Input/Output Processes : Colors and Fonts : Managing colors and fonts in graphical applications
Managing colors and fonts in graphical applications
Graphical interfaces provide a variety of techniques to help manage color and font definitions for an application. Using these techniques, ABL allows a graphical application to manage colors and fonts at four levels of run-time operation:
User access to the color and font tables — Allows the user to change the definitions for current dynamic color and font table entries using the SYSTEM–DIALOG COLOR and SYSTEM–DIALOG FONT statements. For more information, see Allowing the user to change colors and fonts.
Procedure access to the color and font tables — Examines and changes the definitions for color table entries in the current environment using the COLOR–TABLE handle, and examining height and width characteristics of font table entries in the current environment using the FONT–TABLE handle. Also, this section addresses setting the definition for arbitrary colors using the RGB–VALUE function. For more information, see Accessing the current color and font tables.
Procedure access to color and font definitions — Reads and writes color and font definitions for the current environment using the GET–KEY–VALUE and PUT–KEY–VALUE statements. For more information, see Retrieving and changing color and font definitions.
Procedure replacement of the current environment — Replaces the application's current color and font tables with tables from a different environment using the LOAD, USE, and UNLOAD statements. For more information, see Managingapplication environments.
User access to the color and font tables — Allows the user to change the definitions for current dynamic color and font table entries using the SYSTEM–DIALOG COLOR and SYSTEM–DIALOG FONT statements. For more information, see Allowing the user to change colors and fonts.