Document named key functions (per philc)

2 files changed, 16 insertions, 3 deletions

diff --git a/background_page.html b/background_page.html
index 9e43fecd..0f923869 100644
--- a/background_page.html
+++ b/background_page.html
@@ -15,7 +15,9 @@
   var validFirstKeys = {};
   var singleKeyCommands = [];
 
-  var namedKeyRegex = /^(<[amc-].|(?:[amc]-)?[a-z]{2,5}>)(.*)$/;
+  // Keys are either literal characters, or "named" - for example <a-b> (alt+b), <left> (the left arrow) or <f12>
+  // This regular expression captures two groups, the first is a named key, the second is the remainder of the string.
+  var namedKeyRegex = /^(<[amc-].|(?:[amc]-)?[a-z0-9]{2,5}>)(.*)$/;
 
   var defaultSettings = {
     scrollStepSize: 60,
diff --git a/commands.js b/commands.js
index 8e4922f3..de6ce701 100644
--- a/commands.js
+++ b/commands.js
@@ -23,9 +23,20 @@ function mapKeyToCommand(key, command) {
 
 function unmapKey(key) { delete keyToCommandRegistry[key]; }
 
+/* Lower-case the appropriate portions of named keys.
+ *
+ * A key name is one of three forms exemplified by <c-a> <left> or <c-f12>
+ * (prefixed normal key, named key, or prefixed named key). Internally, for
+ * simplicity, we would like prefixes and key names to be lowercase, though
+ * humans may prefer other forms <Left> or <C-a>.
+ * On the other hand, <c-a> and <c-A> are different named keys - for one of
+ * them you have to press "shift" as well.
+ */
 function normalizeKey(key) {
-    return key.replace(/<[amc]-/i, function(m){return m.toLowerCase();})
-              .replace(/<([acm]-)?([a-zA-Z0-9]+)>/, function(m, p, k){return "<" + (p ? p : "") + k.toLowerCase() + ">";});
+    return key.replace(/<[acm]-/ig, function(match){ return match.toLowerCase(); })
+              .replace(/<([acm]-)?([a-zA-Z0-9]{2,5})>/g, function(match, optionalPrefix, keyName){
+                  return "<" + ( optionalPrefix ? optionalPrefix : "") + keyName.toLowerCase() + ">";
+              });
 }
 
 function parseCustomKeyMappings(customKeyMappings) {