Picking

We demonstrated pick events earlier, showing how to select a storm track, changing its thickness, but we haven't incorporated picking into our current design yet. Much in the same vein as the KeymapControl class, let's create a PickControl class that will keep a list of pick functions (pickers) and manage their connection to the callback system for us:

Source: chp2/select_stormcells.py

class PickControl:
    def __init__(self, fig):
        self.fig = fig
        self._pickers = []
        self._pickcids = []

    def connect_picks(self):
        for i, picker in enumerate(self._pickers):
            if self._pickcids[i] is None:
                cid = self.fig.canvas.mpl_connect('pick_event', picker)
                self._pickcids[i] = cid

    def disconnect_picks(self):
        for i, cid in enumerate(self._pickcids):
            if cid is not None:
                self.fig.canvas.mpl_disconnect(cid)
                self._pickcids[i] = None

    def add_pick_action...