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	 265e672179
			
		
	
	
		265e672179
		
	
	
	
	
		
			
			# ignore-this-changeset --HG-- extra : amend_source : 4d301d3b0b8711c4692392aa76088ba7fd7d1022
		
			
				
	
	
		
			112 lines
		
	
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| /* a CSS style sheet returned from nsIStyleSheetService.preloadSheet */
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| 
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| #include "PreloadedStyleSheet.h"
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| 
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| #include "mozilla/css/Loader.h"
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| #include "mozilla/dom/Promise.h"
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| #include "nsICSSLoaderObserver.h"
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| #include "nsLayoutUtils.h"
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| 
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| namespace mozilla {
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| 
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| PreloadedStyleSheet::PreloadedStyleSheet(nsIURI* aURI,
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|                                          css::SheetParsingMode aParsingMode)
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|     : mLoaded(false), mURI(aURI), mParsingMode(aParsingMode) {}
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| 
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| /* static */ nsresult PreloadedStyleSheet::Create(
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|     nsIURI* aURI, css::SheetParsingMode aParsingMode,
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|     PreloadedStyleSheet** aResult) {
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|   *aResult = nullptr;
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| 
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|   RefPtr<PreloadedStyleSheet> preloadedSheet =
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|       new PreloadedStyleSheet(aURI, aParsingMode);
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| 
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|   preloadedSheet.forget(aResult);
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|   return NS_OK;
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| }
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| 
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| NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PreloadedStyleSheet)
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|   NS_INTERFACE_MAP_ENTRY(nsIPreloadedStyleSheet)
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|   NS_INTERFACE_MAP_ENTRY(nsISupports)
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| NS_INTERFACE_MAP_END
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| 
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| NS_IMPL_CYCLE_COLLECTING_ADDREF(PreloadedStyleSheet)
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| NS_IMPL_CYCLE_COLLECTING_RELEASE(PreloadedStyleSheet)
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| 
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| NS_IMPL_CYCLE_COLLECTION(PreloadedStyleSheet, mSheet)
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| 
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| nsresult PreloadedStyleSheet::GetSheet(StyleSheet** aResult) {
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|   *aResult = nullptr;
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| 
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|   MOZ_DIAGNOSTIC_ASSERT(mLoaded);
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| 
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|   if (!mSheet) {
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|     RefPtr<css::Loader> loader = new css::Loader;
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|     nsresult rv = loader->LoadSheetSync(mURI, mParsingMode, true, &mSheet);
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|     NS_ENSURE_SUCCESS(rv, rv);
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|     MOZ_ASSERT(mSheet);
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|   }
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| 
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|   *aResult = mSheet;
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|   return NS_OK;
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| }
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| 
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| nsresult PreloadedStyleSheet::Preload() {
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|   MOZ_DIAGNOSTIC_ASSERT(!mLoaded);
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| 
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|   // The nsIStyleSheetService.preloadSheet API doesn't tell us which backend
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|   // the sheet will be used with, and it seems wasteful to eagerly create
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|   // both a CSSStyleSheet and a ServoStyleSheet.  So instead, we guess that
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|   // the sheet type we will want matches the current value of the stylo pref,
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|   // and preload a sheet of that type.
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|   //
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|   // If we guess wrong, we will re-load the sheet later with the requested type,
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|   // and we won't really have front loaded the loading time as the name
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|   // "preload" might suggest.  Also, in theory we could get different data from
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|   // fetching the URL again, but for the usage patterns of this API this is
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|   // unlikely, and it doesn't seem worth trying to store the contents of the URL
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|   // and duplicating a bunch of css::Loader's logic.
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|   mLoaded = true;
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| 
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|   StyleSheet* sheet;
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|   return GetSheet(&sheet);
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| }
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| 
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| NS_IMPL_ISUPPORTS(PreloadedStyleSheet::StylesheetPreloadObserver,
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|                   nsICSSLoaderObserver)
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| 
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| NS_IMETHODIMP
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| PreloadedStyleSheet::StylesheetPreloadObserver::StyleSheetLoaded(
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|     StyleSheet* aSheet, bool aWasDeferred, nsresult aStatus) {
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|   MOZ_DIAGNOSTIC_ASSERT(!mPreloadedSheet->mLoaded);
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|   mPreloadedSheet->mLoaded = true;
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| 
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|   if (NS_FAILED(aStatus)) {
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|     mPromise->MaybeReject(aStatus);
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|   } else {
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|     mPromise->MaybeResolve(mPreloadedSheet);
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|   }
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| 
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|   return NS_OK;
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| }
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| 
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| // Note: After calling this method, the preloaded sheet *must not* be used
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| // until the observer is notified that the sheet has finished loading.
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| nsresult PreloadedStyleSheet::PreloadAsync(NotNull<dom::Promise*> aPromise) {
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|   MOZ_DIAGNOSTIC_ASSERT(!mLoaded);
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| 
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|   RefPtr<css::Loader> loader = new css::Loader;
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| 
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|   RefPtr<StylesheetPreloadObserver> obs =
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|       new StylesheetPreloadObserver(aPromise, this);
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| 
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|   return loader->LoadSheet(mURI, mParsingMode, false, obs, &mSheet);
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| }
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| 
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| }  // namespace mozilla
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