isCOBOL Evolve : Appendices : Library Routines : W$PALETTE
W$PALETTE
The W$PALETTE library routine provides a number of functions to manage RGB colors and COBOL attributes.
NOTE -   isCOBOL allows you to work with RGB colors. A maximum of 16 million concurrent colors can be displayed on the screen at the same time. However, some old languages display only 16 colors at a time. For compatibility reasons isCOBOL supports this library routine, that allows definition of a palette of usable colors. In any case it is important to pinpoint that the use of this routine is deprecated.
Syntax:
 CALL "W$PALETTE" USING opCode 
                        parameters
                 GIVING paletteResult
Parameters:
opCode
Function to be executed. Valid values, defined in ispalette.def, are:
 
Show a dialog window to choose a color.
Retrieve the RGB color associated to a COBOL attribute.
Creates a mapping between RGB colors and their alternative version.
Retrieve the maximum number of colors that the system can render simultaneously.
Resets all color settings previously made.
Set the RGB color associated to a COBOL attribute.
Check if the host system supports the W$PALETTE library routine.
parameters
Parameters depend on the opcode.
Return code:
returnCode definition and meaning depend on the opcode.
Examples:
Example - Select a color from palette and change a numbered color with the selection
working-storage section.
copy "ispalette.def".
78  78color   value 3.
77  result    pic 9(2).
 
procedure division.
...
change-color.
   initialize wpalette-data 
   call "w$palette" using wpalette-choose-color,
        wpalette-data,
        giving result 
   move 78color to wpal-color-id
   call "w$palette" using wpalette-set-color,
        wpalette-data,
        giving result.
   ...
Example - Select a color from palette and change a numbered color with the selection
working-storage section.
copy "ispalette.def".
78  78color   value 3.
77  result    pic 9(2).
 
procedure division.
...
change-color.
   initialize wpalette-data 
   call "w$palette" using wpalette-choose-color,
        wpalette-data,
        giving result 
   move 78color to wpal-color-id
   call "w$palette" using wpalette-set-color,
        wpalette-data,
        giving result.
   ...
Example - Map the foreground color 12 (high intensity red) to become blue and the RGB X#C0C0C0 (light gray) to become black
 working-storage section.
 copy "ispalette.def".
 
 procedure division.
 ...
 map-colors.
*map FOREGROUND-COLOR 12 (high-intensity red) to become blue
 move 255 to wpal-original-red(1).
 move 0   to wpal-original-blue(1).
 move 0   to wpal-original-green(1).
 move 0   to wpal-new-red(1).
 move 255 to wpal-new-blue(1).
 move 0   to wpal-new-green(1).
*map RGB X#C0C0C0 (light gray) to become black
 move 192 to wpal-original-red(2).
 move 192 to wpal-original-blue(2).
 move 192 to wpal-original-green(2).
 move 0   to wpal-new-red(2).
 move 0   to wpal-new-blue(2).
 move 0   to wpal-new-green(2).
 call "w$palette" using wpalette-map-colors
                        wpalette-original-colors
                        wpalette-new-colors.