Improve the people invite screens

 #904.

Remove a contact from the "Known Contacts" section if a local contact matches with his Matrix identifier.

Vector/ViewController/ContactsTableViewController.m

@@ -38,6 +38,9 @@ @interface ContactsTableViewController ()
 
     // This dictionary tells for each display name whether it appears several times.
     NSMutableDictionary <NSString*,NSNumber*> *isMultiUseNameByDisplayName;
+
+    // Report all the contacts by matrix id
+    NSMutableDictionary <NSString*, MXKContact*> *contactsByMatrixId;
 }
 
 @end
@@ -80,6 +83,7 @@ - (void)finalizeInit
     _ignoredContactsByMatrixId = [NSMutableDictionary dictionary];
 
     isMultiUseNameByDisplayName = [NSMutableDictionary dictionary];
+    contactsByMatrixId = [NSMutableDictionary dictionary];
 
     _forceMatrixIdInDisplayName = NO;
 }
@@ -121,6 +125,7 @@ - (void)destroy
     searchProcessingMatrixContacts = nil;
 
     isMultiUseNameByDisplayName = nil;
+    contactsByMatrixId = nil;
 
     _contactCellAccessoryImage = nil;
 
@@ -224,6 +229,10 @@ - (void)searchWithPattern:(NSString *)searchText forceReset:(BOOL)forceRefresh
             searchProcessingMatrixContacts = [self unfilteredMatrixContactsArray];
         }
 
+        // List all the filtered local Matrix-enabled contacts by their matrix id to remove a contact
+        // from the "Known Contacts" section if a local contact matches with his Matrix identifier.
+        [contactsByMatrixId removeAllObjects];
+
         for (NSUInteger index = 0; index < searchProcessingLocalContacts.count;)
         {
             MXKContact* contact = searchProcessingLocalContacts[index];
@@ -234,6 +243,13 @@ - (void)searchWithPattern:(NSString *)searchText forceReset:(BOOL)forceRefresh
             }
             else
             {
+                NSArray *identifiers = contact.matrixIdentifiers;
+                if (identifiers.count)
+                {
+                    // Here the contact can only have one identifier
+                    contactsByMatrixId[identifiers.firstObject] = contact;
+                }
+
                 // Next
                 index++;
             }
@@ -274,7 +290,33 @@ - (void)searchWithPattern:(NSString *)searchText forceReset:(BOOL)forceRefresh
                     // Update the filtered contacts.
                     currentSearchText = searchProcessingText;
                     filteredLocalContacts = searchProcessingLocalContacts;
-                    filteredMatrixContacts = searchProcessingMatrixContacts;
+
+                    // Check whether some Matrix-enabled contacts are listed in the local contact.
+                    if (contactsByMatrixId.count)
+                    {
+                        // Remove a contact from the "Known Contacts" section if a local contact matches with his Matrix identifier.
+                        filteredMatrixContacts = [NSMutableArray arrayWithArray:searchProcessingMatrixContacts];
+                        for (NSUInteger index = 0; index < filteredMatrixContacts.count;)
+                        {
+                            MXKContact* contact = filteredMatrixContacts[index];
+
+                            // Here the contact can only have one identifier
+                            NSArray *identifiers = contact.matrixIdentifiers;
+                            if (identifiers.count && contactsByMatrixId[identifiers.firstObject])
+                            {
+                                [filteredMatrixContacts removeObjectAtIndex:index];
+                            }
+                            else
+                            {
+                                // Next
+                                index++;
+                            }
+                        }
+                    }
+                    else
+                    {
+                        filteredMatrixContacts = searchProcessingMatrixContacts;
+                    }
 
                     if (!self.forceMatrixIdInDisplayName)
                     {