The old-style font commands from GFA-BASIC for Windows 16 can still be used in GB32. However before using them you should be aware of an essential difference between GB32 and GB16. Beside this you should also know what the consequences are when applying the GB16 font commands.
The GB LOGFONT structure
In GB16 the font commands applies to one, and only one, internally maintained, global LOGFONT structure (user defined type). In GB32 there are multiple LOGFONT structures and none of them is a global variable. The LOGFONT structure is now part of a Form object and the font commands now work on the LOGFONT of the current active Form (Me)
The LOGFONT type is defined in wingdi.inc.g32 located in the Include directory of your GB32 installation.
' Logical Font (wingdi.h) Global Const LF_FACESIZE = 32 Global Const LF_FULLFACESIZE = 64 Type LOGFONT lfHeight As Long lfWidth As Long lfEscapement As Long lfOrientation As Long lfWeight As Long lfItalic As Byte lfUnderline As Byte lfStrikeOut As Byte lfCharSet As Byte lfOutPrecision As Byte lfClipPrecision As Byte lfQuality As Byte lfPitchAndFamily As Byte lfFaceName(LF_FACESIZE) As Byte End Type
Regardless of the GB version, the members of the current LOGFONT variable are set and read using the same set of commands. In GB16 they are applied to the one global variable, but in GB32 they still set and read the LOGFONT members from the current active Form (Me).
|FONT member value||sets a value to a member|
|RFONT member variable||reads a member value into a variable|
|variable$ = _Font$||copies all logfont-members into a string|
|_Font$ = variable$||sets all logfont-members from a string|
|Dlg Font||sets all logfont members from a users font selection|
|Font To hfnt||Creates a logical font from logfont|
|FreeFont hfnt||Deletes a logical font|
|GetFont hfnt||Obtains loglont values from a logical font|
|SetFont hfnt||Selects the logical font into the window's DC|
After filling the LOGFONT members (using Font name, _Font$, or Dlg Font) the Font To hfnt invokes the GDI function CreateFontIndirect() which returns a Windows handle to the font created. This functions allocates memory whose memory handle is returned in the hfnt variable (32-bits). This font memory must be released by the application explicitly using FreeFont hfnt.
The GDI fontmapper creates the font that best matches the values in the LOGFONT structure. However, they might be different from what was requested. To obtain the attributes of the GDI created font, the application would use GetFont hfnt. This reloads the LOGFONT values from the actual font handle.
What about SetFont?
In GB32 this commands invokes a series of complex procedures. In GB16 it was as simple as selecting the logical GDI font handle into the current device context. In addition, in GB16 the current device context could be manipulated using SetDC, which is obsolete in the 32-bits version. Of course, eventually, GB32 will select a font handle into a device context like in GB16, but GB32 goes the COM way. As such the GB command SetFont hfnt creates a hidden Font object and performs a Set Me.Font = hiddenFont (from hfnt).
Finally, any font the application created the old way using Font To must(!) be released explicitly when it is no longer in use. Meaning after that some other font has been set. (Either using SetFont or using the Form's property Font.)