content/xul/templates/src/nsXMLBinding.h

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  15  * The Original Code is mozilla.org code.
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  17  * The Initial Developer of the Original Code is Neil Deakin
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  36
  37 #ifndef nsXMLBinding_h__
  38 #define nsXMLBinding_h__
  39
  40 #include "nsAutoPtr.h"
  41 #include "nsIAtom.h"
  42
  43 class nsXULTemplateResultXML;
  44 class nsXMLBindingValues;
  45
  46 /**
  47  * Classes related to storing bindings for XML handling.
  48  */
  49
  50 /**
  51  * a <binding> description
  52  */
  53 struct nsXMLBinding {
  54   nsCOMPtr<nsIAtom> mVar;
  55   nsCOMPtr<nsIDOMXPathExpression> mExpr;
  56
  57   nsAutoPtr<nsXMLBinding> mNext;
  58
  59   nsXMLBinding(nsIAtom* aVar, nsIDOMXPathExpression* aExpr)
  60     : mVar(aVar), mExpr(aExpr), mNext(nsnull)
  61   {
  62     MOZ_COUNT_CTOR(nsXMLBinding);
  63   }
  64
  65   ~nsXMLBinding()
  66   {
  67     MOZ_COUNT_DTOR(nsXMLBinding);
  68   }
  69 };
  70
  71 /**
  72  * a collection of <binding> descriptors. This object is refcounted by
  73  * nsXMLBindingValues objects and the query processor.
  74  */
  75 class nsXMLBindingSet
  76 {
  77 public:
  78
  79   // results hold a reference to a binding set in their
  80   // nsXMLBindingValues fields
  81   nsAutoRefCnt mRefCnt;
  82
  83   // pointer to the first binding in a linked list
  84   nsAutoPtr<nsXMLBinding> mFirst;
  85
  86 public:
  87
  88   NS_IMETHOD_(nsrefcnt) AddRef();
  89   NS_IMETHOD_(nsrefcnt) Release();
  90   NS_DECL_OWNINGTHREAD
  91
  92   /**
  93    * Add a binding to the set
  94    */
  95   nsresult
  96   AddBinding(nsIAtom* aVar, nsIDOMXPathExpression* aExpr);
  97
  98   /**
  99    * The nsXMLBindingValues class stores an array of values, one for each
 100    * target symbol that could be set by the bindings in the set.
 101    * LookupTargetIndex determines the index into the array for a given
 102    * target symbol.
 103    */
 104   PRInt32
 105   LookupTargetIndex(nsIAtom* aTargetVariable, nsXMLBinding** aBinding);
 106 };
 107
 108 /**
 109  * a set of values of bindings. This object is used once per result.
 110  */
 111 class nsXMLBindingValues
 112 {
 113 protected:
 114
 115   // the binding set
 116   nsRefPtr<nsXMLBindingSet> mBindings;
 117
 118   /**
 119    * A set of values for variable bindings. To look up a binding value,
 120    * scan through the binding set in mBindings for the right target atom.
 121    * Its index will correspond to the index in this array.
 122    */
 123   nsCOMArray<nsIDOMXPathResult> mValues;
 124
 125 public:
 126
 127   nsXMLBindingValues() { MOZ_COUNT_CTOR(nsXMLBindingValues); }
 128   ~nsXMLBindingValues() { MOZ_COUNT_DTOR(nsXMLBindingValues); }
 129
 130   nsXMLBindingSet* GetBindingSet() { return mBindings; }
 131
 132   void SetBindingSet(nsXMLBindingSet* aBindings) { mBindings = aBindings; }
 133
 134   PRInt32
 135   LookupTargetIndex(nsIAtom* aTargetVariable, nsXMLBinding** aBinding)
 136   {
 137     return mBindings ?
 138            mBindings->LookupTargetIndex(aTargetVariable, aBinding) : -1;
 139   }
 140
 141   /**
 142    * Retrieve the assignment for a particular variable
 143    *
 144    * aResult the result generated from the template
 145    * aBinding the binding looked up using LookupTargetIndex
 146    * aIndex the index of the assignment to retrieve
 147    * aType the type of result expected
 148    * aValue the value of the assignment
 149    */
 150   void
 151   GetAssignmentFor(nsXULTemplateResultXML* aResult,
 152                    nsXMLBinding* aBinding,
 153                    PRInt32 idx,
 154                    PRUint16 type,
 155                    nsIDOMXPathResult** aValue);
 156
 157   void
 158   GetNodeAssignmentFor(nsXULTemplateResultXML* aResult,
 159                        nsXMLBinding* aBinding,
 160                        PRInt32 idx,
 161                        nsIDOMNode** aValue);
 162
 163   void
 164   GetStringAssignmentFor(nsXULTemplateResultXML* aResult,
 165                          nsXMLBinding* aBinding,
 166                          PRInt32 idx,
 167                          nsAString& aValue);
 168 };
 169
 170 #endif // nsXMLBinding_h__