Bug #162789 --> need a method on a mdb directory to see if a card exits for an address. this is part of the work

for adding the ability to filter and search based on the sender in an address book.
r=navin
sr=bienvenu

mailnews/addrbook/public/nsIAbMDBDirectory.idl

@@ -84,4 +84,7 @@ interface nsIAbMDBDirectory : nsISupports {
 	[noscript] void notifyDirItemAdded(in nsISupports item);
 	
 	[noscript] void clearDatabase();
+	
+    // Check if the directory has a card for the specified email address
+	boolean hasCardForEmailAddress(in string emailAddress);
 };

mailnews/addrbook/src/nsAbMDBDirProperty.cpp

@@ -210,3 +210,7 @@ NS_IMETHODIMP nsAbMDBDirProperty::SetValueForCard(nsIAbCard *card, const char *n
   return rv;
 }
 
+NS_IMETHODIMP nsAbMDBDirProperty::HasCardForEmailAddress(const char * aEmailAddress, PRBool * aCardExists)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}

mailnews/addrbook/src/nsAbMDBDirectory.cpp

@@ -1010,3 +1010,19 @@ nsresult nsAbMDBDirectory::GetAbDatabase()
     return NS_ERROR_NULL_POINTER;
   return NS_OK;
 }
+
+NS_IMETHODIMP nsAbMDBDirectory::HasCardForEmailAddress(const char * aEmailAddress, PRBool * aCardExists)
+{
+  nsresult rv = NS_OK;
+  *aCardExists = PR_FALSE;
+
+  if (!mDatabase)
+    rv = GetAbDatabase();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIAbCard> cardExists; 
+  mDatabase->GetCardFromAttribute(this, kPriEmailColumn, aEmailAddress, PR_FALSE /* retain case */, getter_AddRefs(cardExists));
+  if (cardExists)
+    *aCardExists = PR_TRUE;
+  return NS_OK;
+}

mailnews/addrbook/src/nsAbMDBDirectory.h

@@ -83,6 +83,7 @@ public:
 	NS_IMETHOD RemoveEmailAddressAt(PRUint32 aIndex);
 	NS_IMETHOD AddDirectory(const char *uriName, nsIAbDirectory **childDir);
 	NS_IMETHOD GetDirUri(char **uri);
+    NS_IMETHOD HasCardForEmailAddress(const char * aEmailAddress, PRBool * aCardExists);
 
 	// nsIAbDirectory methods:
 	NS_IMETHOD GetChildNodes(nsIEnumerator* *result);