Description

Provides access to button states and events of connected Grabba devices.

This class provides access to the driver's button functionality, which is present on all Grabba devices.

Current hardware models have two buttons - one on the left side of the device, the other on the right. This API may be expanded if future models have additional buttons.

Callbacks to user-provided code may be triggered when the user presses or releases a button on a connected device. Refer to the GrabbaButtonListener class for details of these callbacks and how to enable or disable them.

Alternatively, the button states may be queried directly by calling leftButtonState or rightButtonState.

In addition, each button may be configured to control barcode or proxcard scanning. The default behaviour is to only trigger callbacks, but the setLeftButtonBehaviour and setRightButtonBehaviour methods allow for enabling or disabling press-to-scan functionality.

Some calls to this class will not succeed until a connection to a Grabba device has been established. Refer to the GrabbaCoreAPI class for details of how to establish or query this connection.

Note: This is a static class; object construction is unnecessary and consequently disabled. Subclassing is strongly discouraged.

Thread safety: This class is fully thread-safe.

Inheritance diagram for GrabbaButtonAPI:

Instance Methods
(instancetype)	- init
	Not callable (`NS_UNAVAILABLE`) since this is a static class. More...

(GrabbaButtonBehaviour)	- leftButtonBehaviour
	Query the current behaviour of the left button. More...

(BOOL)	- leftButtonState
	Query the left button state of a connected Grabba device. More...

(GrabbaButtonBehaviour)	- rightButtonBehaviour
	Query the current behaviour of the right button. More...

(BOOL)	- rightButtonState
	Query the right button state of a connected Grabba device. More...

(void)	- setLeftButtonBehaviour:
	Set new behaviour for the left button. More...

(void)	- setRightButtonBehaviour:
	Set new behaviour for the right button. More...

Method Documentation

◆ init()

- (instancetype) init

Not callable (NS_UNAVAILABLE) since this is a static class.

◆ leftButtonBehaviour()

- (GrabbaButtonBehaviour) leftButtonBehaviour

Query the current behaviour of the left button.

Returns: Currently-configured behaviour of the left button; default is GrabbaButtonCallbackOnly

◆ leftButtonState()

- (BOOL) leftButtonState

Query the left button state of a connected Grabba device.

This is a non-blocking call; the button states are cached internally by the driver.

Returns: YES if a device is connected and the left button is currently being pressed; NO otherwise.

◆ rightButtonBehaviour()

- (GrabbaButtonBehaviour) rightButtonBehaviour

Query the current behaviour of the right button.

Returns: Currently-configured behaviour of the right button; default is GrabbaButtonCallbackOnly

◆ rightButtonState()

- (BOOL) rightButtonState

Query the right button state of a connected Grabba device.

This is a non-blocking call; the button states are cached internally by the driver.

Returns: YES if a device is connected and the left button is currently being pressed; NO otherwise.

◆ setLeftButtonBehaviour:()

- (void) setLeftButtonBehaviour: (GrabbaButtonBehaviour) behaviour

Set new behaviour for the left button.

Parameters

behaviour New behaviour for the left button. GrabbaButtonCallbackOnly is the initial value.

◆ setRightButtonBehaviour:()

- (void) setRightButtonBehaviour: (GrabbaButtonBehaviour) behaviour

Set new behaviour for the right button.