dom/ipc/jsactor/nsQueryActor.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef nsQueryActor_h
   6 #define nsQueryActor_h
   7
   8 #include <type_traits>
   9
  10 #include "nsCOMPtr.h"
  11 #include "nsPIDOMWindow.h"
  12 #include "mozilla/RefPtr.h"
  13 #include "mozilla/dom/Document.h"
  14 #include "mozilla/dom/JSActor.h"
  15 #include "mozilla/dom/JSActorManager.h"
  16 #include "mozilla/dom/ScriptSettings.h"
  17 #include "mozilla/dom/WindowGlobalChild.h"
  18
  19 class nsIDOMProcessChild;
  20 class nsIDOMProcessParent;
  21
  22 // This type is used to get an XPCOM interface implemented by a JSActor from its
  23 // native manager.
  24 class MOZ_STACK_CLASS nsQueryJSActor final : public nsCOMPtr_helper {
  25  public:
  26   nsQueryJSActor(const nsLiteralCString aActorName,
  27                  mozilla::dom::JSActorManager* aManager)
  28       : mActorName(aActorName), mManager(aManager) {}
  29
  30   nsresult NS_FASTCALL operator()(const nsIID& aIID,
  31                                   void** aResult) const override {
  32     if (!mManager) {
  33       return NS_ERROR_NO_INTERFACE;
  34     }
  35
  36     mozilla::dom::AutoJSAPI jsapi;
  37     jsapi.Init();
  38
  39     RefPtr<mozilla::dom::JSActor> actor =
  40         mManager->GetActor(jsapi.cx(), mActorName, mozilla::IgnoreErrors());
  41     if (!actor) {
  42       return NS_ERROR_NO_INTERFACE;
  43     }
  44
  45     return actor->QueryInterfaceActor(aIID, aResult);
  46   }
  47
  48  private:
  49   const nsLiteralCString mActorName;
  50   mozilla::dom::JSActorManager* mManager;
  51 };
  52
  53 // Request an XPCOM interface from a JSActor managed by `aManager`.
  54 //
  55 // These APIs will work with both JSWindowActors and JSProcessActors.
  56 template <size_t length>
  57 inline nsQueryJSActor do_QueryActor(const char (&aActorName)[length],
  58                                     mozilla::dom::JSActorManager* aManager) {
  59   return nsQueryJSActor(nsLiteralCString(aActorName), aManager);
  60 }
  61
  62 // Overload for directly querying a JSWindowActorChild from an inner window.
  63 template <size_t length>
  64 inline nsQueryJSActor do_QueryActor(const char (&aActorName)[length],
  65                                     nsPIDOMWindowInner* aWindow) {
  66   return nsQueryJSActor(nsLiteralCString(aActorName),
  67                         aWindow ? aWindow->GetWindowGlobalChild() : nullptr);
  68 }
  69
  70 // Overload for directly querying a JSWindowActorChild from a document.
  71 template <size_t length>
  72 inline nsQueryJSActor do_QueryActor(const char (&aActorName)[length],
  73                                     mozilla::dom::Document* aDoc) {
  74   return nsQueryJSActor(nsLiteralCString(aActorName),
  75                         aDoc ? aDoc->GetWindowGlobalChild() : nullptr);
  76 }
  77
  78 // Overload for directly querying from a nsIDOMProcess{Parent,Child} without
  79 // confusing overload selection for types inheriting from both
  80 // nsIDOMProcess{Parent,Child} and JSActorManager.
  81 template <size_t length, typename T,
  82           typename = std::enable_if_t<std::is_same_v<T, nsIDOMProcessParent> ||
  83                                       std::is_same_v<T, nsIDOMProcessChild>>>
  84 inline nsQueryJSActor do_QueryActor(const char (&aActorName)[length],
  85                                     T* aManager) {
  86   return nsQueryJSActor(nsLiteralCString(aActorName),
  87                         aManager ? aManager->AsJSActorManager() : nullptr);
  88 }
  89
  90 #endif  // defined nsQueryActor_h