Paletteindex() relates to RGB() as...


My question is: can some give the code for a procedure
BLA (Paletteindex: word; var Red,Green,Blue: word/integer?)

such that Shape1 will give the same color as Shape2

Shape1.Brush.Color:=paletteindex(x);

yields the same as

BLA(PaletteIndex(x), Red,GReen,Blue);
Shape2.Brush.Color:=RGB(Red,Green,Blue);
yonasbAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

mirek071497Commented:
You'r have problem because each control can have different palette and when you type
Shape1.Brush.Color := paletteindex(n) then you specify number in logical palette but when you type
Shape1.Brush.Color := RGB( ....) then windows calculate which entry of this paleete need to use.

I don't fully understand your question. Do you need read RGB values for PaletteEntry which have Index=n ?
If this is true you need to use GetPaletteEntries which retrive palette RGB values.
0
yonasbAuthor Commented:
To Mirek:

I know :
UINT GetPaletteEntries(
    HPALETTE  hpal,UINT  iStartIndex,      
    UINT  nEntries,    LPPALETTEENTRY  lppe );

-> But I do not understand how to use it.

I want the code for the following procedure.

Procedure GetRGBFromCurrentPalette
        (index: integer;
         var Red,Green,Blue: integer);
begin
??? <-can someone write this
end.

Example:

Shape1.Brush.Color:=PaletteIndex(12);

GetRGBFromCurrentPalette(12,Red,Green,Blue);

Shape2.Brush.Color:=RGB(Red,Green,Blue).

Shape1 en Shape2 must give the same color ON THE SCREEN.


Can you or someone else please write this little procedure for me?

Thanks
Yonas
0
mirek071497Commented:
Retrive RGB for palette - no problem, but you don't know palette  for tshape ! I think so you try make pogram with wrong way. Tell me what you are doing and i try help you more.

procedure GetRGBFromPalette( Hpal : HPalette; index : integer; var R,G,B : integer );
var lppe : TPaletteEntry;
begin
  if HPal<>0 then
  begin
    GetPaletteEntries ( HPal, index, 1, lppe );
    r:= lppe.peRed;
    g:= lppe.peGreen;
    b:= lppe.peBlue;
  end
  else
    ShowMessage( 'no palette' );
end;

p.s. When you Set color from PaletteIndex then you can't retrive values for R,G,B without Handle to palette.  VCL playing with this handle but you can't get acces to  this handle. This is because TShape is only for simple shape if you need more you need use own component as descendant of TGraphicControl.
0
Cloud Class® Course: Amazon Web Services - Basic

Are you thinking about creating an Amazon Web Services account for your business? Not sure where to start? In this course you’ll get an overview of the history of AWS and take a tour of their user interface.

mirek071497Commented:
Do you understand my comment?
Do you need more help ?
0
yonasbAuthor Commented:
Mirek,

I don't understand. I need more help.

Do you mean this: ?????

I can set  Shape1.Brush.Color := $01000001
When I do, the color of Shape1.Brush.Color becomes
palette color 1 in Windows palette (if that is the
current palette).
You say: I cannot get the RGB value because I don't have
a handle to the palette.
?????????


How can I read the color of Shape1.Brush??

I must be able to use $010000xx because I want to read
the current palette color of Windows. In my program some
shapes must have the same color and when my program is running
and I change the colorscheme in Windows, I want to see
the new colors in my program.

I also must be able to calculate the difference between
two color.

You understand?
Example:
I have DynShape[1].Brush.Color:= $01000001, RGB=R1,G1,B1
I have DynShape[10].Brush.Color:=$01000011, RGB=R10,G10,B10

I calculate Rdelta:= (R10-R1) div (10 -9)
   {  Gdelta, Bdelta  same way}

Then I say, DynShape[2..9] you get the colors in between:

for x:=2 to 9
  DynShape[x].Brush.Color:=RGB(R1 + (x-1)*Rdelta,
                               G1  + (x-1) *Gdelta,
                               B1  + (x-1) * Bdelta).

Do you understand what I want Mirek?

I increase the points (only to 70, I don't have more).





 






0
yonasbAuthor Commented:
Adjusted points to 70
0
yonasbAuthor Commented:
Edited text of question
0
mirek071497Commented:
I think so now I know what you need, and as i say later you do this in bad way. If you set color as $01.... then you don't use system palette but current realized plette for control. You can read system palette entries with GetPaletteEntries (winapi) and then set color as $00BBGGRR where BB is blue GG is green RR is red. This can be done in TShape without limitation.

I post here example after some hours.
0
mirek071497Commented:
1.Change of color scheme don't change system palette! If you need use colors from Color scheme then you must usee constans defined in Graphics.Pas

clScrollBar = TColor(COLOR_SCROLLBAR or $80000000);
  clBackground = TColor(COLOR_BACKGROUND or $80000000);
  clActiveCaption = TColor(COLOR_ACTIVECAPTION or $80000000);
  clInactiveCaption = TColor(COLOR_INACTIVECAPTION or $80000000);
  clMenu = TColor(COLOR_MENU or $80000000);
and many other

2.If you need read system palette and use then this is example :

procedure TForm1.Button1Click(Sender: TObject);
var
  lk : integer;
  r,g,b : byte;

  function GetPalColor( nr : integer; var r,g,b : byte ) : TColor;
  var
    PalEntries : array[0..255] of TPaletteEntry;
    HowMany    : integer;
    l : longint;
    DC : HDC;
  begin
    DC := GetDC( Handle );  { retrive DC for form, it can be any valid DC }
    HowMany := GetSystemPaletteEntries( DC, 0, 255, PalEntries );
    ReleaseDC( Handle, DC );
    if nr>HowMany then
      ShowMessage( 'Palette have only '+IntToSTr(HowMany)+' entries' );
    l := PalEntries[nr].peBlue;
    l := l*256+PalEntries[nr].peGreen;
    l := l*256+PalEntries[nr].peRed;
    result := l;
    r := PalEntries[nr].peRed;
    g := PalEntries[nr].peGreen;
    b := PalEntries[nr].peBlue;
  end;

begin
  lk := 5;
  Shape1.Brush.Color := GetPalColor(lk,r,g,b);
  Shape2.Brush.Color := RGB( r,g,b );
end;

Do you need more ? Ask !
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
mirek071497Commented:
Hi
Are you there ?
0
mirek071497Commented:
Do you understand the colors ?
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Delphi

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.