TGColorPick

    protected:

              void AllocColors()
              void CreateDitheredImage(Pixmap_t image, Int_t which)
              void CreateImages()
      virtual void DoRedraw()
              void DrawHScursor(Int_t onoff)
              void DrawLcursor(Int_t onoff)
              void FreeColors()
              void InitImages()
              void SetHScursor(Int_t x, Int_t y)
              void SetLcursor(Int_t z)
              void SetSliderColor()
              void UpdateCurrentColor()

    public:

                      TGColorPick(const TGWindow* p = 0, Int_t w = 1, Int_t h = 1, Int_t id = -1)
                      TGColorPick(const TGColorPick&)
              virtual ~TGColorPick()
       static TClass* Class()
         virtual void ColorSelected(Pixel_t col = 0)
              Pixel_t GetCurrentColor() const
       virtual Bool_t HandleButton(Event_t* event)
       virtual Bool_t HandleMotion(Event_t* event)
      virtual TClass* IsA() const
                 void SetColor(Pixel_t color)
         virtual void ShowMembers(TMemberInspector& insp, char* parent)
         virtual void Streamer(TBuffer& b)
                 void StreamerNVirtual(TBuffer& b)

    private:

        Int_t fColormap[64][3]  colormap
      Pixel_t fPixel[64]        pixel values

    protected:

         Pixmap_t fHSimage       hue / saturation colormap pixmap
         Pixmap_t fLimage        color lightness slider pixmap
            Int_t fNColors       number of color samples
            Int_t fClick         mouse click location (kCLICK_NONE, kCLICK_HS, kCLICK_L)
            Int_t fCx            x position in hs colormap
            Int_t fCy            y position in hs colormap
            Int_t fCz            position in lightness slider 
          Pixel_t fCurrentColor  currently selected color value
      Rectangle_t fColormapRect  hue / saturation colormap rectangle
      Rectangle_t fSliderRect    color lightness slider rectangle
             TGGC fCursorGC      color lightness slider cursor GC

Class Description

                                                                      
 TGColorPalette, TGColorPick and TGColorDialog.                       
                                                                      
 The TGColorPalette is a widget showing an matrix of color cells. The 
 colors can be set and selected.                                      
                                                                      
 The TGColorPick is a widget which allows a color to be picked from   
 HLS space. It consists of two elements: a color map window from      
 where the user can select the hue and saturation level of a color,   
 and a slider to select color's lightness.                            
                                                                      
 Selecting a color in these two widgets will generate the event:      
 kC_COLORSEL, kCOL_CLICK, widget id, 0.                               
 and the signal:                                                      
 ColorSelected(Pixel_t color)                                         
                                                                      
 The TGColorDialog presents a full featured color selection dialog.   
 It uses 2 TGColorPalette's and the TGColorPick widgets.              
                                                                      

 TGColorPick constructor.
 TGColorPick is a widget which allows a color to be picked from HLS space.
 It consists of two elements: a color map window from where the user can
 select the hue and saturation level of a color, and a slider to select
 color's lightness.

 TGColorPick destructor.

 Handle mouse button events in color pick widget.

 Handle mouse motion events in color pick widget.

 Create colormap and color slider images.

 Try to allocate first a palette of 64 colors. Used by the dithered
 version of the color maps.

 Free allocated colors.

 Create a dithered version of the color map and lightness images for
 display modes with reduced number of colors. The Floyd-Steinberg error
 diffusion dithering algorithm is used.
 This routine is called in PseudoColor modes only.

 Initialize color palette and slider images.

 Set slider colors.

 Position the slider cursor on right color position.

 Assign the current cursor position as currently selected color.

 Redraw the color pick widget.

 Set hue / saturation cursor position.

 Set lightness slider cursor position.

 Draw hue / saturation cursor

 Draw lightness slider cursor