Annotation Tool and relocation after zooming the chart

[JC]

I have an annotation placed in a very specific point basec on X Y values for a series. When the user zoom - the annotaion remains in the same location and is pointing to an invalid location.

I use use :

//
FSessionZoneNames.Shape.Left := DBChartSession.LeftAxis.PosAxis;
FSessionZoneNames.Shape.Top := SeriesHR.CalcYPosValue(FieldByName('high').AsInteger);

//
to get the orginal locations but after zooming the result is incorrect, Recreating after the zoom works but is not what is required.

Any ideas...

[JC]

When resizing the form, the same happens - the annotation floats in teh middle on nowhere. is there no way to keep it relative to the correct location

[Narcís]

Hi JC,

I have posted an example project trying to reproduce what you descrive. Is this the behaviour you get? If not could you please modify the project to reproduce what you are reporting?

The sample project is posted at steema.public.attachments newsgroups.

[Marjan]

Hi.

The following code, placed in chart OnBeforeDrawSeries event should work fine:

Code: Select all

procedure TForm1.Chart1BeforeDrawSeries(Sender: TObject);
begin
  With annotateTool1.Shape do
  begin
    CustomPosition := True;
    Left := Chart1.Axes.Left.PosAxis;
    Top := Chart1.Axes.Left.CalcYPosValue(your_y_value);
  end;
end;

[JC]

Putting the code in OnBeforeDrawSeries works but I am getting exceptions that killing the chart + app.I use wrapper routines to hide and shwo zone overlays as follows:

Code: Select all

procedure TViewAnalyzer.HideZoneOverlay;
var
  i : integer;
begin
  for i := 0 to 19 do
  begin
    if (FSessionZoneBands[i] <> nil) then
    begin
      DBChartSession.Tools.Remove(FSessionZoneBands[i]);    
      FSessionZoneBands[i].Free;
      FSessionZoneBands[i] := nil;
    end;
    if (FSessionZoneNames[i] <> nil) then
    begin
      DBChartSession.Tools.Remove(FSessionZoneNames[i]);    
      FSessionZoneNames[i].Free;
      FSessionZoneNames[i] := nil;
    end;      
  end;
end;

the line

Code: Select all

"FSessionZoneNames[i].Free;"

causes the exception.

Help is appreciated

Thanks

[Marjan]

Hi.

See my reply here