diff --git a/components/tachart/tacustomsource.pas b/components/tachart/tacustomsource.pas
index 95f0fa2e51..196ce85133 100644
--- a/components/tachart/tacustomsource.pas
+++ b/components/tachart/tacustomsource.pas
@@ -128,6 +128,21 @@ type
     function ToImage(AX: Double): Integer; inline;
   end;
 
+  TBasicChartSource = class(TComponent)
+  strict private
+    FBroadcaster: TBroadcaster;
+    FUpdateCount: Integer;
+  strict protected
+    procedure Notify;
+  public
+    constructor Create(AOwner: TComponent); override;
+    destructor Destroy; override;
+    procedure BeginUpdate;
+    procedure EndUpdate; virtual;
+    function IsUpdating: Boolean; inline;
+    property Broadcaster: TBroadcaster read FBroadcaster;
+  end;
+
   TCustomChartSource = class;
 
   TCustomChartSourceEnumerator = class
@@ -142,16 +157,14 @@ type
     property Current: PChartDataItem read GetCurrent;
   end;
 
-  TCustomChartSource = class(TComponent)
+  TCustomChartSource = class(TBasicChartSource)
   strict private
-    FBroadcaster: TBroadcaster;
-    FUpdateCount: Integer;
-
     procedure SortValuesInRange(
       var AValues: TChartValueTextArray; AStart, AEnd: Integer);
   strict protected
     FExtent: TDoubleRect;
     FExtentIsValid: Boolean;
+    FUpdateCount: Integer;
     FValuesTotal: Double;
     FValuesTotalIsValid: Boolean;
     FYCount: Cardinal;
@@ -161,17 +174,13 @@ type
     function GetLink(AIndex: Integer): PChartLinkItem; virtual; abstract;
     function GetLinkCount: Integer; virtual; abstract;
     procedure InvalidateCaches;
-    procedure Notify;
     procedure SetYCount(AValue: Cardinal); virtual; abstract;
   public
     constructor Create(AOwner: TComponent); override;
-    destructor Destroy; override;
   public
     procedure AfterDraw; virtual;
     procedure BeforeDraw; virtual;
-    procedure BeginUpdate;
     procedure EndUpdate; virtual;
-    function IsUpdating: Boolean; inline;
   public
     class procedure CheckFormat(const AFormat: String);
     function Extent: TDoubleRect; virtual;
@@ -190,7 +199,6 @@ type
     function XOfMax: Double;
     function XOfMin: Double;
 
-    property Broadcaster: TBroadcaster read FBroadcaster;
     property Count: Integer read GetCount;
     property Item[AIndex: Integer]: PChartDataItem read GetItem; default;
     property Link[AIndex: Integer]: PChartLinkItem read GetLink;
@@ -449,6 +457,44 @@ begin
     YList[AIndex - 1] := AValue;
 end;
 
+{ TBaisChartSource }
+
+constructor TBasicChartSource.Create(AOwner: TComponent);
+begin
+  inherited Create(AOwner);
+  FBroadcaster := TBroadcaster.Create;
+end;
+
+destructor TBasicChartSource.Destroy;
+begin
+  FreeAndNil(FBroadcaster);
+  inherited Destroy;
+end;
+
+procedure TBasicChartSource.BeginUpdate;
+begin
+  Inc(FUpdateCount);
+end;
+
+procedure TBasicChartSource.EndUpdate;
+begin
+  Dec(FUpdateCount);
+  if FUpdateCount > 0 then exit;
+  Notify;
+end;
+
+function TBasicChartSource.IsUpdating: Boolean; inline;
+begin
+  Result := FUpdateCount > 0;
+end;
+
+procedure TBasicChartSource.Notify;
+begin
+  if not IsUpdating then
+    FBroadcaster.Broadcast(Self);
+end;
+
+
 { TChartSourceBuffer }
 
 procedure TChartSourceBuffer.AddFirst(const AItem: TChartDataItem);
@@ -596,11 +642,6 @@ begin
   // empty
 end;
 
-procedure TCustomChartSource.BeginUpdate;
-begin
-  Inc(FUpdateCount);
-end;
-
 class procedure TCustomChartSource.CheckFormat(const AFormat: String);
 begin
   Format(AFormat, [0.0, 0.0, '', 0.0, 0.0]);
@@ -609,16 +650,9 @@ end;
 constructor TCustomChartSource.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
-  FBroadcaster := TBroadcaster.Create;
   FYCount := 1;
 end;
 
-destructor TCustomChartSource.Destroy;
-begin
-  FreeAndNil(FBroadcaster);
-  inherited;
-end;
-
 procedure TCustomChartSource.EndUpdate;
 begin
   Dec(FUpdateCount);
@@ -761,17 +795,6 @@ begin
   Result := false;
 end;
 
-function TCustomChartSource.IsUpdating: Boolean; inline;
-begin
-  Result := FUpdateCount > 0;
-end;
-
-procedure TCustomChartSource.Notify;
-begin
-  if not IsUpdating then
-    FBroadcaster.Broadcast(Self);
-end;
-
 procedure TCustomChartSource.SortValuesInRange(
   var AValues: TChartValueTextArray; AStart, AEnd: Integer);
 var