InstantExtended: Transient naventry for preview.

chrome/browser/instant/instant_controller.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/instant/instant_controller.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ skipping 165 matching lines @@
       instant_enabled_(false),
       use_local_preview_only_(true),
       model_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
       last_omnibox_text_has_inline_autocompletion_(false),
       last_verbatim_(false),
       last_transition_type_(content::PAGE_TRANSITION_LINK),
       last_match_was_search_(false),
       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() {
 }
 
 bool InstantController::Update(const AutocompleteMatch& match,
                                const string16& user_text,
                                const string16& full_text,
                                size_t selection_start,
                                size_t selection_end,
@@ skipping 729 matching lines @@
 
   // Commit the navigation if either:
   //  - The page is in NTP mode (so it could only navigate on a user click) or
   //  - The page is not in NTP mode and we are navigating to a URL with a
   //    different host or path than the instant URL. This enables the instant
   //    page when it is showing search results to change the query parameters
   //    and fragments of the URL without it navigating.
   if (model_.mode().is_ntp() ||
       (url.host() != instant_url.host() || url.path() != instant_url.path())) {
     CommitIfPossible(INSTANT_COMMIT_NAVIGATED);
+  } else {
+    UpdateTransientHistoryEntry(url);
   }
 }
 
 void InstantController::SetSuggestions(
     const content::WebContents* contents,
     const std::vector<InstantSuggestion>& suggestions) {
   LOG_INSTANT_DEBUG_EVENT(this, "SetSuggestions");
 
   // Ignore if the message is from an unexpected source.
   if (IsContentsFrom(ntp(), contents))
@@ skipping 249 matching lines @@
   // change the state just yet; else we may hide the preview unnecessarily.
   // Instead, the state will be set correctly after the commit is done.
   if (GetPreviewContents()) {
     model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
     allow_preview_to_show_search_suggestions_ = false;
 
     // Send a message asking the preview to clear out old results.
     overlay_->Update(string16(), 0, 0, true);
   }
 
+  ResetTransientHistoryEntry();
+
   // Clear the first interaction timestamp for later use.
   first_interaction_time_ = base::Time();
 }
 
 void InstantController::ShowOverlay(InstantShownReason reason,
                                     int height,
                                     InstantSizeUnits units) {
   // If we are on a committed search results page, the |overlay_| is not in use.
   if (instant_tab_)
     return;
@@ skipping 38 matching lines @@
     model_.SetPreviewState(search_mode_, height, units);
   else
     model_.SetPreviewState(search_mode_, 100, INSTANT_SIZE_PERCENT);
 
   // If the user clicked on a query suggestion, also go ahead and commit the
   // overlay. This is necessary because if the overlay was partially visible
   // when the suggestion was clicked, the click itself would not commit the
   // 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();
+  // If the active tab already has a transient entry, leave it alone.
+  if (active_tab->GetController().GetTransientEntry())
+    return;
+  // 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 =
+    overlay_->base_navigation_entry();
+  DCHECK(base_entry != NULL);
+  content::NavigationEntry* transient_entry =
+      content::NavigationEntry::Create(*base_entry);
+  active_tab->GetController().AddTransientEntry(transient_entry);
+  instant_set_transient_entry_ = true;
+}
+
+void InstantController::UpdateTransientHistoryEntry(const GURL& url) {
+  // URL should update so that if the user presses reload, we reload the page
+  // for the current query, but title remains unchanged so it doesn't flicker.
+  if (instant_set_transient_entry_) {
+    content::WebContents* active_tab = browser_->GetActiveWebContents();
+    content::NavigationEntry* transient_entry =
+        active_tab->GetController().GetTransientEntry();
+    DCHECK(transient_entry != NULL);
+    transient_entry->SetURL(url);
+    transient_entry->SetVirtualURL(url);
+  }
+}
+
+void InstantController::ResetTransientHistoryEntry() {
+  // NavigationController will discard the entry.
+  instant_set_transient_entry_ = false;
 }
 
 void InstantController::SendPopupBoundsToPage() {
   if (last_popup_bounds_ == popup_bounds_ || !overlay_ ||
       overlay_->is_pointer_down_from_activate())
     return;
 
   last_popup_bounds_ = popup_bounds_;
   gfx::Rect preview_bounds = browser_->GetInstantBounds();
   gfx::Rect intersection = gfx::IntersectRects(popup_bounds_, preview_bounds);
@@ skipping 125 matching lines @@
   delete overlay_->ReleaseContents().release();
   MessageLoop::current()->DeleteSoon(FROM_HERE, overlay_.release());
   EnsureOverlayIsCurrent(false);
 }
 
 void InstantController::RemoveFromBlacklist(const std::string& url) {
   if (blacklisted_urls_.erase(url)) {
     RecordEventHistogram(INSTANT_CONTROLLER_EVENT_URL_REMOVED_FROM_BLACKLIST);
   }
 }