dom/base/UIDirectionManager.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/UIDirectionManager.h"
   8 #include "mozilla/Preferences.h"
   9 #include "nsIObserverService.h"
  10 #include "nsIWindowMediator.h"
  11 #include "nsDocShell.h"
  12 #include "nsServiceManagerUtils.h"
  13 #include "mozilla/dom/Document.h"
  14 #include "mozilla/Services.h"
  15 #include "mozilla/SimpleEnumerator.h"
  16
  17 namespace mozilla::dom {
  18
  19 NS_IMPL_ISUPPORTS(UIDirectionManager, nsIObserver)
  20
  21 /* static */
  22 NS_IMETHODIMP
  23 UIDirectionManager::Observe(nsISupports* aSubject, const char* aTopic,
  24                             const char16_t* aData) {
  25   NS_ENSURE_FALSE(strcmp(aTopic, "intl:app-locales-changed"), NS_ERROR_FAILURE);
  26
  27   // Iterate over all of the windows and notify them of the direction change.
  28   nsCOMPtr<nsIWindowMediator> windowMediator =
  29       do_GetService(NS_WINDOWMEDIATOR_CONTRACTID);
  30   NS_ENSURE_TRUE(windowMediator, NS_ERROR_FAILURE);
  31
  32   nsCOMPtr<nsISimpleEnumerator> windowEnumerator;
  33   windowMediator->GetEnumerator(nullptr, getter_AddRefs(windowEnumerator));
  34   NS_ENSURE_TRUE(windowEnumerator, NS_ERROR_FAILURE);
  35
  36   for (auto& elements : SimpleEnumerator<nsISupports>(windowEnumerator)) {
  37     nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryInterface(elements);
  38     if (window->Closed()) {
  39       continue;
  40     }
  41
  42     RefPtr<BrowsingContext> context = window->GetBrowsingContext();
  43     MOZ_DIAGNOSTIC_ASSERT(context);
  44
  45     if (context->IsDiscarded()) {
  46       continue;
  47     }
  48
  49     context->PreOrderWalk([](BrowsingContext* aContext) {
  50       if (dom::Document* doc = aContext->GetDocument()) {
  51         doc->ResetDocumentDirection();
  52       }
  53     });
  54   }
  55   return NS_OK;
  56 }
  57
  58 /* static */
  59 void UIDirectionManager::Initialize() {
  60   MOZ_ASSERT(!gUIDirectionManager);
  61   MOZ_ASSERT(NS_IsMainThread());
  62
  63   RefPtr<UIDirectionManager> observer = new UIDirectionManager();
  64
  65   nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
  66   if (NS_WARN_IF(!obs)) {
  67     return;
  68   }
  69   obs->AddObserver(observer, "intl:app-locales-changed", false);
  70
  71   gUIDirectionManager = observer;
  72 }
  73
  74 /* static */
  75 void UIDirectionManager::Shutdown() {
  76   MOZ_ASSERT(NS_IsMainThread());
  77   if (!gUIDirectionManager) {
  78     return;
  79   }
  80   RefPtr<UIDirectionManager> observer = gUIDirectionManager;
  81   gUIDirectionManager = nullptr;
  82
  83   nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
  84   if (!obs) {
  85     return;
  86   }
  87
  88   obs->RemoveObserver(observer, "intl:app-locales-changed");
  89 }
  90
  91 mozilla::StaticRefPtr<UIDirectionManager>
  92     UIDirectionManager::gUIDirectionManager;
  93
  94 }  // namespace mozilla::dom