Add TabWebContentsTracker

chrome/browser/ui/tab_webcontents_tracker.cc

Index: chrome/browser/ui/tab_webcontents_tracker.cc
diff --git a/chrome/browser/ui/tab_webcontents_tracker.cc b/chrome/browser/ui/tab_webcontents_tracker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e7415f28eda8a8600214b812ac7ee2dda67b4a7a
--- /dev/null
+++ b/chrome/browser/ui/tab_webcontents_tracker.cc
@@ -0,0 +1,90 @@
+// Copyright (c) 2013 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/tab_webcontents_tracker.h"
+
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "content/public/browser/web_contents.h"
+
+// static
+TabWebContentsTracker* TabWebContentsTracker::GetInstance() {
+  return Singleton<TabWebContentsTracker,
+                   DefaultSingletonTraits<TabWebContentsTracker> >::get();

[Bernhard Bauer, 2013/04/26 16:30:10]

I think DefaultSingletonTraits is the default, so it can be omitted, right?

+}
+
+TabWebContentsTracker::TabWebContentsTracker() {
+  BrowserList::AddObserver(this);
+  // Add as observer of all tab strip models currently available.
+  BrowserList* browser_list =
+      BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE);
+  BrowserList::const_iterator it = browser_list->begin();

[Bernhard Bauer, 2013/04/26 16:30:10]

Could you put this into a for loop? That's slightly more idiomatic.

+  while (it != browser_list->end()) {
+    (*it)->tab_strip_model()->AddObserver(this);
+    ++it;
+  }
+}
+
+TabWebContentsTracker::~TabWebContentsTracker() {
+  BrowserList::RemoveObserver(this);
+}
+
+void TabWebContentsTracker::OnBrowserAdded(Browser* browser) {
+  browser->tab_strip_model()->AddObserver(this);
+}
+
+void TabWebContentsTracker::OnBrowserRemoved(Browser* browser) {
+  browser->tab_strip_model()->RemoveObserver(this);
+}
+
+void TabWebContentsTracker::ActiveTabChanged(content::WebContents* old_contents,
+                                             content::WebContents* new_contents,
+                                             int index,
+                                             int reason) {
+  FOR_EACH_OBSERVER(

[Bernhard Bauer, 2013/04/26 16:30:10]

Hmm... Instead of forwarding all these methods from TabStripModelObserver
(assuming that we're using TabStripModelObserver in place of
TabWebContentsTracker::Observer), couldn't we directly add the observers as
observers of the tab strip model? And going a bit further, then we could make
this class a member of every ManagedModeNavigationObserver instead of a
singleton with a list of observers. And *then* we could even optimize a bit by
only registering ourselves as observers of TabStripModels in our own profile
(because we might get moved between browsers, but not between profiles).

+      Observer,
+      observer_list_,
+      OnActiveTabChanged(old_contents, new_contents, index, reason));
+}
+
+void TabWebContentsTracker::TabInsertedAt(content::WebContents* contents,
+                                          int index,
+                                          bool foreground) {
+  FOR_EACH_OBSERVER(
+      Observer, observer_list_, OnTabInsertedAt(contents, index, foreground));
+}
+
+void TabWebContentsTracker::TabClosingAt(TabStripModel* tab_strip_model,
+                                         content::WebContents* contents,
+                                         int index) {
+  FOR_EACH_OBSERVER(Observer,
+                    observer_list_,
+                    OnTabClosingAt(tab_strip_model, contents, index));
+}
+
+void TabWebContentsTracker::TabDetachedAt(content::WebContents* contents,
+                                             int index) {
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnTabDetachedAt(contents, index));
+}
+
+void TabWebContentsTracker::TabReplacedAt(TabStripModel* tab_strip_model,
+                                          content::WebContents* old_contents,
+                                          content::WebContents* new_contents,
+                                          int index) {
+  FOR_EACH_OBSERVER(
+      Observer,
+      observer_list_,
+      OnTabReplacedAt(tab_strip_model, old_contents, new_contents, index));
+}
+
+// static
+void TabWebContentsTracker::AddObserver(Observer* observer) {
+  GetInstance()->observer_list_.AddObserver(observer);
+}
+
+// static
+void TabWebContentsTracker::RemoveObserver(Observer* observer) {
+  GetInstance()->observer_list_.RemoveObserver(observer);
+}