Rework UI component focus handling.

The code to handle the focus for UI components has been tweaked and
adapted over time, and has become quite complicated (and brittle).  This
reworks it from scratch, and co-locates similar code which does related
things.

Fixes #2099.

5 files changed, 67 insertions, 100 deletions

diff --git a/content_scripts/hud.coffee b/content_scripts/hud.coffee
index bbf7c5e9..fb1fd657 100644
--- a/content_scripts/hud.coffee
+++ b/content_scripts/hud.coffee
@@ -25,12 +25,12 @@ HUD =
   show: (text) ->
     return unless @isReady()
     clearTimeout(@_showForDurationTimerId)
-    @hudUI.show {name: "show", text}
+    @hudUI.activate {name: "show", text}
     @tween.fade 1.0, 150
 
   showFindMode: (@findMode = null) ->
     return unless @isReady()
-    @hudUI.show {name: "showFindMode", text: ""}
+    @hudUI.activate name: "showFindMode", text: ""
     @tween.fade 1.0, 150
 
   search: (data) ->
@@ -50,9 +50,7 @@ HUD =
     clearTimeout(@_showForDurationTimerId)
     @tween.stop()
     if immediate
-      unless updateIndicator
-        @hudUI.hide()
-        @hudUI.postMessage {name: "hide"}
+      @hudUI.hide()
       Mode.setIndicator() if updateIndicator
     else
       @tween.fade 0, 150, => @hide true, updateIndicator
@@ -60,9 +58,9 @@ HUD =
   hideFindMode: (data) ->
     @findMode.checkReturnToViewPort()
 
-    # An element element won't receive a focus event if the search landed on it while we were in the HUD
-    # iframe. To end up with the correct modes active, we create a focus/blur event manually after refocusing
-    # this window.
+    # An element won't receive a focus event if the search landed on it while we were in the HUD iframe. To
+    # end up with the correct modes active, we create a focus/blur event manually after refocusing this
+    # window.
     window.focus()
 
     focusNode = DomUtils.getSelectionFocusElement()
diff --git a/content_scripts/mode_key_handler.coffee b/content_scripts/mode_key_handler.coffee
index 08222d98..0b8145fc 100644
--- a/content_scripts/mode_key_handler.coffee
+++ b/content_scripts/mode_key_handler.coffee
@@ -42,9 +42,9 @@ class KeyHandlerMode extends Mode
       @reset()
       @suppressEvent
     # If the help dialog loses the focus, then Escape should hide it; see point 2 in #2045.
-    else if isEscape and HelpDialog?.showing
+    else if isEscape and HelpDialog?.isShowing()
       @keydownEvents[event.keyCode] = true
-      HelpDialog.hide()
+      HelpDialog.toggle()
       @suppressEvent
     else if isEscape
       @continueBubbling
diff --git a/content_scripts/ui_component.coffee b/content_scripts/ui_component.coffee
index d7bdf2a1..bb350ccc 100644
--- a/content_scripts/ui_component.coffee
+++ b/content_scripts/ui_component.coffee
@@ -2,7 +2,8 @@ class UIComponent
   uiComponentIsReady: false
   iframeElement: null
   iframePort: null
-  showing: null
+  iframeFrameId: null
+  showing: false
   options: null
   shadowDOM: null
   styleSheetGetter: null
@@ -27,10 +28,8 @@ class UIComponent
     @shadowDOM = shadowWrapper.createShadowRoot?() ? shadowWrapper
     @shadowDOM.appendChild styleSheet
     @shadowDOM.appendChild @iframeElement
-
-    @showing = true # The iframe is visible now.
-    # Hide the iframe, but don't interfere with the focus.
-    @hide false
+    @iframeElement.classList.remove "vimiumUIComponentVisible"
+    @iframeElement.classList.add "vimiumUIComponentHidden"
 
     # Open a port and pass it to the iframe via window.postMessage.  We use an AsyncDataFetcher to handle
     # requests which arrive before the iframe (and its message handlers) have completed initialization.  See
@@ -45,74 +44,59 @@ class UIComponent
         # Get vimiumSecret so the iframe can determine that our message isn't the page impersonating us.
         chrome.storage.local.get "vimiumSecret", ({ vimiumSecret }) =>
           { port1, port2 } = new MessageChannel
-          port1.onmessage = (event) =>
-            if event?.data == "uiComponentIsReady" then @uiComponentIsReady = true else @handleMessage event
           @iframeElement.contentWindow.postMessage vimiumSecret, chrome.runtime.getURL(""), [ port2 ]
-          setIframePort port1
-
-    chrome.runtime.onMessage.addListener (request) =>
-      if @showing and request.name == "frameFocused" and request.focusFrameId != frameId
-        @postMessage name: "frameFocused", focusFrameId: request.focusFrameId
-      false # Free up the sendResponse handler.
 
-  # Posts a message (if one is provided), then calls continuation (if provided).  The continuation is only
-  # ever called *after* the message has been posted.
+          port1.onmessage = (event) =>
+            switch event?.data?.name ? event?.data
+              when "uiComponentIsReady"
+                # If any other frame receives the focus, then hide the UI component.
+                chrome.runtime.onMessage.addListener ({name, focusFrameId}) =>
+                  if name == "frameFocused" and @options?.focus and focusFrameId not in [frameId, @iframeFrameId]
+                    @hide false
+                  false # We will not be calling sendResponse.
+
+                # If this frame receives the focus, then hide the UI component.
+                window.addEventListener "focus", (event) =>
+                  if event.target == window and @options?.focus and not @options?.allowBlur
+                    @hide false
+                  true # Continue propagating the event.
+
+                @uiComponentIsReady = true
+                setIframePort port1
+
+              when "setIframeFrameId" then @iframeFrameId = event.data.iframeFrameId
+              when "hide" then @hide()
+              else @handleMessage event
+
+  # Post a message (if provided), then call continuation (if provided).
   postMessage: (message = null, continuation = null) ->
     @iframePort.use (port) =>
       port.postMessage message if message?
       continuation?()
 
-  activate: (@options) ->
+  activate: (@options = null) ->
     @postMessage @options, =>
-      @show() unless @showing
-      @iframeElement.focus()
-
-  show: (message) ->
-    @postMessage message, =>
       @iframeElement.classList.remove "vimiumUIComponentHidden"
       @iframeElement.classList.add "vimiumUIComponentVisible"
-      # The window may not have the focus.  We focus it now, to prevent the "focus" listener below from firing
-      # immediately.
-      window.focus()
-      window.addEventListener "focus", @onFocus = (event) =>
-        if event.target == window
-          window.removeEventListener "focus", @onFocus
-          @onFocus = null
-          @postMessage "frameFocused"
+      @iframeElement.focus() if @options?.focus
       @showing = true
 
-  hide: (focusWindow = true)->
-    @refocusSourceFrame @options?.sourceFrameId if focusWindow
-    window.removeEventListener "focus", @onFocus if @onFocus
-    @onFocus = null
-    @iframeElement.classList.remove "vimiumUIComponentVisible"
-    @iframeElement.classList.add "vimiumUIComponentHidden"
-    @iframeElement.blur()
-    @options = null
-    @showing = false
-
-  # 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 first receives the focus, before then focusing the frame which should now have
-  # the focus.
-  refocusSourceFrame: (sourceFrameId) ->
-    if @showing and sourceFrameId? and sourceFrameId != frameId
-      refocusSourceFrame = ->
-        chrome.runtime.sendMessage
-          handler: "sendMessageToFrames"
-          message:
-            name: "focusFrame"
-            frameId: sourceFrameId
-
-      if windowIsFocused()
-        # 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()
+  hide: (shouldRefocusOriginalFrame = true) ->
+    if @showing
+      @showing = false
+      @iframeElement.classList.remove "vimiumUIComponentVisible"
+      @iframeElement.classList.add "vimiumUIComponentHidden"
+      if @options?.focus and shouldRefocusOriginalFrame
+        @iframeElement.blur()
+        if @options?.sourceFrameId?
+          chrome.runtime.sendMessage
+            handler: "sendMessageToFrames",
+            message: name: "focusFrame", frameId: @options.sourceFrameId, forceFocusThisFrame: true
+        else
+          window.focus()
+      @options = null
+      # Inform the UI component that it is hidden.
+      Utils.nextTick => @postMessage "hidden"
 
   # Fetch a Vimium file/resource (such as "content_scripts/vimium.css").
   # We try making an XMLHttpRequest request.  That can fail (see #1817), in which case we fetch the
@@ -135,6 +119,5 @@ class UIComponent
     request.open "GET", (chrome.runtime.getURL file), true
     request.send()
 
-
 root = exports ? window
 root.UIComponent = UIComponent
diff --git a/content_scripts/vimium_frontend.coffee b/content_scripts/vimium_frontend.coffee
index 4dcdfe7d..537dbaa9 100644
--- a/content_scripts/vimium_frontend.coffee
+++ b/content_scripts/vimium_frontend.coffee
@@ -119,7 +119,10 @@ class NormalMode extends KeyHandlerMode
         You have asked Vimium to perform #{count} repetitions of the command: #{registryEntry.description}.\n
         Are you sure you want to continue?"""
 
-    if registryEntry.topFrame
+    if registryEntry.topFrame and window.isVimiumUIComponent? and window.isVimiumUIComponent
+      # We cannot use "topFrame" commands, most notably the Vomnibar, from within a UI component.
+      HUD.showForDuration "#{registryEntry.command} cannot be used here.", 2000
+    else if registryEntry.topFrame
       chrome.runtime.sendMessage
         handler: "sendMessageToFrames", message: {name: "runInTopFrame", sourceFrameId: frameId, registryEntry}
     else if registryEntry.background
@@ -156,7 +159,7 @@ initializePreDomReady = ->
     getScrollPosition: (ignoredA, ignoredB, sendResponse) ->
       sendResponse scrollX: window.scrollX, scrollY: window.scrollY if frameId == 0
     setScrollPosition: setScrollPosition
-    # A frame has received the focus.  We don't care here (the Vomnibar/UI-component handles this).
+    # A frame has received the focus.  We don't care here (UI components handle this).
     frameFocused: ->
     checkEnabledAfterURLChange: checkEnabledAfterURLChange
     runInTopFrame: ({sourceFrameId, registryEntry}) ->
@@ -626,29 +629,16 @@ enterFindMode = ->
 # If we are in the help dialog iframe, HelpDialog is already defined with the necessary functions.
 window.HelpDialog ?=
   helpUI: null
-  container: null
-  showing: false
-
-  init: ->
-    return if @helpUI?
-
-    @helpUI = new UIComponent "pages/help_dialog.html", "vimiumHelpDialogFrame", (event) =>
-      @hide() if event.data == "hide"
-
-  isReady: -> @helpUI
-
-  show: (html) ->
-    @init()
-    return if @showing or !@isReady()
-    @showing = true
-    @helpUI.activate html
-
-  hide: ->
-    @showing = false
-    @helpUI.hide()
+  isShowing: -> @helpUI?.showing
 
   toggle: (html) ->
-    if @showing then @hide() else @show html
+    @helpUI ?= new UIComponent "pages/help_dialog.html", "vimiumHelpDialogFrame", ->
+    if @isShowing()
+      @helpUI.hide()
+    else
+      # On the options page, we allow the help dialog to lose the focus, elsewhere we do not.  This allows
+      # users to view the help dialog while typing in the key-mappings input.
+      @helpUI.activate {name: "activate", html, focus: true, allowBlur: window.isVimiumOptionsPage ? false}
 
 initializePreDomReady()
 DomUtils.documentReady initializeOnDomReady
diff --git a/content_scripts/vomnibar.coffee b/content_scripts/vomnibar.coffee
index c23a4e6f..646fda43 100644
--- a/content_scripts/vomnibar.coffee
+++ b/content_scripts/vomnibar.coffee
@@ -51,10 +51,6 @@ Vomnibar =
     unless @vomnibarUI?
       @vomnibarUI = new UIComponent "pages/vomnibar.html", "vomnibarFrame", (event) =>
         @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:
@@ -65,7 +61,7 @@ Vomnibar =
   open: (sourceFrameId, options) ->
     @init()
     if @vomnibarUI?.uiComponentIsReady
-      @vomnibarUI.activate extend options, { sourceFrameId }
+      @vomnibarUI.activate extend options, { name: "activate", sourceFrameId, focus: true }
 
 root = exports ? window
 root.Vomnibar = Vomnibar