Topic       : TOS - The Operating System
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Version     : tos.hyp (December 19, 2008)
Subject     : Programmieren/Atari
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Compiled on : Atari
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View Ref-File8.3.17  x_appl_font                                                TOS

 Name:         »Change font and window borders« - (Geneva)

 Opcode:       28929

 Syntax:       int16_t x_appl_font( int16_t getset, int16_t zero, 
               XFONTINFO *info );

 Description:  The call x_appl_font changes the characteristics of the 
               large font used by Geneva, and also the window widget 
               borders.

               This function gives one control over what font is used 
               to display characters in the menu bar, dialogs, etc.

               When Geneva first runs, it checks to see if the font ID 
               saved in GENEVA.CNF is anything other than 1 (for a 
               system font). If so, and GDOS is present, it loads all 
               available fonts, and uses the correct font. If the 
               particular font is not available, it reverts to the 
               system font.

               Regardless of the font's availability, the closest 
               point size to the one specified is used. The window 
               widgets will have a width which is equal to the width 
               of one character in the font, plus the value specified 
               by the user. A similar calculation is used for the 
               widget height.

               When any element in the structure pointed to by info is 
               -2, the default value for that element (as though there 
               had been no GENEVA.CNF file when Geneva loaded) is 
               used; in the case of a getset value of zero (get), this 
               default value is returned in the info structure.

               When getset is 1 and any element is -1, that element 
               will cause Geneva to ignore the setting, leaving the 
               old value in tact.

               Setting these values will have no immediate effect. The 
               GENEVA.CNF file must be re-saved, and Geneva must be 
               restarted before a change can be noticed.

               This example:

               XFONTINFO info = { -2, -2, -2, -2 };
               x_appl_font( 0, 0, &info ); /* Get default values           */
               x_appl_font( 1, 0, &info ); /* Set to these values          */
 
               Is the same as:
 
               XFONTINFO info = { -2, -2, -2, -2 };
               x_appl_font( 1, 0, &info ); /* Set to default values        */
 
               Set it to something else:
 
               XFONTINFO info = { 1,       /* Select the system font       */
                                 10,       /* 10 point (8 x 16)            */
                                  5,       /* Widget width = 8+5 pixels    */
                                  4 };     /* Widget height = 16+4 pixels  */
               x_appl_font( 1, 0, &info );

               Cautions:

                  . Only Monospaced fonts should be used.

                  . While Geneva will work properly with any size 
                    font, some programs may not function properly with 
                    larger or smaller fonts. This is especially true 
                    when it comes to fonts which are more than 8 
                    pixels wide.

               The parameter zero is reserved for future expansion. 
               Must always be 0.

 Return value: Return value of the function is unknown at present.

 Availability: The function is available only under Geneva.

 Group:        Application library

 See Also:     Binding