Activate vomnibar in window.top; no flicker and tidy up.

1. Rework event handling to eliminate frame flicker (a la #1485).
2. Tidy up logic.  Which should make this more robust.

5 files changed, 36 insertions, 16 deletions

diff --git a/background_scripts/main.coffee b/background_scripts/main.coffee
index a64c7e37..0c7d9343 100644
--- a/background_scripts/main.coffee
+++ b/background_scripts/main.coffee
@@ -658,7 +658,7 @@ handleFrameFocused = (request, sender) ->
     frameIdsForTab[tabId] =
       [request.frameId, (frameIdsForTab[tabId].filter (id) -> id != request.frameId)...]
   # Inform all frames that a frame has received the focus.
-  chrome.tabs.sendMessage sender.tab.id, 
+  chrome.tabs.sendMessage sender.tab.id,
     name: "frameFocused"
     focusFrameId: request.frameId
 
diff --git a/content_scripts/ui_component.coffee b/content_scripts/ui_component.coffee
index ee74c3a8..ea0bf776 100644
--- a/content_scripts/ui_component.coffee
+++ b/content_scripts/ui_component.coffee
@@ -55,7 +55,7 @@ class UIComponent
     @showing = true
 
   hide: (focusWindow = true)->
-    @refocusSourceFrame @options?.sourceFrameId if focusWindow and @options?.sourceFrameId?
+    @refocusSourceFrame @options?.sourceFrameId if focusWindow
     window.removeEventListener "focus", @onFocus if @onFocus
     @onFocus = null
     @iframeElement.classList.remove "vimiumUIComponentShowing"
@@ -63,14 +63,13 @@ class UIComponent
     @options = null
     @showing = false
 
-  # Refocus the frame from which the UI component was opened.
+  # Refocus the frame from which the UI component was opened.  This may be different from the current frame.
   # After hiding the UI component, Chrome refocuses the containing frame. To avoid a race condition, we need
-  # to wait until that frame receives the focus, before then focusing the frame which should now have the
-  # focus.
+  # to wait until that frame first receives the focus, before then focusing the frame which should now have
+  # the focus.
   refocusSourceFrame: (sourceFrameId) ->
-    window.addEventListener "focus", handler = (event) ->
-      if event.target == window
-        window.removeEventListener "focus", handler
+    if @showing and sourceFrameId? and sourceFrameId != frameId
+      refocusSourceFrame = ->
         chrome.runtime.sendMessage
           handler: "sendMessageToFrames"
           message:
@@ -79,5 +78,15 @@ class UIComponent
             highlight: false
             highlightOnlyIfNotTop: true
 
+      if windowIsFocused() and false
+        # We already have the focus.
+        refocusSourceFrame()
+      else
+        # We don't yet have the focus (but we'll be getting it soon).
+        window.addEventListener "focus", handler = (event) ->
+          if event.target == window
+            window.removeEventListener "focus", handler
+            refocusSourceFrame()
+
 root = exports ? window
 root.UIComponent = UIComponent
diff --git a/content_scripts/vimium_frontend.coffee b/content_scripts/vimium_frontend.coffee
index c5bc185f..931b8edf 100644
--- a/content_scripts/vimium_frontend.coffee
+++ b/content_scripts/vimium_frontend.coffee
@@ -19,6 +19,13 @@ keyQueue = null
 currentCompletionKeys = ""
 validFirstKeys = ""
 
+# We track whther the current window has the focus or not.
+windowIsFocused = do ->
+  windowHasFocus = document.hasFocus()
+  window.addEventListener "focus", (event) -> windowHasFocus = true if event.target == window; true
+  window.addEventListener "blur", (event) -> windowHasFocus = false if event.target == window; true
+  -> windowHasFocus
+
 # The types in <input type="..."> that we consider for focusInput command. Right now this is recalculated in
 # each content script. Alternatively we could calculate it once in the background page and use a request to
 # fetch it each time.
@@ -192,7 +199,7 @@ initializePreDomReady = ->
     # We handle the message if we're enabled, or if it's one of these listed message types.
     return unless isEnabledForUrl or request.name in [ "getActiveState", "setState", "executePageCommand" ]
     # These requests are delivered to the options page, but there are no handlers there.
-    return if request.handler in [ "registerFrame", "frameFocused", "unregisterFrame" ]
+    return if request.handler in [ "registerFrame", "unregisterFrame" ]
     # We don't handle these here.  They're handled elsewhere (e.g. in the vomnibar/UI component).
     return if request.name in [ "frameFocused" ]
     # Handle the request.
@@ -1245,4 +1252,5 @@ root.settings = settings
 root.HUD = HUD
 root.handlerStack = handlerStack
 root.frameId = frameId
+root.windowIsFocused = windowIsFocused
 root.bgLog = bgLog
diff --git a/content_scripts/vomnibar.coffee b/content_scripts/vomnibar.coffee
index 3d54e643..2529c077 100644
--- a/content_scripts/vomnibar.coffee
+++ b/content_scripts/vomnibar.coffee
@@ -40,9 +40,11 @@ Vomnibar =
   init: ->
     unless @vomnibarUI?
       @vomnibarUI = new UIComponent "pages/vomnibar.html", "vomnibarFrame", (event) =>
-        if event.data == "hide"
-          @vomnibarUI.hide()
-          @vomnibarUI.postMessage "hidden"
+        @vomnibarUI.hide() if event.data == "hide"
+      # Whenever the window receives the focus, we tell the Vomnibar UI that it has been hidden (regardless of
+      # whether it was previously visible).
+      window.addEventListener "focus", (event) =>
+        @vomnibarUI.postMessage "hidden" if event.target == window; true
 
 
   # This function opens the vomnibar. It accepts options, a map with the values:
diff --git a/pages/vomnibar.coffee b/pages/vomnibar.coffee
index dbb37ebf..b133b126 100644
--- a/pages/vomnibar.coffee
+++ b/pages/vomnibar.coffee
@@ -63,10 +63,11 @@ class VomnibarUI
 
   # The sequence of events when the vomnibar is hidden is as follows:
   # 1. Post a "hide" message to the host page.
-  # 2. The host page hides the vomnibar and posts back a "hidden" message.
-  # 3. Only once "hidden" message is received here is any required action (callback) invoked (in onHidden).
-  # This ensures that the vomnibar is actually hidden, and avoids flicker after opening a link in a new tab
-  # (see #1485).
+  # 2. The host page hides the vomnibar.
+  # 3. When that page receives the focus, and it posts back a "hidden" message.
+  # 3. Only once the "hidden" message is received here is any required action  invoked (in onHidden).
+  # This ensures that the vomnibar is actually hidden before any new tab is created, and avoids flicker after
+  # opening a link in a new tab then returning to the original tab (see #1485).
   hide: (@postHideCallback = null) ->
     UIComponentServer.postMessage "hide"
     @reset()