PROTOCOLS
FocusChainListener
Defined in fuchsia.ui.focus/focus_chain.fidl
A FocusChainListener receives an updated FocusChain when focus changes.
OnFocusChange
Request
| Name | Type |
|---|---|
focus_chain |
FocusChain
|
Response
| Name | Type |
|---|
FocusChainListenerRegistry
Defined in fuchsia.ui.focus/focus_chain.fidl
A FocusChainListenerRegistry allows listening to FocusChain updates.
Register
Request
| Name | Type |
|---|---|
listener |
FocusChainListener
|
TABLES
FocusChain
Defined in fuchsia.ui.focus/focus_chain.fidl
A FocusChain tracks the status of the View hierarchy as View focus changes.
Description. The focus_chain is a vector of ViewRefs in order of
dominance in the View hierarchy; each pair of elements represents a
parent-child relationship. The root View is always present and occupies
slot 0. The newly-focused View receives a fuchsia.ui.input.FocusEvent and
occupies the final slot in the vector. If a View gets destroyed, a
FocusChain holder that listens will receive a ZX_EVENTPAIR_PEER_CLOSED
signal on the corresponding ViewRef.
Invalidation. A FocusChain is invalid if one if its ViewRefs is invalid. If
no View is destroyed, Scenic can still cause invalidation by raising a
ZX_USER_SIGNAL_0 on the root ViewRef.
Reception. Only certain components may receive a FocusChain, as it captures global information about the scene graph.
| Ordinal | Name | Type | Description |
|---|---|---|---|
| 1 | focus_chain |
vector<fuchsia.ui.views/ViewRef>
|