Added support for Delphi 5 and 6 in the Delphi IDE Theme Editor

April 26, 2011 by Rodrigo Leave a comment

Some fellows coders ask me (and request) about add support to the delphi 5 and delphi 6 IDEs. these versions was not originally supported by the  Delphi IDE Theme Editor because these IDEs gives you a 16 fixed colors palette. So this causes  limitations to manage the themes.

Check this image for the IDE editor options in Delphi 5 which shows the 16 colors available

the option to assign any color to the Highlight elements was added in the Delphi 7 version

The first thing I thought to manage the 16 palette colors was use specific themes with contains combinations of colors using these 16 colors. But quickly discarded this solution because would be necessary handle specific themes for specific versions of the delphi IDEs.  So finally I decide convert the colors themes to the 16 color palette using some algorithm to find the closest color to the palette. the algorithm chosen was the Euclidean distance where  closest color is determined by the distance between the two corresponding points in three-dimensional space.  for example to find the distance of two colors  (r₁,g₁,b₁) and (r₂,g₂,b₂)  the formula look like this

Now the dephi implementation of the algorithm to find the “straight-line distance” or “nearest color” using the Euclidean distance:

const
  DelphiOldColorsCount =16;
  //this is the 16 colors palette used by delphi 5 and delphi 6 IDEs (BGR format)
  DelphiOldColorsList: array[0..DelphiOldColorsCount-1] of TColor =
  (
    $000000,$000080,$008000,$008080,
    $800000,$800080,$808000,$C0C0C0,
    $808080,$0000FF,$00FF00,$00FFFF,
    $FF0000,$FF00FF,$FFFF00,$FFFFFF
  )

function GetIndexClosestColor(AColor:TColor) : Integer;
var
  SqrDist,SmallSqrDist  : Double;
  i,R1,G1,B1,R2,G2,B2   : Integer;
begin
  Result:=0;
  //set the max distance possible
  SmallSqrDist := Sqrt(SQR(255)*3);
  //get the RGB components of the original color
  R1 := GetRValue(AColor);
  G1 := GetGValue(AColor);
  B1 := GetBValue(AColor);

    for i := 0 to DelphiOldColorsCount-1 do
    begin
      //get the RGB components of the palette color
      R2 := GetRValue(DelphiOldColorsList[i]);
      G2 := GetGValue(DelphiOldColorsList[i]);
      B2 := GetBValue(DelphiOldColorsList[i]);
      //calculate the euclidean distance
      SqrDist := Sqrt(SQR(R1 - R2) + SQR(G1 - G2) + SQR(B1 - B2));
      if SqrDist < SmallSqrDist then
      begin
       Result := i;
       SmallSqrDist := SqrDist;
      end
    end
end;

Applying the above function the results are

Aqua Theme Original (Delphi 7 and Above)

Aqua Theme Modified (Delphi 5 and Delphi 6)

NightFall Theme Original (Delphi 7 and Above)

NightFall Theme Modified (Delphi 5 and Delphi 6)

I think which the final result is acceptable (remember the palette is 16 colors only) . Now you can download the updated version of the Delphi IDE Theme Editor from here.