=> R1 = pointer to 40-byte buffer
R2 = count, or 0 for first call
R3 = path string, or -1 for Font$Path
<= R2 = count, or -1 if no more
Or :
=> R1 = pointer to buffer for identifier, or font menu
R2 = counter and flags [see notes on RISC OS 2]
R3 = size of buffer in R1
R4 = pointer to buffer for font name, or indirected data
R5 = size of buffer in R4
R6 = pointer to identifier to tick, or 0 for none, or 1 for 'System font'
<= R2 = new counter, or -1 if no more
R3 = required size of buffer in R1 if R1 = 0,
or 0 if building a menu and the menu is null
otherwise the length of data placed in the buffer
R5 = required size of buffer in R4 if R4 = 0,
otherwise the length of data placed in the buffer
This SWI returns, one at a time, the fonts found with the given path, or a font menu.
See PRM 3, page 450.
Font_ListFonts flags
bit meaning if set
0-15 counter, should be 0 on first call
16 return font identifier in R1
17 return local name in R4
18 terminate with 13 rather than 0
19 return menu definition in R1, and indirected data in R4
20 place 'System font' at head of menu
21 tick font in R6, and its parent
22 return list of encodings rather than fonts
23-31 reserved, must be 0
Font_ListFonts Listing Fonts
When using Font_ListFonts to list fonts or encodings, or local names for fonts:
· names are returned alphabetically sorted.
· only bits 16-18 and bit 22 of the flags in R2 should be used. All other bits must be clear.
· do not alter R2 between the calls of finding required memory and finding the actual data.
· when R2 = -1 on exit, then all fonts have been found and the returned data is invalid.
Font_ListFonts Font Menus
When using Font_ListFonts to create a font menu:
· Font_DecodeMenu can be used to work out which font was selected.
· the returned definition is suitable for opening with Wimp_CreateMenu
· only bits 19-21 of the flags in R2 should be used. All other bits must be clear.
Font_ListFonts RISC OS 2 compatibility
· RISC OS 2 compatible mode is used if bits 16-31 of the flags in R2 are clear.
· This mode pretends that bits 16 and 18 of R2 were set, bits 17 and 19-31 were clear and that R3 was 40.
· Under actual RISC OS 2, R3 is meant to point to the path to search, or -1 for Font$Path
[sh-index] Back to list of manuals
|
| |
