Legacy Document

Inside Macintosh: Advanced Color Imaging Reference /

Chapter 2 - Color Picker Manager Reference /

Color Picker-Defined Functions / Responding to Requests to Return and Set Color Picker Information

MyGetColor

Color picker-defined subroutine that handles a kGetColor request.

If you create a color picker, it must respond to the kGetColor request code. The Color Picker Manager sends this code to request your color picker to return an original or a new color. A color picker responds to the kGetColor request code by calling a color picker-defined subroutine (for example, MyGetColor) to handle the request.

pascal ComponentResult MyGetColor (
PickerStorageHndl storage, 
ColorType whichColor,  
PMColorPtr color);

storage

A handle to your color picker's global data.

whichColor

A type of color--either original or new--requested from your color picker. Your function should respond to the value represented by either the kOriginalColor or kNewColor constant.

color

A pointer to a PMColor structure (page 2-15).

DISCUSSION

In the PMColor structure pointed to by the color parameter, your MyGetColor function should return a color. If your MyGetColor function is passed the value represented by the kOriginalColor constant, it should return the color that the user first begins to edit. If your MyGetColor function is passed the value represented by the kNewColor constant, it should return the last color selected by the user.

Your function should return noErr if successful, or an appropriate result code otherwise.

SEE ALSO

Listing 2-24 in Advanced Color Imaging on the Mac OS illustrates how to implement this function.