dom/base/AutoPrintEventDispatcher.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_AutoPrintEventDispatcher_h
   8 #define mozilla_dom_AutoPrintEventDispatcher_h
   9
  10 #include "mozilla/dom/Document.h"
  11 #include "nsContentUtils.h"
  12
  13 namespace mozilla::dom {
  14
  15 class AutoPrintEventDispatcher {
  16   // NOTE(emilio): For fission iframes, we dispatch this event in
  17   // RecvCloneDocumentTreeIntoSelf.
  18   static void CollectInProcessSubdocuments(
  19       Document& aDoc, nsTArray<nsCOMPtr<Document>>& aDocs) {
  20     aDocs.AppendElement(&aDoc);
  21     auto recurse = [&aDocs](Document& aSubDoc) {
  22       CollectInProcessSubdocuments(aSubDoc, aDocs);
  23       return CallState::Continue;
  24     };
  25     aDoc.EnumerateSubDocuments(recurse);
  26   }
  27
  28   void DispatchEvent(bool aBefore) {
  29     for (nsCOMPtr<Document>& doc : mDocuments) {
  30       nsContentUtils::DispatchTrustedEvent(
  31           doc, doc->GetWindow(), aBefore ? u"beforeprint"_ns : u"afterprint"_ns,
  32           CanBubble::eNo, Cancelable::eNo, nullptr);
  33     }
  34   }
  35
  36  public:
  37   explicit AutoPrintEventDispatcher(Document& aDoc) {
  38     if (!aDoc.IsStaticDocument()) {
  39       CollectInProcessSubdocuments(aDoc, mDocuments);
  40     }
  41
  42     DispatchEvent(true);
  43   }
  44
  45   ~AutoPrintEventDispatcher() { DispatchEvent(false); }
  46
  47   AutoTArray<nsCOMPtr<Document>, 8> mDocuments;
  48 };
  49
  50 }  // namespace mozilla::dom
  51
  52 #endif