InstantExtended: Transient naventry for preview.

chrome/browser/instant/instant_controller.cc

Index: chrome/browser/instant/instant_controller.cc
diff --git a/chrome/browser/instant/instant_controller.cc b/chrome/browser/instant/instant_controller.cc
index acb9583c85849f88a7e1d93d5ca684c5db1ac6b2..6e36b987a8322e8c5c102cd64bf0f1f6cee00b05 100644
--- a/chrome/browser/instant/instant_controller.cc
+++ b/chrome/browser/instant/instant_controller.cc
@@ -180,7 +180,8 @@ InstantController::InstantController(chrome::BrowserInstantController* browser,
       omnibox_focus_state_(OMNIBOX_FOCUS_NONE),
       start_margin_(0),
       end_margin_(0),
-      allow_preview_to_show_search_suggestions_(false) {
+      allow_preview_to_show_search_suggestions_(false),
+      instant_set_transient_entry_(false) {
 }
 
 InstantController::~InstantController() {
@@ -348,6 +349,7 @@ bool InstantController::Update(const AutocompleteMatch& match,
     last_suggestion_ = InstantSuggestion();
 
   last_omnibox_text_ = full_text;
+  SetTransientHistoryEntry();
 
   if (!extended_enabled_) {
     // In non-extended mode, the query is verbatim if there's any selection
@@ -809,6 +811,8 @@ void InstantController::SetSuggestions(
     }
   }
 
+  SetTransientHistoryEntry();
+
   // Extended mode pages will call ShowLoader() when they are ready.
   if (!extended_enabled_)
     ShowLoader(INSTANT_SHOWN_QUERY_SUGGESTIONS, 100, INSTANT_SIZE_PERCENT);
@@ -1088,6 +1092,8 @@ void InstantController::HideInternal() {
     loader_->Update(string16(), 0, 0, true);
   }
 
+  ResetTransientHistoryEntry();
+
   // Clear the first interaction timestamp for later use.
   first_interaction_time_ = base::Time();
 }
@@ -1145,6 +1151,51 @@ void InstantController::ShowLoader(InstantShownReason reason,
   // overlay (because we're not full height).
   if (reason == INSTANT_SHOWN_CLICKED_QUERY_SUGGESTION)
     CommitIfPossible(INSTANT_COMMIT_CLICKED_QUERY_SUGGESTION);
+  else if (extended_enabled_ && IsFullHeight(model_))
+    SetTransientHistoryEntry();
+}
+
+void InstantController::SetTransientHistoryEntry() {
+  content::WebContents* active_tab = browser_->GetActiveWebContents();
+  // Save any transient entry already associated with the active tab.
+  content::NavigationEntry* old_transient_entry =
+      active_tab->GetController().GetTransientEntry();
+  if (old_transient_entry && !instant_set_transient_entry_)
+    transient_entry_.reset(
+        content::NavigationEntry::Create(*old_transient_entry));
+  // The loader's base navigation entry should describe the search provider
+  // without reference to a specific query. The alternative, updating the query
+  // in the tab title as the user types, would be distracting.
+  const content::NavigationEntry* base_entry = loader_->base_navigation_entry();
+  DCHECK(base_entry != NULL);
+  content::NavigationEntry* new_transient_entry =
+      content::NavigationEntry::Create(*base_entry);
+  // The URL should update so that if the user presses reload, we reload the
+  // page for the current query.
+  const TemplateURL* template_url = TemplateURLServiceFactory::GetForProfile(
+      Profile::FromBrowserContext(active_tab->GetBrowserContext()))->
+      GetDefaultSearchProvider();
+  const TemplateURLRef& url_ref = template_url->url_ref();
+  DCHECK(url_ref.IsValid());
+  TemplateURLRef::SearchTermsArgs search_terms(last_omnibox_text_ +
+                                               last_suggestion_.text);
+  std::string url = url_ref.ReplaceSearchTerms(search_terms);
+  new_transient_entry->SetURL(GURL(url));
+  new_transient_entry->SetVirtualURL(GURL(url));
+  active_tab->GetController().AddTransientEntry(new_transient_entry);
+  instant_set_transient_entry_ = true;

[sreeram, 2013/01/22 05:28:34]

Wow. This is really hacky. Why do we need this? Can't we just update the
transient entry URL whenever the InstantLoader observes a navigation? Yes, if
you type quickly and press Reload (before 3 seconds are up), you'll end up
reloading the "wrong" URL, but I'm not really concerned about that. I think it's
an extreme corner case brought about by the user's pathological action that we
don't have to worry about.

[Jered, 2013/01/23 21:52:07]

Navigating after 3 seconds is a very Google-specific behavior, so depending on
that would feel like more of a hack to me. This way seems like a portable way to
make reload search for what the user has typed, no?

+}
+
+void InstantController::ResetTransientHistoryEntry() {
+  content::NavigationEntry* old_transient_entry = transient_entry_.release();
+  if (old_transient_entry) {
+    DVLOG(1) << "ResetTransientHistoryEntry: restoring old transient entry";
+    content::WebContents* active_tab = browser_->GetActiveWebContents();
+    active_tab->GetController().AddTransientEntry(old_transient_entry);
+    chrome::search::SearchTabHelper::FromWebContents(active_tab)->
+        NavigationEntryUpdated();
+  }
+  instant_set_transient_entry_ = false;
 }
 
 void InstantController::SendPopupBoundsToPage() {