Area Series different colours for XAxis values?

[Doogie]

Hi,

I have a ppDBChart on a ppReport (ReportBuilder).
The X Axis of the series represents dates.
The Y Axis a integer values.

I want to give the graph diffrent colours depending on the date range:
ie:
Sept-Oct - Gradient Brown to Green from left to Right
Nov-March - Green
April-May - Gradient from Left to right Green to Brown
June-August - Brown

Where do I set this?
What on-event do I use, as the chart is part of a ppReport that is called as follows:
ppReport1.print;

Any help will be appreciated.
I attach the 'uncoloured' graph below.

Regards

Adrian

[Doogie]

The only Events exposed in the object inspector are:
OnDrawCommandClick
OnDrawCommandCreate
OnPrint

How would I get to the Series1AfterAdd event for instance, as I cannot see how to expose it at design time to add code for the event, for the DBChart on the ppReport.

[Yeray]

Hello Adrian,

I see you seem to be using Area series with Stairs. I'd recommend you to use Bar series as they have OnGetBarStyle that can help you in this.
However, setting a gradient to a range of values applies the gradient for each bar, and I'm not sure if that's what you expected:

Code: Select all

procedure Series1GetBarStyle(Sender:TCustomBarSeries; ValueIndex:Integer; var TheBarStyle:TBarStyle);
//...
uses DateUtils, TeCanvas;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
    tmpDate: TDateTime;
begin
  Chart1.Legend.Visible:=false;
  Chart1.Axes.Bottom.LabelsAngle:=90;
  Chart1.Axes.Bottom.Increment:=30;
  Chart1.Axes.Bottom.DateTimeFormat:='MMM-yyyy';

  tmpDate:=StrToDateTime('01/09/2010');

  with Chart1.AddSeries(TBarSeries) as TBarSeries do
  begin
    Marks.Visible:=false;
    XValues.DateTime:=true;
    Gradient.Visible:=true;
    OnGetBarStyle:=Series1GetBarStyle;
    for i:=0 to 364 do
    begin
      AddXY(tmpDate, random*100);
      tmpDate:=tmpDate+1;
    end;
  end;
end;

procedure TForm1.Series1GetBarStyle(Sender:TCustomBarSeries; ValueIndex:Integer; var TheBarStyle:TBarStyle);
begin
  case (MonthOfTheYear(Sender.XValue[ValueIndex])) of
    9,10:
    begin
      TheBarStyle:=bsRectGradient;
      Sender.Gradient.Direction:=gdLeftRight;
      Sender.NormalBarColor:=RGB(128,64,0);
      Sender.Gradient.StartColor:=clGreen;
    end;
    11,12,1,2,3:
    begin
      TheBarStyle:=bsRectangle;
      Sender.Color:=clGreen;
    end;
    4,5:
    begin
      TheBarStyle:=bsRectGradient;
      Sender.Gradient.Direction:=gdLeftRight;
      Sender.NormalBarColor:=clGreen;
      Sender.Gradient.StartColor:=RGB(128,64,0);
    end;
    6,7,8:
    begin
      TheBarStyle:=bsRectangle;
      Sender.Color:=RGB(128,64,0);
    end;
  end;
end;

chart1.png (22.42 KiB) Viewed 5126 times

If you would like to have the first value in September in solid brown ... to the last value in October in solid green, you could calculate the color to set to each bar manually. It would be something similar to creating a custom palette.