The Photoshop-Like Color Palette Dialog

• Download dialog demo - 48.8 KB
• Download dialog file source - 9.9 KB

Introduction 

I developed a Photoshop-like color palette. It support  RGB color space, HSB color space, CMYK color space and Lab color space. The dialog is shown below:

Background

The palette dialog is developed under MFC framework.  

Using the code

The palette dialog is named CSelectColorDialogDlg. Its base class is CDialog. This dialog has only two parameters: the input color and the father dialog pointer (optional). The input color parameter is a reference type which also gives the output color when the dialog closed.  The input color type is COLORREF. 

The illustration of my dialog.

//
//How to use the dialog
//
COLORREF rgb = RGB(250,70,0);
CSelectColorDialogDlg dlg(rgb);
if (dlg.DoModal() == IDOK)
{
   COLORREF output = rgb;
}

//
//The main process is the transform between different color spaces
//
class CSelectColorDialogDlg : public CDialog
{
...
    //The transform functions
    COLORREF getColorFromRGB(struct rgbcolor rgb);
    COLORREF getColorFromCMYK(struct cmykcolor cmyk);
    COLORREF getColorFromHSB(struct hsbcolor hsb);
    COLORREF getColorFromLab(struct labcolor lab);

    struct rgbcolor getRGBFromColor(COLORREF color);
    struct cmykcolor getCMYKFromColor(COLORREF color);
    struct hsbcolor getHSBFromColor(COLORREF color);
    struct labcolor getLabFromColor(COLORREF color);
    //Get the color form coordinate  or get coordinate from color;
    void getCoordinateFromColor(COLORREF color,ColorType type,SelectWeight selectw);
    COLORREF getColorFromCoordinate(int x,int y,int w,ColorType type,SelectWeight selectw);
...
}

//
//draw the color palette on the dialog
//
void CSelectColorDialogDlg::drawColorPalette(){
    CDC* pDC  = GetDC();

    getCoordinateFromColor(currentColor,curType,curSelectWeight);

    for(int i = 0; i < 256; ++i){
        for(int j = 0; j < 256; ++j){
            COLORREF color = getColorFromOrdinate(i,j,curWeight,curType,curSelectWeight);
            memdc.SetPixel(poffsetx + i,poffsety + j,   color   ); 
        }
    }

    for(int i = 0; i < 25; ++i){
        for(int j = 0; j < 256; ++j){
            
            COLORREF color;
            if (curSelectWeight == H1 && curType == HSBTYPE){
                color = getColorFromCoordinate(255,255,j,curType,curSelectWeight);
            }else{
                color = getColorFromCoordinate(curX,curY,j,curType,curSelectWeight);
            }
            memdc.SetPixel(boffsetx + i,boffsety + j,color); 
        }
    }


    for(int i = 0; i < 65; ++i){
        for(int j = 0; j < 30; ++j){
            memdc.SetPixel(roffsetx + i,roffsety + j,currentColor); 
            memdc.SetPixel(roffsetx + i,roffsety + j + 30,inputColor); 
        }
    }
    pDC->BitBlt(0,0,350,400,&memdc,0,0,SRCCOPY);
    pDC->BitBlt(roffsetx,roffsety,65,60,&memdc,roffsetx,roffsety,SRCCOPY);


    CBrush *pbrush=CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));
    pDC->SelectObject(pbrush);
    pDC->RoundRect(poffsetx + curX - 6, poffsety + curY - 6,
        poffsetx + curX + 6,poffsety + curY + 6,12,12);

    POINT   labelPoints[4] = {CPoint(boffsetx + 30,boffsety + curWeight) , 
        CPoint(boffsetx + 40,boffsety - 5 + curWeight) , 
        CPoint(boffsetx + 40,boffsety + 5 + curWeight),
        CPoint(boffsetx + 30,boffsety + curWeight) }; 
    BYTE   types[4] = {PT_MOVETO ,PT_LINETO,PT_LINETO,PT_LINETO}; 
    pDC->PolyDraw(labelPoints,types,4);

    //pen.DeleteObject();
    ReleaseDC(pDC);
}

Drawbacks  

The color transform between different color space still have some problem and it will be settled later. 

History  

Version 1.0