The Listener class defines a set of callback functions that you can override in a subclass to respond to events dispatched by the Controller object. More...
Public Member Functions | |
Listener () | |
Constructs a Listener object. More... | |
void | onConnect (Controller arg0) |
Called when the Controller object connects to the Leap Motion software and the Leap Motion hardware device is plugged in, or when this Listener object is added to a Controller that is already connected. More... | |
void | onDeviceChange (Controller arg0) |
Called when a Leap Motion controller is plugged in, unplugged, or the device changes state. More... | |
void | onDeviceFailure (Controller arg0) |
Called when a Leap Motion controller device is plugged into the client computer, but fails to operate properly. More... | |
void | onDisconnect (Controller arg0) |
Called when the Controller object disconnects from the Leap Motion software or the Leap Motion hardware is unplugged. More... | |
void | onExit (Controller arg0) |
Called when this Listener object is removed from the Controller or the Controller instance is destroyed. More... | |
void | onFocusGained (Controller arg0) |
Called when this application becomes the foreground application. More... | |
void | onFocusLost (Controller arg0) |
Called when this application loses the foreground focus. More... | |
void | onFrame (Controller arg0) |
Called when a new frame of hand and finger tracking data is available. More... | |
void | onImages (Controller arg0) |
Called when new images are available. More... | |
void | onInit (Controller arg0) |
Called once, when this Listener object is newly added to a Controller. More... | |
void | onLogMessage (Controller arg0, MessageSeverity severity, long timestamp, String msg) |
Called when the service emits a log message to report an error, warning, or status change. More... | |
void | onServiceChange (Controller arg0) |
Called when the Leap Motion service is paused or resumed or when a controller policy is changed. More... | |
void | onServiceConnect (Controller arg0) |
Called when the Leap Motion daemon/service connects to your application Controller. More... | |
void | onServiceDisconnect (Controller arg0) |
Called if the Leap Motion daemon/service disconnects from your application Controller. More... | |
The Listener class defines a set of callback functions that you can override in a subclass to respond to events dispatched by the Controller object.
To handle Leap Motion events, create an instance of a Listener subclass and assign it to the Controller instance. The Controller calls the relevant Listener callback function when an event occurs, passing in a reference to itself. You do not have to implement callbacks for events you do not want to handle.
The Controller object calls these Listener functions from a thread created by the Leap Motion library, not the thread used to create or set the Listener instance.
void onConnect | ( | Controller | arg0 | ) |
Called when the Controller object connects to the Leap Motion software and the Leap Motion hardware device is plugged in, or when this Listener object is added to a Controller that is already connected.
When this callback is invoked, Controller::isServiceConnected is true, Controller::devices() is not empty, and, for at least one of the Device objects in the list, Device::isStreaming() is true.
controller | The Controller object invoking this callback function. |
void onDeviceChange | ( | Controller | arg0 | ) |
Called when a Leap Motion controller is plugged in, unplugged, or the device changes state.
State changes include entering or leaving robust mode and low resource mode. Note that there is no direct way to query whether the device is in these modes, although you can use Controller::isLightingBad() to check if there are environmental IR lighting problems.
controller | The Controller object invoking this callback function. |
void onDeviceFailure | ( | Controller | arg0 | ) |
Called when a Leap Motion controller device is plugged into the client computer, but fails to operate properly.
Get the list containing all failed devices using Controller::failedDevices(). The members of this list provide the device pnpID and reason for failure.
controller | The Controller object invoking this callback function. |
void onDisconnect | ( | Controller | arg0 | ) |
Called when the Controller object disconnects from the Leap Motion software or the Leap Motion hardware is unplugged.
The controller can disconnect when the Leap Motion device is unplugged, the user shuts the Leap Motion software down, or the Leap Motion software encounters an unrecoverable error.
Note: When you launch a Leap-enabled application in a debugger, the Leap Motion library does not disconnect from the application. This is to allow you to step through code without losing the connection because of time outs.
controller | The Controller object invoking this callback function. |
void onExit | ( | Controller | arg0 | ) |
Called when this Listener object is removed from the Controller or the Controller instance is destroyed.
controller | The Controller object invoking this callback function. |
void onFocusGained | ( | Controller | arg0 | ) |
Called when this application becomes the foreground application.
Only the foreground application receives tracking data from the Leap Motion Controller. This function is only called when the controller object is in a connected state.
controller | The Controller object invoking this callback function. |
void onFocusLost | ( | Controller | arg0 | ) |
Called when this application loses the foreground focus.
Only the foreground application receives tracking data from the Leap Motion Controller. This function is only called when the controller object is in a connected state.
controller | The Controller object invoking this callback function. |
void onFrame | ( | Controller | arg0 | ) |
Called when a new frame of hand and finger tracking data is available.
Access the new frame data using the Controller::frame() function.
Note, the Controller skips any pending onFrame events while your onFrame handler executes. If your implementation takes too long to return, one or more frames can be skipped. The Controller still inserts the skipped frames into the frame history. You can access recent frames by setting the history parameter when calling the Controller::frame() function. You can determine if any pending onFrame events were skipped by comparing the ID of the most recent frame with the ID of the last received frame.
controller | The Controller object invoking this callback function. |
void onImages | ( | Controller | arg0 | ) |
Called when new images are available.
Access the new frame data using the Controller::images() function.
controller | The Controller object invoking this callback function. |
void onInit | ( | Controller | arg0 | ) |
Called once, when this Listener object is newly added to a Controller.
controller | The Controller object invoking this callback function. |
void onLogMessage | ( | Controller | arg0, |
MessageSeverity | severity, | ||
long | timestamp, | ||
String | msg | ||
) |
Called when the service emits a log message to report an error, warning, or status change.
Log message text is provided as ASCII-encoded english.
controller | The Controller object invoking this callback function. |
severity | The severity of the error, if known. |
timestamp | The timestamp of the error in microseconds. (Use Controller::now() - timestamp to compute the age of the message.) |
msg | The log message. |
void onServiceChange | ( | Controller | arg0 | ) |
Called when the Leap Motion service is paused or resumed or when a controller policy is changed.
The service can change states because the computer user changes settings in the Leap Motion Control Panel application or because an application connected to the service triggers a change. Any application can pause or unpause the service, but only runtime policy changes you make apply to your own application.
You can query the pause state of the controller with Controller::isPaused(). You can check the state of those policies you are interested in with Controller::isPolicySet().
controller | The Controller object invoking this callback function. |
void onServiceConnect | ( | Controller | arg0 | ) |
Called when the Leap Motion daemon/service connects to your application Controller.
controller | The Controller object invoking this callback function. |
void onServiceDisconnect | ( | Controller | arg0 | ) |
Called if the Leap Motion daemon/service disconnects from your application Controller.
Normally, this callback is not invoked. It is only called if some external event or problem shuts down the service or otherwise interrupts the connection.
controller | The Controller object invoking this callback function. |