From ac90db47aa2671cd663cc6a9cdf783dc30a582e9 Mon Sep 17 00:00:00 2001
From: Stephen Blott
Date: Sat, 10 Jan 2015 00:00:11 +0000
Subject: Modes; more changes...

- Better comments.
- Strip unnecessary handlers for leaving post-find mode.
- Simplify passKeys.
- focusInput now re-bubbles its triggering keydown event.
---
 lib/handler_stack.coffee | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

(limited to 'lib')

diff --git a/lib/handler_stack.coffee b/lib/handler_stack.coffee
index 97e189c5..44c7538b 100644
--- a/lib/handler_stack.coffee
+++ b/lib/handler_stack.coffee
@@ -14,6 +14,11 @@ class HandlerStack
     # processing should take place.
     @stopBubblingAndFalse = new Object()
 
+    # A handler should return this value to indicate that bubbling should be restarted.  Typically, this is
+    # used when, while bubbling an event, a new mode is pushed onto the stack.  See `focusInput` for an
+    # example.
+    @restartBubbling = new Object()
+
   # Adds a handler to the top of the stack. Returns a unique ID for that handler that can be used to remove it
   # later.
   push: (handler) ->
@@ -30,30 +35,26 @@ class HandlerStack
   # event's propagation by returning a falsy value, or stop bubbling by returning @stopBubblingAndFalse or
   # @stopBubblingAndTrue.
   bubbleEvent: (type, event) ->
-    # extra is passed to each handler.  This allows handlers to pass information down the stack.
-    extra = {}
-    # We take a copy of the array, here, in order to avoid interference from concurrent removes (for example,
-    # to avoid calling the same handler twice).
+    # We take a copy of the array in order to avoid interference from concurrent removes (for example, to
+    # avoid calling the same handler twice, because elements have been spliced out of the array by remove).
     for handler in @stack[..].reverse()
-      # A handler may have been removed (handler.id == null).
-      if handler and handler.id
+      # A handler may have been removed (handler.id == null), so check.
+      if handler?.id and handler[type]
         @currentId = handler.id
-        # A handler can register a handler for type "all", which will be invoked on all events.  Such an "all"
-        # handler will be invoked first.
-        for func in [ handler.all, handler[type] ]
-          if func
-            passThrough = func.call @, event, extra
-            if not passThrough
-              DomUtils.suppressEvent(event) if @isChromeEvent event
-              return false
-            return true if passThrough == @stopBubblingAndTrue
-            return false if passThrough == @stopBubblingAndFalse
+        result = handler[type].call @, event
+        if not result
+          DomUtils.suppressEvent(event) if @isChromeEvent event
+          return false
+        return true if result == @stopBubblingAndTrue
+        return false if result == @stopBubblingAndFalse
+        return @bubbleEvent type, event if result == @restartBubbling
     true
 
   remove: (id = @currentId) ->
     for i in [(@stack.length - 1)..0] by -1
       handler = @stack[i]
       if handler.id == id
+        # Mark the handler as removed.
         handler.id = null
         @stack.splice(i, 1)
         break
@@ -63,7 +64,9 @@ class HandlerStack
   isChromeEvent: (event) ->
     event?.preventDefault? or event?.stopImmediatePropagation?
 
-  # Convenience wrappers.
+  # Convenience wrappers.  Handlers must return an approriate value.  These are wrappers which handlers can
+  # use to always return the same value.  This then means that the handler itself can be implemented without
+  # regard to its return value.
   alwaysContinueBubbling: (handler) ->
     handler()
     true
-- 
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