dom/base/WindowProxyHolder.h

   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 #ifndef mozilla_dom_WindowProxyHolder_h__
   8 #define mozilla_dom_WindowProxyHolder_h__
   9
  10 #include "mozilla/dom/BrowsingContext.h"
  11
  12 struct JSContext;
  13 class JSObject;
  14
  15 namespace JS {
  16 template <typename T>
  17 class MutableHandle;
  18 }  // namespace JS
  19
  20 namespace mozilla::dom {
  21
  22 /**
  23  * This class is used for passing arguments and the return value for WebIDL
  24  * binding code that takes/returns a WindowProxy object and for WebIDL
  25  * unions/dictionaries that contain a WindowProxy member. It should never
  26  * contain null; if the value in WebIDL is nullable the binding code will use a
  27  * Nullable<WindowProxyHolder>.
  28  */
  29 class WindowProxyHolder {
  30  public:
  31   WindowProxyHolder() = default;
  32   explicit WindowProxyHolder(BrowsingContext* aBC) : mBrowsingContext(aBC) {
  33     MOZ_ASSERT(mBrowsingContext, "Don't set WindowProxyHolder to null.");
  34   }
  35   explicit WindowProxyHolder(RefPtr<BrowsingContext>&& aBC)
  36       : mBrowsingContext(std::move(aBC)) {
  37     MOZ_ASSERT(mBrowsingContext, "Don't set WindowProxyHolder to null.");
  38   }
  39   WindowProxyHolder& operator=(BrowsingContext* aBC) {
  40     mBrowsingContext = aBC;
  41     MOZ_ASSERT(mBrowsingContext, "Don't set WindowProxyHolder to null.");
  42     return *this;
  43   }
  44   WindowProxyHolder& operator=(RefPtr<BrowsingContext>&& aBC) {
  45     mBrowsingContext = std::move(aBC);
  46     MOZ_ASSERT(mBrowsingContext, "Don't set WindowProxyHolder to null.");
  47     return *this;
  48   }
  49
  50   BrowsingContext* get() const {
  51     MOZ_ASSERT(mBrowsingContext, "WindowProxyHolder hasn't been initialized.");
  52     return mBrowsingContext;
  53   }
  54
  55  private:
  56   friend void ImplCycleCollectionUnlink(WindowProxyHolder& aProxy);
  57
  58   RefPtr<BrowsingContext> mBrowsingContext;
  59 };
  60
  61 inline void ImplCycleCollectionTraverse(
  62     nsCycleCollectionTraversalCallback& aCallback, WindowProxyHolder& aProxy,
  63     const char* aName, uint32_t aFlags = 0) {
  64   CycleCollectionNoteChild(aCallback, aProxy.get(), "mBrowsingContext", aFlags);
  65 }
  66
  67 inline void ImplCycleCollectionUnlink(WindowProxyHolder& aProxy) {
  68   aProxy.mBrowsingContext = nullptr;
  69 }
  70
  71 extern bool GetRemoteOuterWindowProxy(JSContext* aCx, BrowsingContext* aContext,
  72                                       JS::Handle<JSObject*> aTransplantTo,
  73                                       JS::MutableHandle<JSObject*> aValue);
  74
  75 }  // namespace mozilla::dom
  76
  77 #endif /* mozilla_dom_WindowProxyHolder_h__ */