harmony 鸿蒙@ohos.deviceStatus.dragInteraction (Drag Interaction)

2023-10-30
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@ohos.deviceStatus.dragInteraction (Drag Interaction)

The dragInteraction module provides the APIs to enable and disable listening for dragging status changes.

NOTE

The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version.

The APIs provided by this module are system APIs.

Modules to Import

import dragInteraction from '@ohos.deviceStatus.dragInteraction'

DragState

Enumerates dragging states.

System capability: SystemCapability.Msdp.DeviceStatus.Drag

Name	Value	Description
MSG_DRAG_STATE_START	1	Dragging starts.
MSG_DRAG_STATE_STOP	2	Dragging is ended.
MSG_DRAG_STATE_CANCEL	3	Dragging is canceled.

Example

enum DragState {
    MSG_DRAG_STATE_START = 1,
    MSG_DRAG_STATE_STOP = 2,
    MSG_DRAG_STATE_CANCEL = 3
}

dragInteraction.on(‘drag’)

on(type: ‘drag’, callback: Callback<DragState>): void;

Enables listening for dragging status changes.

System capability: SystemCapability.Msdp.DeviceStatus.Drag

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. This field has a fixed value of drag.
callback	Callback<DragState>	Yes	Callback used to return the dragging status.

Example

try {
  dragInteraction.on('drag', (data : DragState) => {
    console.log(`Drag interaction event: ${JSON.stringify(data)}`);
  });
} catch (error) {
  console.log(`Register failed, error: ${JSON.stringify(error, [`code`, `message`])}`);
}

dragInteraction.off(‘drag’)

off(type: ‘drag’, callback?: Callback<DragState>): void;

Disables listening for dragging status changes.

System capability: SystemCapability.Msdp.DeviceStatus.Drag

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. This field has a fixed value of drag.
callback	Callback<DragState>	No	Callback to be unregistered. If this parameter is not specified, all callbacks registered by the current application will be unregistered.

Example

// Unregister a single callback.
function single_callback(event : DragState) {
  console.log(`Drag interaction event: ${JSON.stringify(event)}`);
  return false;
}
try {
  dragInteraction.on('drag', single_callback);
  dragInteraction.off("drag", single_callback);
} catch (error) {
  console.log(`Execute failed, error: ${JSON.stringify(error, [`code`, `message`])}`);
}

// Unregister all callbacks.
function all_callback(event : DragState) {
  console.log(`Drag interaction event: ${JSON.stringify(event)}`);
  return false;
}
try {
  dragInteraction.on('drag', all_callback);
  dragInteraction.off("drag");
} catch (error) {
  console.log(`Execute failed, error: ${JSON.stringify(error, [`code`, `message`])}`);
}