1 files changed, 70 insertions, 8 deletions
diff --git a/content_scripts/mode.coffee b/content_scripts/mode.coffee
index f7bf9e69..e4b6017c 100644
--- a/content_scripts/mode.coffee
+++ b/content_scripts/mode.coffee
@@ -1,12 +1,74 @@
-root = exports ? window
 
-class root.Mode
-  constructor: (onKeydown, onKeypress, onKeyup, @popModeCallback) ->
+class Mode
+  # Static members.
+  @modes: []
+  @current: -> Mode.modes[0]
+  @suppressPropagation = false
+  @propagate = true
+
+  # Default values.
+  name: ""             # The name of this mode.
+  badge: ""            # A badge to display on the popup when this mode is active.
+  keydown: "suppress"  # A function, or "suppress" or "pass"; the latter are replaced with suitable functions.
+  keypress: "suppress" # A function, or "suppress" or "pass"; the latter are replaced with suitable functions.
+  keyup: "suppress"    # A function, or "suppress" or "pass"; the latter are replaced with suitable functions.
+  onDeactivate: ->     # Called when leaving this mode.
+  onReactivate: ->     # Called when this mode is reactivated.
+
+  constructor: (options) ->
+    extend @, options
+
     @handlerId = handlerStack.push
-      keydown: onKeydown
-      keypress: onKeypress
-      keyup: onKeyup
+      keydown: @checkForBuiltInHandler "keydown", @keydown
+      keypress: @checkForBuiltInHandler "keypress", @keypress
+      keyup: @checkForBuiltInHandler "keyup", @keyup
+      reactivateMode: =>
+        @onReactivate()
+        Mode.setBadge()
+        return Mode.suppressPropagation
+
+    Mode.modes.unshift @
+    Mode.setBadge()
+
+  # Allow the strings "suppress" and "pass" to be used as proxies for the built-in handlers.
+  checkForBuiltInHandler: (type, handler) ->
+    switch handler
+      when "suppress" then @generateSuppressPropagation type
+      when "pass" then @generatePassThrough type
+      else handler
 
-  popMode: ->
+  # Generate a default handler which always passes through; except Esc, which pops the current mode.
+  generatePassThrough: (type) ->
+    me = @
+    (event) ->
+      if type == "keydown" and KeyboardUtils.isEscape event
+        me.popMode event
+        return Mode.suppressPropagation
+      handlerStack.passThrough
+
+  # Generate a default handler which always suppresses propagation; except Esc, which pops the current mode.
+  generateSuppressPropagation: (type) ->
+    handler = @generatePassThrough type
+    (event) -> handler(event) and Mode.suppressPropagation # Always falsy.
+
+  # Leave the current mode; event may or may not be provide.  It is the responsibility of the creator of this
+  # object to know whether or not an event will be provided.  Bubble a "reactivateMode" event to notify the
+  # now-active mode that it is once again top dog.
+  popMode: (event) ->
+    Mode.modes = Mode.modes.filter (mode) => mode != @
     handlerStack.remove @handlerId
-    @popModeCallback()
+    @onDeactivate event
+    handlerStack.bubbleEvent "reactivateMode", event
+
+  # Set the badge on the browser popup to indicate the current mode; static method.
+  @setBadge: ->
+    badge = Mode.getBadge()
+    chrome.runtime.sendMessage({ handler: "setBadge", badge: badge })
+
+  # Static convenience methods.
+  @is: (mode) -> Mode.current()?.name == mode
+  @getBadge: -> Mode.current()?.badge || ""
+  @isInsert: -> Mode.is "insert"
+
+root = exports ? window
+root.Mode = Mode