Key bindings; more small tweaks.

1 files changed, 38 insertions, 28 deletions

diff --git a/content_scripts/mode_key_handler.coffee b/content_scripts/mode_key_handler.coffee
index 78ce3680..df177c4a 100644
--- a/content_scripts/mode_key_handler.coffee
+++ b/content_scripts/mode_key_handler.coffee
@@ -1,9 +1,26 @@
+# Example key mapping (@keyMapping):
+#   i:
+#     command: "enterInsertMode", ... # This is a registryEntry object (as too are the other commands).
+#   g:
+#     g:
+#       command: "scrollToTop", ...
+#     t:
+#       command: "nextTab", ...
+#
+# This key-mapping structure is generated by Commands.generateKeyStateMapping() and may be arbitrarily deep.
+# Observe that @keyMapping["g"] is itself also a valid key mapping.  At any point, the key state (@keyState)
+# consists of a (non-empty) list of such mappings.
 
 class KeyHandlerMode extends Mode
   keydownEvents: {}
   setKeyMapping: (@keyMapping) -> @reset()
   setPassKeys: (@passKeys) -> @reset()
 
+  # Reset the key state, optionally retaining the count provided.
+  reset: (@countPrefix = 0) ->
+    bgLog "Clearing key state, set count=#{@countPrefix}."
+    @keyState = [@keyMapping]
+
   constructor: (options) ->
     @commandHandler = options.commandHandler ? (->)
     @setKeyMapping options.keyMapping ? {}
@@ -17,22 +34,22 @@ class KeyHandlerMode extends Mode
 
   onKeydown: (event) ->
     keyChar = KeyboardUtils.getKeyCharString event
-    if KeyboardUtils.isEscape event
-      if @countPrefix == 0 and @keyState.length == 1
-        @continueBubbling
-      else
-        @keydownEvents[event.keyCode] = true
-        @reset()
-        false # Suppress event.
-    else if keyChar and @keyCharIsMapped keyChar
+    isEscape = KeyboardUtils.isEscape event
+    if isEscape and @countPrefix == 0 and @keyState.length == 1
+      @continueBubbling
+    else if isEscape
+      @keydownEvents[event.keyCode] = true
+      @reset()
+      false # Suppress event.
+    else if @keyCharIsMapped keyChar
       @unlessKeyCharIsPassKey keyChar, =>
         @keydownEvents[event.keyCode] = true
         @handleKeyChar event, keyChar
     else if keyChar
       @continueBubbling
     else if (keyChar = KeyboardUtils.getKeyChar event) and (@keyCharIsMapped(keyChar) or @isCountKey keyChar)
-      # It looks like we will be handling a subsequent keypress event, so suppress propagation of this event
-      # to prevent triggering page event listeners (e.g. Google instant Search).
+      # It looks like we will possibly be handling a subsequent keypress event, so suppress propagation of
+      # this event to prevent triggering page event listeners (e.g. Google instant Search).
       @unlessKeyCharIsPassKey keyChar, =>
         @keydownEvents[event.keyCode] = true
         DomUtils.suppressPropagation event
@@ -43,7 +60,7 @@ class KeyHandlerMode extends Mode
   onKeypress: (event) ->
     keyChar = KeyboardUtils.getKeyCharString event
     @unlessKeyCharIsPassKey keyChar, =>
-      if keyChar and @keyCharIsMapped keyChar
+      if @keyCharIsMapped keyChar
         @handleKeyChar event, keyChar
       else if @isCountKey keyChar
         digit = parseInt keyChar
@@ -61,35 +78,28 @@ class KeyHandlerMode extends Mode
     else
       @continueBubbling
 
+  # This tests whether there is a mapping of keyChar in the current key state.
+  keyCharIsMapped: (keyChar) ->
+    (mapping for mapping in @keyState when keyChar of mapping)[0]?
+
   handleKeyChar: (event, keyChar) ->
     bgLog "Handling key #{keyChar}, mode=#{@name}."
-    @advanceKeyState keyChar
-    command = (@keyState.filter (entry) -> entry.command)[0]
+    # Advance the key state.  The new key state is the current mappings of keyChar, plus @keyMapping.
+    @keyState = (mapping[keyChar] for mapping in @keyState when keyChar of mapping)
+    @keyState.push @keyMapping
+    command = (mapping for mapping in @keyState when mapping.command)[0]
     if command?
       count = if 0 < @countPrefix then @countPrefix else 1
-      @reset()
       bgLog "Calling mode=#{@name}, command=#{command.command}, count=#{count}."
+      @reset()
       @commandHandler {command, count}
     false # Suppress event.
 
-  keyCharIsMapped: (keyChar) ->
-    (mapping for mapping in @keyState when keyChar of mapping)[0]?
-
-  # The next key state is the current mappings matching keyChar plus @keyMapping.
-  advanceKeyState: (keyChar) ->
-    newMappings = (mapping[keyChar] for mapping in @keyState when keyChar of mapping)
-    @keyState = [newMappings..., @keyMapping]
-
-  # Reset the state (as if no keys had been handled), but optionally retaining the count provided.
-  reset: (@countPrefix = 0) ->
-    bgLog "Clearing key queue, set count=#{@countPrefix}."
-    @keyState = [@keyMapping]
-
   isCountKey: (keyChar) ->
     keyChar?.length == 1 and (if 0 < @countPrefix then '0' else '1') <= keyChar <= '9'
 
   # Keystrokes are *never* considered passKeys if the user has begun entering a command.  So, for example, if
-  # 't' is a passKey, then 'gt' and '99t' are neverthless handled as regular keys.
+  # 't' is a passKey, then the "t"-s of 'gt' and '99t' are neverthless handled as regular keys.
   unlessKeyCharIsPassKey: (keyChar, nonPassKeyCallback) ->
     if @countPrefix == 0 and @keyState.length == 1 and keyChar in (@passKeys ? "")
       @stopBubblingAndTrue