ios/web/web_state/web_state_observer.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ios/web/public/web_state/web_state_observer.h"
   6
   7 #include "ios/web/public/load_committed_details.h"
   8 #include "ios/web/public/web_state/web_state.h"
   9
  10 namespace web {
  11
  12 WebStateObserver::WebStateObserver(WebState* web_state) : web_state_(nullptr) {
  13   Observe(web_state);
  14 }
  15
  16 WebStateObserver::WebStateObserver() : web_state_(nullptr) {
  17 }
  18
  19 WebStateObserver::~WebStateObserver() {
  20   if (web_state_)
  21     web_state_->RemoveObserver(this);
  22 }
  23
  24 void WebStateObserver::Observe(WebState* web_state) {
  25   if (web_state == web_state_) {
  26     // Early exit to avoid infinite loops if we're in the middle of a callback.
  27     return;
  28   }
  29   if (web_state_)
  30     web_state_->RemoveObserver(this);
  31   web_state_ = web_state;
  32   if (web_state_)
  33     web_state_->AddObserver(this);
  34 }
  35
  36 void WebStateObserver::ResetWebState() {
  37   web_state_->RemoveObserver(this);
  38   web_state_ = nullptr;
  39 }
  40
  41 }  // namespace web