content/xul/templates/src/nsTemplateMatch.h
author Michael Wu <mwu@mozilla.com>
Wed, 28 Sep 2011 23:19:26 -0700
changeset 79445 e7854b4d29ba905ae3994f821b160c989bac4260
parent 72851 6cf983334e7add24d79ec85f1a5c2386e69d4d23
child 98983 f4157e8c410708d76703f19e4dfb61859bfe32d8
child 112094 cad26d2fb5af799dfe030fd2a8948d617eac2f52
permissions -rw-r--r--
Bug 675553 - Switch from PRBool to bool on a CLOSED TREE , r=bsmedberg,khuey,bz,cjones

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Chris Waterson <waterson@netscape.com>
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 * either of the GNU General Public License Version 2 or later (the "GPL"),
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#ifndef nsTemplateMatch_h__
#define nsTemplateMatch_h__

#include "nsFixedSizeAllocator.h"
#include "nsIContent.h"
#include "nsIXULTemplateQueryProcessor.h"
#include "nsIXULTemplateResult.h"
#include "nsRuleNetwork.h"
#include NEW_H

/**
 * A match object, where each match object is associated with one result.
 * There will be one match list for each unique id generated. However, since
 * there are multiple querysets and each may generate results with the same
 * id, they are all chained together in a linked list, ordered in the same
 * order as the respective <queryset> elements they were generated from.
 * A match can be identified by the container and id. The id is retrievable
 * from the result.
 *
 * Only one match per container and id pair is active at a time, but which
 * match is active may change as new results are added or removed. When a
 * match is active, content is generated for that match.
 *
 * Matches are stored and owned by the mMatchToMap hash in the template
 * builder.
 */

class nsTemplateRule;
class nsTemplateQuerySet;

class nsTemplateMatch {
private:
    // Hide so that only Create() and Destroy() can be used to
    // allocate and deallocate from the heap
    void* operator new(size_t) CPP_THROW_NEW { return 0; }
    void operator delete(void*, size_t) {}

public:
    nsTemplateMatch(PRUint16 aQuerySetPriority,
                    nsIXULTemplateResult* aResult,
                    nsIContent* aContainer)
        : mRuleIndex(-1),
          mQuerySetPriority(aQuerySetPriority),
          mContainer(aContainer),
          mResult(aResult),
          mNext(nsnull)
    {
      MOZ_COUNT_CTOR(nsTemplateMatch);
    }

    ~nsTemplateMatch()
    {
      MOZ_COUNT_DTOR(nsTemplateMatch);
    }

    static nsTemplateMatch*
    Create(nsFixedSizeAllocator& aPool,
           PRUint16 aQuerySetPriority,
           nsIXULTemplateResult* aResult,
           nsIContent* aContainer) {
        void* place = aPool.Alloc(sizeof(nsTemplateMatch));
        return place ? ::new (place) nsTemplateMatch(aQuerySetPriority,
                                                     aResult, aContainer)
                     : nsnull; }

    static void Destroy(nsFixedSizeAllocator& aPool,
                        nsTemplateMatch*& aMatch,
                        bool aRemoveResult);

    // return true if the the match is active, and has generated output
    bool IsActive() {
        return mRuleIndex >= 0;
    }

    // indicate that a rule is no longer active, used when a query with a
    // lower priority has overriden the match
    void SetInactive() {
        mRuleIndex = -1;
    }

    // return matching rule index
    PRInt16 RuleIndex() {
        return mRuleIndex;
    }

    // return priority of query set
    PRUint16 QuerySetPriority() {
        return mQuerySetPriority;
    }

    // return container, not addrefed. May be null.
    nsIContent* GetContainer() {
        return mContainer;
    }

    nsresult RuleMatched(nsTemplateQuerySet* aQuerySet,
                         nsTemplateRule* aRule,
                         PRInt16 aRuleIndex,
                         nsIXULTemplateResult* aResult);

private:

    /**
     * The index of the rule that matched, or -1 if the match is not active.
     */
    PRInt16 mRuleIndex;

    /**
     * The priority of the queryset for this rule
     */
    PRUint16 mQuerySetPriority;

    /**
     * The container the content generated for the match is inside.
     */
    nsCOMPtr<nsIContent> mContainer;

public:

    /**
     * The result associated with this match
     */
    nsCOMPtr<nsIXULTemplateResult> mResult;

    /**
     * Matches are stored in a linked list, in priority order. This first
     * match that has a rule set (mRule) is the active match and generates
     * content. The next match is owned by the builder, which will delete
     * template matches when needed.
     */
    nsTemplateMatch *mNext;

private:

    nsTemplateMatch(const nsTemplateMatch& aMatch); // not to be implemented
    void operator=(const nsTemplateMatch& aMatch); // not to be implemented
};

#endif // nsTemplateMatch_h__