connected and disconnected ports hierarchy

[websterek]

Connection and Disconnection signals are emitting variables with source and target port sadly it depends on the "grabbed" port. So if you try to connect the output port of node A to the input port of node B you will have different output than if you grab at first the input port of node B and connect it to the output port of node A... it's confusing so here are some screens.

Why it's a problem?
There is no function like "get input nodes" or "get output node" so you can't get the flow of the nodes to create an operation chain.

Solution proposal
Target and source should be always the same (target should be input port and source should be output port).
Or add a function to get connected nodes for input and output ports.

[mikeporetti]

vote for "function to get connected nodes for input and output ports."

[jchanvfx]

Hey guys,

I've released a v0.0.15 with updated port_connected signals and added a few new functions to the BaseNode class.

Here's an example snippet :)

from NodeGraphQt import BaseNode, NodeGraph, QtWidgets, setup_context_menu


class MyNode(BaseNode):

    # set the initial default node name.
    NODE_NAME = 'my node'

    def __init__(self):
        super(MyNode, self).__init__()
        self.add_input('foo')
        self.add_output('bar')

    # re-implementing these functions will work with the undo stack.
    def on_input_connected(self, in_port, out_port):
        print('"{}" connected to "{}:{}"'
              .format(self.name(), out_port.node().name(), out_port.name()))

    def on_input_disconnected(self, in_port, out_port):
        print('"{}" disconnected from "{}:{}"'
              .format(self.name(), out_port.node().name(), out_port.name()))


def connection_changed(in_port, out_port):
    print('hello world')


if __name__ == '__main__':
    app = QtWidgets.QApplication([])

    graph = NodeGraph()
    graph.register_node(MyNode)
    graph.widget.resize(1100, 800)
    graph.widget.show()

    setup_context_menu(graph)

    # create a couple nodes.
    node_a = graph.create_node('nodeGraphQt.nodes.MyNode',
                               name='node a',
                               pos=[0, 0])
    node_b = graph.create_node('nodeGraphQt.nodes.MyNode',
                               name='node b',
                               pos=[350, 0])

    # connect the nodes.
    node_a.set_output(0, node_b.input(0))

    # wire up connection changed func.
    graph.port_connected.connect(connection_changed)

    print(node_a.connected_output_nodes())
    print(node_b.connected_input_nodes())

    app.exec_()