scanner-ui/com.composea11yscanner.ui/A11yScannerController

A11yScannerController

class A11yScannerController(nodeProvider: suspend () -> List<A11yNode>, screenDensity: Float, ruleNodeOverridesProvider: suspend () -> Map<String, List<A11yNode>> = { emptyMap() })

Public SDK entry point for running accessibility scans.

Typical usage:

val controller = A11yScannerController(
    nodeProvider  = { A11yNodeExtractor().extract(semanticsOwner) },
    screenDensity = resources.displayMetrics.density,
)
    .configure(ScannerConfig(enabledRules = ScannerRules.allRuleIds().toSet()))
    .withRules(MyCustomRule())

lifecycleScope.launch {
    controller.startScan().collect { state -> /* update UI */}
}
// ...
controller.stopScan()
// ...
controller.destroy()   // cancel the internal scope when the host is destroyed

Parameters

nodeProvider

Called once per startScan invocation on the main dispatcher to produce the node list. It may suspend while rendered pixels are copied from the application window.

ruleNodeOverridesProvider

Optionally supplies specialized nodes for individual rules. Rules without an override continue to evaluate nodeProvider's accessibility tree.

screenDensity

DisplayMetrics.density, forwarded to density-dependent rules.

Constructors

A11yScannerController

constructor(nodeProvider: suspend () -> List<A11yNode>, screenDensity: Float, ruleNodeOverridesProvider: suspend () -> Map<String, List<A11yNode>> = { emptyMap() })

Properties

stateFlow

val stateFlow: Flow<ScannerState>

Hot Flow backed by the internal MutableSharedFlow.

Functions

clearState

fun clearState()

Stops any active scan and emits ScannerState.Idle.

configure

fun configure(config: ScannerConfig): A11yScannerController

Replaces the active scanner configuration.

destroy

fun destroy()

Cancels the internal CoroutineScope. Call when the host (Activity/Fragment/ViewModel) is destroyed.

startScan

fun startScan(): Flow<ScannerState>

Cancels any in-progress scan, then starts a new one.

stopScan

fun stopScan()

Cancels the current scan if one is running. The Flow returned by startScan stops emitting.

withRules

fun withRules(vararg rules: A11yRule): A11yScannerController

Appends rules to the set that will run alongside the standard rule set. Custom rules are automatically added to ScannerConfig.enabledRules so the engine never filters them out. Returns this controller for chaining.