node
====

The node module is the main interface with ROS. The root component
must always inherit from the `ROSNode` class and client side widgets
should generally inherit from `ROSWidget` to make interacting with
the library smoother. The following example shows how one may structure
a service client application using these techniques.

.. code:: python

    from flexx import flx, config
    from flexxros import node
    from flexxros.node import ROSNode, ROSWidget
    import rospy
    from std_srvs.srv import SetBool, SetBoolResponse

    node_name = "action_example_interface"
    service_name = "simple_service"
    config.hostname = "localhost"
    config.port = 8097

    class SimpleService(object):

        def __init__(self, service_name):
            self.service = rospy.Service(service_name, SetBool, self.handle_request)

        def handle_request(self, req):
            return SetBoolResponse(req.data, "flexxros!")

    class ServiceClientWidget(ROSWidget):

        def callback(self, resp):
            self.receive_message.set_text(str(resp.success) + " " + resp.message)

        @flx.reaction("send_message.pointer_click")
        def _request_service(self, *events):
            self.call_service(service_name, "std_srvs/SetBool", {"data": self.type_message.checked}, self.callback)

        def init(self):
            with flx.FormLayout(flex=1, maxsize=400):
                self.type_message = flx.CheckBox(title="Checked?")
                self.send_message = flx.Button(text="Request service")
                self.receive_message = flx.Label(title="Response:", text="Waiting for response...")

    class ServiceExampleInterface(ROSNode):

        def init(self):
            self.client = ServiceClientWidget()

    rospy.init_node(node_name, anonymous=True)
    service = SimpleService(service_name)
    node.spin(ServiceExampleInterface)

.. automodule:: flexxros.node
     :members:
     :undoc-members: