TPieseries: Gradient and shadow properties
lazarus / 55-TAChart

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tk · 2014-07-16 20:39

Hi,
Delphi has Gradient and Shadow properties on TPieSeries which allow to
create professional looking charts in Delphi (when using GDI+).

Is there any plan to add these properties to TaChart? I know there is
BGRAbitmap but this afaik does not allow codeless approach to achieve
this look.

I use many charts in different units and modules so I would like to
minimize code usage.
Even if the only way now is via some custom draw events, can you point
out the most effective way?

I wish to create a pie chart with radial gradient (light colors in the
center) and a shadow around the circle.

In Delphi following is enough (here in code but all those properties
are published):

Code: [Select]    with PieSeries do
    begin
      Circled := True;
      Shadow.Color := 15592941;
      Shadow.HorizSize := 2;
      Shadow.SmoothBlur := 75;
      Shadow.VertSize := 2;
      Gradient.Direction := gdRadial;
      Gradient.EndColor := clGreen;
      Gradient.StartColor := 7138412;
      Gradient.Visible := True;
      GradientBright := 108;
    end;             

Thanks

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wp · 2014-07-16 22:44

QuoteIs there any plan to add these properties to TaChart?I don't know
why Ask, the maintainer of TAChart, has not been active for more than
a year, he is probably very busy... I do have write permission to
modify TAChart, but currently I don't have plans for brushing up the
series.

There is an example in the folder demo/bgra of the TAChart
installation (see also 
http://wiki.lazarus.freepascal.org/TAChart_Demos#bgra for a
screenshot, and the link to a tutorial showing how to get nicer
drawing by using bgrabitmap,
http://wiki.lazarus.freepascal.org/BGRABitmap_tutorial_TAChart).
Although this covers only a bar chart, it will certainly give a good
starting point for a pie chart. It shouldn't be too difficult. You
will have to do some coding, though. I can try myself, but I am quite
busy with fpspreadsheet at the moment, so it will take some time. If
you find a solution it would be great if you could post it here, I
could add it to the sample folder.

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tk · 2014-07-17 07:17

Quote from: wp on July 17, 2014, 12:44:36 amI don't know why Ask, the
maintainer of TAChart, has not been active for more than a year, he is
probably very busy...

I know this situation very well, was very busy in last 3 years,
grounded my own company.

Anyway thank you for info, I know this wiki, I'll try to use this
sample for pie chart.