ios/web/active_state_manager_impl.mm

   1 // Copyright 2015 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/active_state_manager_impl.h"
   6
   7 #include "base/logging.h"
   8 #include "ios/web/public/browser_state.h"
   9 #include "ios/web/public/web_thread.h"
  10
  11 namespace web {
  12
  13 namespace {
  14 // The number of ActiveStateManagers that are currently in active state.
  15 // At most one ActiveStateManager can be active at any given time.
  16 int g_active_state_manager_active_count = 0;
  17 }  // namespace
  18
  19 ActiveStateManagerImpl::ActiveStateManagerImpl(BrowserState* browser_state)
  20     : browser_state_(browser_state), active_(false) {
  21   DCHECK_CURRENTLY_ON_WEB_THREAD(WebThread::UI);
  22   DCHECK(browser_state_);
  23 }
  24
  25 ActiveStateManagerImpl::~ActiveStateManagerImpl() {
  26   FOR_EACH_OBSERVER(Observer, observer_list_, WillBeDestroyed());
  27   DCHECK(!IsActive());
  28 }
  29
  30 void ActiveStateManagerImpl::SetActive(bool active) {
  31   DCHECK_CURRENTLY_ON_WEB_THREAD(WebThread::UI);
  32
  33   if (active == active_) {
  34     return;
  35   }
  36   if (active) {
  37     ++g_active_state_manager_active_count;
  38   } else {
  39     --g_active_state_manager_active_count;
  40   }
  41   DCHECK_GE(1, g_active_state_manager_active_count);
  42   active_ = active;
  43
  44   if (active) {
  45     FOR_EACH_OBSERVER(Observer, observer_list_, OnActive());
  46   } else {
  47     FOR_EACH_OBSERVER(Observer, observer_list_, OnInactive());
  48   }
  49 }
  50
  51 bool ActiveStateManagerImpl::IsActive() {
  52   DCHECK_CURRENTLY_ON_WEB_THREAD(WebThread::UI);
  53   return active_;
  54 }
  55
  56 void ActiveStateManagerImpl::AddObserver(Observer* obs) {
  57   DCHECK_CURRENTLY_ON_WEB_THREAD(WebThread::UI);
  58   observer_list_.AddObserver(obs);
  59 }
  60
  61 void ActiveStateManagerImpl::RemoveObserver(Observer* obs) {
  62   DCHECK_CURRENTLY_ON_WEB_THREAD(WebThread::UI);
  63   observer_list_.RemoveObserver(obs);
  64 }
  65
  66 }  // namespace web