1 files changed, 66 insertions, 0 deletions
diff --git a/lib/keyboard_utils.js b/lib/keyboard_utils.js
new file mode 100644
index 00000000..52544c73
--- /dev/null
+++ b/lib/keyboard_utils.js
@@ -0,0 +1,66 @@
+var keyCodes = {
+  ESC: 27, backspace: 8, deleteKey: 46, enter: 13, space: 32, shiftKey: 16, f1: 112, f12: 123, tab: 9
+};
+var keyNames = { 37: "left", 38: "up", 39: "right", 40: "down" }
+
+// This is a mapping of the incorrect keyIdentifiers generated by Webkit on Windows during keydown events to
+// the correct identifiers, which are correctly generated on Mac. We require this mapping to properly handle
+// these keys on Windows. See https://bugs.webkit.org/show_bug.cgi?id=19906 for more details.
+var keyIdentifierCorrectionMap = {
+  "U+00C0": ["U+0060", "U+007E"], // `~
+  "U+00BD": ["U+002D", "U+005F"], // -_
+  "U+00BB": ["U+003D", "U+002B"], // =+
+  "U+00DB": ["U+005B", "U+007B"], // [{
+  "U+00DD": ["U+005D", "U+007D"], // ]}
+  "U+00DC": ["U+005C", "U+007C"], // \|
+  "U+00BA": ["U+003B", "U+003A"], // ;:
+  "U+00DE": ["U+0027", "U+0022"], // '"
+  "U+00BC": ["U+002C", "U+003C"], // ,<
+  "U+00BE": ["U+002E", "U+003E"], // .>
+  "U+00BF": ["U+002F", "U+003F"] // /?
+};
+
+var platform;
+if (navigator.userAgent.indexOf("Mac") != -1)
+  platform = "Mac";
+else if (navigator.userAgent.indexOf("Linux") != -1)
+  platform = "Linux";
+else
+  platform = "Windows";
+
+function getKeyChar(event) {
+    // Not a letter
+    if (event.keyIdentifier.slice(0, 2) != "U+") {
+        // Named key
+        if (keyNames[event.keyCode]) {
+          return keyNames[event.keyCode];
+        }
+        // F-key
+        if (event.keyCode >= keyCodes.f1 && event.keyCode <= keyCodes.f12) {
+          return "f" + (1 + event.keyCode - keyCodes.f1);
+        }
+        return "";
+    }
+    var keyIdentifier = event.keyIdentifier;
+    // On Windows, the keyIdentifiers for non-letter keys are incorrect. See
+    // https://bugs.webkit.org/show_bug.cgi?id=19906 for more details.
+    if ((platform == "Windows" || platform == "Linux") && keyIdentifierCorrectionMap[keyIdentifier]) {
+      correctedIdentifiers = keyIdentifierCorrectionMap[keyIdentifier];
+      keyIdentifier = event.shiftKey ? correctedIdentifiers[1] : correctedIdentifiers[0];
+    }
+    var unicodeKeyInHex = "0x" + keyIdentifier.substring(2);
+    var character = String.fromCharCode(parseInt(unicodeKeyInHex)).toLowerCase();
+    return event.shiftKey ? character.toUpperCase() : character;
+}
+
+function isPrimaryModifierKey(event) {
+  if (platform == "Mac")
+    return event.metaKey;
+  else
+    return event.ctrlKey;
+}
+
+function isEscape(event) {
+  return event.keyCode == keyCodes.ESC ||
+    (event.ctrlKey && getKeyChar(event) == '['); // c-[ is mapped to ESC in Vim by default.
+}