/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* loading of CSS style sheets using the network APIs */ #ifndef mozilla_css_Loader_h #define mozilla_css_Loader_h #include "nsIPrincipal.h" #include "nsAString.h" #include "nsAutoPtr.h" #include "nsCompatibility.h" #include "nsDataHashtable.h" #include "nsInterfaceHashtable.h" #include "nsRefPtrHashtable.h" #include "nsTArray.h" #include "nsTObserverArray.h" #include "nsURIHashKey.h" #include "mozilla/Attributes.h" #include "mozilla/CORSMode.h" #include "mozilla/MemoryReporting.h" class nsIAtom; class nsICSSLoaderObserver; class nsCSSStyleSheet; class nsIContent; class nsIDocument; class nsCSSParser; class nsMediaList; class nsIStyleSheetLinkingElement; class nsCycleCollectionTraversalCallback; namespace mozilla { namespace dom { class Element; } } namespace mozilla { class URIPrincipalAndCORSModeHashKey : public nsURIHashKey { public: typedef URIPrincipalAndCORSModeHashKey* KeyType; typedef const URIPrincipalAndCORSModeHashKey* KeyTypePointer; URIPrincipalAndCORSModeHashKey(const URIPrincipalAndCORSModeHashKey* aKey) : nsURIHashKey(aKey->mKey), mPrincipal(aKey->mPrincipal), mCORSMode(aKey->mCORSMode) { MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey); } URIPrincipalAndCORSModeHashKey(nsIURI* aURI, nsIPrincipal* aPrincipal, CORSMode aCORSMode) : nsURIHashKey(aURI), mPrincipal(aPrincipal), mCORSMode(aCORSMode) { MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey); } URIPrincipalAndCORSModeHashKey(const URIPrincipalAndCORSModeHashKey& toCopy) : nsURIHashKey(toCopy), mPrincipal(toCopy.mPrincipal), mCORSMode(toCopy.mCORSMode) { MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey); } ~URIPrincipalAndCORSModeHashKey() { MOZ_COUNT_DTOR(URIPrincipalAndCORSModeHashKey); } URIPrincipalAndCORSModeHashKey* GetKey() const { return const_cast(this); } const URIPrincipalAndCORSModeHashKey* GetKeyPointer() const { return this; } bool KeyEquals(const URIPrincipalAndCORSModeHashKey* aKey) const { if (!nsURIHashKey::KeyEquals(aKey->mKey)) { return false; } if (!mPrincipal != !aKey->mPrincipal) { // One or the other has a principal, but not both... not equal return false; } if (mCORSMode != aKey->mCORSMode) { // Different CORS modes; we don't match return false; } bool eq; return !mPrincipal || (NS_SUCCEEDED(mPrincipal->Equals(aKey->mPrincipal, &eq)) && eq); } static const URIPrincipalAndCORSModeHashKey* KeyToPointer(URIPrincipalAndCORSModeHashKey* aKey) { return aKey; } static PLDHashNumber HashKey(const URIPrincipalAndCORSModeHashKey* aKey) { return nsURIHashKey::HashKey(aKey->mKey); } nsIURI* GetURI() const { return nsURIHashKey::GetKey(); } enum { ALLOW_MEMMOVE = true }; protected: nsCOMPtr mPrincipal; CORSMode mCORSMode; }; namespace css { class SheetLoadData; class ImportRule; /*********************************************************************** * Enum that describes the state of the sheet returned by CreateSheet. * ***********************************************************************/ enum StyleSheetState { eSheetStateUnknown = 0, eSheetNeedsParser, eSheetPending, eSheetLoading, eSheetComplete }; class Loader MOZ_FINAL { public: Loader(); Loader(nsIDocument*); ~Loader(); NS_INLINE_DECL_REFCOUNTING(Loader) void DropDocumentReference(); // notification that doc is going away void SetCompatibilityMode(nsCompatibility aCompatMode) { mCompatMode = aCompatMode; } nsCompatibility GetCompatibilityMode() { return mCompatMode; } nsresult SetPreferredSheet(const nsAString& aTitle); // XXXbz sort out what the deal is with events! When should they fire? /** * Load an inline style sheet. If a successful result is returned and * *aCompleted is false, then aObserver is guaranteed to be notified * asynchronously once the sheet is marked complete. If an error is * returned, or if *aCompleted is true, aObserver will not be notified. In * addition to parsing the sheet, this method will insert it into the * stylesheet list of this CSSLoader's document. * * @param aElement the element linking to the stylesheet. This must not be * null and must implement nsIStyleSheetLinkingElement. * @param aBuffer the stylesheet data * @param aLineNumber the line number at which the stylesheet data started. * @param aTitle the title of the sheet. * @param aMedia the media string for the sheet. * @param aObserver the observer to notify when the load completes. * May be null. * @param [out] aCompleted whether parsing of the sheet completed. * @param [out] aIsAlternate whether the stylesheet ended up being an * alternate sheet. */ nsresult LoadInlineStyle(nsIContent* aElement, const nsAString& aBuffer, uint32_t aLineNumber, const nsAString& aTitle, const nsAString& aMedia, mozilla::dom::Element* aScopeElement, nsICSSLoaderObserver* aObserver, bool* aCompleted, bool* aIsAlternate); /** * Load a linked (document) stylesheet. If a successful result is returned, * aObserver is guaranteed to be notified asynchronously once the sheet is * loaded and marked complete. If an error is returned, aObserver will not * be notified. In addition to loading the sheet, this method will insert it * into the stylesheet list of this CSSLoader's document. * * @param aElement the element linking to the the stylesheet. May be null. * @param aURL the URL of the sheet. * @param aTitle the title of the sheet. * @param aMedia the media string for the sheet. * @param aHasAlternateRel whether the rel for this link included * "alternate". * @param aCORSMode the CORS mode for this load. * @param aObserver the observer to notify when the load completes. * May be null. * @param [out] aIsAlternate whether the stylesheet actually ended up beinga * an alternate sheet. Note that this need not match * aHasAlternateRel. */ nsresult LoadStyleLink(nsIContent* aElement, nsIURI* aURL, const nsAString& aTitle, const nsAString& aMedia, bool aHasAlternateRel, CORSMode aCORSMode, nsICSSLoaderObserver* aObserver, bool* aIsAlternate); /** * Load a child (@import-ed) style sheet. In addition to loading the sheet, * this method will insert it into the child sheet list of aParentSheet. If * there is no sheet currently being parsed and the child sheet is not * complete when this method returns, then when the child sheet becomes * complete aParentSheet will be QIed to nsICSSLoaderObserver and * asynchronously notified, just like for LoadStyleLink. Note that if the * child sheet is already complete when this method returns, no * nsICSSLoaderObserver notification will be sent. * * @param aParentSheet the parent of this child sheet * @param aURL the URL of the child sheet * @param aMedia the already-parsed media list for the child sheet * @param aRule the @import rule importing this child. This is used to * properly order the child sheet list of aParentSheet. */ nsresult LoadChildSheet(nsCSSStyleSheet* aParentSheet, nsIURI* aURL, nsMediaList* aMedia, ImportRule* aRule); /** * Synchronously load and return the stylesheet at aURL. Any child sheets * will also be loaded synchronously. Note that synchronous loads over some * protocols may involve spinning up a new event loop, so use of this method * does NOT guarantee not receiving any events before the sheet loads. This * method can be used to load sheets not associated with a document. * * @param aURL the URL of the sheet to load * @param aEnableUnsafeRules whether unsafe rules are enabled for this * sheet load * Unsafe rules are rules that can violate key Gecko invariants if misused. * In particular, most anonymous box pseudoelements must be very carefully * styled or we will have severe problems. Therefore unsafe rules should * never be enabled for stylesheets controlled by untrusted sites; preferably * unsafe rules should only be enabled for agent sheets. * @param aUseSystemPrincipal if true, give the resulting sheet the system * principal no matter where it's being loaded from. * @param [out] aSheet the loaded, complete sheet. * * NOTE: At the moment, this method assumes the sheet will be UTF-8, but * ideally it would allow arbitrary encodings. Callers should NOT depend on * non-UTF8 sheets being treated as UTF-8 by this method. * * NOTE: A successful return from this method doesn't indicate anything about * whether the data could be parsed as CSS and doesn't indicate anything * about the status of child sheets of the returned sheet. */ nsresult LoadSheetSync(nsIURI* aURL, bool aEnableUnsafeRules, bool aUseSystemPrincipal, nsCSSStyleSheet** aSheet); /** * As above, but aUseSystemPrincipal and aEnableUnsafeRules are assumed false. */ nsresult LoadSheetSync(nsIURI* aURL, nsCSSStyleSheet** aSheet) { return LoadSheetSync(aURL, false, false, aSheet); } /** * Asynchronously load the stylesheet at aURL. If a successful result is * returned, aObserver is guaranteed to be notified asynchronously once the * sheet is loaded and marked complete. This method can be used to load * sheets not associated with a document. * * @param aURL the URL of the sheet to load * @param aOriginPrincipal the principal to use for security checks. This * can be null to indicate that these checks should * be skipped. * @param aCharset the encoding to use for converting the sheet data * from bytes to Unicode. May be empty to indicate that the * charset of the CSSLoader's document should be used. This * is only used if neither the network transport nor the * sheet itself indicate an encoding. * @param aObserver the observer to notify when the load completes. * Must not be null. * @param [out] aSheet the sheet to load. Note that the sheet may well * not be loaded by the time this method returns. */ nsresult LoadSheet(nsIURI* aURL, nsIPrincipal* aOriginPrincipal, const nsCString& aCharset, nsICSSLoaderObserver* aObserver, nsCSSStyleSheet** aSheet); /** * Same as above, to be used when the caller doesn't care about the * not-yet-loaded sheet. */ nsresult LoadSheet(nsIURI* aURL, nsIPrincipal* aOriginPrincipal, const nsCString& aCharset, nsICSSLoaderObserver* aObserver, CORSMode aCORSMode = CORS_NONE); /** * Stop loading all sheets. All nsICSSLoaderObservers involved will be * notified with NS_BINDING_ABORTED as the status, possibly synchronously. */ nsresult Stop(void); /** * nsresult Loader::StopLoadingSheet(nsIURI* aURL), which notifies the * nsICSSLoaderObserver with NS_BINDING_ABORTED, was removed in Bug 556446. * It can be found in revision 2c44a32052ad. */ /** * Whether the loader is enabled or not. * When disabled, processing of new styles is disabled and an attempt * to do so will fail with a return code of * NS_ERROR_NOT_AVAILABLE. Note that this DOES NOT disable * currently loading styles or already processed styles. */ bool GetEnabled() { return mEnabled; } void SetEnabled(bool aEnabled) { mEnabled = aEnabled; } /** * Get the document we live for. May return null. */ nsIDocument* GetDocument() const { return mDocument; } /** * Return true if this loader has pending loads (ones that would send * notifications to an nsICSSLoaderObserver attached to this loader). * If called from inside nsICSSLoaderObserver::StyleSheetLoaded, this will * return false if and only if that is the last StyleSheetLoaded * notification the CSSLoader knows it's going to send. In other words, if * two sheets load at once (via load coalescing, e.g.), HasPendingLoads() * will return true during notification for the first one, and false * during notification for the second one. */ bool HasPendingLoads(); /** * Add an observer to this loader. The observer will be notified * for all loads that would have notified their own observers (even * if those loads don't have observers attached to them). * Load-specific observers will be notified before generic * observers. The loader holds a reference to the observer. * * aObserver must not be null. */ nsresult AddObserver(nsICSSLoaderObserver* aObserver); /** * Remove an observer added via AddObserver. */ void RemoveObserver(nsICSSLoaderObserver* aObserver); // These interfaces are public only for the benefit of static functions // within nsCSSLoader.cpp. // IsAlternate can change our currently selected style set if none // is selected and aHasAlternateRel is false. bool IsAlternate(const nsAString& aTitle, bool aHasAlternateRel); typedef nsTArray > LoadDataArray; // Traverse the cached stylesheets we're holding on to. This should // only be called from the document that owns this loader. void TraverseCachedSheets(nsCycleCollectionTraversalCallback& cb); // Unlink the cached stylesheets we're holding on to. Again, this // should only be called from the document that owns this loader. void UnlinkCachedSheets(); // Measure our size. size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; // Marks all the sheets at the given URI obsolete, and removes them from the // cache. nsresult ObsoleteSheet(nsIURI* aURI); private: friend class SheetLoadData; static PLDHashOperator RemoveEntriesWithURI(URIPrincipalAndCORSModeHashKey* aKey, nsRefPtr &aSheet, void* aUserData); // Note: null aSourcePrincipal indicates that the content policy and // CheckLoadURI checks should be skipped. nsresult CheckLoadAllowed(nsIPrincipal* aSourcePrincipal, nsIURI* aTargetURI, nsISupports* aContext); // For inline style, the aURI param is null, but the aLinkingContent // must be non-null then. The loader principal must never be null // if aURI is not null. // *aIsAlternate is set based on aTitle and aHasAlternateRel. nsresult CreateSheet(nsIURI* aURI, nsIContent* aLinkingContent, nsIPrincipal* aLoaderPrincipal, CORSMode aCORSMode, bool aSyncLoad, bool aHasAlternateRel, const nsAString& aTitle, StyleSheetState& aSheetState, bool *aIsAlternate, nsCSSStyleSheet** aSheet); // Pass in either a media string or the nsMediaList from the // CSSParser. Don't pass both. // This method will set the sheet's enabled state based on isAlternate void PrepareSheet(nsCSSStyleSheet* aSheet, const nsAString& aTitle, const nsAString& aMediaString, nsMediaList* aMediaList, dom::Element* aScopeElement, bool isAlternate); nsresult InsertSheetInDoc(nsCSSStyleSheet* aSheet, nsIContent* aLinkingContent, nsIDocument* aDocument); nsresult InsertChildSheet(nsCSSStyleSheet* aSheet, nsCSSStyleSheet* aParentSheet, ImportRule* aParentRule); nsresult InternalLoadNonDocumentSheet(nsIURI* aURL, bool aAllowUnsafeRules, bool aUseSystemPrincipal, nsIPrincipal* aOriginPrincipal, const nsCString& aCharset, nsCSSStyleSheet** aSheet, nsICSSLoaderObserver* aObserver, CORSMode aCORSMode = CORS_NONE); // Post a load event for aObserver to be notified about aSheet. The // notification will be sent with status NS_OK unless the load event is // canceled at some point (in which case it will be sent with // NS_BINDING_ABORTED). aWasAlternate indicates the state when the load was // initiated, not the state at some later time. aURI should be the URI the // sheet was loaded from (may be null for inline sheets). aElement is the // owning element for this sheet. nsresult PostLoadEvent(nsIURI* aURI, nsCSSStyleSheet* aSheet, nsICSSLoaderObserver* aObserver, bool aWasAlternate, nsIStyleSheetLinkingElement* aElement); // Start the loads of all the sheets in mPendingDatas void StartAlternateLoads(); // Handle an event posted by PostLoadEvent void HandleLoadEvent(SheetLoadData* aEvent); // Note: LoadSheet is responsible for releasing aLoadData and setting the // sheet to complete on failure. nsresult LoadSheet(SheetLoadData* aLoadData, StyleSheetState aSheetState); // Parse the stylesheet in aLoadData. The sheet data comes from aInput. // Set aCompleted to true if the parse finished, false otherwise (e.g. if the // sheet had an @import). If aCompleted is true when this returns, then // ParseSheet also called SheetComplete on aLoadData. nsresult ParseSheet(const nsAString& aInput, SheetLoadData* aLoadData, bool& aCompleted); // The load of the sheet in aLoadData is done, one way or another. Do final // cleanup, including releasing aLoadData. void SheetComplete(SheetLoadData* aLoadData, nsresult aStatus); // The guts of SheetComplete. This may be called recursively on parent datas // or datas that had glommed on to a single load. The array is there so load // datas whose observers need to be notified can be added to it. void DoSheetComplete(SheetLoadData* aLoadData, nsresult aStatus, LoadDataArray& aDatasToNotify); struct Sheets { nsRefPtrHashtable mCompleteSheets; nsDataHashtable mLoadingDatas; // weak refs nsDataHashtable mPendingDatas; // weak refs }; nsAutoPtr mSheets; // We're not likely to have many levels of @import... But likely to have // some. Allocate some storage, what the hell. nsAutoTArray mParsingDatas; // The array of posted stylesheet loaded events (SheetLoadDatas) we have. // Note that these are rare. LoadDataArray mPostedEvents; // Our array of "global" observers // XXXbz these are strong refs; should we be cycle collecting CSS loaders? nsTObserverArray > mObservers; // the load data needs access to the document... nsIDocument* mDocument; // the document we live for // Number of datas still waiting to be notified on if we're notifying on a // whole bunch at once (e.g. in one of the stop methods). This is used to // make sure that HasPendingLoads() won't return false until we're notifying // on the last data we're working with. uint32_t mDatasToNotifyOn; nsCompatibility mCompatMode; nsString mPreferredSheet; // title of preferred sheet bool mEnabled; // is enabled to load new styles #ifdef DEBUG bool mSyncCallback; #endif }; } // namespace css } // namespace mozilla #endif /* mozilla_css_Loader_h */