Add opener-opened relationship between WebState in WebStateList.

ios/shared/chrome/browser/tabs/web_state_list.mm

Index: ios/shared/chrome/browser/tabs/web_state_list.mm
diff --git a/ios/shared/chrome/browser/tabs/web_state_list.mm b/ios/shared/chrome/browser/tabs/web_state_list.mm
index cb85ed433ee72233257fc0c3181adf4e9dfaca74..09d4539a504cac82030c843e29af024f475a295c 100644
--- a/ios/shared/chrome/browser/tabs/web_state_list.mm
+++ b/ios/shared/chrome/browser/tabs/web_state_list.mm
@@ -7,6 +7,7 @@
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #import "ios/shared/chrome/browser/tabs/web_state_list_observer.h"
+#import "ios/web/public/navigation_manager.h"
 #import "ios/web/public/web_state/web_state.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -22,10 +23,26 @@ class WebStateList::WebStateWrapper {
   ~WebStateWrapper();
 
   web::WebState* web_state() const { return web_state_; }
-  void set_web_state(web::WebState* web_state) { web_state_ = web_state; }
+  web::WebState* opener() const { return opener_; }
+
+  // Resets the wrapped WebState (and clear associated state).
+  void SetWebState(web::WebState* web_state);
+
+  // Sets the opener for the wrapped WebState and record the opener navigation
+  // index to allow detecting navigation changes during the same session.
+  void SetOpener(web::WebState* opener);
+
+  // Returns whether opener spawned the wrapped WebState. If |use_group| is

[marq (ping after 24h), 2017/02/16 15:19:17]

|opener|

[sdefresne, 2017/02/16 15:42:01]

Done.

+  // true, also use the opener navigation index to detect navigation changes
+  // during the same session.
+  bool WasOpenBy(const web::WebState* opener,

[marq (ping after 24h), 2017/02/16 15:19:17]

WasOpenedBy(). yay, English!

[sdefresne, 2017/02/16 15:42:01]

Done.

+                 int opener_navigation_index,
+                 bool use_group) const;
 
  private:
   web::WebState* web_state_;
+  web::WebState* opener_ = nullptr;
+  int opener_last_committed_index_;
   const bool has_web_state_ownership_;
 
   DISALLOW_COPY_AND_ASSIGN(WebStateWrapper);
@@ -33,13 +50,42 @@ class WebStateList::WebStateWrapper {
 
 WebStateList::WebStateWrapper::WebStateWrapper(web::WebState* web_state,
                                                bool assume_ownership)
-    : web_state_(web_state), has_web_state_ownership_(assume_ownership) {}
+    : web_state_(web_state), has_web_state_ownership_(assume_ownership) {
+  DCHECK(web_state_);
+}
 
 WebStateList::WebStateWrapper::~WebStateWrapper() {
   if (has_web_state_ownership_)
     delete web_state_;
 }
 
+void WebStateList::WebStateWrapper::SetWebState(web::WebState* web_state) {
+  DCHECK(web_state);
+  web_state_ = web_state;
+  opener_ = nullptr;
+}
+
+void WebStateList::WebStateWrapper::SetOpener(web::WebState* opener) {
+  opener_ = opener;
+  if (opener_) {
+    opener_last_committed_index_ =
+        opener_->GetNavigationManager()->GetLastCommittedItemIndex();
+  }
+}
+
+bool WebStateList::WebStateWrapper::WasOpenBy(const web::WebState* opener,
+                                              int opener_navigation_index,
+                                              bool use_group) const {
+  DCHECK(opener);
+  if (opener_ != opener)
+    return false;
+
+  if (!use_group)
+    return true;
+
+  return opener_last_committed_index_ == opener_navigation_index;
+}
+
 WebStateList::WebStateList(WebStateOwnership ownership)
     : web_state_ownership_(ownership) {}
 
@@ -62,13 +108,35 @@ int WebStateList::GetIndexOfWebState(const web::WebState* web_state) const {
   return kInvalidIndex;
 }
 
-void WebStateList::InsertWebState(int index, web::WebState* web_state) {
+web::WebState* WebStateList::GetOpenerOfWebStateAt(int index) const {
+  DCHECK(ContainsIndex(index));
+  return web_state_wrappers_[index]->opener();
+}
+
+int WebStateList::GetIndexOfNextWebStateOpenedBy(const web::WebState* opener,
+                                                 int start_index,
+                                                 bool use_group) const {
+  return GetIndexOfNthWebStateOpenedBy(opener, start_index, 1, use_group);
+}
+
+int WebStateList::GetIndexOfLastWebStateOpenedBy(const web::WebState* opener,
+                                                 int start_index,
+                                                 bool use_group) const {
+  return GetIndexOfNthWebStateOpenedBy(opener, start_index, INT_MAX, use_group);
+}
+
+void WebStateList::InsertWebState(int index,
+                                  web::WebState* web_state,
+                                  web::WebState* opener) {
   DCHECK(ContainsIndex(index) || index == count());
   web_state_wrappers_.insert(
       web_state_wrappers_.begin() + index,
       base::MakeUnique<WebStateWrapper>(web_state,
                                         web_state_ownership_ == WebStateOwned));
 
+  if (opener)
+    SetOpenerOfWebStateAt(index, opener);
+
   for (auto& observer : observers_)
     observer.WebStateInsertedAt(this, web_state, index);
 }
@@ -91,10 +159,17 @@ void WebStateList::MoveWebStateAt(int from_index, int to_index) {
 }
 
 web::WebState* WebStateList::ReplaceWebStateAt(int index,
-                                               web::WebState* web_state) {
+                                               web::WebState* web_state,
+                                               web::WebState* opener) {
   DCHECK(ContainsIndex(index));
-  web::WebState* old_web_state = web_state_wrappers_[index]->web_state();
-  web_state_wrappers_[index]->set_web_state(web_state);
+  FixOpenersReferencing(index);
+
+  auto& web_state_wrapper = web_state_wrappers_[index];
+  web::WebState* old_web_state = web_state_wrapper->web_state();
+  web_state_wrapper->SetWebState(web_state);
+
+  if (opener && opener != old_web_state)
+    SetOpenerOfWebStateAt(index, opener);
 
   for (auto& observer : observers_)
     observer.WebStateReplacedAt(this, old_web_state, web_state, index);
@@ -104,6 +179,8 @@ web::WebState* WebStateList::ReplaceWebStateAt(int index,
 
 void WebStateList::DetachWebStateAt(int index) {
   DCHECK(ContainsIndex(index));
+  FixOpenersReferencing(index);
+
   web::WebState* web_state = web_state_wrappers_[index]->web_state();
   web_state_wrappers_.erase(web_state_wrappers_.begin() + index);
 
@@ -119,5 +196,44 @@ void WebStateList::RemoveObserver(WebStateListObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
+void WebStateList::SetOpenerOfWebStateAt(int index, web::WebState* opener) {
+  DCHECK(ContainsIndex(index));
+  DCHECK(ContainsIndex(GetIndexOfWebState(opener)));
+  web_state_wrappers_[index]->SetOpener(opener);
+}
+
+void WebStateList::FixOpenersReferencing(int index) {
+  web::WebState* old_web_state = web_state_wrappers_[index]->web_state();
+  for (auto& web_state_wrapper : web_state_wrappers_) {
+    if (web_state_wrapper->opener() == old_web_state)
+      web_state_wrapper->SetOpener(nullptr);
+  }
+}
+
+int WebStateList::GetIndexOfNthWebStateOpenedBy(const web::WebState* opener,
+                                                int start_index,
+                                                int skip_up_to,
+                                                bool use_group) const {
+  DCHECK_GT(skip_up_to, 0);

[marq (ping after 24h), 2017/02/16 15:19:17]

Document this precondition in the header comments.

[sdefresne, 2017/02/16 15:42:01]

Done.

+  if (!opener || !ContainsIndex(start_index) || start_index == INT_MAX)
+    return kInvalidIndex;
+
+  const int opener_navigation_index =
+      use_group ? opener->GetNavigationManager()->GetCurrentItemIndex() : -1;
+
+  int found_index = kInvalidIndex;
+  for (int index = start_index + 1; index < count() && skip_up_to; ++index) {
+    if (web_state_wrappers_[index]->WasOpenBy(opener, opener_navigation_index,
+                                              use_group)) {
+      found_index = index;
+      --skip_up_to;
+    } else if (found_index != kInvalidIndex) {
+      return found_index;
+    }
+  }
+
+  return found_index;
+}
+
 // static
 const int WebStateList::kInvalidIndex;