tor-browser

The Tor Browser
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PreloadedStyleSheet.cpp (2668B)

      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 /* a CSS style sheet returned from nsIStyleSheetService.preloadSheet */
      8 
      9 #include "PreloadedStyleSheet.h"
     10 
     11 #include "mozilla/css/Loader.h"
     12 #include "mozilla/dom/Promise.h"
     13 #include "nsICSSLoaderObserver.h"
     14 #include "nsLayoutUtils.h"
     15 
     16 namespace mozilla {
     17 
     18 PreloadedStyleSheet::PreloadedStyleSheet(nsIURI* aURI,
     19                                         css::SheetParsingMode aParsingMode)
     20    : mLoaded(false), mURI(aURI), mParsingMode(aParsingMode) {}
     21 
     22 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PreloadedStyleSheet)
     23  NS_INTERFACE_MAP_ENTRY(nsIPreloadedStyleSheet)
     24  NS_INTERFACE_MAP_ENTRY(nsISupports)
     25 NS_INTERFACE_MAP_END
     26 
     27 NS_IMPL_CYCLE_COLLECTING_ADDREF(PreloadedStyleSheet)
     28 NS_IMPL_CYCLE_COLLECTING_RELEASE(PreloadedStyleSheet)
     29 
     30 NS_IMPL_CYCLE_COLLECTION(PreloadedStyleSheet, mSheet)
     31 
     32 Result<StyleSheet*, nsresult> PreloadedStyleSheet::GetSheet() {
     33  MOZ_DIAGNOSTIC_ASSERT(mLoaded);
     34 
     35  if (!mSheet) {
     36    auto loader = MakeRefPtr<css::Loader>();
     37    mSheet = MOZ_TRY(loader->LoadSheetSync(
     38        mURI, mParsingMode, css::Loader::UseSystemPrincipal::Yes));
     39  }
     40  return {mSheet.get()};
     41 }
     42 
     43 nsresult PreloadedStyleSheet::Preload() {
     44  MOZ_DIAGNOSTIC_ASSERT(!mLoaded);
     45  mLoaded = true;
     46  MOZ_TRY(GetSheet());
     47  return NS_OK;
     48 }
     49 
     50 NS_IMPL_ISUPPORTS(PreloadedStyleSheet::StylesheetPreloadObserver,
     51                  nsICSSLoaderObserver)
     52 
     53 NS_IMETHODIMP
     54 PreloadedStyleSheet::StylesheetPreloadObserver::StyleSheetLoaded(
     55    StyleSheet* aSheet, bool aWasDeferred, nsresult aStatus) {
     56  MOZ_DIAGNOSTIC_ASSERT(!mPreloadedSheet->mLoaded);
     57  mPreloadedSheet->mLoaded = true;
     58 
     59  if (NS_FAILED(aStatus)) {
     60    mPromise->MaybeReject(aStatus);
     61  } else {
     62    mPromise->MaybeResolve(mPreloadedSheet);
     63  }
     64 
     65  return NS_OK;
     66 }
     67 
     68 // Note: After calling this method, the preloaded sheet *must not* be used
     69 // until the observer is notified that the sheet has finished loading.
     70 nsresult PreloadedStyleSheet::PreloadAsync(NotNull<dom::Promise*> aPromise) {
     71  MOZ_DIAGNOSTIC_ASSERT(!mLoaded);
     72 
     73  auto loader = MakeRefPtr<css::Loader>();
     74  auto obs = MakeRefPtr<StylesheetPreloadObserver>(aPromise, this);
     75  auto result = loader->LoadSheet(mURI, mParsingMode,
     76                                  css::Loader::UseSystemPrincipal::No, obs);
     77  if (result.isErr()) {
     78    return result.unwrapErr();
     79  }
     80  mSheet = result.unwrap();
     81  return NS_OK;
     82 }
     83 
     84 }  // namespace mozilla