Upstream Chrome on iOS source code [6/11].

ios/chrome/browser/ui/ntp/recent_tabs/synced_sessions.mm

+// Copyright 2014 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 "ios/chrome/browser/ui/ntp/recent_tabs/synced_sessions.h"
+
+#include <functional>
+#include <memory>
+
+#include "base/logging.h"
+#include "base/mac/scoped_nsobject.h"
+#include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial.h"
+#include "base/strings/utf_string_conversions.h"
+#include "components/sync/driver/sync_service.h"
+#include "components/sync_sessions/open_tabs_ui_delegate.h"
+#include "ios/chrome/browser/sync/sync_setup_service.h"
+
+namespace {
+
+// Comparator function for sorting the sessions_ vector so that the most
+// recently used sessions are at the beginning.
+bool SortSessionsByTime(
+    std::unique_ptr<const synced_sessions::DistantSession>& a,
+    std::unique_ptr<const synced_sessions::DistantSession>& b) {
+  return a->modified_time > b->modified_time;
+}
+
+// Helper to extract the relevant content from a SessionTab and add it to a
+// DistantSession.
+void AddTabToDistantSession(const sessions::SessionTab& session_tab,
+                            const std::string& session_tag,
+                            synced_sessions::DistantSession* distant_session) {
+  if (session_tab.navigations.size() > 0) {
+    distant_session->tabs.push_back(
+        base::MakeUnique<synced_sessions::DistantTab>());
+    synced_sessions::DistantTab& distant_tab = *distant_session->tabs.back();
+    distant_tab.session_tag = session_tag;
+    distant_tab.tab_id = session_tab.tab_id.id();
+    int index = session_tab.current_navigation_index;
+    if (index < 0)
+      index = 0;
+    if (index > (int)session_tab.navigations.size() - 1)
+      index = session_tab.navigations.size() - 1;
+    const sessions::SerializedNavigationEntry* navigation =
+        &session_tab.navigations[index];
+    distant_tab.title = navigation->title();
+    distant_tab.virtual_url = navigation->virtual_url();
+    if (distant_tab.title.empty()) {
+      std::string url = navigation->virtual_url().spec();
+      distant_tab.title = base::UTF8ToUTF16(url);
+    }
+  }
+}
+
+}  // namespace
+
+namespace synced_sessions {
+
+DistantTab::DistantTab() {}
+
+size_t DistantTab::hashOfUserVisibleProperties() {
+  std::stringstream ss;
+  ss << title << std::endl << virtual_url.spec();
+  return std::hash<std::string>()(ss.str());
+}
+
+DistantSession::DistantSession() {}
+
+DistantSession::DistantSession(syncer::SyncService* sync_service,
+                               const std::string& tag) {
+  if (sync_service->CanSyncStart() && sync_service->GetOpenTabsUIDelegate()) {
+    sync_sessions::OpenTabsUIDelegate* open_tabs =
+        sync_service->GetOpenTabsUIDelegate();
+
+    std::vector<const sync_sessions::SyncedSession*> sessions;
+    open_tabs->GetAllForeignSessions(&sessions);
+    for (const auto& session : sessions) {
+      if (tag == session->session_tag) {
+        this->InitWithSyncedSession(session, open_tabs);
+      }
+    }
+  }
+}
+
+DistantSession::~DistantSession() {}
+
+void DistantSession::InitWithSyncedSession(
+    const sync_sessions::SyncedSession* synced_session,
+    sync_sessions::OpenTabsUIDelegate* open_tabs) {
+  tag = synced_session->session_tag;
+  name = synced_session->session_name;
+  modified_time = synced_session->modified_time;
+  device_type = synced_session->device_type;
+
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("TabSyncByRecency");
+  if (group_name == "Enabled") {
+    // Order tabs by recency.
+    std::vector<const sessions::SessionTab*> session_tabs;
+    open_tabs->GetForeignSessionTabs(synced_session->session_tag,
+                                     &session_tabs);
+    for (const auto& session_tab : session_tabs) {
+      AddTabToDistantSession(*session_tab, synced_session->session_tag, this);
+    }
+  } else {
+    // Order tabs by their visual position within window.
+    for (const auto& kv : synced_session->windows) {
+      for (const auto& session_tab : kv.second->tabs) {
+        AddTabToDistantSession(*session_tab, synced_session->session_tag, this);
+      }
+    }
+  }
+}
+
+SyncedSessions::SyncedSessions() {}
+
+SyncedSessions::SyncedSessions(syncer::SyncService* sync_service) {
+  DCHECK(sync_service);
+  // Reload Sync open tab sesions.
+  if (sync_service->CanSyncStart() && sync_service->GetOpenTabsUIDelegate()) {
+    sync_sessions::OpenTabsUIDelegate* open_tabs =
+        sync_service->GetOpenTabsUIDelegate();
+
+    // Iterating through all remote sessions, then all remote windows, then all
+    // remote tabs to retrieve the tabs to display to the user. This will
+    // flatten all of those data into a sequential vector of tabs.
+
+    std::vector<const sync_sessions::SyncedSession*> sessions;
+    open_tabs->GetAllForeignSessions(&sessions);
+    for (const auto& session : sessions) {
+      std::unique_ptr<DistantSession> distant_session(new DistantSession());
+      distant_session->InitWithSyncedSession(session, open_tabs);
+      // Don't display sessions with no tabs.
+      if (distant_session->tabs.size() > 0)
+        sessions_.push_back(std::move(distant_session));
+    }
+  }
+  std::sort(sessions_.begin(), sessions_.end(), SortSessionsByTime);
+}
+
+SyncedSessions::~SyncedSessions() {}
+
+// Returns the session at index |index|.
+DistantSession const* SyncedSessions::GetSession(size_t index) const {
+  DCHECK_LE(index, GetSessionCount());
+  return sessions_[index].get();
+}
+
+const DistantSession* SyncedSessions::GetSessionWithTag(
+    const std::string& tag) const {
+  for (auto const& distant_session : sessions_) {
+    if (distant_session->tag == tag) {
+      return distant_session.get();
+    }
+  }
+  return nullptr;
+}
+
+// Returns the number of distant sessions.
+size_t SyncedSessions::GetSessionCount() const {
+  return sessions_.size();
+}
+
+// Deletes the session at index |index|.
+void SyncedSessions::EraseSession(size_t index) {
+  DCHECK_LE(index, GetSessionCount());
+  sessions_.erase(sessions_.begin() + index);
+}
+
+void SyncedSessions::AddDistantSessionForTest(
+    std::unique_ptr<const DistantSession> distant_session) {
+  sessions_.push_back(std::move(distant_session));
+}
+
+}  // synced_sessions namespace