LCOV - code coverage report
Current view: directory - layout/style - nsIMediaList.h (source / functions) Found Hit Coverage
Test: app.info Lines: 28 0 0.0 %
Date: 2012-06-02 Functions: 21 0 0.0 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
       2                 :  *
       3                 :  * ***** BEGIN LICENSE BLOCK *****
       4                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       5                 :  *
       6                 :  * The contents of this file are subject to the Mozilla Public License Version
       7                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       8                 :  * the License. You may obtain a copy of the License at
       9                 :  * http://www.mozilla.org/MPL/
      10                 :  *
      11                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      12                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      13                 :  * for the specific language governing rights and limitations under the
      14                 :  * License.
      15                 :  *
      16                 :  * The Original Code is mozilla.org code.
      17                 :  *
      18                 :  * The Initial Developer of the Original Code is
      19                 :  * Boris Zbarsky <bzbarsky@mit.edu>.
      20                 :  * Portions created by the Initial Developer are Copyright (C) 2001
      21                 :  * the Initial Developer. All Rights Reserved.
      22                 :  *
      23                 :  * Contributor(s):
      24                 :  *   L. David Baron <dbaron@dbaron.org>, Mozilla Corporation
      25                 :  *
      26                 :  * Alternatively, the contents of this file may be used under the terms of
      27                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      28                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      29                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      30                 :  * of those above. If you wish to allow use of your version of this file only
      31                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      32                 :  * use your version of this file under the terms of the MPL, indicate your
      33                 :  * decision by deleting the provisions above and replace them with the notice
      34                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      35                 :  * the provisions above, a recipient may use your version of this file under
      36                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      37                 :  *
      38                 :  * ***** END LICENSE BLOCK ***** */
      39                 : 
      40                 : /*
      41                 :  * representation of media lists used when linking to style sheets or by
      42                 :  * @media rules
      43                 :  */
      44                 : 
      45                 : #ifndef nsIMediaList_h_
      46                 : #define nsIMediaList_h_
      47                 : 
      48                 : #include "nsIDOMMediaList.h"
      49                 : #include "nsTArray.h"
      50                 : #include "nsIAtom.h"
      51                 : #include "nsCSSValue.h"
      52                 : 
      53                 : class nsPresContext;
      54                 : class nsCSSStyleSheet;
      55                 : class nsAString;
      56                 : struct nsMediaFeature;
      57                 : 
      58               0 : struct nsMediaExpression {
      59                 :   enum Range { eMin, eMax, eEqual };
      60                 : 
      61                 :   const nsMediaFeature *mFeature;
      62                 :   Range mRange;
      63                 :   nsCSSValue mValue;
      64                 : 
      65                 :   // aActualValue must be obtained from mFeature->mGetter
      66                 :   bool Matches(nsPresContext* aPresContext,
      67                 :                  const nsCSSValue& aActualValue) const;
      68                 : };
      69                 : 
      70                 : /**
      71                 :  * An nsMediaQueryResultCacheKey records what feature/value combinations
      72                 :  * a set of media query results are valid for.  This allows the caller
      73                 :  * to quickly learn whether a prior result of media query evaluation is
      74                 :  * still valid (e.g., due to a window size change) without rerunning all
      75                 :  * of the evaluation and rebuilding the list of rules.
      76                 :  *
      77                 :  * This object may not be used after any media rules in any of the
      78                 :  * sheets it was given to have been modified.  However, this is
      79                 :  * generally not a problem since ClearRuleCascades is called on the
      80                 :  * sheet whenever this happens, and these objects are stored inside the
      81                 :  * rule cascades.  (FIXME: We're not actually doing this all the time.)
      82                 :  *
      83                 :  * The implementation could be further optimized in the future to store
      84                 :  * ranges (combinations of less-than, less-than-or-equal, greater-than,
      85                 :  * greater-than-or-equal, equal, not-equal, present, not-present) for
      86                 :  * each feature rather than simply storing the list of expressions.
      87                 :  * However, this requires combining any such ranges.
      88                 :  */
      89               0 : class nsMediaQueryResultCacheKey {
      90                 : public:
      91               0 :   nsMediaQueryResultCacheKey(nsIAtom* aMedium)
      92               0 :     : mMedium(aMedium)
      93               0 :   {}
      94                 : 
      95                 :   /**
      96                 :    * Record that aExpression was tested while building the cached set
      97                 :    * that this cache key is for, and that aExpressionMatches was whether
      98                 :    * it matched.
      99                 :    */
     100                 :   void AddExpression(const nsMediaExpression* aExpression,
     101                 :                      bool aExpressionMatches);
     102                 :   bool Matches(nsPresContext* aPresContext) const;
     103                 : private:
     104               0 :   struct ExpressionEntry {
     105                 :     // FIXME: if we were better at maintaining invariants about clearing
     106                 :     // rule cascades when media lists change, this could be a |const
     107                 :     // nsMediaExpression*| instead.
     108                 :     nsMediaExpression mExpression;
     109                 :     bool mExpressionMatches;
     110                 :   };
     111               0 :   struct FeatureEntry {
     112                 :     const nsMediaFeature *mFeature;
     113                 :     InfallibleTArray<ExpressionEntry> mExpressions;
     114                 :   };
     115                 :   nsCOMPtr<nsIAtom> mMedium;
     116                 :   nsTArray<FeatureEntry> mFeatureCache;
     117                 : };
     118                 : 
     119               0 : class nsMediaQuery {
     120                 : public:
     121               0 :   nsMediaQuery()
     122                 :     : mNegated(false)
     123                 :     , mHasOnly(false)
     124                 :     , mTypeOmitted(false)
     125               0 :     , mHadUnknownExpression(false)
     126                 :   {
     127               0 :   }
     128                 : 
     129                 : private:
     130                 :   // for Clone only
     131               0 :   nsMediaQuery(const nsMediaQuery& aOther)
     132                 :     : mNegated(aOther.mNegated)
     133                 :     , mHasOnly(aOther.mHasOnly)
     134                 :     , mTypeOmitted(aOther.mTypeOmitted)
     135                 :     , mHadUnknownExpression(aOther.mHadUnknownExpression)
     136                 :     , mMediaType(aOther.mMediaType)
     137                 :     // Clone checks the result of this deep copy for allocation failure
     138               0 :     , mExpressions(aOther.mExpressions)
     139                 :   {
     140               0 :   }
     141                 : 
     142                 : public:
     143                 : 
     144               0 :   void SetNegated()                     { mNegated = true; }
     145               0 :   void SetHasOnly()                     { mHasOnly = true; }
     146               0 :   void SetTypeOmitted()                 { mTypeOmitted = true; }
     147               0 :   void SetHadUnknownExpression()        { mHadUnknownExpression = true; }
     148               0 :   void SetType(nsIAtom* aMediaType)     { 
     149               0 :                                           NS_ASSERTION(aMediaType,
     150                 :                                                        "expected non-null");
     151               0 :                                           mMediaType = aMediaType;
     152               0 :                                         }
     153                 : 
     154                 :   // Return a new nsMediaExpression in the array for the caller to fill
     155                 :   // in.  The caller must either fill it in completely, or call
     156                 :   // SetHadUnknownExpression on this nsMediaQuery.
     157                 :   // Returns null on out-of-memory.
     158               0 :   nsMediaExpression* NewExpression()    { return mExpressions.AppendElement(); }
     159                 : 
     160                 :   void AppendToString(nsAString& aString) const;
     161                 : 
     162                 :   nsMediaQuery* Clone() const;
     163                 : 
     164                 :   // Does this query apply to the presentation?
     165                 :   // If |aKey| is non-null, add cache information to it.
     166                 :   bool Matches(nsPresContext* aPresContext,
     167                 :                  nsMediaQueryResultCacheKey* aKey) const;
     168                 : 
     169                 : private:
     170                 :   bool mNegated;
     171                 :   bool mHasOnly; // only needed for serialization
     172                 :   bool mTypeOmitted; // only needed for serialization
     173                 :   bool mHadUnknownExpression;
     174                 :   nsCOMPtr<nsIAtom> mMediaType;
     175                 :   nsTArray<nsMediaExpression> mExpressions;
     176                 : };
     177                 : 
     178                 : class nsMediaList : public nsIDOMMediaList {
     179                 : public:
     180                 :   nsMediaList();
     181                 : 
     182                 :   NS_DECL_ISUPPORTS
     183                 : 
     184                 :   NS_DECL_NSIDOMMEDIALIST
     185                 : 
     186                 :   nsresult GetText(nsAString& aMediaText);
     187                 :   nsresult SetText(const nsAString& aMediaText);
     188                 : 
     189                 :   // Does this query apply to the presentation?
     190                 :   // If |aKey| is non-null, add cache information to it.
     191                 :   bool Matches(nsPresContext* aPresContext,
     192                 :                  nsMediaQueryResultCacheKey* aKey);
     193                 : 
     194                 :   nsresult SetStyleSheet(nsCSSStyleSheet* aSheet);
     195               0 :   void AppendQuery(nsAutoPtr<nsMediaQuery>& aQuery) {
     196                 :     // Takes ownership of aQuery
     197               0 :     mArray.AppendElement(aQuery.forget());
     198               0 :   }
     199                 : 
     200                 :   nsresult Clone(nsMediaList** aResult);
     201                 : 
     202               0 :   PRInt32 Count() { return mArray.Length(); }
     203                 :   nsMediaQuery* MediumAt(PRInt32 aIndex) { return mArray[aIndex]; }
     204               0 :   void Clear() { mArray.Clear(); }
     205                 : 
     206                 : protected:
     207                 :   ~nsMediaList();
     208                 : 
     209                 :   nsresult Delete(const nsAString & aOldMedium);
     210                 :   nsresult Append(const nsAString & aOldMedium);
     211                 : 
     212                 :   InfallibleTArray<nsAutoPtr<nsMediaQuery> > mArray;
     213                 :   // not refcounted; sheet will let us know when it goes away
     214                 :   // mStyleSheet is the sheet that needs to be dirtied when this medialist
     215                 :   // changes
     216                 :   nsCSSStyleSheet*         mStyleSheet;
     217                 : };
     218                 : #endif /* !defined(nsIMediaList_h_) */

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