chrome/browser/instant/instant_loader.cc

// Copyright (c) 2010 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_loader.h"

#include <algorithm>
#include <utility>

#include "app/l10n_util.h"
#include "base/command_line.h"
#include "base/string_number_conversions.h"
#include "base/timer.h"
#include "base/utf_string_conversions.h"
#include "base/values.h"
#include "chrome/browser/favicon_service.h"
#include "chrome/browser/history/history_marshaling.h"
#include "chrome/browser/instant/instant_loader_delegate.h"
#include "chrome/browser/profile.h"
#include "chrome/browser/renderer_host/render_view_host.h"
#include "chrome/browser/renderer_host/render_widget_host.h"
#include "chrome/browser/renderer_host/render_widget_host_view.h"
#include "chrome/browser/search_engines/template_url.h"
#include "chrome/browser/tab_contents/navigation_controller.h"
#include "chrome/browser/tab_contents/navigation_entry.h"
#include "chrome/browser/tab_contents/tab_contents.h"
#include "chrome/browser/tab_contents/tab_contents_delegate.h"
#include "chrome/browser/tab_contents/tab_contents_view.h"
#include "chrome/browser/tab_contents_wrapper.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/notification_observer.h"
#include "chrome/common/notification_registrar.h"
#include "chrome/common/notification_service.h"
#include "chrome/common/notification_type.h"
#include "chrome/common/page_transition_types.h"
#include "chrome/common/render_messages.h"
#include "chrome/common/renderer_preferences.h"
#include "gfx/codec/png_codec.h"
#include "ipc/ipc_message.h"
#include "net/http/http_util.h"

namespace {

// Number of ms to delay before updating the omnibox bounds. This is a bit long
// as updating the bounds ends up being quite expensive.
const int kUpdateBoundsDelayMS = 500;

// If this status code is seen instant is disabled for the specified host.
const int kHostBlacklistStatusCode = 403;

// Header and value set for all loads.
const char kPreviewHeader[] = "X-Purpose:";
const char kPreviewHeaderValue[] = "preview";

}  // namespace

// FrameLoadObserver is responsible for determining if the page supports
// instant after it has loaded.
class InstantLoader::FrameLoadObserver : public NotificationObserver {
 public:
  FrameLoadObserver(TabContents* tab_contents,
                    const string16& text,
                    bool verbatim)
      : tab_contents_(tab_contents),
        text_(text),
        verbatim_(verbatim),
        unique_id_(tab_contents_->controller().pending_entry()->unique_id()) {
    registrar_.Add(this, NotificationType::LOAD_COMPLETED_MAIN_FRAME,
                   Source<TabContents>(tab_contents_));
  }

  // Sets the text to send to the page.
  void set_text(const string16& text) { text_ = text; }

  // Sets whether verbatim results are obtained rather than predictive.
  void set_verbatim(bool verbatim) { verbatim_ = verbatim; }

  // NotificationObserver:
  virtual void Observe(NotificationType type,
                       const NotificationSource& source,
                       const NotificationDetails& details) {
    switch (type.value) {
      case NotificationType::LOAD_COMPLETED_MAIN_FRAME: {
        int page_id = *(Details<int>(details).ptr());
        NavigationEntry* active_entry =
            tab_contents_->controller().GetActiveEntry();
        if (!active_entry || active_entry->page_id() != page_id ||
            active_entry->unique_id() != unique_id_) {
          return;
        }
        tab_contents_->render_view_host()->DetermineIfPageSupportsInstant(
            text_, verbatim_);
        break;
      }
      default:
        NOTREACHED();
        break;
    }
  }

 private:
  // The TabContents we're listening for changes on.
  TabContents* tab_contents_;

  // Text to send down to the page.
  string16 text_;

  // Whether verbatim results are obtained.
  bool verbatim_;

  // unique_id of the NavigationEntry we're waiting on.
  const int unique_id_;

  // Registers and unregisters us for notifications.
  NotificationRegistrar registrar_;

  DISALLOW_COPY_AND_ASSIGN(FrameLoadObserver);
};

// PaintObserver implementation. When the RenderWidgetHost paints itself this
// notifies the TabContentsDelegateImpl which ultimately notifies InstantLoader
// and shows the preview.
// The ownership of this class is tricky. It's created and
// tracked by TabContentsDelegateImpl, but owned by RenderWidgetHost. When
// deleted this notifies the TabContentsDelegateImpl so that it can clean
// up appropriately.
class InstantLoader::PaintObserverImpl
    : public RenderWidgetHost::PaintObserver {
 public:
  PaintObserverImpl(TabContentsDelegateImpl* delegate,
                    RenderWidgetHost* rwh)
      : delegate_(delegate),
        rwh_(rwh) {
    rwh_->set_paint_observer(this);
  }

  ~PaintObserverImpl();

  // Deletes this object by resetting the PaintObserver on the RenderWidgetHost.
  void Destroy() {
    rwh_->set_paint_observer(NULL);
  }

  virtual void RenderWidgetHostWillPaint(RenderWidgetHost* rwh) {}

  virtual void RenderWidgetHostDidPaint(RenderWidgetHost* rwh);

 private:
  TabContentsDelegateImpl* delegate_;
  RenderWidgetHost* rwh_;

  DISALLOW_COPY_AND_ASSIGN(PaintObserverImpl);
};

class InstantLoader::TabContentsDelegateImpl : public TabContentsDelegate {
 public:
  explicit TabContentsDelegateImpl(InstantLoader* loader)
      : loader_(loader),
        paint_observer_(NULL),
        waiting_for_new_page_(true),
        is_mouse_down_from_activate_(false),
        user_typed_before_load_(false) {
  }

  // Invoked prior to loading a new URL.
  void PrepareForNewLoad() {
    user_typed_before_load_ = false;
    waiting_for_new_page_ = true;
    add_page_vector_.clear();
    DestroyPaintObserver();
  }

  // Invoked when removed as the delegate. Gives a chance to do any necessary
  // cleanup.
  void Reset() {
    is_mouse_down_from_activate_ = false;
    DestroyPaintObserver();
  }

  // Invoked when the preview paints. Invokes PreviewPainted on the loader.
  void PreviewPainted() {
    loader_->PreviewPainted();
  }

  // Invoked when the PaintObserverImpl is deleted.
  void PaintObserverDestroyed(PaintObserverImpl* observer) {
    if (observer == paint_observer_)
      paint_observer_ = NULL;
  }

  bool is_mouse_down_from_activate() const {
    return is_mouse_down_from_activate_;
  }

  void set_user_typed_before_load() { user_typed_before_load_ = true; }

  // Commits the currently buffered history.
  void CommitHistory() {
    TabContents* tab = loader_->preview_contents()->tab_contents();
    if (tab->profile()->IsOffTheRecord())
      return;

    for (size_t i = 0; i < add_page_vector_.size(); ++i)
      tab->UpdateHistoryForNavigation(add_page_vector_[i].get());

    NavigationEntry* active_entry = tab->controller().GetActiveEntry();
    if (!active_entry) {
      // It appears to be possible to get here with no active entry. This seems
      // to be possible with an auth dialog, but I can't narrow down the
      // circumstances. If you hit this, file a bug with the steps you did and
      // assign it to me (sky).
      NOTREACHED();
      return;
    }
    tab->UpdateHistoryPageTitle(*active_entry);

    FaviconService* favicon_service =
        tab->profile()->GetFaviconService(Profile::EXPLICIT_ACCESS);

    if (favicon_service && active_entry->favicon().is_valid() &&
        !active_entry->favicon().bitmap().empty()) {
      std::vector<unsigned char> image_data;
      gfx::PNGCodec::EncodeBGRASkBitmap(active_entry->favicon().bitmap(), false,
                                        &image_data);
      favicon_service->SetFavicon(active_entry->url(),
                                  active_entry->favicon().url(),
                                  image_data);
    }
  }

  virtual void OpenURLFromTab(TabContents* source,
                              const GURL& url, const GURL& referrer,
                              WindowOpenDisposition disposition,
                              PageTransition::Type transition) {}
  virtual void NavigationStateChanged(const TabContents* source,
                                      unsigned changed_flags) {
    if (!loader_->ready() && !paint_observer_ &&
        source->controller().entry_count()) {
      // The load has been committed. Install an observer that waits for the
      // first paint then makes the preview active. We wait for the load to be
      // committed before waiting on paint as there is always an initial paint
      // when a new renderer is created from the resize so that if we showed the
      // preview after the first paint we would end up with a white rect.
      paint_observer_ = new PaintObserverImpl(this,
          source->GetRenderWidgetHostView()->GetRenderWidgetHost());
    }
  }
  virtual std::string GetNavigationHeaders(const GURL& url) {
    std::string header;
    net::HttpUtil::AppendHeaderIfMissing(kPreviewHeader, kPreviewHeaderValue,
                                         &header);
    return header;
  }
  virtual void AddNewContents(TabContents* source,
                              TabContents* new_contents,
                              WindowOpenDisposition disposition,
                              const gfx::Rect& initial_pos,
                              bool user_gesture) {}
  virtual void ActivateContents(TabContents* contents) {
  }
  virtual void DeactivateContents(TabContents* contents) {}
  virtual void LoadingStateChanged(TabContents* source) {}
  virtual void CloseContents(TabContents* source) {}
  virtual void MoveContents(TabContents* source, const gfx::Rect& pos) {}
  virtual void DetachContents(TabContents* source) {}
  virtual bool IsPopup(const TabContents* source) const {
    return false;
  }
  virtual bool ShouldFocusConstrainedWindow() {
    // Return false so that constrained windows are not initially focused. If
    // we did otherwise the preview would prematurely get committed when focus
    // goes to the constrained window.
    return false;
  }
  virtual void WillShowConstrainedWindow(TabContents* source) {
    if (!loader_->ready()) {
      // A constrained window shown for an auth may not paint. Show the preview
      // contents.
      DestroyPaintObserver();
      loader_->ShowPreview();
    }
  }
  virtual void ToolbarSizeChanged(TabContents* source, bool is_animating) {}
  virtual void URLStarredChanged(TabContents* source, bool starred) {}
  virtual void UpdateTargetURL(TabContents* source, const GURL& url) {}
  virtual void ContentsMouseEvent(
      TabContents* source, const gfx::Point& location, bool motion) {}
  virtual void ContentsZoomChange(bool zoom_in) {}
  virtual void OnContentSettingsChange(TabContents* source) {}
  virtual bool IsApplication() const { return false; }
  virtual void ConvertContentsToApplication(TabContents* source) {}
  virtual bool CanReloadContents(TabContents* source) const { return true; }
  virtual void ShowHtmlDialog(HtmlDialogUIDelegate* delegate,
                              gfx::NativeWindow parent_window) {}
  virtual bool ShouldSuppressDialogs() {
    // Any message shown during instant cancels instant, so we suppress them.
    return true;
  }
  virtual void BeforeUnloadFired(TabContents* tab,
                                 bool proceed,
                                 bool* proceed_to_fire_unload) {}
  virtual void ForwardMessageToExternalHost(const std::string& message,
                                            const std::string& origin,
                                            const std::string& target) {}
  virtual bool IsExternalTabContainer() const { return false; }
  virtual void SetFocusToLocationBar(bool select_all) {}
  virtual bool ShouldFocusPageAfterCrash() { return false; }
  virtual void RenderWidgetShowing() {}
  virtual bool TakeFocus(bool reverse) { return false; }
  virtual void LostCapture() {
    CommitFromMouseReleaseIfNecessary();
  }
  virtual void SetTabContentBlocked(TabContents* contents, bool blocked) {}
  virtual void TabContentsFocused(TabContents* tab_content) {
  }
  virtual int GetExtraRenderViewHeight() const { return 0; }
  virtual bool CanDownload(int request_id) { return false; }
  virtual void OnStartDownload(DownloadItem* download, TabContents* tab) {}
  virtual bool HandleContextMenu(const ContextMenuParams& params) {
    return false;
  }
  virtual bool ExecuteContextMenuCommand(int command) {
    return false;
  }
  virtual void ConfirmAddSearchProvider(const TemplateURL* template_url,
                                        Profile* profile) {}
  virtual void ShowPageInfo(Profile* profile,
                            const GURL& url,
                            const NavigationEntry::SSLStatus& ssl,
                            bool show_history) {}
  virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                      bool* is_keyboard_shortcut) {
    return false;
  }
  virtual void HandleMouseUp() {
    CommitFromMouseReleaseIfNecessary();
  }
  virtual void HandleMouseActivate() {
    is_mouse_down_from_activate_ = true;
  }
  virtual void ShowRepostFormWarningDialog(TabContents* tab_contents) {}
  virtual void ShowContentSettingsWindow(ContentSettingsType content_type) {}
  virtual void ShowCollectedCookiesDialog(TabContents* tab_contents) {}
  virtual bool OnGoToEntryOffset(int offset) { return false; }
  virtual bool ShouldAddNavigationToHistory(
      const history::HistoryAddPageArgs& add_page_args,
      NavigationType::Type navigation_type) {
    if (waiting_for_new_page_ && navigation_type == NavigationType::NEW_PAGE)
      waiting_for_new_page_ = false;

    if (!waiting_for_new_page_) {
      add_page_vector_.push_back(
          scoped_refptr<history::HistoryAddPageArgs>(add_page_args.Clone()));
    }
    return false;
  }
  virtual void OnDidGetApplicationInfo(TabContents* tab_contents,
                                       int32 page_id) {}
  virtual gfx::NativeWindow GetFrameNativeWindow() {
    return NULL;
  }
  virtual void TabContentsCreated(TabContents* new_contents) {}
  virtual bool infobars_enabled() { return false; }
  virtual bool ShouldEnablePreferredSizeNotifications() { return false; }
  virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}
  virtual void ContentTypeChanged(TabContents* source) {}

  virtual void OnSetSuggestions(int32 page_id,
                                const std::vector<std::string>& suggestions) {
    TabContentsWrapper* source = loader_->preview_contents();
    if (!source->controller().GetActiveEntry() ||
        page_id != source->controller().GetActiveEntry()->page_id())
      return;

    // TODO: only allow for default search provider.
    // TODO(sky): Handle multiple suggestions.
    if (suggestions.empty())
      loader_->SetCompleteSuggestedText(string16());
    else
      loader_->SetCompleteSuggestedText(UTF8ToUTF16(suggestions[0]));
  }

  virtual void OnInstantSupportDetermined(int32 page_id, bool result) {
    TabContents* source = loader_->preview_contents()->tab_contents();
    if (!source->controller().GetActiveEntry() ||
        page_id != source->controller().GetActiveEntry()->page_id())
      return;

    if (result) {
      gfx::Rect bounds = loader_->GetOmniboxBoundsInTermsOfPreview();
      loader_->last_omnibox_bounds_ = loader_->omnibox_bounds_;
      loader_->PageFinishedLoading();
    } else {
      loader_->PageDoesntSupportInstant(user_typed_before_load_);
    }
  }

 private:
  typedef std::vector<scoped_refptr<history::HistoryAddPageArgs> >
      AddPageVector;

  void CommitFromMouseReleaseIfNecessary() {
    bool was_down = is_mouse_down_from_activate_;
    is_mouse_down_from_activate_ = false;
    if (was_down && loader_->ShouldCommitInstantOnMouseUp())
      loader_->CommitInstantLoader();
  }

  // If the PaintObserver is non-null Destroy is invoked on it.
  void DestroyPaintObserver() {
    if (paint_observer_) {
      paint_observer_->Destroy();
      // Destroy should result in invoking PaintObserverDestroyed and NULLing
      // out paint_observer_.
      DCHECK(!paint_observer_);
    }
  }

  InstantLoader* loader_;

  // Used to listen for paint so that we know when to show the preview. See
  // comment in NavigationStateChanged for details on this.
  // Ownership of this is tricky, see comment above PaintObserverImpl class.
  PaintObserverImpl* paint_observer_;

  // Used to cache data that needs to be added to history. Normally entries are
  // added to history as the user types, but for instant we only want to add the
  // items to history if the user commits instant. So, we cache them here and if
  // committed then add the items to history.
  AddPageVector add_page_vector_;

  // Are we we waiting for a NavigationType of NEW_PAGE? If we're waiting for
  // NEW_PAGE navigation we don't add history items to add_page_vector_.
  bool waiting_for_new_page_;

  // True if the mouse is down from an activate.
  bool is_mouse_down_from_activate_;

  // True if the user typed in the search box before the page loaded.
  bool user_typed_before_load_;

  DISALLOW_COPY_AND_ASSIGN(TabContentsDelegateImpl);
};

InstantLoader::PaintObserverImpl::~PaintObserverImpl() {
  delegate_->PaintObserverDestroyed(this);
}

void InstantLoader::PaintObserverImpl::RenderWidgetHostDidPaint(
    RenderWidgetHost* rwh) {
  TabContentsDelegateImpl* delegate = delegate_;
  // Set the paint observer to NULL, which deletes us. Showing the preview may
  // reset the paint observer, and delete us. By resetting the delegate first we
  // know we've been deleted and can deal correctly.
  rwh->set_paint_observer(NULL);
  // WARNING: we've been deleted.
  if (delegate)
    delegate->PreviewPainted();
}

InstantLoader::InstantLoader(InstantLoaderDelegate* delegate, TemplateURLID id)
    : delegate_(delegate),
      template_url_id_(id),
      ready_(false),
      last_transition_type_(PageTransition::LINK) {
  preview_tab_contents_delegate_.reset(new TabContentsDelegateImpl(this));
}

InstantLoader::~InstantLoader() {
  registrar_.RemoveAll();

  preview_tab_contents_delegate_->Reset();

  // Delete the TabContents before the delegate as the TabContents holds a
  // reference to the delegate.
  preview_contents_.reset();
}

void InstantLoader::Update(TabContentsWrapper* tab_contents,
                           const TemplateURL* template_url,
                           const GURL& url,
                           PageTransition::Type transition_type,
                           const string16& user_text,
                           bool verbatim,
                           string16* suggested_text) {
  // Strip leading ?.
  string16 new_user_text =
      !user_text.empty() && (UTF16ToWide(user_text)[0] == L'?') ?
      user_text.substr(1) : user_text;

  // We should preserve the transition type regardless of whether we're already
  // showing the url.
  last_transition_type_ = transition_type;

  // If state hasn't changed, just reuse the last suggestion. If the user
  // modifies the text of the omnibox in anyway the URL changes. We also need to
  // update if verbatim changes and we're showing instant results. We have to be
  // careful in checking user_text as in some situations InstantController
  // passes in an empty string (when it knows the user_text won't matter). In
  // these cases, we don't worry about whether the new user text matches the old
  // user text.
  if ((url_ == url) &&
      (new_user_text.empty() || user_text_ == new_user_text) &&
      (!template_url || verbatim == verbatim_)) {
    suggested_text->assign(last_suggestion_);
    return;
  }

  DCHECK(!url.is_empty() && url.is_valid());

  url_ = url;
  user_text_ = new_user_text;
  verbatim_ = verbatim;
  last_suggestion_.clear();

  bool created_preview_contents = preview_contents_.get() == NULL;
  if (created_preview_contents)
    CreatePreviewContents(tab_contents);

  preview_tab_contents_delegate_->PrepareForNewLoad();

  if (template_url) {
    DCHECK(template_url_id_ == template_url->id());
    if (!created_preview_contents) {
      if (is_waiting_for_load()) {
        // The page hasn't loaded yet. We'll send the script down when it does.
        frame_load_observer_->set_text(user_text_);
        frame_load_observer_->set_verbatim(verbatim);
        preview_tab_contents_delegate_->set_user_typed_before_load();
        return;
      }
      preview_contents_->render_view_host()->SearchBoxChange(
          user_text_, verbatim, 0, 0);

      string16 complete_suggested_text_lower = l10n_util::ToLower(
          complete_suggested_text_);
      string16 user_text_lower = l10n_util::ToLower(user_text_);
      if (!verbatim &&
          complete_suggested_text_lower.size() > user_text_lower.size() &&
          !complete_suggested_text_lower.compare(0, user_text_lower.size(),
                                                 user_text_lower)) {
        *suggested_text = last_suggestion_ =
            complete_suggested_text_.substr(user_text_.size());
      }
    } else {
      // Load the instant URL. We don't reflect the url we load in url() as
      // callers expect that we're loading the URL they tell us to.
      //
      // This uses an empty string for the replacement text as the url doesn't
      // really have the search params, but we need to use the replace
      // functionality so that embeded tags (like {google:baseURL}) are escaped
      // correctly.
      // TODO(sky): having to use a replaceable url is a bit of a hack here.
      GURL instant_url(
          template_url->instant_url()->ReplaceSearchTerms(
              *template_url, std::wstring(), -1, std::wstring()));
      CommandLine* cl = CommandLine::ForCurrentProcess();
      if (cl->HasSwitch(switches::kInstantURL))
        instant_url = GURL(cl->GetSwitchValueASCII(switches::kInstantURL));
      preview_contents_->controller().LoadURL(
          instant_url, GURL(), transition_type);
      frame_load_observer_.reset(
          new FrameLoadObserver(preview_contents()->tab_contents(),
                                user_text_, verbatim));
    }
  } else {
    DCHECK(template_url_id_ == 0);
    frame_load_observer_.reset(NULL);
    preview_contents_->controller().LoadURL(url_, GURL(), transition_type);
  }
}

void InstantLoader::SetOmniboxBounds(const gfx::Rect& bounds) {
  if (omnibox_bounds_ == bounds)
    return;

  omnibox_bounds_ = bounds;
  if (preview_contents_.get() && is_showing_instant() &&
      !is_waiting_for_load()) {
    // Updating the bounds is rather expensive, and because of the async nature
    // of the omnibox the bounds can dance around a bit. Delay the update in
    // hopes of things settling down.
    if (update_bounds_timer_.IsRunning())
      update_bounds_timer_.Stop();
    update_bounds_timer_.Start(
        base::TimeDelta::FromMilliseconds(kUpdateBoundsDelayMS),
        this, &InstantLoader::ProcessBoundsChange);
  }
}

bool InstantLoader::IsMouseDownFromActivate() {
  return preview_tab_contents_delegate_->is_mouse_down_from_activate();
}

TabContentsWrapper* InstantLoader::ReleasePreviewContents(
    InstantCommitType type) {
  if (!preview_contents_.get())
    return NULL;

  // FrameLoadObserver is only used for instant results, and instant results are
  // only committed if active (when the FrameLoadObserver isn't installed).
  DCHECK(type == INSTANT_COMMIT_DESTROY || !frame_load_observer_.get());

  if (type != INSTANT_COMMIT_DESTROY && is_showing_instant()) {
    if (type == INSTANT_COMMIT_FOCUS_LOST)
      preview_contents_->render_view_host()->SearchBoxCancel();
    else
      preview_contents_->render_view_host()->SearchBoxSubmit(
          user_text_, type == INSTANT_COMMIT_PRESSED_ENTER);
  }
  omnibox_bounds_ = gfx::Rect();
  last_omnibox_bounds_ = gfx::Rect();
  url_ = GURL();
  user_text_.clear();
  complete_suggested_text_.clear();
  if (preview_contents_.get()) {
    if (type != INSTANT_COMMIT_DESTROY)
      preview_tab_contents_delegate_->CommitHistory();
    // Destroy the paint observer.
    // RenderWidgetHostView may be null during shutdown.
    if (preview_contents_->tab_contents()->GetRenderWidgetHostView()) {
      preview_contents_->tab_contents()->GetRenderWidgetHostView()->
          GetRenderWidgetHost()->set_paint_observer(NULL);
#if defined(OS_MACOSX)
      preview_contents_->tab_contents()->GetRenderWidgetHostView()->
          SetTakesFocusOnlyOnMouseDown(false);
      registrar_.Remove(
          this,
          NotificationType::RENDER_VIEW_HOST_CHANGED,
          Source<NavigationController>(&preview_contents_->controller()));
#endif
    }
    preview_contents_->set_delegate(NULL);
    preview_tab_contents_delegate_->Reset();
    ready_ = false;
  }
  update_bounds_timer_.Stop();
  return preview_contents_.release();
}

bool InstantLoader::ShouldCommitInstantOnMouseUp() {
  return delegate_->ShouldCommitInstantOnMouseUp();
}

void InstantLoader::CommitInstantLoader() {
  delegate_->CommitInstantLoader(this);
}

void InstantLoader::SetCompleteSuggestedText(
    const string16& complete_suggested_text) {
  ShowPreview();

  if (complete_suggested_text == complete_suggested_text_)
    return;

  if (verbatim_) {
    // Don't show suggest results for verbatim queries.
    return;
  }

  string16 user_text_lower = l10n_util::ToLower(user_text_);
  string16 complete_suggested_text_lower = l10n_util::ToLower(
      complete_suggested_text);
  last_suggestion_.clear();
  if (user_text_lower.compare(0, user_text_lower.size(),
                              complete_suggested_text_lower,
                              0, user_text_lower.size())) {
    // The user text no longer contains the suggested text, ignore it.
    complete_suggested_text_.clear();
    delegate_->SetSuggestedTextFor(this, string16());
    return;
  }

  complete_suggested_text_ = complete_suggested_text;
  last_suggestion_ = complete_suggested_text_.substr(user_text_.size());
  delegate_->SetSuggestedTextFor(this, last_suggestion_);
}

void InstantLoader::PreviewPainted() {
  // If instant is supported then we wait for the first suggest result before
  // showing the page.
  if (!template_url_id_)
    ShowPreview();
}

void InstantLoader::ShowPreview() {
  if (!ready_) {
    ready_ = true;
    delegate_->ShowInstantLoader(this);
  }
}

void InstantLoader::Observe(NotificationType type,
                            const NotificationSource& source,
                            const NotificationDetails& details) {
#if defined(OS_MACOSX)
  if (type.value == NotificationType::RENDER_VIEW_HOST_CHANGED) {
    if (preview_contents_->tab_contents()->GetRenderWidgetHostView()) {
      preview_contents_->tab_contents()->GetRenderWidgetHostView()->
          SetTakesFocusOnlyOnMouseDown(true);
    }
    return;
  }
#endif
  if (type.value == NotificationType::NAV_ENTRY_COMMITTED) {
    NavigationController::LoadCommittedDetails* load_details =
        Details<NavigationController::LoadCommittedDetails>(details).ptr();
    if (load_details->is_main_frame &&
        load_details->http_status_code == kHostBlacklistStatusCode) {
      delegate_->AddToBlacklist(this, load_details->entry->url());
    }
    return;
  }

  NOTREACHED() << "Got a notification we didn't register for.";
}

void InstantLoader::PageFinishedLoading() {
  frame_load_observer_.reset();
  // Wait for the user input before showing, this way the page should be up to
  // date by the time we show it.
}

// TODO(tonyg): This method only fires when the omnibox bounds change. It also
// needs to fire when the preview bounds change (e.g. open/close info bar).
gfx::Rect InstantLoader::GetOmniboxBoundsInTermsOfPreview() {
  gfx::Rect preview_bounds(delegate_->GetInstantBounds());
  gfx::Rect intersection(omnibox_bounds_.Intersect(preview_bounds));

  // Translate into window's coordinates.
  if (!intersection.IsEmpty()) {
    intersection.Offset(-preview_bounds.origin().x(),
                        -preview_bounds.origin().y());
  }

  // In the current Chrome UI, these must always be true so they sanity check
  // the above operations. In a future UI, these may be removed or adjusted.
  DCHECK_EQ(0, intersection.y());
  DCHECK_LE(0, intersection.x());
  DCHECK_LE(0, intersection.width());
  DCHECK_LE(0, intersection.height());

  return intersection;
}

void InstantLoader::PageDoesntSupportInstant(bool needs_reload) {
  frame_load_observer_.reset(NULL);

  delegate_->InstantLoaderDoesntSupportInstant(this);
}

void InstantLoader::ProcessBoundsChange() {
  if (last_omnibox_bounds_ == omnibox_bounds_)
    return;

  last_omnibox_bounds_ = omnibox_bounds_;
  if (preview_contents_.get() && is_showing_instant() &&
      !is_waiting_for_load()) {
    preview_contents_->render_view_host()->SearchBoxResize(
        GetOmniboxBoundsInTermsOfPreview());
  }
}

void InstantLoader::CreatePreviewContents(TabContentsWrapper* tab_contents) {
  TabContents* new_contents =
      new TabContents(
          tab_contents->profile(), NULL, MSG_ROUTING_NONE, NULL, NULL);
  preview_contents_.reset(new TabContentsWrapper(new_contents));
  new_contents->SetAllContentsBlocked(true);
  // Propagate the max page id. That way if we end up merging the two
  // NavigationControllers (which happens if we commit) none of the page ids
  // will overlap.
  int32 max_page_id = tab_contents->tab_contents()->GetMaxPageID();
  if (max_page_id != -1)
    preview_contents_->controller().set_max_restored_page_id(max_page_id + 1);

  new_contents->set_delegate(preview_tab_contents_delegate_.get());

  gfx::Rect tab_bounds;
  tab_contents->view()->GetContainerBounds(&tab_bounds);
  preview_contents_->view()->SizeContents(tab_bounds.size());

#if defined(OS_MACOSX)
  // If |preview_contents_| does not currently have a RWHV, we will call
  // SetTakesFocusOnlyOnMouseDown() as a result of the
  // RENDER_VIEW_HOST_CHANGED notification.
  if (preview_contents_->tab_contents()->GetRenderWidgetHostView()) {
    preview_contents_->tab_contents()->GetRenderWidgetHostView()->
        SetTakesFocusOnlyOnMouseDown(true);
  }
  registrar_.Add(
      this,
      NotificationType::RENDER_VIEW_HOST_CHANGED,
      Source<NavigationController>(&preview_contents_->controller()));
#endif

  registrar_.Add(
      this,
      NotificationType::NAV_ENTRY_COMMITTED,
      Source<NavigationController>(&preview_contents_->controller()));

  preview_contents_->tab_contents()->ShowContents();
}