NTP Zombie Code Slayer II: Suggestions Page

chrome/browser/ui/webui/ntp/suggestions_combiner.cc

-// Copyright (c) 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/ui/webui/ntp/suggestions_combiner.h"
-
-#include <algorithm>
-
-#include "base/values.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/ui/browser.h"
-#include "chrome/browser/ui/browser_iterator.h"
-#include "chrome/browser/ui/tabs/tab_strip_model.h"
-#include "chrome/browser/ui/webui/ntp/suggestions_page_handler.h"
-#include "chrome/browser/ui/webui/ntp/suggestions_source.h"
-#include "content/public/browser/web_contents.h"
-
-namespace {
-
-static const size_t kSuggestionsCount = 8;
-
-}  // namespace
-
-SuggestionsCombiner::SuggestionsCombiner(
-    SuggestionsCombiner::Delegate* delegate,
-    Profile* profile)
-    : sources_fetching_count_(0),
-      delegate_(delegate),
-      suggestions_count_(kSuggestionsCount),
-      page_values_(new base::ListValue()),
-      debug_enabled_(false),
-      profile_(profile) {
-}
-
-SuggestionsCombiner::~SuggestionsCombiner() {
-}
-
-void SuggestionsCombiner::AddSource(SuggestionsSource* source) {
-  source->SetCombiner(this);
-  source->SetDebug(debug_enabled_);
-  sources_.push_back(source);
-}
-
-void SuggestionsCombiner::EnableDebug(bool enable) {
-  debug_enabled_ = enable;
-  for (size_t i = 0; i < sources_.size(); ++i) {
-    sources_[i]->SetDebug(enable);
-  }
-}
-
-void SuggestionsCombiner::FetchItems(Profile* profile) {
-  sources_fetching_count_ = sources_.size();
-  for (size_t i = 0; i < sources_.size(); ++i) {
-    sources_[i]->FetchItems(profile);
-  }
-}
-
-base::ListValue* SuggestionsCombiner::GetPageValues() {
-  return page_values_.get();
-}
-
-void SuggestionsCombiner::OnItemsReady() {
-  DCHECK_GT(sources_fetching_count_, 0);
-  sources_fetching_count_--;
-  if (sources_fetching_count_ == 0) {
-    FillPageValues();
-    delegate_->OnSuggestionsReady();
-  }
-}
-
-void SuggestionsCombiner::SetSuggestionsCount(size_t suggestions_count) {
-  suggestions_count_ = suggestions_count;
-}
-
-void SuggestionsCombiner::FillPageValues() {
-  int total_weight = 0;
-  for (size_t i = 0; i < sources_.size(); ++i)
-    total_weight += sources_[i]->GetWeight();
-  DCHECK_GT(total_weight, 0);
-
-  page_values_.reset(new base::ListValue());
-
-  // Evaluate how many items to obtain from each source. We use error diffusion
-  // to ensure that we get the total desired number of items.
-  int error = 0;
-
-  // Holds the index at which the next item should be added for each source.
-  std::vector<size_t> next_item_index_for_source;
-  next_item_index_for_source.reserve(sources_.size());
-  for (size_t i = 0; i < sources_.size(); ++i) {
-    int numerator = sources_[i]->GetWeight() * suggestions_count_ + error;
-    error = numerator % total_weight;
-    int item_count = std::min(numerator / total_weight,
-        sources_[i]->GetItemCount());
-
-    for (int j = 0; j < item_count; ++j)
-      page_values_->Append(sources_[i]->PopItem());
-    next_item_index_for_source.push_back(page_values_->GetSize());
-  }
-
-  // Fill in extra items, prioritizing the first source.
-  // Rather than updating |next_item_index_for_source| we keep track of the
-  // number of extra items that were added and offset indices by that much.
-  size_t extra_items_added = 0;
-  for (size_t i = 0; i < sources_.size() &&
-      page_values_->GetSize() < suggestions_count_; ++i) {
-
-    size_t index = next_item_index_for_source[i] + extra_items_added;
-    while (page_values_->GetSize() < suggestions_count_) {
-      base::DictionaryValue* item = sources_[i]->PopItem();
-      if (!item)
-        break;
-      page_values_->Insert(index++, item);
-      extra_items_added++;
-    }
-  }
-
-  // Add page value information common to all sources.
-  for (size_t i = 0; i < page_values_->GetSize(); i++) {
-    base::DictionaryValue* page_value;
-    if (page_values_->GetDictionary(i, &page_value))
-      AddExtendedInformation(page_value);
-  }
-}
-
-void SuggestionsCombiner::AddExtendedInformation(
-    base::DictionaryValue* page_value) {
-  if (debug_enabled_) {
-    std::string url_string;
-    if (page_value->GetString("url", &url_string)) {
-      GURL url(url_string);
-      page_value->SetBoolean("already_open", IsUrlAlreadyOpen(url));
-    }
-  }
-}
-
-bool SuggestionsCombiner::IsUrlAlreadyOpen(const GURL &url) {
-  for (chrome::BrowserIterator it; !it.done(); it.Next()) {
-    const Browser* browser = *it;
-    if (browser->profile()->IsOffTheRecord() ||
-        !browser->profile()->IsSameProfile(profile_))
-      continue;
-
-    for (int i = 0; i < browser->tab_strip_model()->count(); i++) {
-      const content::WebContents* tab =
-          browser->tab_strip_model()->GetWebContentsAt(i);
-      if (tab->GetURL() == url)
-        return true;
-    }
-  }
-  return false;
-}