TouchInteractionController
class TouchInteractionController
| kotlin.Any | |
| ↳ | android.accessibilityservice.TouchInteractionController |
This class allows a service to handle touch exploration and the detection of specialized accessibility gestures. The service receives motion events and can match those motion events against the gestures it supports. The service can also request the framework enter three other states of operation for the duration of this interaction. Upon entering any of these states the framework will take over and the service will not receive motion events until the start of a new interaction. The states are as follows:
- The service can tell the framework that this interaction is touch exploration. The user is trying to explore the screen rather than manipulate it. The framework will then convert the motion events to hover events to support touch exploration.
- The service can tell the framework that this interaction is a dragging interaction where two fingers are used to execute a one-finger gesture such as scrolling the screen. The service must specify which of the two fingers should be passed through to rest of the input pipeline.
- Finally, the service can request that the framework delegate this interaction, meaning pass it through to the rest of the input pipeline as-is.
AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE is enabled, this controller will receive all motion events received by the framework for the specified display when not touch-exploring or delegating. If the service classifies this interaction as touch exploration or delegating the framework will stop sending motion events to the service for the duration of this interaction. If the service classifies this interaction as a dragging interaction the framework will send motion events to the service to allow the service to determine if the interaction still qualifies as dragging or if it has become a delegating interaction. If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE is disabled this controller will not receive any motion events because touch interactions are being passed through to the input pipeline unaltered. Note that AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE requires setting android.R.attr#canRequestTouchExplorationMode as well.
Summary
| Nested classes | |
|---|---|
| abstract |
callbacks allow services to receive motion events and state change updates. |
| Constants | |
|---|---|
| static Int |
The state where the user is not touching the screen. |
| static Int |
The user is performing a gesture which is being passed through to the input pipeline as-is. |
| static Int |
The state where the user is dragging with two fingers. |
| static Int |
The state where the user is explicitly exploring the screen. |
| static Int |
The state where the user is touching the screen and the service is receiving motion events. |
Constants
STATE_CLEAR
static val STATE_CLEAR: Int
The state where the user is not touching the screen.
Value: 0
STATE_DELEGATING
static val STATE_DELEGATING: Int
The user is performing a gesture which is being passed through to the input pipeline as-is. The service is not receiving motion events.
Value: 4
STATE_DRAGGING
static val STATE_DRAGGING: Int
The state where the user is dragging with two fingers. The service is not receiving motion events. The selected finger is being dispatched to the rest of the input pipeline to execute the drag.
Value: 3
STATE_TOUCH_EXPLORING
static val STATE_TOUCH_EXPLORING: Int
The state where the user is explicitly exploring the screen. The service is not receiving motion events.
Value: 2
STATE_TOUCH_INTERACTING
static val STATE_TOUCH_INTERACTING: Int
The state where the user is touching the screen and the service is receiving motion events.
Value: 1
Public methods
getDisplayId
fun getDisplayId(): Int
| Return | |
|---|---|
Int |
the display id associated with this controller. |
getMaxPointerCount
fun getMaxPointerCount(): Int
| Return | |
|---|---|
Int |
the maximum number of pointers that this display will accept. |
performClick
fun performClick(): Unit
If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE and AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE
performLongClickAndStartDrag
fun performLongClickAndStartDrag(): Unit
If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE and AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE
registerCallback
fun registerCallback(
executor: Executor?,
callback: TouchInteractionController.Callback
): Unit
Adds the specified callback to the list of callbacks. The callback will run using on the specified Executor', or on the service's main thread if the Executor is null.
| Parameters | |
|---|---|
callback |
TouchInteractionController.Callback: the callback to add, must be non-null |
executor |
Executor?: the executor for this callback, or null to execute on the service's main thread |
requestDelegating
fun requestDelegating(): Unit
If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE and AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE
requestDragging
fun requestDragging(pointerId: Int): Unit
If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE and AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE
requestTouchExploration
fun requestTouchExploration(): Unit
If AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE is enabled and at least one callback has been added for this display this function tells the framework to initiate touch exploration. Touch exploration will continue for the duration of this interaction.
stateToString
static fun stateToString(state: Int): String
Returns a string representation of the specified state.
| Return | |
|---|---|
String |
This value cannot be null. |
unregisterAllCallbacks
fun unregisterAllCallbacks(): Unit
Removes all callbacks and returns control of touch interactions to the framework.
unregisterCallback
fun unregisterCallback(callback: TouchInteractionController.Callback): Boolean
Unregisters the specified callback.
| Parameters | |
|---|---|
callback |
TouchInteractionController.Callback: the callback to remove, must be non-null |
| Return | |
|---|---|
Boolean |
true if the callback was removed, false otherwise |