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 "mozilla/dom/DocumentInlines.h"
  12 #include "nsContentUtils.h"
  13 #include "nsGlobalWindowOuter.h"
  14 #include "nsIPrintSettings.h"
  15
  16 namespace mozilla::dom {
  17
  18 class AutoPrintEventDispatcher {
  19   // NOTE(emilio): For fission iframes, we dispatch this event in
  20   // RecvCloneDocumentTreeIntoSelf.
  21   static void CollectInProcessSubdocuments(
  22       Document& aDoc, nsTArray<nsCOMPtr<Document>>& aDocs) {
  23     aDoc.EnumerateSubDocuments([&aDocs](Document& aSubDoc) {
  24       aDocs.AppendElement(&aSubDoc);
  25       CollectInProcessSubdocuments(aSubDoc, aDocs);
  26       return CallState::Continue;
  27     });
  28   }
  29
  30   MOZ_CAN_RUN_SCRIPT void DispatchEvent(bool aBefore) {
  31     for (auto& doc : mDocuments) {
  32       nsContentUtils::DispatchTrustedEvent(
  33           doc, nsGlobalWindowOuter::Cast(doc->GetWindow()),
  34           aBefore ? u"beforeprint"_ns : u"afterprint"_ns, CanBubble::eNo,
  35           Cancelable::eNo, nullptr);
  36       if (RefPtr<nsPresContext> presContext = doc->GetPresContext()) {
  37         presContext->EmulateMedium(aBefore ? nsGkAtoms::print : nullptr);
  38         // Ensure media query listeners fire.
  39         // FIXME(emilio): This is hacky, at best, but is required for compat
  40         // with some pages, see bug 774398.
  41         doc->EvaluateMediaQueriesAndReportChanges(/* aRecurse = */ false);
  42       }
  43     }
  44   }
  45
  46  public:
  47   MOZ_CAN_RUN_SCRIPT explicit AutoPrintEventDispatcher(Document& aDoc) {
  48     if (!aDoc.IsStaticDocument()) {
  49       mDocuments.AppendElement(&aDoc);
  50       CollectInProcessSubdocuments(aDoc, mDocuments);
  51     }
  52
  53     DispatchEvent(true);
  54   }
  55
  56   MOZ_CAN_RUN_SCRIPT ~AutoPrintEventDispatcher() { DispatchEvent(false); }
  57
  58   AutoTArray<nsCOMPtr<Document>, 8> mDocuments;
  59   const nsSize mPageSize;
  60   nsRect mVisibleAreaToRestore;
  61 };
  62
  63 }  // namespace mozilla::dom
  64
  65 #endif