Uploaded & applied on behalf of Roger Tawa (rogerta@google.com).

BUG=11200
R=aa,rafaelw

http://codereview.chromium.org/115250

Review URL: http://codereview.chromium.org/113442

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16146 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 136 insertions, 20 deletions

diff --git a/chrome/browser/extensions/extension_browser_event_router.cc b/chrome/browser/extensions/extension_browser_event_router.cc
index f4853ea..869b02c 100644
--- a/chrome/browser/extensions/extension_browser_event_router.cc
+++ b/chrome/browser/extensions/extension_browser_event_router.cc
@@ -10,11 +10,11 @@
 #include "chrome/browser/profile.h"
 #include "chrome/browser/extensions/extension.h"
 #include "chrome/browser/extensions/extension_message_service.h"
-#include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/common/notification_service.h"
 
 const char* kOnPageActionExecuted = "page-action-executed";
 const char* kOnTabCreated = "tab-created";
+const char* kOnTabUpdated = "tab-updated";
 const char* kOnTabMoved = "tab-moved";
 const char* kOnTabSelectionChanged = "tab-selection-changed";
 const char* kOnTabAttached = "tab-attached";
@@ -24,6 +24,22 @@ const char* kOnWindowCreated = "window-created";
 const char* kOnWindowRemoved = "window-removed";
 const char* kOnWindowFocusedChanged = "window-focus-changed";
 
+ExtensionBrowserEventRouter::TabEntry::TabEntry()
+    : state_(ExtensionTabUtil::TAB_COMPLETE) {
+}
+
+ExtensionBrowserEventRouter::TabEntry::TabEntry(const TabContents* contents)
+    : state_(ExtensionTabUtil::TAB_COMPLETE) {
+  UpdateState(contents);
+}
+
+bool ExtensionBrowserEventRouter::TabEntry::UpdateState(
+    const TabContents* contents) {
+  ExtensionTabUtil::TabStatus old_state = state_;
+  state_ = ExtensionTabUtil::GetTabStatus(contents);
+  return old_state != state_;
+}
+
 ExtensionBrowserEventRouter* ExtensionBrowserEventRouter::GetInstance() {
   return Singleton<ExtensionBrowserEventRouter>::get();
 }
@@ -61,7 +77,7 @@ ExtensionBrowserEventRouter::ExtensionBrowserEventRouter()
 void ExtensionBrowserEventRouter::OnBrowserAdded(const Browser* browser) {
   // Start listening to TabStripModel events for this browser.
   browser->tabstrip_model()->AddObserver(this);
-  
+
   DispatchSimpleBrowserEvent(browser->profile(),
                              ExtensionTabUtil::GetWindowId(browser),
                              kOnWindowCreated);
@@ -99,8 +115,8 @@ void ExtensionBrowserEventRouter::TabInsertedAt(TabContents* contents,
                                                 bool foreground) {
   // If tab is new, send tab-created event.
   int tab_id = ExtensionTabUtil::GetTabId(contents);
-  if (tab_ids_.find(tab_id) == tab_ids_.end()) {
-    tab_ids_.insert(tab_id);
+  if (tab_entries_.find(tab_id) == tab_entries_.end()) {
+    tab_entries_[tab_id] = TabEntry(contents);
 
     TabCreatedAt(contents, index, foreground);
     return;
@@ -108,7 +124,7 @@ void ExtensionBrowserEventRouter::TabInsertedAt(TabContents* contents,
 
   ListValue args;
   args.Append(Value::CreateIntegerValue(tab_id));
-  
+
   DictionaryValue *object_args = new DictionaryValue();
   object_args->Set(L"newWindowId", Value::CreateIntegerValue(
       ExtensionTabUtil::GetWindowIdOfTab(contents)));
@@ -124,14 +140,14 @@ void ExtensionBrowserEventRouter::TabInsertedAt(TabContents* contents,
 void ExtensionBrowserEventRouter::TabDetachedAt(TabContents* contents,
                                                 int index) {
   int tab_id = ExtensionTabUtil::GetTabId(contents);
-  if (tab_ids_.find(tab_id) == tab_ids_.end()) {
+  if (tab_entries_.find(tab_id) == tab_entries_.end()) {
     // The tab was removed. Don't send detach event.
     return;
   }
 
   ListValue args;
   args.Append(Value::CreateIntegerValue(tab_id));
-  
+
   DictionaryValue *object_args = new DictionaryValue();
   object_args->Set(L"oldWindowId", Value::CreateIntegerValue(
       ExtensionTabUtil::GetWindowIdOfTab(contents)));
@@ -156,7 +172,7 @@ void ExtensionBrowserEventRouter::TabClosingAt(TabContents* contents,
 
   DispatchEvent(contents->profile(), kOnTabRemoved, json_args);
 
-  int removed_count = tab_ids_.erase(tab_id);
+  int removed_count = tab_entries_.erase(tab_id);
   DCHECK(removed_count > 0);
 }
 
@@ -167,7 +183,7 @@ void ExtensionBrowserEventRouter::TabSelectedAt(TabContents* old_contents,
   ListValue args;
   args.Append(Value::CreateIntegerValue(
       ExtensionTabUtil::GetTabId(new_contents)));
-  
+
   DictionaryValue *object_args = new DictionaryValue();
   object_args->Set(L"windowId", Value::CreateIntegerValue(
       ExtensionTabUtil::GetWindowIdOfTab(new_contents)));
@@ -184,7 +200,7 @@ void ExtensionBrowserEventRouter::TabMoved(TabContents* contents,
                                            int to_index) {
   ListValue args;
   args.Append(Value::CreateIntegerValue(ExtensionTabUtil::GetTabId(contents)));
-  
+
   DictionaryValue *object_args = new DictionaryValue();
   object_args->Set(L"windowId", Value::CreateIntegerValue(
       ExtensionTabUtil::GetWindowIdOfTab(contents)));
@@ -200,7 +216,26 @@ void ExtensionBrowserEventRouter::TabMoved(TabContents* contents,
 
 void ExtensionBrowserEventRouter::TabChangedAt(TabContents* contents,
                                                int index,
-                                               bool loading_only) { }
+                                               bool loading_only) {
+  int tab_id = ExtensionTabUtil::GetTabId(contents);
+  std::map<int, TabEntry>::iterator i = tab_entries_.find(tab_id);
+  if (tab_entries_.end() == i)
+    return;
+
+  TabEntry& entry = i->second;
+  if (entry.UpdateState(contents)) {
+    // The state of the tab (as seen from the extension point of view) has
+    // changed.  Send a notification to the extension.
+    ListValue args;
+    args.Append(Value::CreateIntegerValue(tab_id));
+    args.Append(ExtensionTabUtil::CreateTabChangedValue(contents));
+
+    std::string json_args;
+    JSONWriter::Write(&args, false, &json_args);
+
+    DispatchEvent(contents->profile(), kOnTabUpdated, json_args);
+  }
+}
 
 void ExtensionBrowserEventRouter::TabStripEmpty() { }
 
diff --git a/chrome/browser/extensions/extension_browser_event_router.h b/chrome/browser/extensions/extension_browser_event_router.h
index afebdd3..749c6e3 100644
--- a/chrome/browser/extensions/extension_browser_event_router.h
+++ b/chrome/browser/extensions/extension_browser_event_router.h
@@ -5,13 +5,14 @@
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSER_EVENT_ROUTER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSER_EVENT_ROUTER_H_
 
+#include <map>
 #include <vector>
-#include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/singleton.h"
 #include "chrome/browser/browser_list.h"
+#include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/common/notification_observer.h"
 
@@ -64,9 +65,37 @@ class ExtensionBrowserEventRouter : public TabStripModelObserver,
 
   bool initialized_;
 
-  // Maintain set of known tab ids, so we can distinguish between tab creation
-  // and tab insertion. Also used to not send tab-detached after tab-removed.
-  std::set<int> tab_ids_;
+  // Maintain some information about known tabs, so we can:
+  //
+  //  - distinguish between tab creation and tab insertion
+  //  - not send tab-detached after tab-removed
+  //  - reduce the "noise" of TabChangedAt() when sending events to extensions
+  class TabEntry {
+   public:
+    // Create a new tab entry whose initial state is TAB_COMPLETE.  This
+    // constructor is required because TabEntry objects placed inside an
+    // std::map<> by value.
+    TabEntry();
+
+    // Create a new tab entry whose initial state is derived from the given
+    // tab contents.
+    explicit TabEntry(const TabContents* contents);
+
+    // Returns the current state of the tab.
+    ExtensionTabUtil::TabStatus state() const { return state_; }
+
+    // Update the state of the tab based on its TabContents.  Returns true if
+    // the state changed, false otherwise.  Whether the state has changed or not
+    // is used to determine if events needs to be sent to extensions during
+    // processing of TabChangedAt().
+    bool UpdateState(const TabContents* contents);
+
+   private:
+    // Tab state used for last notification to extensions.
+    ExtensionTabUtil::TabStatus state_;
+  };
+
+  std::map<int, TabEntry> tab_entries_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionBrowserEventRouter);
 };
diff --git a/chrome/browser/extensions/extension_tabs_module.cc b/chrome/browser/extensions/extension_tabs_module.cc
index 6752449..073f54d 100644
--- a/chrome/browser/extensions/extension_tabs_module.cc
+++ b/chrome/browser/extensions/extension_tabs_module.cc
@@ -28,6 +28,7 @@ const wchar_t* kIndexKey = L"index";
 const wchar_t* kWindowIdKey = L"windowId";
 const wchar_t* kUrlKey = L"url";
 const wchar_t* kTitleKey = L"title";
+const wchar_t* kStatusKey = L"status";
 const wchar_t* kSelectedKey = L"selected";
 const wchar_t* kFocusedKey = L"focused";
 const wchar_t* kFavIconUrlKey = L"favIconUrl";
@@ -37,6 +38,10 @@ const wchar_t* kWidthKey = L"width";
 const wchar_t* kHeightKey = L"height";
 const wchar_t* kTabsKey = L"tabs";
 
+// Tab status text
+const char* kStatusValueLoading = "loading";
+const char* kStatusValueComplete = "complete";
+
 // Error messages.
 const char* kWindowNotFoundError = "No window with id: *.";
 const char* kTabNotFoundError = "No tab with id: *.";
@@ -73,6 +78,25 @@ int ExtensionTabUtil::GetTabId(const TabContents* tab_contents) {
   return tab_contents->controller().session_id().id();
 }
 
+ExtensionTabUtil::TabStatus ExtensionTabUtil::GetTabStatus(
+    const TabContents* tab_contents) {
+  return tab_contents->is_loading() ? TAB_LOADING : TAB_COMPLETE;
+}
+
+std::string ExtensionTabUtil::GetTabStatusText(TabStatus status) {
+  std::string text;
+  switch (status) {
+    case TAB_LOADING:
+      text = kStatusValueLoading;
+      break;
+    case TAB_COMPLETE:
+      text = kStatusValueComplete;
+      break;
+  }
+
+  return text;
+}
+
 int ExtensionTabUtil::GetWindowIdOfTab(const TabContents* tab_contents) {
   return tab_contents->controller().window_id().id();
 }
@@ -93,22 +117,37 @@ DictionaryValue* ExtensionTabUtil::CreateTabValue(
   return ExtensionTabUtil::CreateTabValue(contents, NULL, -1);
 }
 
+DictionaryValue* ExtensionTabUtil::CreateTabChangedValue(
+    const TabContents* contents) {
+  // A tab changed event should include a tab value that contains only the
+  // changed properties.  For now, this means only the status property.
+  DictionaryValue* result = new DictionaryValue();
+  result->SetString(kStatusKey, GetTabStatusText(GetTabStatus(contents)));
+  return result;
+}
+
 DictionaryValue* ExtensionTabUtil::CreateTabValue(
     const TabContents* contents, TabStripModel* tab_strip, int tab_index) {
+  TabStatus status = GetTabStatus(contents);
+
   DictionaryValue* result = new DictionaryValue();
   result->SetInteger(kIdKey, ExtensionTabUtil::GetTabId(contents));
   result->SetInteger(kIndexKey, tab_index);
   result->SetInteger(kWindowIdKey,
                      ExtensionTabUtil::GetWindowIdOfTab(contents));
   result->SetString(kUrlKey, contents->GetURL().spec());
-  result->SetString(kTitleKey, UTF16ToWide(contents->GetTitle()));
+  result->SetString(kStatusKey, GetTabStatusText(status));
   result->SetBoolean(kSelectedKey,
                      tab_strip && tab_index == tab_strip->selected_index());
 
-  NavigationEntry* entry = contents->controller().GetActiveEntry();
-  if (entry) {
-    if (entry->favicon().is_valid())
-      result->SetString(kFavIconUrlKey, entry->favicon().url().spec());
+  if (status != TAB_LOADING) {
+    result->SetString(kTitleKey, UTF16ToWide(contents->GetTitle()));
+
+    NavigationEntry* entry = contents->controller().GetActiveEntry();
+    if (entry) {
+      if (entry->favicon().is_valid())
+        result->SetString(kFavIconUrlKey, entry->favicon().url().spec());
+    }
   }
 
   return result;
diff --git a/chrome/browser/extensions/extension_tabs_module.h b/chrome/browser/extensions/extension_tabs_module.h
index 8a004185..2dd2c27 100644
--- a/chrome/browser/extensions/extension_tabs_module.h
+++ b/chrome/browser/extensions/extension_tabs_module.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_TABS_MODULE_H__
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_TABS_MODULE_H__
 
+#include <string>
+
 #include "chrome/browser/extensions/extension_function.h"
 
 class Browser;
@@ -14,13 +16,24 @@ class TabStripModel;
 
 class ExtensionTabUtil {
  public:
+  // Possible tab states.  These states are used to calculate the "status"
+  // property of the Tab object that is used in the extension tab API.
+  enum TabStatus {
+    TAB_LOADING,  // Waiting for the DOM to load.
+    TAB_COMPLETE  // Tab loading and rendering is complete.
+  };
+
   static int GetWindowId(const Browser* browser);
   static int GetTabId(const TabContents* tab_contents);
+  static TabStatus GetTabStatus(const TabContents* tab_contents);
+  static std::string GetTabStatusText(TabStatus status);
   static int GetWindowIdOfTab(const TabContents* tab_contents);
   static DictionaryValue* CreateTabValue(const TabContents* tab_contents);
   static DictionaryValue* CreateTabValue(const TabContents* tab_contents,
                                          TabStripModel* tab_strip,
                                          int tab_index);
+  static DictionaryValue* CreateTabChangedValue(const TabContents* contents);
+
   // Any out parameter (|browser|, |tab_strip|, |contents|, & |tab_index|) may
   // be NULL and will not be set within the function.
   static bool GetTabById(int tab_id, Profile* profile, Browser** browser,