Revert of [ios] Move WebStateList to ios/chrome/browser/web_state_list.

ios/chrome/browser/web_state_list/web_state_list.mm

-// Copyright 2017 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.
-
-#import "ios/chrome/browser/web_state_list/web_state_list.h"
-
-#include <algorithm>
-#include <utility>
-
-#include "base/logging.h"
-#include "base/memory/ptr_util.h"
-#import "ios/chrome/browser/web_state_list/web_state_list_delegate.h"
-#import "ios/chrome/browser/web_state_list/web_state_list_observer.h"
-#import "ios/chrome/browser/web_state_list/web_state_list_order_controller.h"
-#import "ios/chrome/browser/web_state_list/web_state_opener.h"
-#import "ios/web/public/navigation_manager.h"
-#import "ios/web/public/web_state/web_state.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-// Wrapper around a WebState stored in a WebStateList.
-class WebStateList::WebStateWrapper {
- public:
-  explicit WebStateWrapper(std::unique_ptr<web::WebState> web_state);
-  ~WebStateWrapper();
-
-  web::WebState* web_state() const { return web_state_.get(); }
-
-  // Replaces the wrapped WebState (and clear associated state) and returns the
-  // old WebState after forfeiting ownership.
-  std::unique_ptr<web::WebState> ReplaceWebState(
-      std::unique_ptr<web::WebState> web_state);
-
-  // Gets and sets information about this WebState opener. The navigation index
-  // is used to detect navigation changes during the same session.
-  WebStateOpener opener() const { return opener_; }
-  void set_opener(WebStateOpener opener) { opener_ = opener; }
-
-  // Returns whether |opener| spawned the wrapped WebState. If |use_group| is
-  // true, also use the opener navigation index to detect navigation changes
-  // during the same session.
-  bool WasOpenedBy(const web::WebState* opener,
-                   int opener_navigation_index,
-                   bool use_group) const;
-
- private:
-  std::unique_ptr<web::WebState> web_state_;
-  WebStateOpener opener_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebStateWrapper);
-};
-
-WebStateList::WebStateWrapper::WebStateWrapper(
-    std::unique_ptr<web::WebState> web_state)
-    : web_state_(std::move(web_state)), opener_(nullptr) {
-  DCHECK(web_state_);
-}
-
-WebStateList::WebStateWrapper::~WebStateWrapper() = default;
-
-std::unique_ptr<web::WebState> WebStateList::WebStateWrapper::ReplaceWebState(
-    std::unique_ptr<web::WebState> web_state) {
-  DCHECK_NE(web_state.get(), web_state_.get());
-  std::swap(web_state, web_state_);
-  opener_ = WebStateOpener(nullptr);
-  return web_state;
-}
-
-bool WebStateList::WebStateWrapper::WasOpenedBy(const web::WebState* opener,
-                                                int opener_navigation_index,
-                                                bool use_group) const {
-  DCHECK(opener);
-  if (opener_.opener != opener)
-    return false;
-
-  if (!use_group)
-    return true;
-
-  return opener_.navigation_index == opener_navigation_index;
-}
-
-WebStateList::WebStateList(WebStateListDelegate* delegate)
-    : delegate_(delegate),
-      order_controller_(base::MakeUnique<WebStateListOrderController>(this)) {
-  DCHECK(delegate_);
-}
-
-WebStateList::~WebStateList() {
-  CloseAllWebStates();
-}
-
-bool WebStateList::ContainsIndex(int index) const {
-  return 0 <= index && index < count();
-}
-
-web::WebState* WebStateList::GetActiveWebState() const {
-  if (active_index_ != kInvalidIndex)
-    return GetWebStateAt(active_index_);
-  return nullptr;
-}
-
-web::WebState* WebStateList::GetWebStateAt(int index) const {
-  DCHECK(ContainsIndex(index));
-  return web_state_wrappers_[index]->web_state();
-}
-
-int WebStateList::GetIndexOfWebState(const web::WebState* web_state) const {
-  for (int index = 0; index < count(); ++index) {
-    if (web_state_wrappers_[index]->web_state() == web_state)
-      return index;
-  }
-  return kInvalidIndex;
-}
-
-WebStateOpener WebStateList::GetOpenerOfWebStateAt(int index) const {
-  DCHECK(ContainsIndex(index));
-  return web_state_wrappers_[index]->opener();
-}
-
-void WebStateList::SetOpenerOfWebStateAt(int index, WebStateOpener opener) {
-  DCHECK(ContainsIndex(index));
-  DCHECK(ContainsIndex(GetIndexOfWebState(opener.opener)));
-  web_state_wrappers_[index]->set_opener(opener);
-}
-
-int WebStateList::GetIndexOfNextWebStateOpenedBy(const web::WebState* opener,
-                                                 int start_index,
-                                                 bool use_group) const {
-  return GetIndexOfNthWebStateOpenedBy(opener, start_index, use_group, 1);
-}
-
-int WebStateList::GetIndexOfLastWebStateOpenedBy(const web::WebState* opener,
-                                                 int start_index,
-                                                 bool use_group) const {
-  return GetIndexOfNthWebStateOpenedBy(opener, start_index, use_group, INT_MAX);
-}
-
-void WebStateList::InsertWebState(int index,
-                                  std::unique_ptr<web::WebState> web_state) {
-  DCHECK(ContainsIndex(index) || index == count());
-  delegate_->WillAddWebState(web_state.get());
-
-  web::WebState* web_state_ptr = web_state.get();
-  web_state_wrappers_.insert(
-      web_state_wrappers_.begin() + index,
-      base::MakeUnique<WebStateWrapper>(std::move(web_state)));
-
-  if (active_index_ >= index)
-    ++active_index_;
-
-  for (auto& observer : observers_)
-    observer.WebStateInsertedAt(this, web_state_ptr, index);
-}
-
-void WebStateList::AppendWebState(ui::PageTransition transition,
-                                  std::unique_ptr<web::WebState> web_state,
-                                  WebStateOpener opener) {
-  int index =
-      order_controller_->DetermineInsertionIndex(transition, opener.opener);
-  if (index < 0 || count() < index)
-    index = count();
-
-  InsertWebState(index, std::move(web_state));
-
-  if (opener.opener)
-    SetOpenerOfWebStateAt(index, opener);
-}
-
-void WebStateList::MoveWebStateAt(int from_index, int to_index) {
-  DCHECK(ContainsIndex(from_index));
-  DCHECK(ContainsIndex(to_index));
-  if (from_index == to_index)
-    return;
-
-  std::unique_ptr<WebStateWrapper> web_state_wrapper =
-      std::move(web_state_wrappers_[from_index]);
-  web::WebState* web_state = web_state_wrapper->web_state();
-  web_state_wrappers_.erase(web_state_wrappers_.begin() + from_index);
-  web_state_wrappers_.insert(web_state_wrappers_.begin() + to_index,
-                             std::move(web_state_wrapper));
-
-  if (active_index_ == from_index) {
-    active_index_ = to_index;
-  } else {
-    int min = std::min(from_index, to_index);
-    int max = std::max(from_index, to_index);
-    int delta = from_index < to_index ? -1 : +1;
-    if (min <= active_index_ && active_index_ <= max)
-      active_index_ += delta;
-  }
-
-  for (auto& observer : observers_)
-    observer.WebStateMoved(this, web_state, from_index, to_index);
-}
-
-std::unique_ptr<web::WebState> WebStateList::ReplaceWebStateAt(
-    int index,
-    std::unique_ptr<web::WebState> web_state) {
-  DCHECK(ContainsIndex(index));
-  delegate_->WillAddWebState(web_state.get());
-
-  ClearOpenersReferencing(index);
-
-  web::WebState* web_state_ptr = web_state.get();
-  std::unique_ptr<web::WebState> old_web_state =
-      web_state_wrappers_[index]->ReplaceWebState(std::move(web_state));
-
-  for (auto& observer : observers_)
-    observer.WebStateReplacedAt(this, old_web_state.get(), web_state_ptr,
-                                index);
-
-  delegate_->WebStateDetached(old_web_state.get());
-  return old_web_state;
-}
-
-std::unique_ptr<web::WebState> WebStateList::DetachWebStateAt(int index) {
-  DCHECK(ContainsIndex(index));
-  int new_active_index = order_controller_->DetermineNewActiveIndex(index);
-
-  web::WebState* web_state = web_state_wrappers_[index]->web_state();
-  for (auto& observer : observers_)
-    observer.WillDetachWebStateAt(this, web_state, index);
-
-  ClearOpenersReferencing(index);
-  std::unique_ptr<web::WebState> detached_web_state =
-      web_state_wrappers_[index]->ReplaceWebState(nullptr);
-  web_state_wrappers_.erase(web_state_wrappers_.begin() + index);
-
-  // Update the active index to prevent observer from seeing an invalid WebState
-  // as the active one but only send the WebStateActivatedAt notification after
-  // the WebStateDetachedAt one.
-  bool active_web_state_was_closed = (index == active_index_);
-  if (active_index_ > index)
-    --active_index_;
-  else if (active_index_ == index)
-    active_index_ = new_active_index;
-
-  for (auto& observer : observers_)
-    observer.WebStateDetachedAt(this, web_state, index);
-
-  if (active_web_state_was_closed)
-    NotifyIfActiveWebStateChanged(web_state, false);
-
-  delegate_->WebStateDetached(web_state);
-  return detached_web_state;
-}
-
-void WebStateList::CloseWebStateAt(int index) {
-  auto detached_web_state = DetachWebStateAt(index);
-
-  for (auto& observer : observers_)
-    observer.WillCloseWebStateAt(this, detached_web_state.get(), index);
-
-  detached_web_state.reset();
-}
-
-void WebStateList::CloseAllWebStates() {
-  while (!empty())
-    CloseWebStateAt(count() - 1);
-}
-
-void WebStateList::ActivateWebStateAt(int index) {
-  DCHECK(ContainsIndex(index));
-  web::WebState* old_web_state = GetActiveWebState();
-  active_index_ = index;
-  NotifyIfActiveWebStateChanged(old_web_state, true);
-}
-
-void WebStateList::AddObserver(WebStateListObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void WebStateList::RemoveObserver(WebStateListObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-void WebStateList::ClearOpenersReferencing(int index) {
-  web::WebState* old_web_state = web_state_wrappers_[index]->web_state();
-  for (auto& web_state_wrapper : web_state_wrappers_) {
-    if (web_state_wrapper->opener().opener == old_web_state)
-      web_state_wrapper->set_opener(WebStateOpener(nullptr));
-  }
-}
-
-void WebStateList::NotifyIfActiveWebStateChanged(web::WebState* old_web_state,
-                                                 bool user_action) {
-  web::WebState* new_web_state = GetActiveWebState();
-  if (old_web_state == new_web_state)
-    return;
-
-  for (auto& observer : observers_) {
-    observer.WebStateActivatedAt(this, old_web_state, new_web_state,
-                                 active_index_, user_action);
-  }
-}
-
-int WebStateList::GetIndexOfNthWebStateOpenedBy(const web::WebState* opener,
-                                                int start_index,
-                                                bool use_group,
-                                                int n) const {
-  DCHECK_GT(n, 0);
-  if (!opener || !ContainsIndex(start_index) || start_index == INT_MAX)
-    return kInvalidIndex;
-
-  const int opener_navigation_index =
-      use_group ? opener->GetNavigationManager()->GetLastCommittedItemIndex()
-                : -1;
-
-  int found_index = kInvalidIndex;
-  for (int index = start_index + 1; index < count() && n; ++index) {
-    if (web_state_wrappers_[index]->WasOpenedBy(opener, opener_navigation_index,
-                                                use_group)) {
-      found_index = index;
-      --n;
-    } else if (found_index != kInvalidIndex) {
-      return found_index;
-    }
-  }
-
-  return found_index;
-}
-
-// static
-const int WebStateList::kInvalidIndex;