TAChart: Extract TBroadcaster from TCustomChartSource

* Move TBroadcaster and TListener to TAChartUtils

git-svn-id: trunk@24466 -

components/tachart/tachartutils.pas

@@ -42,6 +42,7 @@ const
 type
   EChartError = class(Exception);
   EChartIntervalError = class(EChartError);
+  EListenerError = class(EChartError);
 
   TDoublePoint = record
     X, Y: Double;
@@ -139,6 +140,28 @@ type
     property Index: Integer read GetIndex write SetIndex;
   end;
 
+  { TListener }
+
+  TListener = class
+  private
+    FIsListening: Boolean;
+  public
+    procedure Forget; virtual;
+    procedure Notify; virtual; abstract;
+    property IsListening: Boolean read FIsListening;
+  end;
+
+  { TBroadcaster }
+
+  TBroadcaster = class(TFPList)
+  public
+    destructor Destroy; override;
+  public
+    procedure Broadcast;
+    procedure Subscribe(AListener: TListener);
+    procedure Unsubscribe(AListener: TListener);
+  end;
+
 const
   // 0-value, 1-percent, 2-label, 3-total, 4-xvalue
   SERIES_MARK_FORMATS: array [TSeriesMarksStyle] of String = (
@@ -703,4 +726,53 @@ begin
   FOnChange := AValue;
 end;
 
+{ TListener }
+
+procedure TListener.Forget;
+begin
+  FIsListening := false;
+end;
+
+{ TBroadcaster }
+
+procedure TBroadcaster.Broadcast;
+var
+  i: Integer;
+begin
+  for i := 0 to Count - 1 do
+    TListener(Items[i]).Notify;
+end;
+
+destructor TBroadcaster.Destroy;
+var
+  i: Integer;
+begin
+  for i := 0 to Count - 1 do
+    TListener(Items[i]).Forget;
+  inherited Destroy;
+end;
+
+procedure TBroadcaster.Subscribe(AListener: TListener);
+begin
+  if AListener.IsListening then
+    raise EListenerError.Create('Listener subscribed twice');
+  if IndexOf(AListener) >= 0 then
+    raise EListenerError.Create('Duplicate listener');
+  AListener.FIsListening := true;
+  Add(AListener);
+end;
+
+procedure TBroadcaster.Unsubscribe(AListener: TListener);
+var
+  i: Integer;
+begin
+  if not AListener.IsListening then
+    raise EListenerError.Create('Listener not subscribed');
+  AListener.FIsListening := false;
+  i := IndexOf(AListener);
+  if i < 0 then
+    raise EListenerError.Create('Listener not found');
+  Delete(i);
+end;
+
 end.

components/tachart/tacustomseries.pas

@@ -96,12 +96,12 @@ type
     procedure AfterDraw; override;
     procedure BeforeDraw; override;
     function ColorOrDefault(AColor: TColor; ADefault: TColor = clTAColor): TColor;
+    procedure GetBounds(out ABounds: TDoubleRect); override;
     function GetGraphPoint(AIndex: Integer): TDoublePoint;
     function GetGraphPointX(AIndex: Integer): Double; inline;
     function GetGraphPointY(AIndex: Integer): Double; inline;
     function GetSeriesColor: TColor; virtual;
     function GetXMaxVal: Integer;
-    procedure GetBounds(out ABounds: TDoubleRect); override;
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
@@ -379,7 +379,7 @@ begin
   FListener := TChartSeriesListener.Create(Self);
   FBuiltinSource := TListChartSource.Create(Self);
   FBuiltinSource.Name := BUILTIN_SOURCE_NAME;
-  FBuiltinSource.Subscribe(FListener);
+  FBuiltinSource.Broadcaster.Subscribe(FListener);
   FMarks := TChartMarks.Create(FChart);
 end;
 
@@ -391,7 +391,7 @@ end;
 destructor TChartSeries.Destroy;
 begin
   if FListener.IsListening then
-    Source.Unsubscribe(FListener);
+    Source.Broadcaster.Unsubscribe(FListener);
   FBuiltinSource.Free;
   FMarks.Free;
   FListener.Free;
@@ -553,9 +553,9 @@ procedure TChartSeries.SetSource(AValue: TCustomChartSource);
 begin
   if FSource = AValue then exit;
   if FListener.IsListening then
-    Source.Unsubscribe(FListener);
+    Source.Broadcaster.Unsubscribe(FListener);
   FSource := AValue;
-  Source.Subscribe(FListener);
+  Source.Broadcaster.Subscribe(FListener);
   UpdateParentChart;
 end;
 

components/tachart/tasources.pas

@@ -26,7 +26,6 @@ uses
 
 type
   EEditableSourceRequired = class(EChartError);
-  EListenerError = class(EChartError);
 
   TChartDataItem = record
     X, Y: Double;
@@ -35,24 +34,12 @@ type
   end;
   PChartDataItem = ^TChartDataItem;
 
-  { TListener }
-
-  TListener = class
-  private
-    FIsListening: Boolean;
-  public
-    procedure Forget; virtual;
-    procedure Notify; virtual; abstract;
-    property IsListening: Boolean read FIsListening;
-  end;
-
   { TCustomChartSource }
 
   TCustomChartSource = class(TComponent)
   private
-    FListeners: array of TListener;
+    FBroadcaster: TBroadcaster;
     FUpdateCount: Integer;
-    function FindListener(AListener: TListener): Integer;
   protected
     FExtent: TDoubleRect;
     FExtentIsValid: Boolean;
@@ -63,6 +50,7 @@ type
     procedure InvalidateCaches;
     procedure Notify;
   public
+    constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
   public
     procedure AfterDraw; virtual;
@@ -70,8 +58,6 @@ type
     procedure BeginUpdate;
     procedure EndUpdate;
     function IsUpdating: Boolean; inline;
-    procedure Subscribe(AListener: TListener);
-    procedure Unsubscribe(AListener: TListener);
   public
     function Extent: TDoubleRect; virtual;
     function FormatItem(const AFormat: String; AIndex: Integer): String;
@@ -79,6 +65,7 @@ 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;
   end;
@@ -252,14 +239,16 @@ begin
   Inc(FUpdateCount);
 end;
 
-destructor TCustomChartSource.Destroy;
-var
-  i: Integer;
+constructor TCustomChartSource.Create(AOwner: TComponent);
 begin
-  for i := 0 to High(FListeners) do
-    FListeners[i].Forget;
-  FListeners := nil;
-  inherited Destroy;
+  inherited Create(AOwner);
+  FBroadcaster := TBroadcaster.Create;
+end;
+
+destructor TCustomChartSource.Destroy;
+begin
+  FBroadcaster.Free;
+  inherited;
 end;
 
 procedure TCustomChartSource.EndUpdate;
@@ -283,13 +272,6 @@ begin
   Result := FExtent;
 end;
 
-function TCustomChartSource.FindListener(AListener: TListener): Integer;
-begin
-  for Result := 0 to High(FListeners) do
-    if FListeners[Result] = AListener then exit;
-  Result := -1;
-end;
-
 function TCustomChartSource.FormatItem(
   const AFormat: String; AIndex: Integer): String;
 const
@@ -319,38 +301,9 @@ begin
 end;
 
 procedure TCustomChartSource.Notify;
-var
-  i: Integer;
 begin
-  if IsUpdating then exit;
-  for i := 0 to High(FListeners) do
-    FListeners[i].Notify;
-end;
-
-procedure TCustomChartSource.Subscribe(AListener: TListener);
-begin
-  if AListener.IsListening then
-    raise EListenerError.Create('Listener subscribed twice');
-  if FindListener(AListener) >= 0 then
-    raise EListenerError.Create('Duplicate listener');
-  AListener.FIsListening := true;
-  SetLength(FListeners, Length(FListeners) + 1);
-  FListeners[High(FListeners)] := AListener;
-end;
-
-procedure TCustomChartSource.Unsubscribe(AListener: TListener);
-var
-  i, j: Integer;
-begin
-  if not AListener.IsListening then
-    raise EListenerError.Create('Listener not subscribed');
-  AListener.FIsListening := false;
-  j := FindListener(AListener);
-  if j < 0 then
-    raise EListenerError.Create('Listener not found');
-  for i := j to High(FListeners) - 1 do
-    FListeners[i] := FListeners[i + 1];
-  SetLength(FListeners, Length(FListeners) - 1);
+  if not IsUpdating then
+    FBroadcaster.Broadcast;
 end;
 
 function TCustomChartSource.ValuesTotal: Double;
@@ -774,13 +727,6 @@ begin
   Notify;
 end;
 
-{ TListener }
-
-procedure TListener.Forget;
-begin
-  FIsListening := false;
-end;
-
 { TUserDefinedChartSource }
 
 function TUserDefinedChartSource.GetCount: Integer;