Colors set as constants in program are permanent
lazarus / 39-Graphics

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jdlinke · 2014-06-13 03:08

I was attempting to have some color templating capability in my new
project, so I set aside a unit for gui-related constants to be shared
among my form. I added some new colors as constants. I thought I would
be able to change them, but now no matter what value I set, the
original colors I set remain when I run my program. I even tried
completely closing Lazarus and reopening my project. Also, I get the
same result whether I run from IDE or directly from the .exe.

Here's the unit in which I defined my new colors:
Code: [Select]unit unitDefinitions;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Graphics;

const
  // Use the 'mono' on following site to help with scheme:
  // http://colorschemedesigner.com/
  cllbLightest = TColor($FFA4A4);
  cllbLight = TColor($FF8383);
  cllbMedium = TColor($FF5959);
  cllbDark = TColor($BF6262);
  cllbDarkest = TColor($A61D1D);



implementation

end.

Am I doing something wrong? How can I fix this?

The gaudy purple tones I originally chose are driving me up the wall!

Running Lazarus 1.2.2 on Windows 8.1

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Windsurfer · 2014-06-13 05:40

This may be a 'Doh' moment for you, constants do not change. Use
variables. ;o)

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Blaazen · 2014-06-13 06:17

Initialized variables can do the job:
Code: [Select]var
  Color: TColor = $4455FF;

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howardpc · 2014-06-13 06:59

Or use typed constants:

Code: [Select]{$J+}
const
  cllbLightest = TColor($FFA4A4);
  ...

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taazz · 2014-06-13 07:01

Quote from: howardpc on June 13, 2014, 08:59:51 amOr use typed
constants:

Code: [Select]{$J+}
const
  cllbLightest = TColor($FFA4A4);
  ...
that is a writable const this is a typed const
Code: [Select]const
  cllbLightest :TColor = $FFA4A4;

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Blaazen · 2014-06-13 07:30

AFAIK there's no practical difference between:
Code: [Select]var
  Color: TColor = $4455FF; and
Code: [Select]const
  Color: TColor = $4455FF;

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taazz · 2014-06-13 07:35

Code: [Select]procedure Test;
{J+}
const  MyValue : Byte = 0;
begin
  writeln(myValue);
  myvalue := myvalue +1;
end;

begin
  test;
  test;
  test;
end;

that can not be done with a variable;

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Leledumbo · 2014-06-13 07:48

Quote from: Blaazen on June 13, 2014, 09:30:37 amAFAIK there's no
practical difference between:
Code: [Select]var
  Color: TColor = $4455FF; and
Code: [Select]const
  Color: TColor = $4455FF; Except if it's a local declaration

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circular · 2014-06-13 10:16

Well anyway if you want to change it, you better declare it as "var",
because you never know what implementation you will have. Using
"const" and changing it is not guaranteed to work all the time.