DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (a81015259a98)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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):
 *
 * 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 ***** */

/* 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"

class nsIAtom;
class nsICSSLoaderObserver;
class nsCSSStyleSheet;
class nsIContent;
class nsIDocument;
class nsCSSParser;
class nsMediaList;
class nsIStyleSheetLinkingElement;

namespace mozilla {

class URIAndPrincipalHashKey : public nsURIHashKey
{
public:
  typedef URIAndPrincipalHashKey* KeyType;
  typedef const URIAndPrincipalHashKey* KeyTypePointer;

  URIAndPrincipalHashKey(const URIAndPrincipalHashKey* aKey)
    : nsURIHashKey(aKey->mKey), mPrincipal(aKey->mPrincipal)
  {
    MOZ_COUNT_CTOR(URIAndPrincipalHashKey);
  }
  URIAndPrincipalHashKey(nsIURI* aURI, nsIPrincipal* aPrincipal)
    : nsURIHashKey(aURI), mPrincipal(aPrincipal)
  {
    MOZ_COUNT_CTOR(URIAndPrincipalHashKey);
  }
  URIAndPrincipalHashKey(const URIAndPrincipalHashKey& toCopy)
    : nsURIHashKey(toCopy), mPrincipal(toCopy.mPrincipal)
  {
    MOZ_COUNT_CTOR(URIAndPrincipalHashKey);
  }
  ~URIAndPrincipalHashKey()
  {
    MOZ_COUNT_DTOR(URIAndPrincipalHashKey);
  }

  URIAndPrincipalHashKey* GetKey() const {
    return const_cast<URIAndPrincipalHashKey*>(this);
  }
  const URIAndPrincipalHashKey* GetKeyPointer() const { return this; }

  bool KeyEquals(const URIAndPrincipalHashKey* 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;
    }

    bool eq;
    return !mPrincipal ||
      (NS_SUCCEEDED(mPrincipal->Equals(aKey->mPrincipal, &eq)) && eq);
  }

  static const URIAndPrincipalHashKey*
  KeyToPointer(URIAndPrincipalHashKey* aKey) { return aKey; }
  static PLDHashNumber HashKey(const URIAndPrincipalHashKey* aKey) {
    return nsURIHashKey::HashKey(aKey->mKey);
  }

  enum { ALLOW_MEMMOVE = true };

protected:
  nsCOMPtr<nsIPrincipal> mPrincipal;
};



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 {
public:
  Loader();
  Loader(nsIDocument*);
  ~Loader();

  // This isn't a COM class but it's reference-counted like one.
  NS_IMETHOD_(nsrefcnt) AddRef();
  NS_IMETHOD_(nsrefcnt) Release();

  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,
                           PRUint32 aLineNumber,
                           const nsAString& aTitle,
                           const nsAString& aMedia,
                           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 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,
                         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);

  /**
   * 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<nsRefPtr<SheetLoadData> > LoadDataArray;

private:
  friend class SheetLoadData;

  // 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,
                       bool aSyncLoad,
                       StyleSheetState& aSheetState,
                       nsCSSStyleSheet** 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(nsCSSStyleSheet* aSheet,
                        const nsAString& aTitle,
                        const nsAString& aMediaString,
                        nsMediaList* aMediaList,
                        bool aHasAlternateRel = false,
                        bool *aIsAlternate = nsnull);

  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);

  // 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);

  nsRefPtrHashtable<URIAndPrincipalHashKey, nsCSSStyleSheet>
                    mCompleteSheets;
  nsDataHashtable<URIAndPrincipalHashKey, SheetLoadData*>
                    mLoadingDatas; // weak refs
  nsDataHashtable<URIAndPrincipalHashKey, 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.
  nsAutoTArray<SheetLoadData*, 8> 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<nsCOMPtr<nsICSSLoaderObserver> > mObservers;

  // the load data needs access to the document...
  nsIDocument*      mDocument;  // the document we live for

  // Refcounting
  nsAutoRefCnt      mRefCnt;
  NS_DECL_OWNINGTHREAD

  // 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;

  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 */