TDragBar Change event
lazarus / 10-Designer

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GAlex · 2005-01-02 18:33

Maybe I've found a new bug, maybe not, but have a look at the
following
Code: [Select]
unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs,
ComCtrls,
  StdCtrls;

type
  TForm1 = class(TForm)
    StaticText1: TStaticText;
    TrackBar1: TTrackBar;
    procedure TrackBar1Change(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{ TForm1 }

procedure TForm1.TrackBar1Change(Sender: TObject);
var s: string;
begin
  str(trackbar1.position:2, s);
  statictext1.caption:=s;
end;

initialization
  {$I unit1.lrs}

end.

There is a standard Form, a StaticText, a DragBar;
 ... running the app and dragging the dragbar ...
 ... NOTHING HAPPENS!!!

the callback routine has never been called!!!

In Delphi6 the above code runs well, and the static text displays the
dragbar position.

What's wrong?

BTW I'm actually running win32 + Laz-0.9.2 beta.

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GAlex · 2005-01-06 12:02

Ahem ... is anybody out there???

I've Updated to the latest Lazarus Build, but the problem remains, and
the previous code doesn't work.

I've also looked at the control source code, but found nothing
interesting (it should work well), maybe I've trascurated somthing
important but can't think of anything wrong.

Please help, I'm stuck with my current project 'cause it makes use of
the DragBar.

Thanks in advance.

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matthijs · 2005-01-06 16:23

I just started a new project (under Linux) and had the following code
working correctly:
Code: [Select]
procedure TForm1.TrackBar1Change(Sender: TObject);
begin
  StaticText1.Caption := 'TrackBar.pos: ' +
IntToStr(TrackBar1.Position);
end;

I'm running the latest Lazarus version, under Windows I see the same
problem as you do. The caption doesnot get update.

I even added StaticText1.Invalidate and Application.ProcessMessages to
the method, nothings helps.

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Vincent Snijders · 2005-01-06 19:19

Well, if two people got the same problem, it is more likely a lazarus
bug (maybe a NOT-YET-IMPLEMENTED) than a programmer error. Please,
submit a bug report in the bug tracker.

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matthijs · 2005-01-06 19:52

Quote from: "Vincent"Well, if two people got the same problem, it is
more likely a lazarus bug (maybe a NOT-YET-IMPLEMENTED) than a
programmer error. Please, submit a bug report in the bug tracker.

Done that now.  Nr. 534.

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GAlex · 2005-01-09 21:57

Ok, as stated in the bug tracking list, the bug #534 has been FIXED.

So, what must I do to get it working?

I've tried to download the latest cvs source, but that doesn't
compile.

HELP!!! :cry:

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Vincent Snijders · 2005-01-09 22:04

You must use the CVS version of lazarus, there is no new release yet.

 I have no problems compiling the CVS version. What errors do you get?

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GAlex · 2005-01-11 21:10

Mhmhh, I've successfully compiled the VCS version and got a brand new
0.9.5 version running, but...

Opening my old project, I got errors on myproject.lfm about properties
on statictext, then I'm unable to edit my form in form editor, cause
it shows only the form code in the code editor  :twisted: buggy
:twisted: .

Well, it seems that all my other old projects are working well, and
new projects runs without problems, so I should only rewrite my
project from scratch, since it were at an early stage, only a little
accident.

Thanks very much to all, and by the way, yes, the bug has really benn
fixed. :lol:

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C#R# · 2007-09-28 02:38

HI,
I´m here because I have the same problem.
I don´t know if it is helpfull, but I have an application
with old version of lazaus that´s running very well with
this component. Wen I try to compile with 9.22, on debug,
the GDB show the message:
Error reading trackbar1.ShowScale; unknown property: ShowScale.

Best regards.

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Marc · 2007-09-28 09:01

Big chance that the ShowScale property got renamed or removed.
When you open your form in Lazarus do you get a editform to manually
remove the property ?

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C#R# · 2007-10-27 15:14

Hi,
Yes, I had this message.

Thanks.