How to develop a component...
lazarus / 5-Lazarus Extra Components

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Salvador · 2007-04-05 02:26

Hi everybody!  I'm new in Lazarus and I'm looking for a clear
explanation of how to develop a visual component in Lazarus...

Should I develop it along a test project? 
Can I use visual design to do it?

I need very desperately a powerfull multi-editor grid like TMS
TAdvancedStringGrid for Delphi (www.tmssoftware.com), and since I have
not found anything like it I need to slowly make myself one from
scratch...

So any help claryfing the developmente methodology will be much
appreciated.  (or else any pointers to a usefull port).

Thanks in advance...

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Phil · 2007-04-05 14:01

Quote from: "Salvador"I need very desperately a powerfull multi-editor
grid like TMS TAdvancedStringGrid for Delphi (www.tmssoftware.com),
and since I have not found anything like it I need to slowly make
myself one from scratch...

Have you tried the Orpheus table control yet?

  http://wiki.lazarus.freepascal.org/OrphPort

If you have a couple of years of free time, you could probably create
one from scratch. A better idea would be to adapt an existing grid
control like TOvcTable.

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Salvador · 2007-04-05 16:29

Phil:

No, I have not tried Orpheus but I will test it imediatley, thanks for
the link.

I know that developing a feature-rich grid is very complex, but my
modest desire is to slowly add one feature at a time... Thats why I'd
like to know the general methodology to develop a component...

Any tips you could give me?

Thanks in advance...

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vins · 2007-04-20 12:57

QuoteCan I use visual design to do it?
No, you can't.

Components are developed like in Delphi. Try searching google for some
delphi tutorials.

I usually test my components runtime only and If all is working I pack
them so they can be integrated into the IDE.

For example, your test project could have a form with a TPanel
component.
Then you could create your control and assign it to the panel at
runtime:

Code: [Select]...
var
  Form1: TForm1;
  DBGrid1: TDBGrid;

implementation

{ TForm1 }

procedure TForm1.FormCreate(Sender: TObject);
begin
     DBGrid1 := TDBGrid.Create(nil);
     DBGrid1.Parent := Panel1;
     DBGrid1.Align := alClient;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
     FreeAndNil(DBGrid1);
end;
...