Suppress trailing key events (after link hints).

This ensures that -- on leaving link hints mode -- we consume any trailing keyup events (and don't let the underlying page see them).

Additional notes:

- There are other places where we seem to be leaking keyup events.

- A separate bug... It looks like we're calling `exit()` on link-hints
  mode twice.

2 files changed, 20 insertions, 0 deletions

diff --git a/content_scripts/link_hints.coffee b/content_scripts/link_hints.coffee
index a5e94fd0..cdd2dfac 100644
--- a/content_scripts/link_hints.coffee
+++ b/content_scripts/link_hints.coffee
@@ -69,6 +69,7 @@ class LinkHintsMode
       indicator: false
       passInitialKeyupEvents: true
       suppressAllKeyboardEvents: true
+      suppressTrailingKeyEvents: true
       exitOnEscape: true
       exitOnClick: true
       exitOnScroll: true
diff --git a/content_scripts/mode.coffee b/content_scripts/mode.coffee
index 508b1b2c..49da03e2 100644
--- a/content_scripts/mode.coffee
+++ b/content_scripts/mode.coffee
@@ -144,6 +144,25 @@ class Mode
         keyup: (event) =>
           if KeyboardUtils.isPrintable event then @stopBubblingAndFalse else @stopBubblingAndTrue
 
+    # if @options.suppressTrailingKeyEvents is set, then we suppress all key events until a subsquent
+    # (non-repeat) keydown or keypress.  In particular, the intention is to catch keyup events for keys which
+    # we have handled, but which otherwise might trigger page actions (if the page is listening for keyup
+    # events).
+    if @options.suppressTrailingKeyEvents
+      @onExit ->
+        handler = (event) ->
+          if event.repeat
+            false # Suppress event.
+          else
+            keyEventSuppressor.exit()
+            true # Do not suppress event.
+
+        keyEventSuppressor = new Mode
+          name: "suppress-trailing-key-events"
+          keydown: handler
+          keypress: handler
+          keyup: -> handlerStack.stopBubblingAndFalse
+
     Mode.modes.push @
     @setIndicator()
     @logModes()