whats new ¦  programming tips ¦  indy articles ¦  intraweb articles ¦  informations ¦  links ¦  interviews
 misc ¦  tutorials ¦  Add&Win Game

Tips (1541)

Database (90)
Files (137)
Forms (107)
Graphic (114)
IDE (21)
Indy (5)
Internet / LAN (130)
IntraWeb (0)
Math (76)
Misc (126)
Multimedia (45)
Objects/
ActiveX (51)

OpenTools API (3)
Printing (35)
Strings (83)
System (266)
VCL (242)

Top15

Tips sort by
component


Search Tip

Add new Tip

Add&Win Game

Advertising

66 Visitors Online


 
...get an inverse color value to a color?
Autor: Neil Rubenking
[ Print tip ]  

Tip Rating (9):  
     


procedure EdBackColor(FontC: TColor; var EditableColor,
  ReadOnlyColor: TColor);
  // Calculate the luminance of the color using the simplified formula
  //     luminance = 0.25*red + 0.625*green + 0.125*blue
  // If greater than 0.5, use a dark background
var
  
R, G, B: Integer;
begin
  
R := GetRValue(FontC) * 2;
  G := GetGValue(FontC) * 5;
  B := GetBValue(FontC);
  if R + G + B < 1024 then
  begin
    
EditableColor := clWhite;
    ReadOnlyColor := clSilver;
  end
  else
  begin
    
EditableColor := clBlack;
    ReadOnlyColor := clDkGray;
  end;
end;

 

Rate this tip:

poor
very good


Copyright © by SwissDelphiCenter.ch
All trademarks are the sole property of their respective owners