gecko/layout/style/nsCSSLoader.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: ft=cpp tw=78 sw=2 et ts=2
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Boris Zbarsky <bzbarsky@mit.edu>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK *****
*
* This Original Code has been modified by IBM Corporation. Modifications made by IBM
* described herein are Copyright (c) International Business Machines Corporation, 2000.
* Modifications to Mozilla code or documentation identified per MPL Section 3.3
*
* Date Modified by Description of modification
* 04/20/2000 IBM Corp. OS/2 VisualAge build.
*/
/* loading of CSS style sheets using the network APIs */
#ifndef nsCSSLoader_h__
#define nsCSSLoader_h__
class CSSLoaderImpl;
class nsIURI;
class nsICSSStyleSheet;
class nsIStyleSheetLinkingElement;
class nsICSSLoaderObserver;
class nsICSSParser;
class nsICSSImportRule;
class nsMediaList;
#include "nsICSSLoader.h"
#include "nsIRunnable.h"
#include "nsIUnicharStreamLoader.h"
#include "nsCOMPtr.h"
#include "nsCOMArray.h"
#include "nsString.h"
#include "nsURIHashKey.h"
#include "nsInterfaceHashtable.h"
#include "nsDataHashtable.h"
#include "nsAutoPtr.h"
#include "nsTArray.h"
#include "nsIPrincipal.h"
#include "nsTObserverArray.h"
/**
* OVERALL ARCHITECTURE
*
* The CSS Loader gets requests to load various sorts of style sheets:
* inline style from <style> elements, linked style, @import-ed child
* sheets, non-document sheets. The loader handles the following tasks:
*
* 1) Checking whether the load is allowed: CheckLoadAllowed()
* 2) Creation of the actual style sheet objects: CreateSheet()
* 3) setting of the right media, title, enabled state, etc on the
* sheet: PrepareSheet()
* 4) Insertion of the sheet in the proper cascade order:
* InsertSheetInDoc() and InsertChildSheet()
* 5) Load of the sheet: LoadSheet()
* 6) Parsing of the sheet: ParseSheet()
* 7) Cleanup: SheetComplete()
*
* The detailed documentation for these functions is found with the
* function implementations.
*
* The following helper object is used:
* SheetLoadData -- a small class that is used to store all the
* information needed for the loading of a sheet;
* this class handles listening for the stream
* loader completion and also handles charset
* determination.
*/
/*********************************************
* Data needed to properly load a stylesheet *
*********************************************/
class SheetLoadData : public nsIRunnable,
public nsIUnicharStreamLoaderObserver
{
public:
virtual ~SheetLoadData(void);
// Data for loading a sheet linked from a document
SheetLoadData(CSSLoaderImpl* aLoader,
const nsSubstring& aTitle,
nsIURI* aURI,
nsICSSStyleSheet* aSheet,
nsIStyleSheetLinkingElement* aOwningElement,
PRBool aIsAlternate,
nsICSSLoaderObserver* aObserver,
nsIPrincipal* aLoaderPrincipal);
// Data for loading a sheet linked from an @import rule
SheetLoadData(CSSLoaderImpl* aLoader,
nsIURI* aURI,
nsICSSStyleSheet* aSheet,
SheetLoadData* aParentData,
nsICSSLoaderObserver* aObserver,
nsIPrincipal* aLoaderPrincipal);
// Data for loading a non-document sheet
SheetLoadData(CSSLoaderImpl* aLoader,
nsIURI* aURI,
nsICSSStyleSheet* aSheet,
PRBool aSyncLoad,
PRBool aAllowUnsafeRules,
nsICSSLoaderObserver* aObserver,
nsIPrincipal* aLoaderPrincipal);
already_AddRefed<nsIURI> GetReferrerURI();
NS_DECL_ISUPPORTS
NS_DECL_NSIRUNNABLE
NS_DECL_NSIUNICHARSTREAMLOADEROBSERVER
// Hold a ref to the CSSLoader so we can call back to it to let it
// know the load finished
CSSLoaderImpl* mLoader; // strong ref
// Title needed to pull datas out of the pending datas table when
// the preferred title is changed
nsString mTitle;
// Charset we decided to use for the sheet
nsCString mCharset;
// URI we're loading. Null for inline sheets
nsCOMPtr<nsIURI> mURI;
// Should be 1 for non-inline sheets.
PRUint32 mLineNumber;
// The sheet we're loading data for
nsCOMPtr<nsICSSStyleSheet> mSheet;
// Linked list of datas for the same URI as us
SheetLoadData* mNext; // strong ref
// Load data for the sheet that @import-ed us if we were @import-ed
// during the parse
SheetLoadData* mParentData; // strong ref
// Number of sheets we @import-ed that are still loading
PRUint32 mPendingChildren;
// mSyncLoad is true when the load needs to be synchronous -- right
// now only for LoadSheetSync and children of sync loads.
PRPackedBool mSyncLoad : 1;
// mIsNonDocumentSheet is true if the load was triggered by LoadSheetSync or
// LoadSheet or an @import from such a sheet. Non-document sheet loads can
// proceed even if we have no document.
PRPackedBool mIsNonDocumentSheet : 1;
// mIsLoading is true from the moment we are placed in the loader's
// "loading datas" table (right after the async channel is opened)
// to the moment we are removed from said table (due to the load
// completing or being cancelled).
PRPackedBool mIsLoading : 1;
// mIsCancelled is set to true when a sheet load is stopped by
// Stop() or StopLoadingSheet(). SheetLoadData::OnStreamComplete()
// checks this to avoid parsing sheets that have been cancelled and
// such.
PRPackedBool mIsCancelled : 1;
// mMustNotify is true if the load data is being loaded async and
// the original function call that started the load has returned.
// XXXbz sort our relationship with load/error events!
PRPackedBool mMustNotify : 1;
// mWasAlternate is true if the sheet was an alternate when the load data was
// created.
PRPackedBool mWasAlternate : 1;
// mAllowUnsafeRules is true if we should allow unsafe rules to be parsed
// in the loaded sheet.
PRPackedBool mAllowUnsafeRules : 1;
// This is the element that imported the sheet. Needed to get the
// charset set on it.
nsCOMPtr<nsIStyleSheetLinkingElement> mOwningElement;
// The observer that wishes to be notified of load completion
nsCOMPtr<nsICSSLoaderObserver> mObserver;
// The principal that identifies who started loading us.
nsCOMPtr<nsIPrincipal> mLoaderPrincipal;
};
class nsURIAndPrincipalHashKey : public nsURIHashKey
{
public:
typedef nsURIAndPrincipalHashKey* KeyType;
typedef const nsURIAndPrincipalHashKey* KeyTypePointer;
nsURIAndPrincipalHashKey(const nsURIAndPrincipalHashKey* aKey)
: nsURIHashKey(aKey->mKey), mPrincipal(aKey->mPrincipal)
{
MOZ_COUNT_CTOR(nsURIAndPrincipalHashKey);
}
nsURIAndPrincipalHashKey(nsIURI* aURI, nsIPrincipal* aPrincipal)
: nsURIHashKey(aURI), mPrincipal(aPrincipal)
{
MOZ_COUNT_CTOR(nsURIAndPrincipalHashKey);
}
nsURIAndPrincipalHashKey(const nsURIAndPrincipalHashKey& toCopy)
: nsURIHashKey(toCopy), mPrincipal(toCopy.mPrincipal)
{
MOZ_COUNT_CTOR(nsURIAndPrincipalHashKey);
}
~nsURIAndPrincipalHashKey()
{
MOZ_COUNT_DTOR(nsURIAndPrincipalHashKey);
}
nsURIAndPrincipalHashKey* GetKey() const {
return const_cast<nsURIAndPrincipalHashKey*>(this);
}
const nsURIAndPrincipalHashKey* GetKeyPointer() const { return this; }
PRBool KeyEquals(const nsURIAndPrincipalHashKey* aKey) const {
if (!nsURIHashKey::KeyEquals(aKey->mKey)) {
return PR_FALSE;
}
if (!mPrincipal != !aKey->mPrincipal) {
// One or the other has a principal, but not both... not equal
return PR_FALSE;
}
PRBool eq;
return !mPrincipal ||
NS_SUCCEEDED(mPrincipal->Equals(aKey->mPrincipal, &eq)) && eq;
}
static const nsURIAndPrincipalHashKey*
KeyToPointer(nsURIAndPrincipalHashKey* aKey) { return aKey; }
static PLDHashNumber HashKey(const nsURIAndPrincipalHashKey* aKey) {
return nsURIHashKey::HashKey(aKey->mKey);
}
enum { ALLOW_MEMMOVE = PR_TRUE };
protected:
nsCOMPtr<nsIPrincipal> mPrincipal;
};
/***********************************************************************
* Enum that describes the state of the sheet returned by CreateSheet. *
***********************************************************************/
enum StyleSheetState {
eSheetStateUnknown = 0,
eSheetNeedsParser,
eSheetPending,
eSheetLoading,
eSheetComplete
};
/**********************
* Loader Declaration *
**********************/
class CSSLoaderImpl : public nsICSSLoader
{
public:
CSSLoaderImpl(void);
virtual ~CSSLoaderImpl(void);
NS_DECL_ISUPPORTS
static void Shutdown(); // called at app shutdown
// nsICSSLoader methods
NS_IMETHOD Init(nsIDocument* aDocument);
NS_IMETHOD DropDocumentReference(void);
NS_IMETHOD SetCaseSensitive(PRBool aCaseSensitive);
NS_IMETHOD SetCompatibilityMode(nsCompatibility aCompatMode);
NS_IMETHOD SetPreferredSheet(const nsAString& aTitle);
NS_IMETHOD GetPreferredSheet(nsAString& aTitle);
NS_IMETHOD GetParserFor(nsICSSStyleSheet* aSheet,
nsICSSParser** aParser);
NS_IMETHOD RecycleParser(nsICSSParser* aParser);
NS_IMETHOD LoadInlineStyle(nsIContent* aElement,
nsIUnicharInputStream* aStream,
PRUint32 aLineNumber,
const nsSubstring& aTitle,
const nsSubstring& aMedia,
nsICSSLoaderObserver* aObserver,
PRBool* aCompleted,
PRBool* aIsAlternate);
NS_IMETHOD LoadStyleLink(nsIContent* aElement,
nsIURI* aURL,
const nsSubstring& aTitle,
const nsSubstring& aMedia,
PRBool aHasAlternateRel,
nsICSSLoaderObserver* aObserver,
PRBool* aIsAlternate);
NS_IMETHOD LoadChildSheet(nsICSSStyleSheet* aParentSheet,
nsIURI* aURL,
nsMediaList* aMedia,
nsICSSImportRule* aRule);
NS_IMETHOD LoadSheetSync(nsIURI* aURL, PRBool aAllowUnsafeRules,
nsICSSStyleSheet** aSheet);
NS_IMETHOD LoadSheet(nsIURI* aURL,
nsIPrincipal* aOriginPrincipal,
nsICSSLoaderObserver* aObserver,
nsICSSStyleSheet** aSheet);
NS_IMETHOD LoadSheet(nsIURI* aURL,
nsIPrincipal* aOriginPrincipal,
nsICSSLoaderObserver* aObserver);
// stop loading all sheets
NS_IMETHOD Stop(void);
// stop loading one sheet
NS_IMETHOD StopLoadingSheet(nsIURI* aURL);
/**
* Is the loader 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.
*/
NS_IMETHOD GetEnabled(PRBool *aEnabled);
NS_IMETHOD SetEnabled(PRBool aEnabled);
NS_IMETHOD_(PRBool) HasPendingLoads();
NS_IMETHOD AddObserver(nsICSSLoaderObserver* aObserver);
NS_IMETHOD_(void) RemoveObserver(nsICSSLoaderObserver* aObserver);
// local helper methods (some are public for access from statics)
// IsAlternate can change our currently selected style set if none
// is selected and aHasAlternateRel is false.
PRBool IsAlternate(const nsAString& aTitle, PRBool aHasAlternateRel);
private:
// 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.
nsresult CreateSheet(nsIURI* aURI,
nsIContent* aLinkingContent,
nsIPrincipal* aLoaderPrincipal,
PRBool aSyncLoad,
StyleSheetState& aSheetState,
nsICSSStyleSheet** aSheet);
// Pass in either a media string or the nsMediaList from the
// CSSParser. Don't pass both.
// If aIsAlternate is non-null, this method will set *aIsAlternate to
// correspond to the sheet's enabled state (which it will set no matter what)
nsresult PrepareSheet(nsICSSStyleSheet* aSheet,
const nsSubstring& aTitle,
const nsSubstring& aMediaString,
nsMediaList* aMediaList,
PRBool aHasAlternateRel = PR_FALSE,
PRBool *aIsAlternate = nsnull);
nsresult InsertSheetInDoc(nsICSSStyleSheet* aSheet,
nsIContent* aLinkingContent,
nsIDocument* aDocument);
nsresult InsertChildSheet(nsICSSStyleSheet* aSheet,
nsICSSStyleSheet* aParentSheet,
nsICSSImportRule* aParentRule);
nsresult InternalLoadNonDocumentSheet(nsIURI* aURL,
PRBool aAllowUnsafeRules,
nsIPrincipal* aOriginPrincipal,
nsICSSStyleSheet** aSheet,
nsICSSLoaderObserver* aObserver);
// 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).
nsresult PostLoadEvent(nsIURI* aURI,
nsICSSStyleSheet* aSheet,
nsICSSLoaderObserver* aObserver,
PRBool aWasAlternate);
// Start the loads of all the sheets in mPendingDatas
void StartAlternateLoads();
public:
// Handle an event posted by PostLoadEvent
void HandleLoadEvent(SheetLoadData* aEvent);
protected:
// Note: LoadSheet is responsible for releasing aLoadData and setting the
// sheet to complete on failure.
nsresult LoadSheet(SheetLoadData* aLoadData, StyleSheetState aSheetState);
friend class SheetLoadData;
// Protected functions and members are ones that SheetLoadData needs
// access to.
// Parse the stylesheet in aLoadData. The sheet data comes from aStream.
// 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(nsIUnicharInputStream* aStream,
SheetLoadData* aLoadData,
PRBool& 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);
public:
typedef nsTArray<nsRefPtr<SheetLoadData> > LoadDataArray;
private:
// 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);
static nsCOMArray<nsICSSParser>* gParsers; // array of idle CSS parsers
// the load data needs access to the document...
nsIDocument* mDocument; // the document we live for
#ifdef DEBUG
PRPackedBool mSyncCallback;
#endif
PRPackedBool mCaseSensitive; // is document CSS case sensitive
PRPackedBool mEnabled; // is enabled to load new styles
nsCompatibility mCompatMode;
nsString mPreferredSheet; // title of preferred sheet
nsInterfaceHashtable<nsURIAndPrincipalHashKey,
nsICSSStyleSheet> mCompleteSheets;
nsDataHashtable<nsURIAndPrincipalHashKey,
SheetLoadData*> mLoadingDatas; // weak refs
nsDataHashtable<nsURIAndPrincipalHashKey,
SheetLoadData*> mPendingDatas; // weak refs
// We're not likely to have many levels of @import... But likely to have
// some. Allocate some storage, what the hell.
nsAutoVoidArray mParsingDatas;
// The array of posted stylesheet loaded events (SheetLoadDatas) we have.
// Note that these are rare.
LoadDataArray mPostedEvents;
// 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.
PRUint32 mDatasToNotifyOn;
// Our array of "global" observers
nsTObserverArray<nsICSSLoaderObserver> mObservers;
};
#endif // nsCSSLoader_h__