TAChart: Add axis transformations and ability to bind series to axises.

This implements most of the issue #13832, although the interface
is very crude yet.

git-svn-id: trunk@23217 -

components/tachart/tachartaxis.pas

@@ -69,6 +69,44 @@ type
     property Style default psDot;
   end;
 
+  { TChartAxisTransformation }
+
+  TChartAxisTransformation = class (TPersistent)
+  private
+    FOnChanged: TNotifyEvent;
+    procedure SetOnChanged(const AValue: TNotifyEvent);
+  protected
+    procedure Changed;
+  public
+    function AxisToGraph(AX: Double): Double; virtual;
+    function GraphToAxis(AX: Double): Double; virtual;
+
+    property OnChanged: TNotifyEvent read FOnChanged write SetOnChanged;
+  end;
+
+  { TChartAxisLogLinearTransformation }
+
+  TChartAxisLogLinearTransformation = class (TChartAxisTransformation)
+  private
+    FLogarithmic: Boolean;
+    FOffset: Double;
+    FScale: Double;
+    procedure SetLogarithmic(AValue: Boolean);
+    procedure SetOffset(AValue: Double);
+    procedure SetScale(AValue: Double);
+  public
+    constructor Create;
+  public
+    procedure Assign(Source: TPersistent); override;
+
+    function AxisToGraph(AX: Double): Double; override;
+    function GraphToAxis(AX: Double): Double; override;
+  published
+    property Logarithmic: Boolean read FLogarithmic write SetLogarithmic default false;
+    property Offset: Double read FOffset write SetOffset;
+    property Scale: Double read FScale write SetScale;
+  end;
+
   { TChartAxis }
 
   TChartAxis = class(TCollectionItem)
@@ -86,6 +124,7 @@ type
     FTickColor: TColor;
     FTickLength: Integer;
     FTitle: TChartAxisTitle;
+    FTransformation: TChartAxisLogLinearTransformation;
     FVisible: Boolean;
 
     procedure SetAlignment(AValue: TChartAxisAlignment);
@@ -97,6 +136,7 @@ type
     procedure SetTickColor(AValue: TColor);
     procedure SetTickLength(AValue: Integer);
     procedure SetTitle(AValue: TChartAxisTitle);
+    procedure SetTransformation(AValue: TChartAxisLogLinearTransformation);
     procedure SetVisible(const AValue: Boolean);
 
     procedure StyleChanged(ASender: TObject);
@@ -130,6 +170,8 @@ type
     property TickLength: Integer
       read FTickLength write SetTickLength default DEF_TICK_LENGTH;
     property Title: TChartAxisTitle read FTitle write SetTitle;
+    property Transformation: TChartAxisLogLinearTransformation
+      read FTransformation write SetTransformation;
     property Visible: Boolean read FVisible write SetVisible default true;
   published
     property OnMarkToText: TChartAxisMarkToTextEvent
@@ -245,11 +287,14 @@ begin
   FTickColor := clBlack;
   FTickLength := DEF_TICK_LENGTH;
   FTitle := TChartAxisTitle.Create(ACollection.Owner as TCustomChart);
+  FTransformation := TChartAxisLogLinearTransformation.Create;
+  FTransformation.OnChanged := @StyleChanged;
   FVisible := true;
 end;
 
 destructor TChartAxis.Destroy;
 begin
+  FTransformation.Free;
   FTitle.Free;
   FGrid.Free;
   inherited;
@@ -265,7 +310,7 @@ procedure TChartAxis.Draw(
     sz: TSize;
     markText: String;
   begin
-    x := ATransf.XGraphToImage((AMark - Offset) / Scale);
+    x := ATransf.XGraphToImage(Transformation.AxisToGraph(AMark));
 
     if Grid.Visible then begin
       ACanvas.Pen.Assign(Grid);
@@ -297,7 +342,7 @@ procedure TChartAxis.Draw(
     markText: String;
     sz: TSize;
   begin
-    y := ATransf.YGraphToImage((AMark - Offset) / Scale);
+    y := ATransf.YGraphToImage(Transformation.AxisToGraph(AMark));
 
     if Grid.Visible then begin
       ACanvas.Pen.Assign(Grid);
@@ -394,8 +439,8 @@ end;
 
 function TChartAxis.GetMarks(AMin, AMax: Double): TDoubleDynArray;
 begin
-  AMin := AMin * Scale + Offset;
+  AMin := Transformation.GraphToAxis(AMin);
-  AMax := AMax * Scale + Offset;
+  AMax := Transformation.GraphToAxis(AMax);
   if AMin > AMax then
     Exchange(AMin, AMax);
   Result := GetIntervals(AMin, AMax, Inverted);
@@ -550,6 +595,14 @@ begin
   StyleChanged(Self);
 end;
 
+procedure TChartAxis.SetTransformation(
+  AValue: TChartAxisLogLinearTransformation);
+begin
+  if FTransformation = AValue then exit;
+  FTransformation.Assign(AValue);
+  StyleChanged(Self);
+end;
+
 procedure TChartAxis.SetVisible(const AValue: Boolean);
 begin
   if FVisible = AValue then exit;
@@ -610,5 +663,87 @@ begin
   a.FAlignment := AXIS_INDEX[AIndex];
 end;
 
+{ TChartAxisTransformation }
+
+function TChartAxisTransformation.AxisToGraph(AX: Double): Double;
+begin
+  Result := AX;
+end;
+
+procedure TChartAxisTransformation.Changed;
+begin
+  if Assigned(FOnChanged) then
+    FOnChanged(Self);
+end;
+
+function TChartAxisTransformation.GraphToAxis(AX: Double): Double;
+begin
+  Result := AX;
+end;
+
+procedure TChartAxisTransformation.SetOnChanged(const AValue: TNotifyEvent);
+begin
+  if TMethod(FOnChanged) = TMethod(AValue) then exit;
+  FOnChanged := AValue;
+end;
+
+{ TChartAxisLogLinearTransformation }
+
+procedure TChartAxisLogLinearTransformation.Assign(Source: TPersistent);
+begin
+  if Source is TChartAxisLogLinearTransformation then
+    with Source as TChartAxisLogLinearTransformation do begin
+      Self.Logarithmic := Logarithmic;
+      Self.Offset := Offset;
+      Self.Scale := Scale;
+    end;
+end;
+
+function TChartAxisLogLinearTransformation.AxisToGraph(AX: Double): Double;
+begin
+  if not Logarithmic then
+    Result := AX
+  else if AX > 0 then
+    Result := Ln(AX)
+  else
+    Result := NegInfinity;
+  Result := Result * Scale + Offset;
+end;
+
+constructor TChartAxisLogLinearTransformation.Create;
+begin
+  inherited Create;
+  FScale := 1.0;
+end;
+
+function TChartAxisLogLinearTransformation.GraphToAxis(AX: Double): Double;
+begin
+  Result := (AX - Offset) / Scale;
+  if Logarithmic then
+    Result := Exp(AX);
+end;
+
+procedure TChartAxisLogLinearTransformation.SetLogarithmic(AValue: Boolean);
+begin
+  if FLogarithmic = AValue then exit;
+  FLogarithmic := AValue;
+  Changed;
+end;
+
+procedure TChartAxisLogLinearTransformation.SetOffset(AValue: Double);
+begin
+  if FOffset = AValue then exit;
+  FOffset := AValue;
+  Changed;
+end;
+
+procedure TChartAxisLogLinearTransformation.SetScale(AValue: Double);
+begin
+  if FScale = AValue then exit;
+  FScale := AValue;
+  if FScale = 0 then FScale := 1.0;
+  Changed;
+end;
+
 end.
 

components/tachart/tacustomseries.pas

@@ -26,10 +26,19 @@ uses
   Classes, Graphics, SysUtils,
   TAChartUtils, TAGraph, TASources, TATypes;
 
+const
+  DEF_AXIS_INDEX = -1;
+
 type
   { TCustomChartSeries }
 
   TCustomChartSeries = class(TBasicChartSeries)
+  private
+    FAxisIndexX: Integer;
+    FAxisIndexY: Integer;
+    procedure SetAxisIndexX(AValue: Integer);
+    procedure SetAxisIndexY(AValue: Integer);
+
   protected
     procedure SetActive(AValue: Boolean); override;
     procedure SetDepth(AValue: TChartDistance); override;
@@ -37,8 +46,17 @@ type
     procedure SetZPosition(AValue: TChartDistance); override;
     procedure StyleChanged(Sender: TObject);
     procedure UpdateParentChart;
+
+  protected
+    function AxisToGraphX(AX: Double): Double; override;
+    function AxisToGraphY(AY: Double): Double; override;
+    function GraphToAxisX(AX: Double): Double; override;
+    function GraphToAxisY(AY: Double): Double; override;
+
   public
     constructor Create(AOwner: TComponent); override;
+    property AxisIndexX: Integer read FAxisIndexX write SetAxisIndexX default DEF_AXIS_INDEX;
+    property AxisIndexY: Integer read FAxisIndexY write SetAxisIndexY default DEF_AXIS_INDEX;
   end;
 
   TChartGetMarkEvent = procedure (
@@ -114,6 +132,21 @@ type
 
 implementation
 
+uses
+  Math, TAChartAxis;
+
+var
+  VIdentityTransformation: TChartAxisTransformation;
+
+function TransformationByAxis(
+  AChart: TChart; AAxisIndex: Integer): TChartAxisTransformation;
+begin
+  if InRange(AAxisIndex, 0, AChart.AxisList.Count - 1) then
+    Result := AChart.AxisList[AAxisIndex].Transformation
+  else
+    Result := VIdentityTransformation;
+end;
+
 type
 
   { TChartSeriesListener }
@@ -147,11 +180,33 @@ end;
 
 { TCustomChartSeries }
 
+function TCustomChartSeries.AxisToGraphX(AX: Double): Double;
+begin
+  Result := TransformationByAxis(FChart, AxisIndexX).AxisToGraph(AX)
+end;
+
+function TCustomChartSeries.AxisToGraphY(AY: Double): Double;
+begin
+  Result := TransformationByAxis(FChart, AxisIndexY).AxisToGraph(AY)
+end;
+
 constructor TCustomChartSeries.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
   FActive := true;
   FShowInLegend := true;
+  FAxisIndexX := DEF_AXIS_INDEX;
+  FAxisIndexY := DEF_AXIS_INDEX;
+end;
+
+function TCustomChartSeries.GraphToAxisX(AX: Double): Double;
+begin
+  Result := TransformationByAxis(FChart, AxisIndexX).GraphToAxis(AX)
+end;
+
+function TCustomChartSeries.GraphToAxisY(AY: Double): Double;
+begin
+  Result := TransformationByAxis(FChart, AxisIndexY).GraphToAxis(AY)
 end;
 
 procedure TCustomChartSeries.SetActive(AValue: Boolean);
@@ -161,6 +216,20 @@ begin
   UpdateParentChart;
 end;
 
+procedure TCustomChartSeries.SetAxisIndexX(AValue: Integer);
+begin
+  if FAxisIndexX = AValue then exit;
+  FAxisIndexX := AValue;
+  UpdateParentChart;
+end;
+
+procedure TCustomChartSeries.SetAxisIndexY(AValue: Integer);
+begin
+  if FAxisIndexY = AValue then exit;
+  FAxisIndexY := AValue;
+  UpdateParentChart;
+end;
+
 procedure TCustomChartSeries.SetDepth(AValue: TChartDistance);
 begin
   if FDepth = AValue then exit;
@@ -453,5 +522,8 @@ begin
   ListSource.SetYValue(AIndex, AValue);
 end;
 
+initialization
+  VIdentityTransformation := TChartAxisTransformation.Create;
+
 end.
 

components/tachart/taseries.pas

@@ -84,6 +84,8 @@ type
     procedure Draw(ACanvas: TCanvas); override;
     function Extent: TDoubleRect; override;
   published
+    property AxisIndexX;
+    property AxisIndexY;
     property BarBrush: TBrush read FBarBrush write SetBarBrush;
     property BarPen: TPen read FBarPen write SetBarPen;
     property BarWidthPercent: Integer
@@ -136,6 +138,8 @@ type
 
     procedure Draw(ACanvas: TCanvas); override;
   published
+    property AxisIndexX;
+    property AxisIndexY;
     property AreaBrush: TBrush read FAreaBrush write SetAreaBrush;
     property AreaLinesPen: TPen read FAreaLinesPen write FAreaLinesPen;
     property Depth;
@@ -184,6 +188,8 @@ type
     procedure BeginUpdate;
     procedure EndUpdate;
   published
+    property AxisIndexX;
+    property AxisIndexY;
     property Depth;
     property LinePen: TPen read FLinePen write SetLinePen;
     property LineType: TLineType