key. Doesn't allow remapping of modifiers, nor does it disambiguate left from right shift keys etc.
Keyboard input on OSX -- answer points towards addGlobalMonitorForEventsMatchingMask in NSEvent (in AppKit)
Base Tier (IOKit)
IOKitFundamentals <-- Also IOKit ("Interrupt Handling in the I/O Kit... Two types of events trigger an interrupt: ... Asynchronous events, such as keyboard presses")
https://developer.apple.com/library/mac/documentation/DeviceDrivers/Conceptual/AccessingHardware/AH_Other_APIs/AH_Other_APIs.html
How can Mac OS X games receive low-level keyboard input events? <-- gamers are interested in this!
http://phrack.org/issues/66/16.html#article -- sometimes the hackers present things most clearly, haven't read through this yet. IOKit again, it seems.
More Links...
How do you implement global keyboard hooks in Mac OS X? <-- links to an article.
OS X: Detect system-wide keyDown events? <-- slightly OT as this is just to do with global monitoring, i.e. read-only.
http://www.codeitive.com/7QHSeVjPWq/where-can-i-find-kcgkeyboardeventkeycode-list-of-key-codes-for-cyrillic-language.html
Have you checked out Karabiner (which does all that you want to do.. up till OSX 10.11 .. MacOS 10.12 changed the keyboard driver model, and the authors - mainly Tekezo- are still re writing Karabiner to take account of the new model - this is as of feb 2017)
Karabiner is open source, and you can download the code from Github and twiddle with it.
As part of the re-write they have released Karabiner-elements which works on 10.12 Sierra, but cannot yet do everything that karabiner did.
Karabiner is very powerful, and I miss it greatly on 10.12
NSEvent keyCode gives a keyboard scan code, which is a hardware specific code representing the physical key. I want to convert the scan code to a virtual key code, which is the logical key based on the users keyboard layout (QWERTY, AZERTY, etc).
In Windows I can do this via MapVirtualKey. What is the OS X equivalent?
The virtual key code is precisely not based on the user's keyboard layout. It indicates which key was pressed, not what character that key would produce nor how it's labeled.
For example, kVK_ANSI_A (from Carbon/HIToolbox/Events.h, value 0x00) does not mean the key which produces the 'A' character, it means the key which is in the position that the 'A' key is in an ANSI standard keyboard. If a French keyboard layout is active, that key will produce 'Q'. If the physical keyboard is a French keyboard, that key will probably be labeled 'Q', too.
So, the virtual key code is sort of akin to a scan code, but from an idealized, standard keyboard. It is, as noted, hardware-independent. It is also independent of the keyboard layout.
To translate from the virtual key code to a character, you can use UCKeyTranslate(). You need the 'uchr' data for the current keyboard layout. You can get that using TISCopyCurrentKeyboardLayoutInputSource() and then TISGetInputSourceProperty() with kTISPropertyUnicodeKeyLayoutData as the property key.
You also need the keyboard type code. I believe it's still supported to use LMGetKbdType() to get that, even though it's no longer documented except in the legacy section. If you don't like that, you can obtain a CGEvent from the NSEvent, create a CGEventSource from that using CGEventCreateSourceFromEvent(), and then use CGEventSourceGetKeyboardType()and call CGEventGetIntegerValueField() with kCGKeyboardEventKeyboardType to get the keyboard type.
Of course, it's much easier to simply use -[NSEvent characters] or -[NSEvent charactersIgnoringModifiers]. Or, if you're implementing a text view, send key-down events to -[NSResponder interpretKeyEvents:] (as discussed in Cocoa Event Handling Guide: Handling Key Events) or -[NSTextInputContext handleEvent:] (as discussed in Cocoa Text Architecture Guide:Text Editing). Either of those will call back to the view with the appropriate action selector, like moveBackward:, or with -insertText: if the keystroke (in context of recent events and the input source) would produce text.
According to the NSEvent documentation, -[NSEvent keyCode] returns the hardware-independent virtual key code.
I want to create a new keymapping on macosx, so I can create advanced multi-key commands.
Basically, I want to create a a keymapping for transforming a normal keyboard into a chorded keyboard, optimized for writing code in c-like languages.
What I am wondering, is it possible to create that general keymaps, or is it possible to create a layer in the OS, intercepting the keyboard input at a low level and implementing the transform there.
If not, does anybody know where I can find sourcecode for a driver for a general HID-keyboard, that I can use as a base for a keyboard driver doing this?
I think this is where you want to start:
https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/EventOverview/HandlingKeyEvents/HandlingKeyEvents.html
I'm interested in trying out the same thing actually, I really dislike most of the chorded keyboards I see and would prefer to prototype w/o building the h/w.
Let's say you're creating a game for Mac OS X. In fact, let's say you're creating Quake, only it's 2011 and you'd prefer to only use modern, non-deprecated frameworks.
You want your game to be notified when the user presses (or releases) a key, any key, on the keyboard. This includes modifer keys, like shift and control. Edited to add: Also, you want to know if the left or right version of a modifier key was pressed.
You also want your game to have a config screen, where the user can inspect and modify the keyboard config. It should contain things like:
Move forward: W
Jump: SPACE
Fire: LCTRL
What do you do? I've been trying to find a good answer to this for a day or so now, but haven't succeeded.
This is what I've came up with:
Subclass NSResponder, implement keyUp: and keyDown:, like in this answer. A problem with this approach, is that keyUp: and keyDown: won't get called when the user presses only a modifier key. To work around that, you can implement flagsChanged:, but that feels like a hack.
Use a Quartz Event Tap. This only works if the app runs as root, or the user has enabled access for assistive devices. Also, modifier key events still do not count as regular key events.
Use the HIToolbox. There is virtually no mention at all of it in the 10.6 developer docs. It appears to be very, very deprecated.
So, what's the proper way to do this? This really feels like a problem that should have a well-known, well-documented solution. It's not like games are incredibly niche.
As others have said, there’s nothing wrong with using -flagsChanged:. There is another option: use the IOKit HID API. You should be using this anyway for joystick/gamepad input, and arguably mouse input; it may or may not be convenient for keyboard input too, depending on what you’re doing.
This looks promising:
+[ NSEvent addLocalMonitorForEventsMatchingMask:handler: ]
Seems to be new in 10.6 and sounds just like what you're looking for. More here:
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/ApplicationKit/Classes/NSEvent_Class/Reference/Reference.html%23//apple_ref/occ/clm/NSEvent/addLocalMonitorForEventsMatchingMask:handler:
How can I find out, which keyboard layout the user of my ruby application is using?
My aim is to have a game, where you can move the player on a map. To go one step down and one step left you press "Y" on a german keyboard. On an American keyboard, you would press "Z". We optimized the game for windows and mac, so I would like a solution for both platforms (and we don't use any command/shift/control-keys).
For Windows, you probably have to use the Windows API GetKeyboardLayout(), unless Ruby provides a wrapper for that.
There are a lot of useful I18n resources for Windows on the MSDN web site.
It might be easier to simply allow them to configure it themselves as a preference if you don't have a good portable way of detecting it.
I think it'll be much easier and naturally to allow users to define keys themselves.
As Alexander recommended, let the user define the keys themselves.
But, if you really want to recognize the layout, you could always ask the user to press keys in certain positions, particular to some layouts.
"Press the second key to the left of the return key. If your return key is two rows high, press the lower one"
[presses ä]
"Looks like you have a scandinavian keyboard"
That, however, is a horrible cludge, and, in the game context, would recommend the custom keymapping method