FREEFONT: Difference between revisions

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**'''_FONT 9, 15''' and '''17''' are the double width versions of 8, 14 and 16 respectively in text '''SCREEN 0'''.
**'''_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|error]] will occur. '''Check handle values before using or freeing them.'''
* If the font handle is invalid (equals -1 or 0), an [[ERROR Codes|error]] will occur. '''Check handle values before using or freeing them.'''
* You cannot free inbuilt/default QB64 fonts nor do they ever need freed.  
* You cannot free inbuilt/default QB64 fonts nor do they ever need freed.




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{{Cl|SCREEN (statement)|SCREEN}} 12
{{Cl|SCREEN (statement)|SCREEN}} 12
path$ = "C:\WINDOWS\Fonts\"                  'path to the font folder
path$ = "C:\WINDOWS\Fonts\"                  'path to the font folder
{{Cl|SHELL}} {{Cl|_HIDE}} "DIR /b " + path$ + "\*.ttf > TTFonts.INF"
{{Cl|SHELL}} {{Cl|_HIDE}} "DIR /b " + path$ + "\*.ttf > TTFonts.INF"
style$ = "monospace"                        'set style to MONOSPACE
style$ = "monospace"                        'set style to MONOSPACE
{{Cl|OPEN}} "TTFonts.INF" {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #1          'list of TTF fonts only
{{Cl|OPEN}} "TTFonts.INF" {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #1          'list of TTF fonts only
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{{Cl|DO}} {{Cl|UNTIL}} {{Cl|EOF}}(1): found = found + 1
{{Cl|DO}} {{Cl|UNTIL}} {{Cl|EOF}}(1): found = found + 1
   {{Cl|LINE INPUT (file statement)|LINE INPUT}} #1, font$        
   {{Cl|LINE INPUT (file statement)|LINE INPUT}} #1, font$
   f& ={{Cl|_LOADFONT}}(path$ + font$, 30, style$)  
   f& ={{Cl|_LOADFONT}}(path$ + font$, 30, style$)
   {{Cl|IF}} f& > 0 {{Cl|THEN}}                  'check for valid handle values > 0
   {{Cl|IF}} f& > 0 {{Cl|THEN}}                  'check for valid handle values > 0
     OK = OK + 1
     OK = OK + 1
     {{Cl|PRINT (file statement)|PRINT}} #2, font$
     {{Cl|PRINT (file statement)|PRINT}} #2, font$
     {{Cl|_FONT}} f&                      'will create error if handle is invalid!
     {{Cl|_FONT}} f&                      'will create error if handle is invalid!
     {{Cl|PRINT}} "Hello World!"  
     {{Cl|PRINT}} "Hello World!"
     {{Cl|PRINT}}: {{Cl|PRINT}}: {{Cl|PRINT}} font$; f&  
     {{Cl|PRINT}}: {{Cl|PRINT}}: {{Cl|PRINT}} font$; f&
     {{Cl|PRINT}} "Press any key."  
     {{Cl|PRINT}} "Press any key."
     K$ = {{Cl|INPUT$}}(1)
     K$ = {{Cl|INPUT$}}(1)
     {{Cl|_FONT}} 16                      'use QB64 default font to free tested font
     {{Cl|_FONT}} 16                      'use QB64 default font to free tested font
     {{Cl|_FREEFONT}} f&                  'returns an error if handle <= 0!  
     {{Cl|_FREEFONT}} f&                  'returns an error if handle <= 0!
     {{Cl|CLS}}
     {{Cl|CLS}}
   {{Cl|END IF}}    
   {{Cl|END IF}}
   {{Cl|PRINT}}
   {{Cl|PRINT}}
{{Cl|IF}} K$ = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}}
{{Cl|IF}} K$ = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}}
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{{Cl|CLOSE}}
{{Cl|CLOSE}}
{{Cl|PRINT}}: {{Cl|PRINT}}: {{Cl|PRINT}} "Found"; found; "TTF files,"; OK; "can use Monospace,"
{{Cl|PRINT}}: {{Cl|PRINT}}: {{Cl|PRINT}} "Found"; found; "TTF files,"; OK; "can use Monospace,"
{{Cl|END}}  
{{Cl|END}}
{{CodeEnd}}
{{CodeEnd}}
{{small|Code by Ted Weissgerber}}
{{small|Code by Ted Weissgerber}}
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''Example 2:'' Using a _FREEFONT sub-procedure.  
''Example 2:'' Using a _FREEFONT sub-procedure.
{{CodeStart}}
{{CodeStart}}
fontpath$ = {{Cl|ENVIRON$}}("SYSTEMROOT") + "\fonts\lucon.ttf"  
fontpath$ = {{Cl|ENVIRON$}}("SYSTEMROOT") + "\fonts\lucon.ttf"
style$ = "MONOSPACE, ITALIC, BOLD"
style$ = "MONOSPACE, ITALIC, BOLD"
fontsize% = 20
fontsize% = 20
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{{Cl|END}}
{{Cl|END}}


ClearFont:  
ClearFont:
{{Cl|IF}} font& > 0 {{Cl|THEN}}
{{Cl|IF}} font& > 0 {{Cl|THEN}}
     {{Cl|_FONT|_FONT }}16  'change used font to the QB64 8x16 default font
     {{Cl|_FONT|_FONT }}16  'change used font to the QB64 8x16 default font
Line 88: Line 88:
{{Cl|ELSE}} : {{Cl|PRINT}}: {{Cl|PRINT}} "_FREEFONT was not used!"
{{Cl|ELSE}} : {{Cl|PRINT}}: {{Cl|PRINT}} "_FREEFONT was not used!"
{{Cl|END IF}}
{{Cl|END IF}}
{{Cl|RETURN}}  
{{Cl|RETURN}}
{{CodeEnd}}
{{CodeEnd}}


Revision as of 01:40, 23 January 2023

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 1, 2, 7, 8 or 13
    • _FONT 14 - default font for SCREEN 9 or 10
    • _FONT 16 - default font for SCREEN 0 (Template:KW 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 will occur. Check handle values before using or freeing them.
  • You cannot free inbuilt/default QB64 fonts nor do they ever need freed.


Examples

Example 1: 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
Code by Ted Weissgerber
Found 106 TTF files, 13 can use Monospace.


Example 2: 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


Navigation:
Main Page with Articles and Tutorials
Keyword Reference - Alphabetical
Keyword Reference - By usage
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