content/xul/templates/src/nsTemplateMatch.h

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   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
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   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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  14  *
  15  * The Original Code is Mozilla Communicator client code.
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  17  * The Initial Developer of the Original Code is
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  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
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  22  * Contributor(s):
  23  *   Chris Waterson <waterson@netscape.com>
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  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #ifndef nsTemplateMatch_h__
  40 #define nsTemplateMatch_h__
  41
  42 #include "nsFixedSizeAllocator.h"
  43 #include "nsIContent.h"
  44 #include "nsIXULTemplateQueryProcessor.h"
  45 #include "nsIXULTemplateResult.h"
  46 #include "nsRuleNetwork.h"
  47 #include NEW_H
  48
  49 /**
  50  * A match object, where each match object is associated with one result.
  51  * There will be one match list for each unique id generated. However, since
  52  * there are multiple querysets and each may generate results with the same
  53  * id, they are all chained together in a linked list, ordered in the same
  54  * order as the respective <queryset> elements they were generated from.
  55  * A match can be identified by the container and id. The id is retrievable
  56  * from the result.
  57  *
  58  * Only one match per container and id pair is active at a time, but which
  59  * match is active may change as new results are added or removed. When a
  60  * match is active, content is generated for that match.
  61  *
  62  * Matches are stored and owned by the mMatchToMap hash in the template
  63  * builder.
  64  */
  65
  66 class nsTemplateRule;
  67 class nsTemplateQuerySet;
  68
  69 class nsTemplateMatch {
  70 private:
  71     // Hide so that only Create() and Destroy() can be used to
  72     // allocate and deallocate from the heap
  73     void* operator new(size_t) CPP_THROW_NEW { return 0; }
  74     void operator delete(void*, size_t) {}
  75
  76 public:
  77     nsTemplateMatch(PRUint16 aQuerySetPriority,
  78                     nsIXULTemplateResult* aResult,
  79                     nsIContent* aContainer)
  80         : mRuleIndex(-1),
  81           mQuerySetPriority(aQuerySetPriority),
  82           mContainer(aContainer),
  83           mResult(aResult),
  84           mNext(nsnull) {}
  85
  86     ~nsTemplateMatch() {}
  87
  88     static nsTemplateMatch*
  89     Create(nsFixedSizeAllocator& aPool,
  90            PRUint16 aQuerySetPriority,
  91            nsIXULTemplateResult* aResult,
  92            nsIContent* aContainer) {
  93         void* place = aPool.Alloc(sizeof(nsTemplateMatch));
  94         return place ? ::new (place) nsTemplateMatch(aQuerySetPriority,
  95                                                      aResult, aContainer)
  96                      : nsnull; }
  97
  98     static void Destroy(nsFixedSizeAllocator& aPool,
  99                         nsTemplateMatch*& aMatch,
 100                         PRBool aRemoveResult);
 101
 102     // return true if the the match is active, and has generated output
 103     PRBool IsActive() {
 104         return mRuleIndex >= 0;
 105     }
 106
 107     // indicate that a rule is no longer active, used when a query with a
 108     // lower priority has overriden the match
 109     void SetInactive() {
 110         mRuleIndex = -1;
 111     }
 112
 113     // return matching rule index
 114     PRInt16 RuleIndex() {
 115         return mRuleIndex;
 116     }
 117
 118     // return priority of query set
 119     PRUint16 QuerySetPriority() {
 120         return mQuerySetPriority;
 121     }
 122
 123     // return container, not addrefed. May be null.
 124     nsIContent* GetContainer() {
 125         return mContainer;
 126     }
 127
 128     nsresult RuleMatched(nsTemplateQuerySet* aQuerySet,
 129                          nsTemplateRule* aRule,
 130                          PRInt16 aRuleIndex,
 131                          nsIXULTemplateResult* aResult);
 132
 133 private:
 134
 135     /**
 136      * The index of the rule that matched, or -1 if the match is not active.
 137      */
 138     PRInt16 mRuleIndex;
 139
 140     /**
 141      * The priority of the queryset for this rule
 142      */
 143     PRUint16 mQuerySetPriority;
 144
 145     /**
 146      * The container the content generated for the match is inside.
 147      */
 148     nsCOMPtr<nsIContent> mContainer;
 149
 150 public:
 151
 152     /**
 153      * The result associated with this match
 154      */
 155     nsCOMPtr<nsIXULTemplateResult> mResult;
 156
 157     /**
 158      * Matches are stored in a linked list, in priority order. This first
 159      * match that has a rule set (mRule) is the active match and generates
 160      * content. The next match is owned by the builder, which will delete
 161      * template matches when needed.
 162      */
 163     nsTemplateMatch *mNext;
 164
 165 private:
 166
 167     nsTemplateMatch(const nsTemplateMatch& aMatch); // not to be implemented
 168     void operator=(const nsTemplateMatch& aMatch); // not to be implemented
 169 };
 170
 171 #endif // nsTemplateMatch_h__
 172