_FREEFONT - QB64Official/qb64 GitHub Wiki

The _FREEFONT statement frees a font handle that was created by _LOADFONT.

Syntax

_FREEFONT (fontHandle&)

Description

• Unloads fonts that are no longer in use or needed in order to free program memory and resources.
• You cannot free a font which is in use. Change the font to a QB64 default font size before freeing the handle (see example below).
• Predefined QB64 font handle numbers can be used before freeing a font:
  • _FONT 8 - default font for SCREEN (statement) 1, 2, 7, 8 or 13
  • _FONT 14 - default font for SCREEN (statement) 9 or 10
  • _FONT 16 - default font for SCREEN (statement) 0 (WIDTH 80, 25 text only), 11 or 12
  • _FONT 9, 15 and 17 are the double width versions of 8, 14 and 16 respectively in text SCREEN 0.
• If the font handle is invalid (equals -1 or 0), an ERROR Codes will occur. Check handle values before using or freeing them.
• You cannot free inbuilt/default QB64 fonts nor do they ever need freed.

Example(s)

Previews and creates a file list of valid MONOSPACE TTF fonts by checking the _LOADFONT handle values.

SCREEN 12
path$ = "C:\WINDOWS\Fonts\"                  'path to the font folder
SHELL _HIDE "DIR /b " + path$ + "\*.ttf > TTFonts.INF"  
style$ = "monospace"                         'set style to MONOSPACE
OPEN "TTFonts.INF" FOR INPUT AS #1           'list of TTF fonts only
OPEN "TTFMono.INF" FOR OUTPUT AS #2          'will hold list of valid MONOSPACE fonts

DO UNTIL EOF(1): found = found + 1
  LINE INPUT #1, font$          
  f& =_LOADFONT(path$ + font$, 30, style$)   
  IF f& > 0 THEN                  'check for valid handle values > 0
    OK = OK + 1
    PRINT #2, font$
    _FONT f&                      'will create error if handle is invalid!
    PRINT "Hello World!"    
    PRINT: PRINT: PRINT font$; f& 
    PRINT "Press any key."   
    K$ = INPUT$(1)
    _FONT 16                      'use QB64 default font to free tested font
    _FREEFONT f&                  'returns an error if handle <= 0! 
    CLS  
  END IF     
  PRINT
IF K$ = CHR$(27) THEN EXIT DO
LOOP
CLOSE
PRINT: PRINT: PRINT "Found"; found; "TTF files,"; OK; "can use Monospace,"
END 

Found 106 TTF files, 13 can use Monospace.

Using a _FREEFONT sub-procedure.

fontpath$ = ENVIRON$("SYSTEMROOT") + "\fonts\lucon.ttf" 
style$ = "MONOSPACE, ITALIC, BOLD"
fontsize% = 20

_FONT 16
PRINT
PRINT "This is the QB64 default _FONT 16! To change, press any key!"
DO: SLEEP: LOOP UNTIL INKEY$ <> ""

GOSUB ClearFont  'call will not free anything if font& = 0

font& = _LOADFONT(fontpath$, fontsize%, style$)
IF font > 0 THEN _FONT font&  'NEVER try to load a font value less than 1!
PRINT
PRINT "A NEW _FONT style. To change to default, press any key!"
DO: SLEEP: LOOP UNTIL INKEY$ <> ""

GOSUB ClearFont  'call will free a valid font handle from memory

END

ClearFont: 
IF font& > 0 THEN
    _FONT 16   'change used font to the QB64 8x16 default font
    _FREEFONT font&
    PRINT: PRINT "The previous font was freed with _FREEFONT!"
ELSE : PRINT: PRINT "_FREEFONT was not used!"
END IF
RETURN 

See Also

• _FONT
• _LOADFONT