harmony 鸿蒙@ohos.application.AccessibilityExtensionAbility (AccessibilityExtensionAbility)

2022-10-28
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@ohos.application.AccessibilityExtensionAbility (AccessibilityExtensionAbility)

The AccessibilityExtensionAbility module provides accessibility extension capabilities based on the ExtensionAbility framework.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import AccessibilityExtensionAbility from '@ohos.application.AccessibilityExtensionAbility';

Attributes

System capability: SystemCapability.BarrierFree.Accessibility.Core

Name	Type	Readable	Writable	Description
context	AccessibilityExtensionContext	Yes	No	Context of the accessibility extension ability.

AccessibilityEvent

Defines an accessibility event.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Attributes

Name	Type	Readable	Writable	Description
eventType	accessibility.EventType \|accessibility.WindowUpdateType\|TouchGuideType \|GestureType \|PageUpdateType	Yes	No	Event type. EventType: accessibility event type. WindowUpdateType: Window update type. TouchGuideType: touch guide event type. GestureType: gesture type. PageUpdateType: page update type, which is not supported currently.
target	AccessibilityElement	Yes	No	Target component where the event occurs.
timeStamp	number	Yes	No	Timestamp of the event.

GestureType

Enumerates gesture types.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Name	Description
left	Left gesture. String type.
leftThenRight	Left-then-right gesture. String type.
leftThenUp	Left-then-up gesture. String type.
leftThenDown	Left-then-down gesture. String type.
right	Right gesture. String type.
rightThenLeft	Right-then-left gesture. String type.
rightThenUp	Right-then-up gesture. String type.
rightThenDown	Right-then-down gesture. String type.
up	Up gesture. String type.
upThenLeft	Up-then-left gesture. String type.
upThenRight	Up-then-right gesture. String type.
upThenDown	Up-then-down gesture. String type.
down	Down gesture. String type.
downThenLeft	Down-then-left gesture. String type.
downThenRight	Down-then-right gesture. String type.
downThenUp	Down-then-up gesture. String type.

PageUpdateType

Enumerates the page update types. This API is not supported currently.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Name	Description
pageContentUpdate	Update of the page content. String type.
pageStateUpdate	Update of the page status. String type.

TouchGuideType

Enumerates the touch guide event types.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Name	Description
touchBegin	Start of touch in touch guide mode. String type.
touchEnd	End of touch in touch guide mode. String type.

AccessibilityExtensionAbility.onConnect

onConnect(): void;

Called when the AccessibilityExtensionAbility is enabled and connected to the system service. In this API, you can have the service logic initialized. This API can be overridden as required.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Example

import AccessibilityExtensionAbility from '@ohos.application.AccessibilityExtensionAbility';

class MyAccessibilityExtensionAbility extends AccessibilityExtensionAbility {
    onConnect(): void {
        console.log('AxExtensionAbility onConnect');
    }
}

AccessibilityExtensionAbility.onDisconnect

onDisconnect(): void;

Called when the AccessibilityExtensionAbility is disabled and disconnected from the system service. In this API, you can implement the service logic of resource release and exit. This API can be overridden as required.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Example

import AccessibilityExtensionAbility from '@ohos.application.AccessibilityExtensionAbility';

class MyAccessibilityExtensionAbility extends AccessibilityExtensionAbility {
    onDisconnect(): void {
        console.log('AxExtensionAbility onDisconnect');
    }
}

AccessibilityExtensionAbility.onAccessibilityEvent

onAccessibilityEvent(event: AccessibilityEvent): void;

Called when an event that matches the specified bundle and event type occurs. In this API, you can implement event-specific service logic. Generally, this API needs to be overridden.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Parameters

Name	Type	Mandatory	Description
event	AccessibilityEvent	Yes	Accessibility event. No value is returned.

Example

import AccessibilityExtensionAbility , { AccessibilityEvent } from '@ohos.application.AccessibilityExtensionAbility';

class MyAccessibilityExtensionAbility extends AccessibilityExtensionAbility {
    onAccessibilityEvent(event: AccessibilityEvent): void {
        console.log('AxExtensionAbility onAccessibilityEvent');
        if (event.eventType === 'click') {
            console.log('AxExtensionAbility onAccessibilityEvent: click');
        }
    }
}

AccessibilityExtensionAbility.onKeyEvent

onKeyEvent(keyEvent: KeyEvent): boolean;

Called when a physical key is pressed. In this API, you can determine whether to intercept an event based on the service.

System capability: SystemCapability.BarrierFree.Accessibility.Core

Parameters

Name	Type	Mandatory	Description
keyEvent	KeyEvent	Yes	Key event. If true is returned, the key is intercepted.

Example

import AccessibilityExtensionAbility from '@ohos.application.AccessibilityExtensionAbility';
import { KeyEvent } from '@ohos.multimodalInput.keyEvent';

class MyAccessibilityExtensionAbility extends AccessibilityExtensionAbility {
    onKeyEvent(keyEvent: KeyEvent): boolean {
        console.log('AxExtensionAbility onKeyEvent');
        if (keyEvent.key.code === 16) {
            console.log('AxExtensionAbility onKeyEvent: intercept 16');
            return true;
        }
        return false;
    }
}