GlobalKeyMap adds a 'keystroke' string to events

The keystroke is a string representation of the event... like
"alt-ctrl-x" or "q"

src/atom/global-keymap.coffee

@@ -18,6 +18,7 @@ class GlobalKeymap
     @bindKeys(selector, bindings)
 
   handleKeyEvent: (event) ->
+    event.keystroke = @keystrokeStringForEvent(event)
     currentNode = $(event.target)
     while currentNode.length
       candidateBindingSets = @bindingSets.filter (set) -> currentNode.is(set.selector)
@@ -33,14 +34,68 @@ class GlobalKeymap
     true
 
   reset: ->
-    @BindingSets = []
+    @bindingSets = []
 
   triggerCommandEvent: (keyEvent, commandName) ->
     commandEvent = $.Event(commandName)
-    keyEvent.char = @charForKeyEvent(keyEvent)
     commandEvent.keyEvent = keyEvent
     $(keyEvent.target).trigger(commandEvent)
 
-  charForKeyEvent: (keyEvent) ->
-    String.fromCharCode(keyEvent.which).toLowerCase()
+  keystrokeStringForEvent: (event) ->
+    if event.type is 'keypress'
+      char = String.fromCharCode event.which
+    else
+      char = @keyCodeToChar[event.which]
+
+    modifiers = ''
+    if event.altKey and char isnt 'alt'
+      modifiers += 'alt-'
+    if event.ctrlKey and char isnt 'ctrl'
+      modifiers += 'ctrl-'
+    if event.metaKey and char isnt 'meta'
+      modifiers += 'meta-'
+
+    if event.shiftKey
+      if event.type is 'keypress'
+        "#{modifiers}#{char}"
+      else if shiftChar = @shiftKeyCodeToChar[event.which]
+        "#{modifiers}#{shiftChar}"
+      else if char is 'shift'
+        "#{modifiers}shift"
+      else if (char)
+        "#{modifiers}shift-#{char}"
+      else
+        null
+    else if char
+      "#{modifiers}#{char}"
+    else
+      null
+
+  keyCodeToChar:
+    8: 'backspace', 9: 'tab', 13: 'enter', 16: 'shift', 17: 'ctrl',
+    18: 'alt', 19: 'pause', 20: 'capslock', 27: 'esc', 32: 'space',
+    33: 'pageup', 34: 'pagedown', 35: 'end', 36: 'home', 37: 'left',
+    38: 'up', 39: 'right', 40: 'down', 45: 'insert', 46: 'del',
+    48: '0', 49: '1', 50: '2', 51: '3', 52: '4', 53: '5', 54: '6',
+    55: '7', 56: '8', 57: '9', 65: 'a', 66: 'b', 67: 'c', 68: 'd',
+    69: 'e', 70: 'f', 71: 'g', 72: 'h', 73: 'i', 74: 'j', 75: 'k',
+    76: 'l', 77: 'm', 78: 'n', 79: 'o', 80: 'p', 81: 'q', 82: 'r',
+    83: 's', 84: 't', 85: 'u', 86: 'v', 87: 'w', 88: 'x', 89: 'y',
+    90: 'z', 91: 'meta', 93: 'meta', 96: '0', 97: '1', 98: '2',
+    99: '3', 100: '4', 101: '5', 102: '6', 103: '7', 104: '8',
+    105: '9', 106: '*', 107: '+', 109: '-', 110: '.', 111: '/',
+    112: 'f1', 113: 'f2', 114: 'f3', 115: 'f4', 116: 'f5', 117: 'f6',
+    118: 'f7', 119: 'f8', 120: 'f9', 121: 'f10', 122: 'f11',
+    123: 'f12', 144: 'numlock', 145: 'scroll', 186: ';', 187: '=',
+    188: ',', 189: '-', 190: '.', 191: '/', 192: '`', 219: '[',
+    220: '\\', 221: ']', 222: '\''
+
+  shiftKeyCodeToChar:
+    48: ')', 49: '!', 50: '@', 51: '#', 52: '$', 53: '%', 54: '^',
+    55: '&', 56: '*', 57: '(', 65: 'A', 66: 'B', 67: 'C', 68: 'D',
+    69: 'E', 70: 'F', 71: 'G', 72: 'H', 73: 'I', 74: 'J', 75: 'K',
+    76: 'L', 77: 'M', 78: 'N', 79: 'O', 80: 'P', 81: 'Q', 82: 'R',
+    83: 'S', 84: 'T', 85: 'U', 86: 'V', 87: 'W', 88: 'X', 89: 'Y',
+    90: 'Z', 186: ':', 187: '+', 188: '<', 189: '_', 190: '>',
+    191: '?', 192: '~', 219: '{', 220: '|', 221: '}', 222: '"'