Create TimeLine

[Eic]

Hello,

I'm trying to create a "timeline" chart with this code :

Code: Select all

void __fastcall TFormGraphiqueHelper::btnTimeLineClick(TObject *Sender)
{
	int i;
	TDateTime tmpDate;
	TVolumeSeries *serie = new TVolumeSeries(Chart1);
	Chart1->View3D = false;
	Chart1->OnAfterDraw = ChartTmpAfterDraw;
	Chart1->View3DWalls = false;
	Chart1->Legend->Visible = false;
	tmpDate = Now();
	Chart1->AddSeries(serie);

	serie->Marks->Visible = true;
	serie->XValues->DateTime = true;

	for (i = 0; i <= 9; i++)
	{
		serie->AddXY(tmpDate, 10*((i % 3) + 1), tmpDate.FormatString("dd/mm/yy") + "\r\nwith number " + IntToStr(i));
		tmpDate += random(9);
	}

	Chart1->Axes->Left->SetMinMax(0, 40);
	Chart1->Axes->Left->Visible = false;

	Chart1->Axes->Bottom->Grid->Visible = false;
	Chart1->Axes->Bottom->Labels = false;
	Chart1->Axes->Bottom->Increment = 1;
	Chart1->Axes->Bottom->MinimumOffset = 50;
	Chart1->Axes->Bottom->MaximumOffset = 50;
	Chart1->Axes->Bottom->Axis->Color = clGreen;
	Chart1->Axes->Bottom->Axis->Width = 18;
	Chart1->Axes->Bottom->Axis->EndStyle = esRound;
}

void __fastcall TFormGraphiqueHelper::ChartTmpAfterDraw(TObject *Sender)
{
	TChart *chart = static_cast<TChart*>(Sender);
	TTrianglePoints3D triangle;
	TTriangleColors3D triangleCouleur;
	int iHauteurAxe = Chart1->Axes->Bottom->Axis->Width;

	int iPosX = chart->Width;
	int iPosY = chart->LeftAxis->CalcYPosValue(0) + (iHauteurAxe / 2);

	triangle[0].x = iPosX - iHauteurAxe;
	triangle[0].y = iPosY - iHauteurAxe / 2 - 5;
	triangle[1].x = triangle[0].x;
	triangle[1].y = iPosY + iHauteurAxe / 2 + 5;
	triangle[2].x = iPosX;
	triangle[2].y = iPosY;
	triangleCouleur[0] = triangleCouleur[1] = triangleCouleur[2] = clYellow;//chart->Axes->Bottom->Axis->Color;

	chart->Canvas->Pen->Visible = false;
	chart->Canvas->Triangle3D(triangle, triangleCouleur);
}

I don't know how to position the yellow arrow at the end of the bottom axis.
How to know the position of the max of the axis, in pixel?


Thanks for your help.

[Yeray]

Hello,

Try using the bottom axis IEndPos property. Ie:

Code: Select all

uses TeCanvas;

procedure TForm1.Chart1AfterDraw(Sender: TObject);
var triangle: TTrianglePoints3D;
    triangleCouleur: TTriangleColors3D;
begin
  triangle[0].x := Chart1.Axes.Bottom.IEndPos;
  triangle[0].y := Chart1.Axes.Bottom.PosAxis - 5;
  triangle[1].x := triangle[0].x;
  triangle[1].y := triangle[0].y + 10;
  triangle[2].x := triangle[0].x + 10;
  triangle[2].y := Chart1.Axes.Bottom.PosAxis;

  triangleCouleur[0]:=clYellow;
  triangleCouleur[1]:=clYellow;
  triangleCouleur[2]:=clYellow;

  Chart1.Canvas.Triangle3D(triangle, triangleCouleur);
end;

[Eic]

Its' perfect.

Thank you.