/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2004 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 * 
 * This package is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "platform/OSXKeyState.h"
#include "platform/OSXUchrKeyResource.h"
#include "platform/OSXMediaKeySimulator.h"
#include "arch/Arch.h"
#include "base/Log.h"

#include <Carbon/Carbon.h>

// Note that some virtual keys codes appear more than once.  The
// first instance of a virtual key code maps to the KeyID that we
// want to generate for that code.  The others are for mapping
// different KeyIDs to a single key code.
static const UInt32 s_shiftVK    = kVK_Shift;
static const UInt32 s_controlVK  = kVK_Control;
static const UInt32 s_altVK      = kVK_Option;
static const UInt32 s_superVK    = kVK_Command;
static const UInt32 s_capsLockVK = kVK_CapsLock;
static const UInt32 s_numLockVK  = kVK_ANSI_KeypadClear; // 71

static const UInt32 s_brightnessUp = 144;
static const UInt32 s_brightnessDown = 145;
static const UInt32 s_missionControlVK = 160;
static const UInt32 s_launchpadVK = 131;

static const UInt32 s_osxNumLock = 1 << 16;

struct KeyEntry {
public:
	KeyID				m_keyID;
	UInt32				m_virtualKey;
};
static const KeyEntry	s_controlKeys[] = {
	// cursor keys.  if we don't do this we'll may still get these from
	// the keyboard resource but they may not correspond to the arrow
	// keys.
	{ kKeyLeft,		kVK_LeftArrow },
	{ kKeyRight,		kVK_RightArrow },
	{ kKeyUp,		kVK_UpArrow },
	{ kKeyDown,		kVK_DownArrow },
	{ kKeyHome,		kVK_Home },
	{ kKeyEnd,		kVK_End },
	{ kKeyPageUp,		kVK_PageUp },
	{ kKeyPageDown,		kVK_PageDown },
	{ kKeyInsert,		kVK_Help }, // Mac Keyboards have 'Help' on 'Insert'

	// function keys
	{ kKeyF1,		kVK_F1 },
	{ kKeyF2,		kVK_F2 },
	{ kKeyF3,		kVK_F3 },
	{ kKeyF4,		kVK_F4 },
	{ kKeyF5,		kVK_F5 },
	{ kKeyF6,		kVK_F6 },
	{ kKeyF7,		kVK_F7 },
	{ kKeyF8,		kVK_F8 },
	{ kKeyF9,		kVK_F9 },
	{ kKeyF10,		kVK_F10 },
	{ kKeyF11,		kVK_F11 },
	{ kKeyF12,		kVK_F12 },
	{ kKeyF13,		kVK_F13 },
	{ kKeyF14,		kVK_F14 },
	{ kKeyF15,		kVK_F15 },
	{ kKeyF16,		kVK_F16 },

	{ kKeyKP_0,		kVK_ANSI_Keypad0 },
	{ kKeyKP_1,		kVK_ANSI_Keypad1 },
	{ kKeyKP_2,		kVK_ANSI_Keypad2 },
	{ kKeyKP_3,		kVK_ANSI_Keypad3 },
	{ kKeyKP_4,		kVK_ANSI_Keypad4 },
	{ kKeyKP_5,		kVK_ANSI_Keypad5 },
	{ kKeyKP_6,		kVK_ANSI_Keypad6 },
	{ kKeyKP_7,		kVK_ANSI_Keypad7 },
	{ kKeyKP_8,		kVK_ANSI_Keypad8 },
	{ kKeyKP_9,		kVK_ANSI_Keypad9 },
	{ kKeyKP_Decimal,	kVK_ANSI_KeypadDecimal },
	{ kKeyKP_Equal,		kVK_ANSI_KeypadEquals },
	{ kKeyKP_Multiply,	kVK_ANSI_KeypadMultiply },
	{ kKeyKP_Add,		kVK_ANSI_KeypadPlus },
	{ kKeyKP_Divide,	kVK_ANSI_KeypadDivide },
	{ kKeyKP_Subtract,	kVK_ANSI_KeypadMinus },
	{ kKeyKP_Enter,		kVK_ANSI_KeypadEnter },
	
	// virtual key 110 is fn+enter and i have no idea what that's supposed
	// to map to.  also the enter key with numlock on is a modifier but i
	// don't know which.

	// modifier keys.  OS X doesn't seem to support right handed versions
	// of modifier keys so we map them to the left handed versions.
	{ kKeyShift_L,		s_shiftVK },
	{ kKeyShift_R,		s_shiftVK }, // 60
	{ kKeyControl_L,	s_controlVK },
	{ kKeyControl_R,	s_controlVK }, // 62
	{ kKeyAlt_L,		s_altVK },
	{ kKeyAlt_R,		s_altVK },
	{ kKeySuper_L,		s_superVK },
	{ kKeySuper_R,		s_superVK }, // 61
	{ kKeyMeta_L,		s_superVK },
	{ kKeyMeta_R,		s_superVK }, // 61

	// toggle modifiers
	{ kKeyNumLock,		s_numLockVK },
	{ kKeyCapsLock,		s_capsLockVK },
	
	{ kKeyMissionControl, s_missionControlVK },
	{ kKeyLaunchpad, s_launchpadVK },
	{ kKeyBrightnessUp,  s_brightnessUp },
	{ kKeyBrightnessDown, s_brightnessDown }
};


//
// OSXKeyState
//

OSXKeyState::OSXKeyState(IEventQueue* events) :
	KeyState(events)
{
	init();
}

OSXKeyState::OSXKeyState(IEventQueue* events, synergy::KeyMap& keyMap) :
	KeyState(events, keyMap)
{
	init();
}

OSXKeyState::~OSXKeyState()
{
}

void
OSXKeyState::init()
{
	m_deadKeyState = 0;
	m_shiftPressed = false;
	m_controlPressed = false;
	m_altPressed = false;
	m_superPressed = false;
	m_capsPressed = false;

	// build virtual key map
	for (size_t i = 0; i < sizeof(s_controlKeys) / sizeof(s_controlKeys[0]);
		++i) {
		
		m_virtualKeyMap[s_controlKeys[i].m_virtualKey] =
			s_controlKeys[i].m_keyID;
	}
}

KeyModifierMask
OSXKeyState::mapModifiersFromOSX(UInt32 mask) const
{
	KeyModifierMask outMask = 0;
	if ((mask & kCGEventFlagMaskShift) != 0) {
		outMask |= KeyModifierShift;
	}
	if ((mask & kCGEventFlagMaskControl) != 0) {
		outMask |= KeyModifierControl;
	}
	if ((mask & kCGEventFlagMaskAlternate) != 0) {
		outMask |= KeyModifierAlt;
	}
	if ((mask & kCGEventFlagMaskCommand) != 0) {
		outMask |= KeyModifierSuper;
	}
	if ((mask & kCGEventFlagMaskAlphaShift) != 0) {
		outMask |= KeyModifierCapsLock;
	}
	if ((mask & kCGEventFlagMaskNumericPad) != 0) {
		outMask |= KeyModifierNumLock;
	}

	LOG((CLOG_DEBUG1 "mask=%04x outMask=%04x", mask, outMask));
	return outMask;
}

KeyModifierMask
OSXKeyState::mapModifiersToCarbon(UInt32 mask) const
{
	KeyModifierMask outMask = 0;
	if ((mask & kCGEventFlagMaskShift) != 0) {
		outMask |= shiftKey;
	}
	if ((mask & kCGEventFlagMaskControl) != 0) {
		outMask |= controlKey;
	}
	if ((mask & kCGEventFlagMaskCommand) != 0) {
		outMask |= cmdKey;
	}
	if ((mask & kCGEventFlagMaskAlternate) != 0) {
		outMask |= optionKey;
	}
	if ((mask & kCGEventFlagMaskAlphaShift) != 0) {
		outMask |= alphaLock;
	}
	if ((mask & kCGEventFlagMaskNumericPad) != 0) {
		outMask |= s_osxNumLock;
	}
	
	return outMask;
}

KeyButton 
OSXKeyState::mapKeyFromEvent(KeyIDs& ids,
				KeyModifierMask* maskOut, CGEventRef event) const
{
	ids.clear();

	// map modifier key
	if (maskOut != NULL) {
		KeyModifierMask activeMask = getActiveModifiers();
		activeMask &= ~KeyModifierAltGr;
		*maskOut    = activeMask;
	}

	// get virtual key
	UInt32 vkCode = CGEventGetIntegerValueField(event, kCGKeyboardEventKeycode);

	// handle up events
	UInt32 eventKind = CGEventGetType(event);
	if (eventKind == kCGEventKeyUp) {
		// the id isn't used.  we just need the same button we used on
		// the key press.  note that we don't use or reset the dead key
		// state;  up events should not affect the dead key state.
		ids.push_back(kKeyNone);
		return mapVirtualKeyToKeyButton(vkCode);
	}

	// check for special keys
	VirtualKeyMap::const_iterator i = m_virtualKeyMap.find(vkCode);
	if (i != m_virtualKeyMap.end()) {
		m_deadKeyState = 0;
		ids.push_back(i->second);
		return mapVirtualKeyToKeyButton(vkCode);
	}

	// get keyboard info
	TISInputSourceRef currentKeyboardLayout = TISCopyCurrentKeyboardLayoutInputSource(); 

	if (currentKeyboardLayout == NULL) {
		return kKeyNone;
	}

	// get the event modifiers and remove the command and control
	// keys.  note if we used them though.
	// UCKeyTranslate expects old-style Carbon modifiers, so convert.
	UInt32 modifiers;
	modifiers = mapModifiersToCarbon(CGEventGetFlags(event));
	static const UInt32 s_commandModifiers =
		cmdKey | controlKey | rightControlKey;
	bool isCommand = ((modifiers & s_commandModifiers) != 0);
	modifiers &= ~s_commandModifiers;

	// if we've used a command key then we want the glyph produced without
	// the option key (i.e. the base glyph).
	//if (isCommand) {
		modifiers &= ~optionKey;
	//}

	// choose action
	UInt16 action;
	if (eventKind==kCGEventKeyDown) {
		action = kUCKeyActionDown;
	}
	else if (CGEventGetIntegerValueField(event, kCGKeyboardEventAutorepeat)==1) {
		action = kUCKeyActionAutoKey;
	}
	else {
		return 0;
	}

	// translate via uchr resource
	CFDataRef ref = (CFDataRef) TISGetInputSourceProperty(currentKeyboardLayout,
								kTISPropertyUnicodeKeyLayoutData);
	const UCKeyboardLayout* layout = (const UCKeyboardLayout*) CFDataGetBytePtr(ref);
	const bool layoutValid = (layout != NULL);

	if (layoutValid) {
		// translate key
		UniCharCount count;
		UniChar chars[2];
		LOG((CLOG_DEBUG2 "modifiers: %08x", modifiers & 0xffu));
		OSStatus status = UCKeyTranslate(layout,
							vkCode & 0xffu, action,
							(modifiers >> 8) & 0xffu,
							LMGetKbdType(), 0, &m_deadKeyState,
							sizeof(chars) / sizeof(chars[0]), &count, chars);

		// get the characters
		if (status == 0) {
			if (count != 0 || m_deadKeyState == 0) {
				m_deadKeyState = 0;
				for (UniCharCount i = 0; i < count; ++i) {
					ids.push_back(IOSXKeyResource::unicharToKeyID(chars[i]));
				}
				adjustAltGrModifier(ids, maskOut, isCommand);
				return mapVirtualKeyToKeyButton(vkCode);
			}
			return 0;
		}
	}

	return 0;
}

bool
OSXKeyState::fakeCtrlAltDel()
{
	// pass keys through unchanged
	return false;
}

bool
OSXKeyState::fakeMediaKey(KeyID id)
{
	return fakeNativeMediaKey(id);;
}

CGEventFlags
OSXKeyState::getModifierStateAsOSXFlags()
{
    CGEventFlags modifiers = 0;
    
    if (m_shiftPressed) {
        modifiers |= kCGEventFlagMaskShift;
    }
    
    if (m_controlPressed) {
        modifiers |= kCGEventFlagMaskControl;
    }
    
    if (m_altPressed) {
        modifiers |= kCGEventFlagMaskAlternate;
    }
    
    if (m_superPressed) {
        modifiers |= kCGEventFlagMaskCommand;
    }
    
    if (m_capsPressed) {
        modifiers |= kCGEventFlagMaskAlphaShift;
    }
    
    return modifiers;
}

KeyModifierMask
OSXKeyState::pollActiveModifiers() const
{
	// falsely assumed that the mask returned by GetCurrentKeyModifiers()
	// was the same as a CGEventFlags (which is what mapModifiersFromOSX
	// expects). patch by Marc
	UInt32 mask = GetCurrentKeyModifiers();
	KeyModifierMask outMask = 0;

	if ((mask & shiftKey) != 0) {
		outMask |= KeyModifierShift;
	}
	if ((mask & controlKey) != 0) {
		outMask |= KeyModifierControl;
	}
	if ((mask & optionKey) != 0) {
		outMask |= KeyModifierAlt;
	}
	if ((mask & cmdKey) != 0) {
		outMask |= KeyModifierSuper;
	}
	if ((mask & alphaLock) != 0) {
		outMask |= KeyModifierCapsLock;
	}
	if ((mask & s_osxNumLock) != 0) {
		outMask |= KeyModifierNumLock;
	}

	LOG((CLOG_DEBUG1 "mask=%04x outMask=%04x", mask, outMask));
	return outMask;
}

SInt32
OSXKeyState::pollActiveGroup() const
{
	TISInputSourceRef keyboardLayout = TISCopyCurrentKeyboardLayoutInputSource();
	CFDataRef id = (CFDataRef)TISGetInputSourceProperty(
						keyboardLayout, kTISPropertyInputSourceID);
	
	GroupMap::const_iterator i = m_groupMap.find(id);
	if (i != m_groupMap.end()) {
		return i->second;
	}
	
	LOG((CLOG_DEBUG "can't get the active group, use the first group instead"));

	return 0;
}

void
OSXKeyState::pollPressedKeys(KeyButtonSet& pressedKeys) const
{
	::KeyMap km;
	GetKeys(km);
	const UInt8* m = reinterpret_cast<const UInt8*>(km);
	for (UInt32 i = 0; i < 16; ++i) {
		for (UInt32 j = 0; j < 8; ++j) {
			if ((m[i] & (1u << j)) != 0) {
				pressedKeys.insert(mapVirtualKeyToKeyButton(8 * i + j));
			}
		}
	}
}

void
OSXKeyState::getKeyMap(synergy::KeyMap& keyMap)
{
	// update keyboard groups
	if (getGroups(m_groups)) {
		m_groupMap.clear();
		SInt32 numGroups = (SInt32)m_groups.size();
		for (SInt32 g = 0; g < numGroups; ++g) {
			CFDataRef id = (CFDataRef)TISGetInputSourceProperty(
								m_groups[g], kTISPropertyInputSourceID);
			m_groupMap[id] = g;
		}
	}

	UInt32 keyboardType = LMGetKbdType();
	for (SInt32 g = 0, n = (SInt32)m_groups.size(); g < n; ++g) {
		// add special keys
		getKeyMapForSpecialKeys(keyMap, g);

		const void* resource;
		bool layoutValid = false;
		
		// add regular keys
		// try uchr resource first
		CFDataRef resourceRef = (CFDataRef)TISGetInputSourceProperty(
			m_groups[g], kTISPropertyUnicodeKeyLayoutData);

		layoutValid = resourceRef != NULL;
		if (layoutValid)
			resource = CFDataGetBytePtr(resourceRef);

		if (layoutValid) {
			OSXUchrKeyResource uchr(resource, keyboardType);
			if (uchr.isValid()) {
				LOG((CLOG_DEBUG1 "using uchr resource for group %d", g));
				getKeyMap(keyMap, g, uchr);
				continue;
			}
		}

		LOG((CLOG_DEBUG1 "no keyboard resource for group %d", g));
	}
}

void
OSXKeyState::fakeKey(const Keystroke& keystroke)
{
	switch (keystroke.m_type) {
	case Keystroke::kButton: {
		
		KeyButton button = keystroke.m_data.m_button.m_button;
		bool keyDown = keystroke.m_data.m_button.m_press;
		UInt32 client = keystroke.m_data.m_button.m_client;
		CGEventSourceRef source = 0;
		CGKeyCode virtualKey = mapKeyButtonToVirtualKey(button);
		
		LOG((CLOG_DEBUG1
			"  button=0x%04x virtualKey=0x%04x keyDown=%s client=0x%04x",
			button, virtualKey, keyDown ? "down" : "up", client));

		CGEventRef ref = CGEventCreateKeyboardEvent(
			source, virtualKey, keyDown);
		
		if (ref == NULL) {
			LOG((CLOG_CRIT "unable to create keyboard event for keystroke"));
			return;
		}

		// persist modifier state.
		if (virtualKey == s_shiftVK) {
			m_shiftPressed = keyDown;
		}
		
		if (virtualKey == s_controlVK) {
			m_controlPressed = keyDown;
		}
		
		if (virtualKey == s_altVK) {
			m_altPressed = keyDown;
		}
		
		if (virtualKey == s_superVK) {
			m_superPressed = keyDown;
		}
		
		if (virtualKey == s_capsLockVK) {
			m_capsPressed = keyDown;
		}

		// set the event flags for special keys
		// http://tinyurl.com/pxl742y
		CGEventFlags modifiers = 0;
		
		if (m_shiftPressed) {
			modifiers |= kCGEventFlagMaskShift;
		}
		
		if (m_controlPressed) {
			modifiers |= kCGEventFlagMaskControl;
		}
		
		if (m_altPressed) {
			modifiers |= kCGEventFlagMaskAlternate;
		}
		
		if (m_superPressed) {
			modifiers |= kCGEventFlagMaskCommand;
		}
		
		if (m_capsPressed) {
			modifiers |= kCGEventFlagMaskAlphaShift;
		}
		
		CGEventSetFlags(ref, modifiers);
		CGEventPost(kCGHIDEventTap, ref);
		CFRelease(ref);

		// add a delay if client data isn't zero
		// FIXME -- why?
		if (client != 0) {
			ARCH->sleep(0.01);
		}
		break;
	}

	case Keystroke::kGroup: {
		SInt32 group = keystroke.m_data.m_group.m_group;
		if (keystroke.m_data.m_group.m_absolute) {
			LOG((CLOG_DEBUG1 "  group %d", group));
			setGroup(group);
		}
		else {
			LOG((CLOG_DEBUG1 "  group %+d", group));
			setGroup(getEffectiveGroup(pollActiveGroup(), group));
		}
		break;
	}
	}
}

void
OSXKeyState::getKeyMapForSpecialKeys(synergy::KeyMap& keyMap, SInt32 group) const
{
	// special keys are insensitive to modifers and none are dead keys
	synergy::KeyMap::KeyItem item;
	for (size_t i = 0; i < sizeof(s_controlKeys) /
								sizeof(s_controlKeys[0]); ++i) {
		const KeyEntry& entry = s_controlKeys[i];
		item.m_id        = entry.m_keyID;
		item.m_group     = group;
		item.m_button    = mapVirtualKeyToKeyButton(entry.m_virtualKey);
		item.m_required  = 0;
		item.m_sensitive = 0;
		item.m_dead      = false;
		item.m_client    = 0;
		synergy::KeyMap::initModifierKey(item);
		keyMap.addKeyEntry(item);

		if (item.m_lock) {
			// all locking keys are half duplex on OS X
			keyMap.addHalfDuplexButton(item.m_button);
		}
	}

	// note:  we don't special case the number pad keys.  querying the
	// mac keyboard returns the non-keypad version of those keys but
	// a KeyState always provides a mapping from keypad keys to
	// non-keypad keys so we'll be able to generate the characters
	// anyway.
}

bool
OSXKeyState::getKeyMap(synergy::KeyMap& keyMap,
				SInt32 group, const IOSXKeyResource& r) const
{
	if (!r.isValid()) {
		return false;
	}

	// space for all possible modifier combinations
	std::vector<bool> modifiers(r.getNumModifierCombinations());

	// make space for the keys that any single button can synthesize
	std::vector<std::pair<KeyID, bool> > buttonKeys(r.getNumTables());

	// iterate over each button
	synergy::KeyMap::KeyItem item;
	for (UInt32 i = 0; i < r.getNumButtons(); ++i) {
		item.m_button = mapVirtualKeyToKeyButton(i);

		// the KeyIDs we've already handled
		std::set<KeyID> keys;

		// convert the entry in each table for this button to a KeyID
		for (UInt32 j = 0; j < r.getNumTables(); ++j) {
			buttonKeys[j].first  = r.getKey(j, i);
			buttonKeys[j].second = synergy::KeyMap::isDeadKey(buttonKeys[j].first);
		}

		// iterate over each character table
		for (UInt32 j = 0; j < r.getNumTables(); ++j) {
			// get the KeyID for the button/table
			KeyID id = buttonKeys[j].first;
			if (id == kKeyNone) {
				continue;
			}

			// if we've already handled the KeyID in the table then
			// move on to the next table
			if (keys.count(id) > 0) {
				continue;
			}
			keys.insert(id);

			// prepare item.  the client state is 1 for dead keys.
			item.m_id     = id;
			item.m_group  = group;
			item.m_dead   = buttonKeys[j].second;
			item.m_client = buttonKeys[j].second ? 1 : 0;
			synergy::KeyMap::initModifierKey(item);
			if (item.m_lock) {
				// all locking keys are half duplex on OS X
				keyMap.addHalfDuplexButton(i);
			}

			// collect the tables that map to the same KeyID.  we know it
			// can't be any earlier tables because of the check above.
			std::set<UInt8> tables;
			tables.insert(static_cast<UInt8>(j));
			for (UInt32 k = j + 1; k < r.getNumTables(); ++k) {
				if (buttonKeys[k].first == id) {
					tables.insert(static_cast<UInt8>(k));
				}
			}

			// collect the modifier combinations that map to any of the
			// tables we just collected
			for (UInt32 k = 0; k < r.getNumModifierCombinations(); ++k) {
				modifiers[k] = (tables.count(r.getTableForModifier(k)) > 0);
			}

			// figure out which modifiers the key is sensitive to.  the
			// key is insensitive to a modifier if for every modifier mask
			// with the modifier bit unset in the modifiers we also find
			// the same mask with the bit set.
			//
			// we ignore a few modifiers that we know aren't important
			// for generating characters.  in fact, we want to ignore any
			// characters generated by the control key.  we don't map
			// those and instead expect the control modifier plus a key.
			UInt32 sensitive = 0;
			for (UInt32 k = 0; (1u << k) <
								r.getNumModifierCombinations(); ++k) {
				UInt32 bit = (1u << k);
				if ((bit << 8) == cmdKey ||
					(bit << 8) == controlKey ||
					(bit << 8) == rightControlKey) {
					continue;
				}
				for (UInt32 m = 0; m < r.getNumModifierCombinations(); ++m) {
					if (modifiers[m] != modifiers[m ^ bit]) {
						sensitive |= bit;
						break;
					}
				}
			}

			// find each required modifier mask.  the key can be synthesized
			// using any of the masks.
			std::set<UInt32> required;
			for (UInt32 k = 0; k < r.getNumModifierCombinations(); ++k) {
				if ((k & sensitive) == k && modifiers[k & sensitive]) {
					required.insert(k);
				}
			}

			// now add a key entry for each key/required modifier pair.
			item.m_sensitive = mapModifiersFromOSX(sensitive << 16);
			for (std::set<UInt32>::iterator k = required.begin();
											k != required.end(); ++k) {
				item.m_required = mapModifiersFromOSX(*k << 16);
				keyMap.addKeyEntry(item);
			}
		}
	}

	return true;
}

bool
OSXKeyState::mapSynergyHotKeyToMac(KeyID key, KeyModifierMask mask,
				UInt32 &macVirtualKey, UInt32 &macModifierMask) const
{
	// look up button for key
	KeyButton button = getButton(key, pollActiveGroup());
	if (button == 0 && key != kKeyNone) {
		return false;
	}
	macVirtualKey = mapKeyButtonToVirtualKey(button);
	
	// calculate modifier mask
	macModifierMask = 0;
	if ((mask & KeyModifierShift) != 0) {
		macModifierMask |= shiftKey;
	}
	if ((mask & KeyModifierControl) != 0) {
		macModifierMask |= controlKey;
	}
	if ((mask & KeyModifierAlt) != 0) {
		macModifierMask |= cmdKey;
	}
	if ((mask & KeyModifierSuper) != 0) {
		macModifierMask |= optionKey;
	}
	if ((mask & KeyModifierCapsLock) != 0) {
		macModifierMask |= alphaLock;
	}
	if ((mask & KeyModifierNumLock) != 0) {
		macModifierMask |= s_osxNumLock;
	}
	
	return true;
}
						
void
OSXKeyState::handleModifierKeys(void* target,
				KeyModifierMask oldMask, KeyModifierMask newMask)
{
	// compute changed modifiers
	KeyModifierMask changed = (oldMask ^ newMask);

	// synthesize changed modifier keys
	if ((changed & KeyModifierShift) != 0) {
		handleModifierKey(target, s_shiftVK, kKeyShift_L,
							(newMask & KeyModifierShift) != 0, newMask);
	}
	if ((changed & KeyModifierControl) != 0) {
		handleModifierKey(target, s_controlVK, kKeyControl_L,
							(newMask & KeyModifierControl) != 0, newMask);
	}
	if ((changed & KeyModifierAlt) != 0) {
		handleModifierKey(target, s_altVK, kKeyAlt_L,
							(newMask & KeyModifierAlt) != 0, newMask);
	}
	if ((changed & KeyModifierSuper) != 0) {
		handleModifierKey(target, s_superVK, kKeySuper_L,
							(newMask & KeyModifierSuper) != 0, newMask);
	}
	if ((changed & KeyModifierCapsLock) != 0) {
		handleModifierKey(target, s_capsLockVK, kKeyCapsLock,
							(newMask & KeyModifierCapsLock) != 0, newMask);
	}
	if ((changed & KeyModifierNumLock) != 0) {
		handleModifierKey(target, s_numLockVK, kKeyNumLock,
							(newMask & KeyModifierNumLock) != 0, newMask);
	}
}

void
OSXKeyState::handleModifierKey(void* target,
				UInt32 virtualKey, KeyID id,
				bool down, KeyModifierMask newMask)
{
	KeyButton button = mapVirtualKeyToKeyButton(virtualKey);
	onKey(button, down, newMask);
	sendKeyEvent(target, down, false, id, newMask, 0, button);
}

bool
OSXKeyState::getGroups(GroupList& groups) const
{
	CFIndex n;
	bool gotLayouts = false;

	// get number of layouts
	CFStringRef keys[] = { kTISPropertyInputSourceCategory };
	CFStringRef values[] = { kTISCategoryKeyboardInputSource };
	CFDictionaryRef dict = CFDictionaryCreate(NULL, (const void **)keys, (const void **)values, 1, NULL, NULL);
	CFArrayRef kbds = TISCreateInputSourceList(dict, false);
	n = CFArrayGetCount(kbds);
	gotLayouts = (n != 0);

	if (!gotLayouts) {
		LOG((CLOG_DEBUG1 "can't get keyboard layouts"));
		return false;
	}

	// get each layout
	groups.clear();
	for (CFIndex i = 0; i < n; ++i) {
		bool addToGroups = true;
		TISInputSourceRef keyboardLayout = 
			(TISInputSourceRef)CFArrayGetValueAtIndex(kbds, i);

		if (addToGroups)
    		groups.push_back(keyboardLayout);
	}
	return true;
}

void
OSXKeyState::setGroup(SInt32 group)
{
	TISSetInputMethodKeyboardLayoutOverride(m_groups[group]);
}

void
OSXKeyState::checkKeyboardLayout()
{
	// XXX -- should call this when notified that groups have changed.
	// if no notification for that then we should poll.
	GroupList groups;
	if (getGroups(groups) && groups != m_groups) {
		updateKeyMap();
		updateKeyState();
	}
}

void
OSXKeyState::adjustAltGrModifier(const KeyIDs& ids,
				KeyModifierMask* mask, bool isCommand) const
{
	if (!isCommand) {
		for (KeyIDs::const_iterator i = ids.begin(); i != ids.end(); ++i) {
			KeyID id = *i;
			if (id != kKeyNone &&
				((id < 0xe000u || id > 0xefffu) ||
				(id >= kKeyKP_Equal && id <= kKeyKP_9))) {
				*mask |= KeyModifierAltGr;
				return;
			}
		}
	}
}

KeyButton
OSXKeyState::mapVirtualKeyToKeyButton(UInt32 keyCode)
{
	// 'A' maps to 0 so shift every id
	return static_cast<KeyButton>(keyCode + KeyButtonOffset);
}

UInt32
OSXKeyState::mapKeyButtonToVirtualKey(KeyButton keyButton)
{
	return static_cast<UInt32>(keyButton - KeyButtonOffset);
}