About the Color Picker Package and System 7.0

The Color Picker Package allows you to offer users a standard dialog box

for choosing a color. The Color Picker Package also provides routines for

converting color specifications from one color model to an other.

You should be familiar with the material in the Graphics Overview,

especially the discussion of direct and indexed screen devices. Effective use of

the Color Picker also requires familiarity with Color QuickDraw.

The Color Picker Package is available in system 4.1 and later. With

system 7.0 or later the Color Picker dialog box can be displayed on

black-and-white devices.

You need to know about the Color Picker Package if your application uses

the color system introduced with Color QuickDraw (rather than the

eight-color system available with the original QuickDraw) and you need to

solicit color choices from users. If your application limits user selection to a

specific list of colors, you may need to construct your own dialog box for color

selection using Palette Manager routines, because the Color Picker

allows users to choose colors from the entire range of 48-bit RGB values

available with Color QuickDraw.

The Color Picker Package provides you with a standard way of soliciting a

color choice from the user. When your application calls the GetColor

function, the Color Picker presents its dialog box to the user, as shown in

the figure below.When the user is satisfied with a chosen color and clicks the

OK button, GetColor returns that color to your application as an RGB value.

The Color Picker Package also has utility routines for converting between

RGB values and several other color models, and for converting between the

fixed integers Color QuickDraw uses for RGB colors and the SmallFract

values the Color Picker Package uses with alternate color models.

Color Models describes the color models the Color Picker Package

works with. Using the Color Picker Package explains how to set up and

present the Color Picker dialog box to users and how to use the con version

facilities.