diff options
Diffstat (limited to 'libxcb/xcb-proto/doc/xml-xcb.txt')
| -rw-r--r-- | libxcb/xcb-proto/doc/xml-xcb.txt | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/libxcb/xcb-proto/doc/xml-xcb.txt b/libxcb/xcb-proto/doc/xml-xcb.txt index 97ce5bf8e..235958de3 100644 --- a/libxcb/xcb-proto/doc/xml-xcb.txt +++ b/libxcb/xcb-proto/doc/xml-xcb.txt @@ -184,11 +184,12 @@ separated by a single colon. For example, to refer to the PIXMAP type defined in glx rather than the one defined in xproto, use type="glx:PIXMAP" rather than type="PIXMAP". -Note: Most of the below may optionally contain an enum, altenum, or mask +Note: Most of the below may optionally contain an enum, altenum, mask or altmask attribute, which follows the above rules for "type". "enum" is an exhaustive enum; the value is restricted to one of the constants named in the enum. "altenum" may be one of the values contained in the enum, but it need not be. -"mask" refers to an enum to be used as a bitmask. +"mask" refers to an exhaustive enum to be used as a bitmask. +"altmask" may be a mask from the referred enum, but it need not be. <pad bytes="integer" /> @@ -243,18 +244,40 @@ enum; the value is restricted to one of the constants named in the enum. <switch> instead for new protocol definitions. <switch name="identifier"> switch expression - <bitcase> bitcase expression(s), fields </bitcase> </switch> + <bitcase> bitcase expression(s), fields </bitcase> + <case> case expression(s), fields </case> +</switch> This element represents conditional inclusion of fields. It can be viewed - as sequence of multiple ifs: if ( switch expression & bitcase expression ) - is non-zero, bitcase fields are included in structure. It can be used only - as the last field of a structure. + as sequence of multiple ifs: - When a bitcase includes multiple <enumref> clauses, the contents of the - bitcase are only present once regardless of the number of bitcase expressions - that match. + <bitcase>: + if ( switch expression & bitcase expression ) is non-zero, + bitcase fields are included in structure. + + <case>: + if ( switch expression == case expression ) is true, + then case fields are included in structure. + + It can be used only as the last field of a structure. + + When a bitcase or case includes multiple <enumref> clauses, the contents + of the bitcase or case are only present once regardless of the number of + bitcase or case expressions that match. + + <enumref> inside <bitcase> can only refer to an enum's <bit> members. + <enumref> inside <case> can only refer to an enum's <value> members. + + A switch may contain multiple <bitcase> or <case> elements. + Usually it will only contain <bitcase> elements + or only contain <case> elements. + That is, mixing of <case> and <bitcase> usually doesn't make any sense. + + The same value may appear in multiple <case> or <bitcase> elements. + + New protocol definitions should prefer to use this instead of <valueparam> + and instead of <union>. - New protocol definitions should prefer to use this instead of <valueparam>. Expressions ----------- |