CHAPTER 7 


PROGRAMMING IN HWIF 


This document is a beta version and may be subject to change. 


This chapter describes the changes and additions that have been made to the HWIF library as a result of the 
introduction of the Siena and Series 3c machines into the SIBO range. 


Grey lines in menus 


The introduction of small fonts for dialogs on the Workabout and Siena resulted in a change to the data 
structures in the property of the GATE class. This caused an inconsistency in the Hwif library between the 
Series 3a and later machines in the way that it stores the positions of grey lines in menus. For reasons of 
future consistency, the change has been incorporated in all SIBO machines with ROM version numbers of 
Ox356F and above. It is therefore present in Workabout, Siena and Series 3c machines, although Series 3c 
dialogs do not need to make use of the small font. 


A suitably written Hwif application that makes no use of grey lines in menus will run on any SIBO 
machine, regardless of the version of the Hwif library that was used to build it. However, any Hwif 
application that uses grey lines in its menus and was built with the version of Hwif supplied with version 
2.10 of the SIBO C SDK will not run on Series 3a machines. Such applications that were built with earlier 
versions of Hwif will run on the Series 3a, but not on the Workabout, Siena or Series 3c. 


All Hwif programs that are linked with the modified Hwif library that is described below can run on the 
Series 3, Series 3a, Series 3c, Workabout and Siena - provided, of course, that their displays are tailored to 
the various screen sizes and graphics capabilities of these machines. 


Hwif library modification 


The Building the Hwif library section in the Advanced use of Hwif chapter of the Programming in Hwif 
manual explains how to build a customised version of the Hwif library, using the Hwif source files 
provided with the SIBO C SDK. Before making the modification that is described in this section, you 
should verify that you can build the existing Hwif library. 


The required modification is to the hMenuRun function, which can be found in the hhwif-c source file. The 
published source for this function is: 


GLDEF_C INT hMenuRun () 
/* 
Display and use the menu bar 
*/ 
{ 
if (_GreyLines) 
p_bcpy (&DatGate->gate.g.ulines[0], GreyLines,16*sizeof (UWORD) ) ; 
return (p_send3 (DatGate,O GT MENU RUN, MenuPositions) ); 
} 


This needs to be modified as shown below, to take into account the changed data structure that was 
introduced with ROM version 3.56F: 


SIENA/SERIES 3C UPGRADE 


GLDEF_C INT hMenuRun () 
/* 
Display and use the menu bar 
af 
{ 
if (_GreyLines) 
{ 
p_bcpy( (BYTE *) &DatGate->gate.g.ulines [0] 
-((p_version()>0x355f) ? 0 : sizeof (DLG _X CONSTANTS) ), 
_GreyLines,16*sizeof (UWORD) ); 
} 
return (p_send3(DatGate,O GT MENU RUN, MenuPositions) ); 
} 


Once the source file has been modified in this way, you should rebuild the Hwif library and use the rebuilt 
version when developing Hwif applications for any target SIBO machine.