Multi-tab: Adding new Notification when tab selection changes.

chrome/browser/tabs/tab_strip_model.cc

 // Copyright (c) 2011 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_strip_model.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/command_line.h"
@@ skipping 139 matching lines @@
     }
     data->opener = &selected_contents->controller();
   }
 
   contents_data_.insert(contents_data_.begin() + index, data);
 
   selection_model_.IncrementFrom(index);
 
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                     TabInsertedAt(contents, index, active));
-
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model_);
   if (active) {
     selection_model_.SetSelectedIndex(index);
-    NotifyTabSelectedIfChanged(selected_contents, index, false);
+    NotifyIfActiveOrSelectionChanged(selected_contents, false, old_model);
   }
 }
 
 TabContentsWrapper* TabStripModel::ReplaceTabContentsAt(
     int index,
     TabContentsWrapper* new_contents) {
   DCHECK(ContainsIndex(index));
   TabContentsWrapper* old_contents = GetContentsAt(index);
 
   ForgetOpenersAndGroupsReferencing(&(old_contents->controller()));
@@ skipping 25 matching lines @@
   InternalCloseTabs(closing_tabs, CLOSE_NONE);
 }
 
 TabContentsWrapper* TabStripModel::DetachTabContentsAt(int index) {
   if (contents_data_.empty())
     return NULL;
 
   DCHECK(ContainsIndex(index));
 
   TabContentsWrapper* removed_contents = GetContentsAt(index);
+  bool was_selected = IsTabSelected(index);
   int next_selected_index = order_controller_->DetermineNewSelectedIndex(index);
   delete contents_data_.at(index);
   contents_data_.erase(contents_data_.begin() + index);
   ForgetOpenersAndGroupsReferencing(&(removed_contents->controller()));
   if (empty())
     closing_all_ = true;
   FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
       TabDetachedAt(removed_contents, index));
   if (empty()) {
+    selection_model_.Clear();
     // TabDetachedAt() might unregister observers, so send |TabStripEmtpy()| in
     // a second pass.
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_, TabStripEmpty());
   } else {
     int old_active = active_index();
     selection_model_.DecrementFrom(index);
+    TabStripSelectionModel old_model;
+    old_model.Copy(selection_model_);
     if (index == old_active) {
       if (!selection_model_.empty()) {
-        // A selected tab was removed, but there is still something selected.
+        // The active tab was removed, but there is still something selected.
         // Move the active and anchor to the first selected index.
         selection_model_.set_active(selection_model_.selected_indices()[0]);
         selection_model_.set_anchor(selection_model_.active());
-        NotifyTabSelectedIfChanged(removed_contents, active_index(), false);
       } else {
         // The active tab was removed and nothing is selected. Reset the
         // selection and send out notification.
         selection_model_.SetSelectedIndex(next_selected_index);
-        NotifyTabSelectedIfChanged(removed_contents, next_selected_index,
-                                   false);
       }
+      NotifyIfActiveTabChanged(removed_contents, false);
+    }
+
+    // Sending notification in case the detached tab was selected. Using
+    // NotifyIfActiveOrSelectionChanged() here would not guarantee that a
+    // notification is sent even though the tab selection has changed because
+    // |old_model| is stored after calling DecrementFrom().
+    if (was_selected) {
+      FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
+                        TabSelectionChanged(old_model));
     }
   }
   return removed_contents;
 }
 
 void TabStripModel::ActivateTabAt(int index, bool user_gesture) {
   DCHECK(ContainsIndex(index));
-  bool had_multi = selection_model_.selected_indices().size() > 1;
-  TabContentsWrapper* old_contents =
-      (active_index() == TabStripSelectionModel::kUnselectedIndex) ?
-      NULL : GetActiveTabContents();
+  TabContentsWrapper* old_contents = GetActiveTabContents();
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model_);
   selection_model_.SetSelectedIndex(index);
-  TabContentsWrapper* new_contents = GetContentsAt(index);
-  if (old_contents != new_contents && old_contents) {
-    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                      TabDeactivated(old_contents));
-  }
-  if (old_contents != new_contents || had_multi) {
-    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                      ActiveTabChanged(old_contents, new_contents,
-                                       active_index(), user_gesture));
-  }
+  NotifyIfActiveOrSelectionChanged(old_contents, user_gesture, old_model);
 }
 
 void TabStripModel::MoveTabContentsAt(int index,
                                       int to_position,
                                       bool select_after_move) {
   DCHECK(ContainsIndex(index));
   if (index == to_position)
     return;
 
   int first_non_mini_tab = IndexOfFirstNonMiniTab();
@@ skipping 291 matching lines @@
   return count();
 }
 
 int TabStripModel::ConstrainInsertionIndex(int index, bool mini_tab) {
   return mini_tab ? std::min(std::max(0, index), IndexOfFirstNonMiniTab()) :
       std::min(count(), std::max(index, IndexOfFirstNonMiniTab()));
 }
 
 void TabStripModel::ExtendSelectionTo(int index) {
   DCHECK(ContainsIndex(index));
-  int old_active = active_index();
+  TabContentsWrapper* old_contents = GetActiveTabContents();
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model());
   selection_model_.SetSelectionFromAnchorTo(index);
-  // This may not have resulted in a change, but we assume it did.
-  NotifyActiveTabChanged(old_active);
+  NotifyIfActiveOrSelectionChanged(old_contents, false, old_model);
 }
 
 void TabStripModel::ToggleSelectionAt(int index) {
   DCHECK(ContainsIndex(index));
-  int old_active = active_index();
+  TabContentsWrapper* old_contents = GetActiveTabContents();
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model());
   if (selection_model_.IsSelected(index)) {
     if (selection_model_.size() == 1) {
       // One tab must be selected and this tab is currently selected so we can't
       // unselect it.
       return;
     }
     selection_model_.RemoveIndexFromSelection(index);
     selection_model_.set_anchor(index);
     if (selection_model_.active() == TabStripSelectionModel::kUnselectedIndex)
       selection_model_.set_active(selection_model_.selected_indices()[0]);
   } else {
     selection_model_.AddIndexToSelection(index);
     selection_model_.set_anchor(index);
     selection_model_.set_active(index);
   }
-  NotifyActiveTabChanged(old_active);
+  NotifyIfActiveOrSelectionChanged(old_contents, false, old_model);
 }
 
 void TabStripModel::AddSelectionFromAnchorTo(int index) {
-  int old_active = active_index();
+  TabContentsWrapper* old_contents = GetActiveTabContents();
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model());
   selection_model_.AddSelectionFromAnchorTo(index);
-  NotifyActiveTabChanged(old_active);
+  NotifyIfActiveOrSelectionChanged(old_contents, false, old_model);
 }
 
 bool TabStripModel::IsTabSelected(int index) const {
   DCHECK(ContainsIndex(index));
   return selection_model_.IsSelected(index);
 }
 
 void TabStripModel::SetSelectionFromModel(
     const TabStripSelectionModel& source) {
   DCHECK_NE(TabStripSelectionModel::kUnselectedIndex, source.active());
-  int old_active_index = active_index();
+  TabContentsWrapper* old_contents = GetActiveTabContents();
+  TabStripSelectionModel old_model;
+  old_model.Copy(selection_model());
   selection_model_.Copy(source);
-  // This may not have resulted in a change, but we assume it did.
-  NotifyActiveTabChanged(old_active_index);
+  NotifyIfActiveOrSelectionChanged(old_contents, false, old_model);
 }
 
 void TabStripModel::AddTabContents(TabContentsWrapper* contents,
                                    int index,
                                    PageTransition::Type transition,
                                    int add_types) {
   // If the newly-opened tab is part of the same task as the parent tab, we want
   // to inherit the parent's "group" attribute, so that if this tab is then
   // closed we'll jump back to the parent tab.
   bool inherit_group = (add_types & ADD_INHERIT_GROUP) == ADD_INHERIT_GROUP;
@@ skipping 574 matching lines @@
   // and detach it.
   delete contents;
 }
 
 TabContentsWrapper* TabStripModel::GetContentsAt(int index) const {
   CHECK(ContainsIndex(index)) <<
       "Failed to find: " << index << " in: " << count() << " entries.";
   return contents_data_.at(index)->contents;
 }
 
-void TabStripModel::NotifyTabSelectedIfChanged(TabContentsWrapper* old_contents,
-                                               int to_index,
-                                               bool user_gesture) {
-  TabContentsWrapper* new_contents = GetContentsAt(to_index);
-  if (old_contents == new_contents)
-    return;
-
-  TabContentsWrapper* last_selected_contents = old_contents;
-  if (last_selected_contents) {
+void TabStripModel::NotifyIfActiveTabChanged(
+    TabContentsWrapper* old_contents,
+    bool user_gesture) {
+  TabContentsWrapper* new_contents = GetContentsAt(active_index());
+  if (old_contents != new_contents) {
+    if (old_contents) {
+      FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
+                        TabDeactivated(old_contents));
+    }
     FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                      TabDeactivated(last_selected_contents));
+                      ActiveTabChanged(old_contents, new_contents,
+                                       active_index(), user_gesture));
   }
-
-  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                    ActiveTabChanged(last_selected_contents, new_contents,
-                                     active_index(), user_gesture));
 }
 
-void TabStripModel::NotifyActiveTabChanged(int old_active_index) {
-  TabContentsWrapper* old_tab =
-      old_active_index == TabStripSelectionModel::kUnselectedIndex ?
-      NULL : GetTabContentsAt(old_active_index);
-  TabContentsWrapper* new_tab =
-      active_index() == TabStripSelectionModel::kUnselectedIndex ?
-      NULL : GetTabContentsAt(active_index());
-  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
-                    ActiveTabChanged(old_tab, new_tab, active_index(), true));
+void TabStripModel::NotifyIfActiveOrSelectionChanged(
+    TabContentsWrapper* old_contents,
+    bool user_gesture,
+    const TabStripSelectionModel& old_model) {
+  NotifyIfActiveTabChanged(old_contents, user_gesture);
+
+  if (!selection_model().Equals(old_model)) {
+    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
+                      TabSelectionChanged(old_model));
+  }
 }
 
 void TabStripModel::SelectRelativeTab(bool next) {
   // This may happen during automated testing or if a user somehow buffers
   // many key accelerators.
   if (contents_data_.empty())
     return;
 
   int index = active_index();
   int delta = next ? 1 : -1;
@@ skipping 64 matching lines @@
 void TabStripModel::ForgetOpenersAndGroupsReferencing(
     const NavigationController* tab) {
   for (TabContentsDataVector::const_iterator i = contents_data_.begin();
        i != contents_data_.end(); ++i) {
     if ((*i)->group == tab)
       (*i)->group = NULL;
     if ((*i)->opener == tab)
       (*i)->opener = NULL;
   }
 }