Implementation for switching between recently used tabs using ctrl tilde or quoteleft.

chrome/browser/tabs/tab_mru_list_manager.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/tabs/tab_mru_list_manager.h"
+
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+
+///////////////////////////////////////////////////////////////////////////////
+// TabMRUListManager, public:
+
+TabMRUListManager::~TabMRUListManager() {
+  tabs_mru_list_.clear();
+}
+
+void TabMRUListManager::ActivateContents(TabContentsWrapper* new_contents) {
+  if (!new_contents)
+    return;
+
+  // Bring the activated tab content to the front of the list
+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(),
+                tabs_mru_list_.end(),
+                new_contents);
+  if (it != tabs_mru_list_.end()) {
+    tabs_mru_list_.push_front(*it);
+    tabs_mru_list_.erase(it);
+  } else {
+    tabs_mru_list_.push_front(new_contents);
+  }
+}
+
+void TabMRUListManager::AppendContents(TabContentsWrapper* new_contents) {
+  if (!new_contents)
+    return;
+
+  // Bring the activated tab content to the front of the list
+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(),
+                tabs_mru_list_.end(),
+                new_contents);
+  // Append only if the content are not present in the list.
+  // This will avoid duplicates.
+  if (it == tabs_mru_list_.end()) {
+    tabs_mru_list_.push_back(new_contents);
+  }
+}
+
+void TabMRUListManager::ClearContents() {
+  tabs_mru_list_.clear();
+}
+
+TabContentsWrapper* TabMRUListManager::GetNextMRUTab() {
+  std::list<TabContentsWrapper*>::iterator it = tabs_mru_list_.begin();
+  // Advance to second element in MRU list if there are more than one tabs open.
+  if (tabs_mru_list_.size() > 1) {
+    std::advance(it, 1);
+  }
+  return *it;
+}
+
+void TabMRUListManager::RemoveContents(TabContentsWrapper* removed_contents) {
+  // Remove the contents if found in MRU List
+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(),
+                tabs_mru_list_.end(),
+                removed_contents);
+  if (it != tabs_mru_list_.end()) {
+    tabs_mru_list_.erase(it);
+  }
+}
+
+void TabMRUListManager::ReplaceContents(
+    TabContentsWrapper* old_contents, TabContentsWrapper* new_contents) {
+  // Replace the tab contents accordingly in the list. If the tab contents are
+  // not found add to the end of the list.
+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(),
+                tabs_mru_list_.end(),
+                old_contents);
+  if (it != tabs_mru_list_.end()) {
+    tabs_mru_list_.insert(it,new_contents);
+    tabs_mru_list_.erase(it);
+  }
+}