Adding marks to a Tee Chart

rbuser

On charts in Delphi marks (cross hairs on a line plot) can be added to note
events on the chart using a draw on canvas routine. The same marks should
be drawn to the Tee Chart in RB. Can you please instruct me in how to place
marks on the Tee Chart in RB?

(D6, RB 6.01)
Thanks, code follows,
Tore Fossum
tfossum@titrate.cc


If Dest=0 then
begin // these are for the Chart in the main part of the program
ix:=Series2.CalcXPosValue(zx);
iy:=Series2.CalcYPosValue(zy);
end;
If Dest=1 then // This is for the Chart in the Report ie, ppChart
begin
ix:=LineSeries3.CalcXPosValue(zx);
iy:=LineSeries3.CalcYPosValue(zy);
end;

DrawMark(ix,iy,Dest,clBlack);


procedure TTitrData.DrawMark(AX, AY, Dest: integer; CrossHairColor: Tcolor);
begin
If Dest=0 then // mark chart plot

With DBChart2,Canvas do // Chart in main part of program
begin
Pen.Style:=psSolid;
Pen.Width:=1;
MoveTo(ax,ay-5);
LineTo(ax,ChartRect.Bottom-Height3D+6);
MoveTo(ax-5,ay);
LineTo(ax+5,ay);
end;
If Dest=1 then
With ppCHartSmall do // Chart on report
begin
Chart.Canvas.Pen.Style:=psSolid;
Chart.Canvas.Pen.Width:=1;
Chart.Canvas.MoveTo(ax,ay-5);
Chart.Canvas.LineTo(ax,Chart.ChartRect.Bottom-Chart.Height3D+6);
Chart.Canvas.MoveTo(ax-5,ay);
Chart.Canvas.LineTo(ax+5,ay);
end;

rbuser

I have to also say that the marks work on the main chart, but not on the RB
chart.
The RB chart is a plain chart, not a DB chart, and it copies the points from
the
main RB chart. Everything on the reports looks fine, except no cross hair
marks.
I have attempted to draw the marks by using the event "On create preveiw" or
the RB TeeChart "Before Print".
Thanks again, Tore

digitalmetaphors

What about creating TppLine objects in the report that sit on top of the
chart component in the designer?

If you need to create them at runtime, then create TppDrawLine draw commands
in the Report.OnEndPage event. The measurement units are in thousandths of
millimeters. Here's the code to create a horizontal line in the middle of
the page:.

lDrawLine := TppDrawLine.Create(nil);
lDrawLine.Page := ppReport1.Engine.Page;
lDrawLine.LinePosition := lpTop;
lDrawLine.Left := ppReport1.PrinterSetup.PageDef.mmMarginLeft;
lDrawLine.Top := ppReport1.PrinterSetup.PageDef.mmPrintableHeight div
2;
lDrawLine.Width:= ppReport1.PrinterSetup.PageDef.mmPrintableWidth;


Cheers,

Jim Bennett
Digital Metaphors

rbuser

Thank you, Jim, but figuring out exactly where to put them could be a big
problem. Is the chart always going to be in the same place? How to figure
out where the chart is,...hmm, it would mean doing some trials and some
mathematics. This is possible, but it is not the most elegant way. How to
draw on the chart?

Many thanks, Tore Fossum
tfossum@titrate.cc

digitalmetaphors

You're right, we'll have to draw relative to the draw command's position on
the page. The following demo shows how to draw on the canvas of the bitmap
and also how to draw two lines on top of the teechart metafile with draw
commands.

http://www.digital-metaphors.com/tips/DrawOnTeeChartCanvas.zip