Declaration

// Full color palette overload
function IEPromptForColor(var AColor : TColor; PosX: Integer = 0; PosY: Integer = 0): Boolean; overload;

// Select from palette overloads
function IEPromptForColor(var AColor : TColor; Palette: array of TRGB; NumCol: integer; PosX: Integer = 0; PosY: Integer = 0): Boolean; overload;
function IEPromptForColor(var AColor : TColor; Palette: array of TColor; NumCol: integer; PosX: Integer = 0; PosY: Integer = 0): Boolean; overload;
function IEPromptForColor(var AColor : TColor; Palette: PRGBROW; NumCol: integer; PosX: Integer = 0; PosY: Integer = 0): Boolean; overload;

Description

Display a color selection dialog so the user can choose a color. Result is false if user cancels out.
With first overload the standard VCL Color dialog is used allow selection from full color palette.
With remaining overloads, an ImageEn dialog is used allowing only choices from the specified palette (maximum of 256 colors). You can generate color palettes using GenerateDicomColorPalette, GenerateHuePalette, GenerateColorLuminancePalette and GenerateGradientPalette.

You can optionally specify a pop-up location. If it is not specified, the dialog will be centered on the screen.

The "Custom Colors" for the Full Color dialog are specified by ColorDialogCustomColors

Note: To output a palette to an image, you can use: IEDrawColorPalette

Demo

Examples

// Prompt user to specify a fill color for the current layer
var
  aColor: TColor;
begin
  aColor := ImageEnView1.CurrentLayer.FillColor;
  if IEPromptForColor( aColor ) then
    ImageEnView1.CurrentLayer.FillColor := aColor;
  ImageEnView1.Update();
end;


// Select a color used in the image
if IEPromptForColor( aColor, ImageEnView1.IO.Params.ColorMap^, ImageEnView1.IO.Params.ColorMapCount ) then
  Panel1.Color := aColor;


// Show the palette of the file "myfile.gif"
ImageEnView1.IO.LoadFromFile('C:\myfile.gif');
IEPromptForColor( aColor, ImageEnView1.IO.Params.ColorMap^, ImageEnView1.IO.Params.ColorMapCount );


// Let user choose a hue of green for ImageEnView background
const
  Color_Count = 256;
var
  pal: array of TRGB;
  dd: double;
  i: Integer;
  aColor: TColor;
begin
  SetLength( pal, Color_Count );
  dd := 255 / ( Color_Count - 1 );
  for i := 0 to Color_Count - 1 do
    pal[ Color_Count - i - 1 ] := CreateRGB( 0, blimit( Round( i * dd )), 0 );
  if IEPromptForColor( aColor, pal, Color_Count ) then
    ImageEnView1.Background := aColor;
end;




// Show preview of Rainbow color palette
var
  colorMap: TIEArrayOfTRGB;
  aColor: TColor;
begin
  colorMap := GenerateDicomColorPalette( iectRainbow );
  IEPromptForColor( aColor, colorMap, Length( colorMap ));
end;




// Colorize the image based on the user's selection of a color
if IEPromptForColor( cl ) then
begin
  ColorToHSV( cl, h, s, v );
  ImageEnView1.Proc.Colorize( h, s, 1.0 );
end;

// User selected Red...

See Also

◼ TImageEnPaletteDialog
◼ GenerateDicomColorPalette
◼ GenerateColorLuminancePalette
◼ GenerateHuePalette
◼ GenerateGradientPalette

---