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March 17, 2016 13:50
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Workaround for locale problems
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var kbdUtil = (function() { | |
"use strict"; | |
function substituteCodepoint(cp) { | |
// Any Unicode code points which do not have corresponding keysym entries | |
// can be swapped out for another code point by adding them to this table | |
var substitutions = { | |
// {S,s} with comma below -> {S,s} with cedilla | |
0x218 : 0x15e, | |
0x219 : 0x15f, | |
// {T,t} with comma below -> {T,t} with cedilla | |
0x21a : 0x162, | |
0x21b : 0x163 | |
}; | |
var sub = substitutions[cp]; | |
return sub ? sub : cp; | |
} | |
function isMac() { | |
return navigator && !!(/mac/i).exec(navigator.platform); | |
} | |
function isWindows() { | |
return navigator && !!(/win/i).exec(navigator.platform); | |
} | |
function isLinux() { | |
return navigator && !!(/linux/i).exec(navigator.platform); | |
} | |
// Return true if a modifier which is not the specified char modifier (and is not shift) is down | |
function hasShortcutModifier(charModifier, currentModifiers) { | |
var mods = {}; | |
for (var key in currentModifiers) { | |
if (parseInt(key) !== XK_Shift_L) { | |
mods[key] = currentModifiers[key]; | |
} | |
} | |
var sum = 0; | |
for (var k in currentModifiers) { | |
if (mods[k]) { | |
++sum; | |
} | |
} | |
if (hasCharModifier(charModifier, mods)) { | |
return sum > charModifier.length; | |
} | |
else { | |
return sum > 0; | |
} | |
} | |
// Return true if the specified char modifier is currently down | |
function hasCharModifier(charModifier, currentModifiers) { | |
if (charModifier.length === 0) { return false; } | |
for (var i = 0; i < charModifier.length; ++i) { | |
if (!currentModifiers[charModifier[i]]) { | |
return false; | |
} | |
} | |
return true; | |
} | |
// Helper object tracking modifier key state | |
// and generates fake key events to compensate if it gets out of sync | |
function ModifierSync(charModifier) { | |
if (!charModifier) { | |
if (isMac()) { | |
// on Mac, Option (AKA Alt) is used as a char modifier | |
charModifier = [XK_Alt_L]; | |
} | |
else if (isWindows()) { | |
// on Windows, Ctrl+Alt is used as a char modifier | |
charModifier = [XK_Alt_L, XK_Control_L]; | |
} | |
else if (isLinux()) { | |
// on Linux, ISO Level 3 Shift (AltGr) is used as a char modifier | |
charModifier = [XK_ISO_Level3_Shift]; | |
} | |
else { | |
charModifier = []; | |
} | |
} | |
var state = {}; | |
state[XK_Control_L] = false; | |
state[XK_Alt_L] = false; | |
state[XK_ISO_Level3_Shift] = false; | |
state[XK_Shift_L] = false; | |
state[XK_Meta_L] = false; | |
function sync(evt, keysym) { | |
var result = []; | |
function syncKey(keysym) { | |
return {keysym: keysyms.lookup(keysym), type: state[keysym] ? 'keydown' : 'keyup'}; | |
} | |
if (evt.ctrlKey !== undefined && | |
evt.ctrlKey !== state[XK_Control_L] && keysym !== XK_Control_L) { | |
state[XK_Control_L] = evt.ctrlKey; | |
result.push(syncKey(XK_Control_L)); | |
} | |
if (evt.altKey !== undefined && | |
evt.altKey !== state[XK_Alt_L] && keysym !== XK_Alt_L) { | |
state[XK_Alt_L] = evt.altKey; | |
result.push(syncKey(XK_Alt_L)); | |
} | |
if (evt.altGraphKey !== undefined && | |
evt.altGraphKey !== state[XK_ISO_Level3_Shift] && keysym !== XK_ISO_Level3_Shift) { | |
state[XK_ISO_Level3_Shift] = evt.altGraphKey; | |
result.push(syncKey(XK_ISO_Level3_Shift)); | |
} | |
if (evt.shiftKey !== undefined && | |
evt.shiftKey !== state[XK_Shift_L] && keysym !== XK_Shift_L) { | |
state[XK_Shift_L] = evt.shiftKey; | |
result.push(syncKey(XK_Shift_L)); | |
} | |
if (evt.metaKey !== undefined && | |
evt.metaKey !== state[XK_Meta_L] && keysym !== XK_Meta_L) { | |
state[XK_Meta_L] = evt.metaKey; | |
result.push(syncKey(XK_Meta_L)); | |
} | |
return result; | |
} | |
function syncKeyEvent(evt, down) { | |
var obj = getKeysym(evt); | |
var keysym = obj ? obj.keysym : null; | |
// first, apply the event itself, if relevant | |
if (keysym !== null && state[keysym] !== undefined) { | |
state[keysym] = down; | |
} | |
return sync(evt, keysym); | |
} | |
return { | |
// sync on the appropriate keyboard event | |
keydown: function(evt) { return syncKeyEvent(evt, true);}, | |
keyup: function(evt) { return syncKeyEvent(evt, false);}, | |
// Call this with a non-keyboard event (such as mouse events) to use its modifier state to synchronize anyway | |
syncAny: function(evt) { return sync(evt);}, | |
// is a shortcut modifier down? | |
hasShortcutModifier: function() { return hasShortcutModifier(charModifier, state); }, | |
// if a char modifier is down, return the keys it consists of, otherwise return null | |
activeCharModifier: function() { return hasCharModifier(charModifier, state) ? charModifier : null; } | |
}; | |
} | |
// Get a key ID from a keyboard event | |
// May be a string or an integer depending on the available properties | |
function getKey(evt){ | |
if ('keyCode' in evt && 'key' in evt) { | |
//return evt.key + ':' + evt.keyCode; | |
return evt.keyCode; | |
} | |
else if ('keyCode' in evt) { | |
return evt.keyCode; | |
} | |
else { | |
return evt.key; | |
} | |
} | |
// Get the most reliable keysym value we can get from a key event | |
// if char/charCode is available, prefer those, otherwise fall back to key/keyCode/which | |
function getKeysym(evt){ | |
var codepoint; | |
if (evt.char && evt.char.length === 1) { | |
codepoint = evt.char.charCodeAt(); | |
} | |
else if (evt.charCode) { | |
codepoint = evt.charCode; | |
} | |
else if (evt.keyCode && evt.type === 'keypress') { | |
// IE10 stores the char code as keyCode, and has no other useful properties | |
codepoint = evt.keyCode; | |
} | |
if (codepoint) { | |
var res = keysyms.fromUnicode(substituteCodepoint(codepoint)); | |
if (res) { | |
return res; | |
} | |
} | |
// we could check evt.key here. | |
// Legal values are defined in http://www.w3.org/TR/DOM-Level-3-Events/#key-values-list, | |
// so we "just" need to map them to keysym, but AFAIK this is only available in IE10, which also provides evt.key | |
// so we don't *need* it yet | |
if (evt.keyCode) { | |
return keysyms.lookup(keysymFromKeyCode(evt.keyCode, evt.shiftKey)); | |
} | |
if (evt.which) { | |
return keysyms.lookup(keysymFromKeyCode(evt.which, evt.shiftKey)); | |
} | |
return null; | |
} | |
// Given a keycode, try to predict which keysym it might be. | |
// If the keycode is unknown, null is returned. | |
function keysymFromKeyCode(keycode, shiftPressed) { | |
if (typeof(keycode) !== 'number') { | |
return null; | |
} | |
// won't be accurate for azerty | |
if (keycode >= 0x30 && keycode <= 0x39) { | |
return keycode; // digit | |
} | |
if (keycode >= 0x41 && keycode <= 0x5a) { | |
// remap to lowercase unless shift is down | |
return shiftPressed ? keycode : keycode + 32; // A-Z | |
} | |
if (keycode >= 0x60 && keycode <= 0x69) { | |
return XK_KP_0 + (keycode - 0x60); // numpad 0-9 | |
} | |
switch(keycode) { | |
case 0x20: return XK_space; | |
case 0x6a: return XK_KP_Multiply; | |
case 0x6b: return XK_KP_Add; | |
case 0x6c: return XK_KP_Separator; | |
case 0x6d: return XK_KP_Subtract; | |
case 0x6e: return XK_KP_Decimal; | |
case 0x6f: return XK_KP_Divide; | |
case 0xbb: return XK_plus; | |
case 0xbc: return XK_comma; | |
case 0xbd: return XK_minus; | |
case 0xbe: return XK_period; | |
} | |
return nonCharacterKey({keyCode: keycode}); | |
} | |
// if the key is a known non-character key (any key which doesn't generate character data) | |
// return its keysym value. Otherwise return null | |
function nonCharacterKey(evt) { | |
// evt.key not implemented yet | |
if (!evt.keyCode) { return null; } | |
var keycode = evt.keyCode; | |
if (keycode >= 0x70 && keycode <= 0x87) { | |
return XK_F1 + keycode - 0x70; // F1-F24 | |
} | |
switch (keycode) { | |
case 8 : return XK_BackSpace; | |
case 13 : return XK_Return; | |
case 9 : return XK_Tab; | |
case 27 : return XK_Escape; | |
case 46 : return XK_Delete; | |
case 36 : return XK_Home; | |
case 35 : return XK_End; | |
case 33 : return XK_Page_Up; | |
case 34 : return XK_Page_Down; | |
case 45 : return XK_Insert; | |
case 37 : return XK_Left; | |
case 38 : return XK_Up; | |
case 39 : return XK_Right; | |
case 40 : return XK_Down; | |
case 16 : return XK_Shift_L; | |
case 17 : return XK_Control_L; | |
case 18 : return XK_Alt_L; // also: Option-key on Mac | |
case 224 : return XK_Meta_L; | |
case 225 : return XK_ISO_Level3_Shift; // AltGr | |
case 91 : return XK_Super_L; // also: Windows-key | |
case 92 : return XK_Super_R; // also: Windows-key | |
case 93 : return XK_Menu; // also: Windows-Menu, Command on Mac | |
default: return null; | |
} | |
} | |
return { | |
hasShortcutModifier : hasShortcutModifier, | |
hasCharModifier : hasCharModifier, | |
ModifierSync : ModifierSync, | |
getKey : getKey, | |
getKeysym : getKeysym, | |
keysymFromKeyCode : keysymFromKeyCode, | |
nonCharacterKey : nonCharacterKey, | |
substituteCodepoint : substituteCodepoint | |
}; | |
})(); | |
// Takes a DOM keyboard event and: | |
// - determines which keysym it represents | |
// - determines a keyId identifying the key that was pressed (corresponding to the key/keyCode properties on the DOM event) | |
// - synthesizes events to synchronize modifier key state between which modifiers are actually down, and which we thought were down | |
// - marks each event with an 'escape' property if a modifier was down which should be "escaped" | |
// - generates a "stall" event in cases where it might be necessary to wait and see if a keypress event follows a keydown | |
// This information is collected into an object which is passed to the next() function. (one call per event) | |
function KeyEventDecoder(modifierState, next) { | |
"use strict"; | |
function sendAll(evts) { | |
for (var i = 0; i < evts.length; ++i) { | |
next(evts[i]); | |
} | |
} | |
function process(evt, type) { | |
var result = {type: type}; | |
var keyId = kbdUtil.getKey(evt); | |
if (keyId) { | |
result.keyId = keyId; | |
} | |
var keysym = kbdUtil.getKeysym(evt); | |
var hasModifier = modifierState.hasShortcutModifier() || !!modifierState.activeCharModifier(); | |
// Is this a case where we have to decide on the keysym right away, rather than waiting for the keypress? | |
// "special" keys like enter, tab or backspace don't send keypress events, | |
// and some browsers don't send keypresses at all if a modifier is down | |
if (keysym && (type !== 'keydown' || kbdUtil.nonCharacterKey(evt) || hasModifier)) { | |
result.keysym = keysym; | |
} | |
var isShift = evt.keyCode === 0x10 || evt.key === 'Shift'; | |
// Should we prevent the browser from handling the event? | |
// Doing so on a keydown (in most browsers) prevents keypress from being generated | |
// so only do that if we have to. | |
var suppress = !isShift && (type !== 'keydown' || modifierState.hasShortcutModifier() || !!kbdUtil.nonCharacterKey(evt)); | |
// If a char modifier is down on a keydown, we need to insert a stall, | |
// so VerifyCharModifier knows to wait and see if a keypress is comnig | |
var stall = type === 'keydown' && modifierState.activeCharModifier() && !kbdUtil.nonCharacterKey(evt); | |
// if a char modifier is pressed, get the keys it consists of (on Windows, AltGr is equivalent to Ctrl+Alt) | |
var active = modifierState.activeCharModifier(); | |
// If we have a char modifier down, and we're able to determine a keysym reliably | |
// then (a) we know to treat the modifier as a char modifier, | |
// and (b) we'll have to "escape" the modifier to undo the modifier when sending the char. | |
if (active && keysym) { | |
var isCharModifier = false; | |
for (var i = 0; i < active.length; ++i) { | |
if (active[i] === keysym.keysym) { | |
isCharModifier = true; | |
} | |
} | |
if (type === 'keypress' && !isCharModifier) { | |
result.escape = modifierState.activeCharModifier(); | |
} | |
} | |
if (stall) { | |
// insert a fake "stall" event | |
next({type: 'stall'}); | |
} | |
next(result); | |
return suppress; | |
} | |
return { | |
keydown: function(evt) { | |
sendAll(modifierState.keydown(evt)); | |
return process(evt, 'keydown'); | |
}, | |
keypress: function(evt) { | |
return process(evt, 'keypress'); | |
}, | |
keyup: function(evt) { | |
sendAll(modifierState.keyup(evt)); | |
return process(evt, 'keyup'); | |
}, | |
syncModifiers: function(evt) { | |
sendAll(modifierState.syncAny(evt)); | |
}, | |
releaseAll: function() { next({type: 'releaseall'}); } | |
}; | |
} | |
// Combines keydown and keypress events where necessary to handle char modifiers. | |
// On some OS'es, a char modifier is sometimes used as a shortcut modifier. | |
// For example, on Windows, AltGr is synonymous with Ctrl-Alt. On a Danish keyboard layout, AltGr-2 yields a @, but Ctrl-Alt-D does nothing | |
// so when used with the '2' key, Ctrl-Alt counts as a char modifier (and should be escaped), but when used with 'D', it does not. | |
// The only way we can distinguish these cases is to wait and see if a keypress event arrives | |
// When we receive a "stall" event, wait a few ms before processing the next keydown. If a keypress has also arrived, merge the two | |
function VerifyCharModifier(next) { | |
"use strict"; | |
var queue = []; | |
var timer = null; | |
function process() { | |
if (timer) { | |
return; | |
} | |
var delayProcess = function () { | |
clearTimeout(timer); | |
timer = null; | |
process(); | |
}; | |
while (queue.length !== 0) { | |
var cur = queue[0]; | |
queue = queue.splice(1); | |
switch (cur.type) { | |
case 'stall': | |
// insert a delay before processing available events. | |
/* jshint loopfunc: true */ | |
timer = setTimeout(delayProcess, 5); | |
/* jshint loopfunc: false */ | |
return; | |
case 'keydown': | |
// is the next element a keypress? Then we should merge the two | |
if (queue.length !== 0 && queue[0].type === 'keypress') { | |
// Firefox sends keypress even when no char is generated. | |
// so, if keypress keysym is the same as we'd have guessed from keydown, | |
// the modifier didn't have any effect, and should not be escaped | |
if (queue[0].escape && (!cur.keysym || cur.keysym.keysym !== queue[0].keysym.keysym)) { | |
cur.escape = queue[0].escape; | |
} | |
cur.keysym = queue[0].keysym; | |
queue = queue.splice(1); | |
} | |
break; | |
} | |
// swallow stall events, and pass all others to the next stage | |
if (cur.type !== 'stall') { | |
next(cur); | |
} | |
} | |
} | |
return function(evt) { | |
queue.push(evt); | |
process(); | |
}; | |
} | |
// Keeps track of which keys we (and the server) believe are down | |
// When a keyup is received, match it against this list, to determine the corresponding keysym(s) | |
// in some cases, a single key may produce multiple keysyms, so the corresponding keyup event must release all of these chars | |
// key repeat events should be merged into a single entry. | |
// Because we can't always identify which entry a keydown or keyup event corresponds to, we sometimes have to guess | |
function TrackKeyState(next) { | |
"use strict"; | |
var state = []; | |
return function (evt) { | |
var last = state.length !== 0 ? state[state.length-1] : null; | |
switch (evt.type) { | |
case 'keydown': | |
// insert a new entry if last seen key was different. | |
if (!last || !evt.keyId || last.keyId !== evt.keyId) { | |
last = {keyId: evt.keyId, keysyms: {}}; | |
state.push(last); | |
} | |
if (evt.keysym) { | |
// make sure last event contains this keysym (a single "logical" keyevent | |
// can cause multiple key events to be sent to the VNC server) | |
last.keysyms[evt.keysym.keysym] = evt.keysym; | |
last.ignoreKeyPress = true; | |
next(evt); | |
} | |
break; | |
case 'keypress': | |
if (!last) { | |
last = {keyId: evt.keyId, keysyms: {}}; | |
state.push(last); | |
} | |
if (!evt.keysym) { | |
console.log('keypress with no keysym:', evt); | |
} | |
if (evt.keyId > 0x400) { | |
evt.keysym.keysym = last.keyId; | |
} | |
// If we didn't expect a keypress, and already sent a keydown to the VNC server | |
// based on the keydown, make sure to skip this event. | |
if (evt.keysym && !last.ignoreKeyPress) { | |
last.keysyms[evt.keysym.keysym] = evt.keysym; | |
evt.type = 'keydown'; | |
next(evt); | |
} | |
break; | |
case 'keyup': | |
if (state.length === 0) { | |
return; | |
} | |
var idx = null; | |
// do we have a matching key tracked as being down? | |
for (var i = 0; i !== state.length; ++i) { | |
if (state[i].keyId === evt.keyId) { | |
idx = i; | |
break; | |
} | |
} | |
// if we couldn't find a match (it happens), assume it was the last key pressed | |
if (idx === null) { | |
idx = state.length - 1; | |
} | |
var item = state.splice(idx, 1)[0]; | |
// for each keysym tracked by this key entry, clone the current event and override the keysym | |
var clone = (function(){ | |
function Clone(){} | |
return function (obj) { Clone.prototype=obj; return new Clone(); }; | |
}()); | |
for (var key in item.keysyms) { | |
var out = clone(evt); | |
out.keysym = item.keysyms[key]; | |
next(out); | |
} | |
break; | |
case 'releaseall': | |
/* jshint shadow: true */ | |
for (var i = 0; i < state.length; ++i) { | |
for (var key in state[i].keysyms) { | |
var keysym = state[i].keysyms[key]; | |
next({keyId: 0, keysym: keysym, type: 'keyup'}); | |
} | |
} | |
/* jshint shadow: false */ | |
state = []; | |
} | |
}; | |
} | |
// Handles "escaping" of modifiers: if a char modifier is used to produce a keysym (such as AltGr-2 to generate an @), | |
// then the modifier must be "undone" before sending the @, and "redone" afterwards. | |
function EscapeModifiers(next) { | |
"use strict"; | |
return function(evt) { | |
if (evt.type !== 'keydown' || evt.escape === undefined) { | |
next(evt); | |
return; | |
} | |
// undo modifiers | |
for (var i = 0; i < evt.escape.length; ++i) { | |
next({type: 'keyup', keyId: 0, keysym: keysyms.lookup(evt.escape[i])}); | |
} | |
// send the character event | |
next(evt); | |
// redo modifiers | |
/* jshint shadow: true */ | |
for (var i = 0; i < evt.escape.length; ++i) { | |
next({type: 'keydown', keyId: 0, keysym: keysyms.lookup(evt.escape[i])}); | |
} | |
/* jshint shadow: false */ | |
}; | |
} |
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