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

chrome/browser/ui/tabs/tab_mru_list_manager.cc

Index: chrome/browser/ui/tabs/tab_mru_list_manager.cc
diff --git a/chrome/browser/ui/tabs/tab_mru_list_manager.cc b/chrome/browser/ui/tabs/tab_mru_list_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0b8872ba2499226e441186192ec8d949cc9d1e2c
--- /dev/null
+++ b/chrome/browser/ui/tabs/tab_mru_list_manager.cc
@@ -0,0 +1,90 @@
+// 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/tabs/tab_mru_list_manager.h"
+
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+
+///////////////////////////////////////////////////////////////////////////////
+// TabMRUListManager, public:
+
+///////////////////////////////////////////////////////////////////////////////
+// TabMRUListManager, TabStripModelObserver implementation:
+
+TabMRUListManager::TabMRUListManager() {
+}
+
+TabMRUListManager::~TabMRUListManager() {
+  tabs_mru_list_.clear();
+}
+
+void TabMRUListManager::TabInsertedAt(TabContentsWrapper* contents,
+                                      int index,
+                                      bool foreground) {
+  tabs_mru_list_.push_front(contents);

[sky, 2012/05/29 19:48:28]

You only want to add to the front if foreground is true.

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

Done.

+}
+
+void TabMRUListManager::TabClosingAt(TabStripModel* tab_strip_model,
+                                     TabContentsWrapper* contents,
+                                     int index) {
+  // Remove the index if found in MRU List

[sky, 2012/05/29 19:48:28]

You shouldn't need to override this. Instead put logic in TabDetachedAt.

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

Done.

+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(), tabs_mru_list_.end(), contents);
+  if (it != tabs_mru_list_.end()) {
+    tabs_mru_list_.erase(it);
+  }
+}
+
+void TabMRUListManager::TabDetachedAt(TabContentsWrapper* contents,
+                                      int index) {
+  // Remove the index if found in MRU List
+  std::list<TabContentsWrapper*>::iterator it =
+      std::find(tabs_mru_list_.begin(), tabs_mru_list_.end(), contents);
+  if (it != tabs_mru_list_.end()) {
+    tabs_mru_list_.erase(it);
+  }
+}
+
+void TabMRUListManager::ActiveTabChanged(TabContentsWrapper* old_contents,
+                                         TabContentsWrapper* new_contents,
+                                         int index,
+                                         bool user_gesture) {
+  // 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);

[sky, 2012/05/29 19:48:28]

You should always push_front, right?

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

This case would arrive if the tab is manually activated by the user. Then MRU
list item corresponding to this has to be brought to the front.

+  }
+}
+
+void TabMRUListManager::TabReplacedAt(TabStripModel* tab_strip_model,
+                                      TabContentsWrapper* old_contents,
+                                      TabContentsWrapper* new_contents,
+                                      int index) {
+  // 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);
+  } else {
+    tabs_mru_list_.push_back(new_contents);

[sky, 2012/05/29 19:48:28]

This should be NOTREACHED

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

Done.

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

Done.

+  }
+}
+
+void TabMRUListManager::TabStripEmpty() {
+  tabs_mru_list_.clear();
+}
+
+// Public Methods
+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;

[sky, 2012/05/29 19:48:28]

This will crash if empty.

[NaveenBobbili (Motorola), 2012/06/05 05:34:16]

Done.

+}