realm delete many (#153)

Implemented realm.deleteMany for List, RealmList and realmResults to delete objects from realm - fixes #60
Support RealmResults for..in  - fixes #37 without snapshot

.vscode/settings.json

@@ -96,5 +96,6 @@
         "flutter/realm_flutter/ios/src/**": true,
         "flutter/realm_flutter/lib/**": true,
         "flutter/realm_flutter/test/**": true
-    }
+    },
+    "dart.lineLength": 160
 }

lib/src/native/realm_core.dart

@@ -316,7 +316,7 @@ class _RealmCore {
     });
   }
 
-  void removeRealmObject(RealmObject object) {
+  void deleteRealmObject(RealmObject object) {
     _realmLib.invokeGetBool(() => _realmLib.realm_object_delete(object.handle._pointer));
   }
 
@@ -424,10 +424,17 @@ class _RealmCore {
     });
   }
 
+  void listDeleteAll(RealmList list) {
+    _realmLib.invokeGetBool(() => _realmLib.realm_list_remove_all(list.handle._pointer));
+  }
+
+  void resultsDeleteAll(RealmResults results) {
+    _realmLib.invokeGetBool(() => _realmLib.realm_results_delete_all(results.handle._pointer));
+  }
+
   void listClear(RealmList list) {
     _realmLib.invokeGetBool(() => _realmLib.realm_list_clear(list.handle._pointer));
   }
-
 }
 
 class LastError {

lib/src/realm_class.dart

@@ -83,14 +83,37 @@ class Realm {
     return object;
   }
 
+  /// Delete given [RealmObject] from Realm database.
+  /// Throws [RealmException] on error.
+  void delete<T extends RealmObject>(T object) {
+    try {
+      realmCore.deleteRealmObject(object);
+    } catch (e) {
+      throw RealmException("Error deleting object from databse. Error: $e");
+    }
+  }
+
+  /// Deletes [RealmObject] items in given collection from Realm database.
+  void deleteMany<T extends RealmObject>(Iterable<T> items) {
+    if (items is RealmResults<T>) {
+      realmCore.resultsDeleteAll(items);
+    } else if (items is RealmList<T>) {
+      realmCore.listDeleteAll(items);
+    } else {
+      for (T realmObject in items) {
+        realmCore.deleteRealmObject(realmObject);
+      }
+    }
+  }
+
   void addAll<T extends RealmObject>(Iterable<T> items) {
     for (final i in items) {
       add(i);
     }
   }
 
   void remove<T extends RealmObject>(T object) {
-    realmCore.removeRealmObject(object);
+    realmCore.deleteRealmObject(object);
   }
 
   bool get _isInTransaction => realmCore.getIsWritable(this);

lib/src/results.dart

@@ -91,7 +91,7 @@ class _ResultsList<T extends RealmObject> extends collection.ListBase<T> {
 /// Instances of this class are typically live collections returned by [Realm.objects]
 /// that will update as new objects are either added to or deleted from the Realm
 /// that match the underlying query.
-class RealmResults<T extends RealmObject> {
+class RealmResults<T extends RealmObject> extends collection.IterableBase<T> {
   late final RealmResultsHandle _handle;
   late final Realm _realm;
   // RealmResults _results;
@@ -143,16 +143,19 @@ class RealmResults<T extends RealmObject> {
   // }
 
   /// Returns `true` if the Results collection is empty
-  bool isEmpty() {
-    return length == 0;
-  }
+  @override
+  bool get isEmpty => length == 0;
+
+  @override
+  Iterator<T> get iterator => _RealmResultsIterator(this);
 
   /// Returns `true` if this Results collection has not been deleted and is part of a valid Realm.
   ///
   /// Accessing an invalid Results collection will throw an [RealmException]
   // bool get isValid => _results.isValid();
 
   /// Returns the number of values in the Results collection.
+  @override
   int get length => realmCore.getResultsCount(this);
 
   /// Returns a human-readable description of the objects contained in the collection.
@@ -208,3 +211,29 @@ extension RealmResultsInternal on RealmResults {
     return RealmResults<T>._(handle, realm);
   }
 }
+
+class _RealmResultsIterator<T extends RealmObject> implements Iterator<T> {
+  final RealmResults<T> _results;
+  int _index;
+  T? _current;
+
+  _RealmResultsIterator(RealmResults<T> results)
+      : _results = results,
+        _index = -1;
+
+  @override
+  T get current => _current as T;
+
+  @override
+  bool moveNext() {
+    int length = _results.length;
+    _index++;
+    if (_index >= length) {
+      _current = null;
+      return false;
+    }
+    _current = _results[_index];
+
+    return true;
+  }
+}