TcursorTool

[Calou]

Hello,

I use TcursorTool like it :

Code: Select all

Procedure Tform1.CursorSynchronize( Source, Dest: TCursorTool );
begin
  Dest.ParentChart.AutoRepaint:=False; // stop repainting
  Dest.RedrawCursor;   // hide cursor

  Dest.XValue := Source.XValue;
  Dest.RedrawCursor;  // draw cursor again
  Dest.ParentChart.AutoRepaint:=True; // enable repainting
end;

procedure TForm1.FormShow(Sender: TObject);
var
  i:integer;
begin
  for i := 0 to 10do
    Series1.AddXY(i,i+1);
  for i := 80 to 100 do
    Series1.AddXY(i,i+1);
  for i := 0 to 100do
    Series2.AddXY(i,i+1);
end;

procedure TForm1.ChartTool1SnapChange(Sender: TCursorTool; x, y: Integer;
  const XValue, YValue: Double; Series: TChartSeries; ValueIndex: Integer);
begin

  CursorSynchronize(sender,ChartTool1);
  label1.Caption:='Y1='+FormatFloat('0.00',Series1.YValue[ValueIndex]);
  label2.Caption:='X1='+FloatToStr(XValue);
  label3.Caption:='Y2='+FormatFloat('0.00',Series2.YValue[ValueIndex]);
  label4.Caption:='X2='+FloatToStr(XValue);
end;

the problem is that there is not the same number of points between Series1 and Series2. How can i do to have the Series1 Yvalue correct with its Xvalue?
I use ValueIndex but it is not correct in this case. I precise that there is no reason to print the Yvalue of Series1 if its Xvalue doesn't exist

Thanks for help

Regards

[Yeray]

Hi Calou,

You could use the Locate function to retrieve the ValueIndex in a series for a given X or Y value:

Code: Select all

procedure TForm1.ChartTool1SnapChange(Sender: TCursorTool; x, y: Integer;
  const XValue, YValue: Double; Series: TChartSeries; ValueIndex: Integer);
var tmpIndex: Integer;
begin
  CursorSynchronize(sender,ChartTool1);
  tmpIndex:=Series1.XValues.Locate(XValue);
  if (tmpIndex <> -1) then
    label1.Caption:='Y1='+FormatFloat('0.00',Series1.YValue[tmpIndex])
  else
    label1.Caption:='Y1=Not present';

  label2.Caption:='X1='+FloatToStr(XValue);
  label3.Caption:='Y2='+FormatFloat('0.00',Series2.YValue[ValueIndex]);
  label4.Caption:='X2='+FloatToStr(XValue);
end;

[Calou]