[SOLVED] Troubles with TDataPointDragTool

[CM630]

I am trying to fix a bug in a component that I have started to write... 6 or 7 years ago, I have stopped woring on it 5 years ago, at least.
Well, I tried to create a snippet, but I cannot make TDataPointDragTool work in a standalone component.
I tried the ..\lazarus\components\tachart\demo\tools.
Dragging works for the two vertical bars, but it does not work for the Chart1FuncSeries1 (I expect that should be able to move its points).
I have set the AffectedSered of ChartToolset1DataPointDragTool1 to 0,1,2,3 (it was 2,3).
What else should I do?

[wp]

ChartFuncSeries1? No, you cannot drag its points, in fact, it does not even have points, it is defined by a function defined by an event handler.

[CM630]

Okay, I did:

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormCreate(Sender: TObject);
2. begin
3.   myLineSeries:= TLineSeries.Create(Chart1) ;
4.   myLineSeries.ShowPoints := True;
5.   myLineSeries.AddXY (0,-0.5);
6.   chart1.AddSeries(myLineSeries);
7.   ChartToolset1DataPointDragTool1.AffectedSeries := ChartToolset1DataPointDragTool1.AffectedSeries + '0,1,2,3,4,5';
8. end;  

Now I can move the quadrangle, drawn and teh single point of MySeries.


But besides that, sth. seems wrong- I have tried to add a LineSeries in the GUI mode- the series was shown, but when I run the app it is gone. (Laz ver etc are in my signature)/.

[wp]

Did you add data points to the series? Normally you must do this at runtime (even if the series is created at designtime -- ok, you could use a TListChartSource where you can enter values in the DataPoints property at designtime).

[CM630]

Maybe the image will expain it better than words:
On the left: what is shown in the IDE.
On the right : what happens when the app is executed.


Edit: I have just found sth. odd: When I save and close the project and reload it- the values in the DataPoints are lost!
No surprise that they are not shown if the compiler does not see them them saved.

[wp]

In fact, I never used the interal listchartsource of a series for this purpose. I guess the built-in source is not prepared for it, or maybe there is a Clear somewhere. Debugging designtime code is always hard stuff, so I am not very much motivated to begin...

What you can do is to add a separate TListChartSource to the form, attach it to the LineSeries.Source, and add values to the DataPoints property like you did with the internal ListChartSource. This works, for sure -- see attachment.

[CM630]

Generally I do not use the design time editor for TAChart, I just wanted to execute some simple snippet for sth. more complex, which I have succeeded to fix.
But since you confirm that this is a bug, I will try to create a report for it, in case that its time comes, or rather to know that this is not working.

[wp]

But since you confirm that this is a bug, I will try to create a report for it, in case that its time comes, or rather to know that this is not working.

Good idea. Assign it to me. Add a demo project and link also to this discussion.

[CM630]

https://bugs.freepascal.org/view.php?id=37904
I am not sure, that I can assign bugs, currently it is unassigned.