TAChart: Correctly refresh db-aware chart after dataset changes.

* Add BeforeDraw/AfterDraw procedures to series and sources
* Preserve dataset cursor position while drawing db-aware Series
* Update chart after deleting a record

git-svn-id: trunk@20216 -

components/tachart/tadbsource.pas

@@ -29,12 +29,14 @@ type
 
   TDbChartSource = class(TCustomChartSource)
   private
+    FBookmark: TBookmark;
+    FCurItem: TChartDataItem;
     FDataLink: TDataLink;
     FFieldColor: String;
     FFieldText: String;
     FFieldX: String;
     FFieldY: String;
-    FCurItem: TChartDataItem;
+
     function GetDataSource: TDataSource;
     procedure SetDataSource(AValue: TDataSource);
     procedure SetFieldColor(const AValue: String);
@@ -47,6 +49,9 @@ type
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
+  public
+    procedure AfterDraw; override;
+    procedure BeforeDraw; override;
     procedure Reset;
   published
     property DataSource: TDataSource read GetDataSource write SetDataSource;
@@ -86,19 +91,21 @@ end;
 procedure TDbChartSourceDataLink.DataSetChanged;
 begin
   inherited DataSetChanged;
-  //FChartSrc.Reset;
+  if (FChartSrc.FBookmark = nil) and (DataSet.State = dsBrowse) then
+    FChartSrc.Reset;
 end;
 
 procedure TDbChartSourceDataLink.DataSetScrolled(Distance: Integer);
 begin
-  inherited DataSetChanged;
+  Unused(Distance);
   // No need to react on scrolling
 end;
 
 procedure TDbChartSourceDataLink.UpdateData;
 begin
   inherited UpdateData;
-  FChartSrc.Reset;
+  if FChartSrc.FBookmark = nil then
+    FChartSrc.Reset;
 end;
 
 
@@ -109,6 +116,23 @@ end;
 
 { TDbChartSource }
 
+procedure TDbChartSource.AfterDraw;
+begin
+  if not FDataLink.Active or (FBookmark = nil) then exit;
+  try
+    FDataLink.DataSet.GotoBookmark(FBookmark);
+    FDataLink.DataSet.FreeBookmark(FBookmark);
+  finally
+    FBookmark := nil;
+  end;
+end;
+
+procedure TDbChartSource.BeforeDraw;
+begin
+  if FDataLink.Active then
+    FBookmark := FDataLink.DataSet.GetBookmark;
+end;
+
 constructor TDbChartSource.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);

components/tachart/tagraph.pas

@@ -58,6 +58,8 @@ type
     FZPosition: TChartZPosition;
 
     procedure AfterAdd; virtual;
+    procedure AfterDraw; virtual;
+    procedure BeforeDraw; virtual;
     procedure DrawLegend(ACanvas: TCanvas; const ARect: TRect); virtual; abstract;
     function GetLegendCount: Integer; virtual; abstract;
     function GetLegendWidth(ACanvas: TCanvas): Integer; virtual; abstract;
@@ -417,18 +419,26 @@ begin
 end;
 
 procedure TChart.PaintOnCanvas(ACanvas: TCanvas; ARect: TRect);
+var
+  i: Integer;
 begin
   Clean(ACanvas, ARect);
 
   FClipRect := ARect;
   InflateRect(FClipRect, -2, -2);
 
+  for i := 0 to SeriesCount - 1 do
+    Series[i].BeforeDraw;
+
   UpdateExtent;
   DrawTitleFoot(ACanvas);
   DrawLegend(ACanvas);
   DrawAxis(ACanvas, ARect);
   DisplaySeries(ACanvas);
   DrawReticule(ACanvas);
+
+  for i := 0 to SeriesCount - 1 do
+    Series[i].AfterDraw;
 end;
 
 procedure TChart.PrepareXorPen;
@@ -1085,7 +1095,6 @@ begin
   finally
     seriesInZOrder.Free;
   end;
-
 end;
 
 procedure TChart.DrawReticule(ACanvas: TCanvas);
@@ -1374,6 +1383,16 @@ begin
   // nothing
 end;
 
+procedure TBasicChartSeries.AfterDraw;
+begin
+  // empty
+end;
+
+procedure TBasicChartSeries.BeforeDraw;
+begin
+  // empty
+end;
+
 destructor TBasicChartSeries.Destroy;
 begin
   if FChart <> nil then

components/tachart/taseries.pas

@@ -51,6 +51,8 @@ type
     procedure SetSource(AValue: TCustomChartSource);
   protected
     procedure AfterAdd; override;
+    procedure AfterDraw; override;
+    procedure BeforeDraw; override;
     function ColorOrDefault(AColor: TColor; ADefault: TColor = clTAColor): TColor;
     procedure DrawLegend(ACanvas: TCanvas; const ARect: TRect); override;
     procedure GetCoords(AIndex: Integer; out AG: TDoublePoint; out AI: TPoint);
@@ -397,6 +399,16 @@ begin
   FMarks.SetOwner(FChart);
 end;
 
+procedure TChartSeries.AfterDraw;
+begin
+  Source.AfterDraw;
+end;
+
+procedure TChartSeries.BeforeDraw;
+begin
+  Source.BeforeDraw;
+end;
+
 procedure TChartSeries.Clear;
 begin
   ListSource.Clear;

components/tachart/tasources.pas

@@ -65,6 +65,8 @@ type
   public
     destructor Destroy; override;
   public
+    procedure AfterDraw; virtual;
+    procedure BeforeDraw; virtual;
     procedure BeginUpdate;
     procedure EndUpdate;
     function IsUpdating: Boolean; inline;
@@ -229,6 +231,16 @@ end;
 
 { TCustomChartSource }
 
+procedure TCustomChartSource.AfterDraw;
+begin
+  // empty
+end;
+
+procedure TCustomChartSource.BeforeDraw;
+begin
+  // empty
+end;
+
 procedure TCustomChartSource.BeginUpdate;
 begin
   Inc(FUpdateCount);