TAChart: Add MarkPositions property to point-based series

git-svn-id: trunk@30578 -

components/tachart/tacustomseries.pas

@@ -182,10 +182,15 @@ type
 
   TLabelDirection = (ldLeft, ldTop, ldRight, ldBottom);
 
+  TLinearMarkPositions = (lmpOutside, lmpPositive, lmpNegative, lmpInside);
+
   { TBasicPointSeries }
 
   TBasicPointSeries = class(TChartSeries)
   private
+    FMarkPositions: TLinearMarkPositions;
+    function GetLabelDirection(AIndex: Integer): TLabelDirection;
+    procedure SetMarkPositions(AValue: TLinearMarkPositions);
     procedure SetUseReticule(AValue: Boolean);
 
   protected
@@ -196,9 +201,9 @@ type
     FUseReticule: Boolean;
 
     procedure DrawLabels(ADrawer: IChartDrawer);
-    function GetLabelDirection(AIndex: Integer): TLabelDirection; virtual;
     procedure GetLegendItemsRect(AItems: TChartLegendItems; ABrush: TBrush);
     function GetXRange(AX: Double; AIndex: Integer): Double;
+    function GetZeroLevel: Double; virtual;
     procedure PrepareGraphPoints(
       const AExtent: TDoubleRect; AFilterByExtent: Boolean);
     procedure UpdateGraphPoints(AIndex: Integer);
@@ -212,6 +217,8 @@ type
       out AIndex: Integer; out AImg: TPoint; out AValue: TDoublePoint): Boolean;
       override;
     procedure MovePoint(var AIndex: Integer; const ANewPos: TPoint); override;
+    property MarkPositions: TLinearMarkPositions
+      read FMarkPositions write SetMarkPositions default lmpOutside;
   end;
 
 implementation
@@ -775,8 +782,16 @@ function TBasicPointSeries.GetLabelDirection(AIndex: Integer): TLabelDirection;
 const
   DIR: array [Boolean, Boolean] of TLabelDirection =
     ((ldTop, ldBottom), (ldRight, ldLeft));
+var
+  isNeg: Boolean;
 begin
-  Result := DIR[IsRotated, GetGraphPointY(AIndex) < 0];
+  case MarkPositions of
+    lmpOutside: isNeg := GetGraphPointY(AIndex) < GetZeroLevel;
+    lmpPositive: isNeg := false;
+    lmpNegative: isNeg := true;
+    lmpInside: isNeg := GetGraphPointY(AIndex) >= GetZeroLevel;
+  end;
+  Result := DIR[IsRotated, isNeg];
 end;
 
 procedure TBasicPointSeries.GetLegendItemsRect(
@@ -834,6 +849,11 @@ begin
   end;
 end;
 
+function TBasicPointSeries.GetZeroLevel: Double;
+begin
+  Result := 0.0;
+end;
+
 procedure TBasicPointSeries.MovePoint(
   var AIndex: Integer; const ANewPos: TPoint);
 var
@@ -879,6 +899,13 @@ begin
       FGraphPoints[i - FLoBound] := GetGraphPoint(i);
 end;
 
+procedure TBasicPointSeries.SetMarkPositions(AValue: TLinearMarkPositions);
+begin
+  if FMarkPositions = AValue then exit;
+  FMarkPositions := AValue;
+  UpdateParentChart;
+end;
+
 procedure TBasicPointSeries.SetUseReticule(AValue: Boolean);
 begin
   if FUseReticule = AValue then exit;

components/tachart/taseries.pas

@@ -92,6 +92,7 @@ type
     property BarWidthStyle: TBarWidthStyle
       read FBarWidthStyle write SetBarWidthStyle default bwPercent;
     property Depth;
+    property MarkPositions;
     property SeriesColor: TColor
       read GetSeriesColor write SetSeriesColor stored false default clRed;
     property Source;
@@ -138,9 +139,9 @@ type
     procedure SetUseZeroLevel(AValue: Boolean);
     procedure SetZeroLevel(AValue: Double);
   protected
-    function GetLabelDirection(AIndex: Integer): TLabelDirection; override;
     procedure GetLegendItems(AItems: TChartLegendItems); override;
     function GetSeriesColor: TColor; override;
+    function GetZeroLevel: Double; override;
   public
     procedure Assign(ASource: TPersistent); override;
     constructor Create(AOwner: TComponent); override;
@@ -158,6 +159,7 @@ type
     property ConnectType: TConnectType
       read FConnectType write SetConnectType default ctLine;
     property Depth;
+    property MarkPositions;
     property SeriesColor: TColor
       read GetSeriesColor write SetSeriesColor stored false default clWhite;
     property Source;
@@ -213,6 +215,7 @@ type
     property LinePen: TPen read FLinePen write SetLinePen;
     property LineType: TLineType
       read FLineType write SetLineType default ltFromPrevious;
+    property MarkPositions;
     property OnDrawPointer: TSeriesPointerDrawEvent
       read FOnDrawPointer write FOnDrawPointer;
     property Pointer: TSeriesPointer read FPointer write SetPointer;
@@ -1098,15 +1101,6 @@ begin
     UpdateMinMax(ZeroLevel, Result.a.Y, Result.b.Y);
 end;
 
-function TAreaSeries.GetLabelDirection(AIndex: Integer): TLabelDirection;
-const
-  DIR: array [Boolean, Boolean] of TLabelDirection =
-    ((ldTop, ldBottom), (ldRight, ldLeft));
-begin
-  Result :=
-    DIR[IsRotated, UseZeroLevel and (GetGraphPointY(AIndex) < ZeroLevel)];
-end;
-
 procedure TAreaSeries.GetLegendItems(AItems: TChartLegendItems);
 begin
   GetLegendItemsRect(AItems, AreaBrush);
@@ -1117,6 +1111,11 @@ begin
   Result := FAreaBrush.Color;
 end;
 
+function TAreaSeries.GetZeroLevel: Double;
+begin
+  Result := IfThen(UseZeroLevel, ZeroLevel, 0.0);
+end;
+
 function TAreaSeries.IsZeroLevelStored: boolean;
 begin
   Result := ZeroLevel <> 0.0;