For successful communication it is important that data are understood equally on both ends.
We make a deliberate effort to validate our types in atspi.
We leverage zbus-lockstep to match types in our crate against those defined in the AT-SPI2 protocol descriptions.
zbus-lockstep is used to check if a type's (D-Bus type-system) signature corresponds to its counterpart in the protocol's XML.
atspi type |
XML validation | Notes |
|---|---|---|
ObjectRef |
✓ | Formerly: Accessible, used in Available and RemoveAccessible |
CacheItem |
✓ | See: AddAccessible signal of the Cache interface. |
LegacyCacheItem |
⚠ | The signature does not appear in current protocol: test hard coded. |
Interface |
⚠ | Unlike the protocol, which uses strings, we store Interface as bitflags. |
InterfaceSet |
⚠ | We store InterfaceSet as a single u64, not as 'array of strings'. |
State |
⚠ | XML: "au", a list of enum variants. Whereas atspi stores a u64 bitflag. |
StateSet |
⚠ | See State. |
EventBodyOwned |
✓ | Covers many other events. |
EventBodyQt |
⚠ | Signature does not appear in XML. |
EventListeners |
✓ | Represents signals of EventListenerRegistered and EventListenerDeregistered |
SortOrder |
✓ | 'sortby' argument pf member GetMatches |
TreeTraversalType |
✓ | 'tree' argument of member GetMatchesTo |
MatchType |
✓ | Found at index 3, in the 'rule' argument in GetMatches |
CoordType |
✓ | Argument of GetImagePosition of org.a11y.atspi.Image |
ClipType |
✓ | Text::GetTextAtOffset argument type |
Granularity |
✓ | Text::GetStringAtOffset argument granularity |
Layer |
✓ | Component::GetLayer return type. |
ScrollType |
✓ | Component::ScrollTo argument type |
Politeness |
✓ | Event.Object::Announcement argument politeness |
ObjectMatchRule |
⚠ | Collection::GetMatches argument 'rule' contains Vec<Role> and StateSet which are defined as "ai", but Role and StateSet are not. |
TextSelection |
✓ | Document::GetTextSelections argument selections contains Vec<TextSelection> |