from gviewer import StaticDataStore
data_store = StaticDataStore(data)

def register_func(on_message):
    some_listener.on_message(on_message)

data_store = AsyncDataStore(register_func)

from gviewer import BaseDisplayer, View, Group, PropsGroup, Text, Prop

class MyDisplayer(BaseDisplayer):
    def to_summary(self, message):
        """
        return a str or text markup
        reference: http://urwid.org/manual/displayattributes.html#text-markup
        """
        return message["summary"]

    def get_views(self):
        """return an array of tuple that contains view title and a function that transform message to detail"""
        return [
            ("view1", self.view1),
            ("view2", self.view2),
        ]

    def view1(self, message):
        """return groups"""
        return View(
            [Group("title", [Text(m) for m in message["view1"]])]
        )

    def view2(self, message):
        """return groups"""
        return View(
            [PropsGroup("title", [Prop(p[0], p[1]) for p in message["view2"]])]
        )

from gviewer import GViewer, DisplayerContext
context = DisplayerContext(data_store, displayer)
viewer = GViewer(context)
viewer.start()

from gviewer import GViewer, DisplayerContext

def custom_export(controller, message, widget, *args, **kwargs):
    with open("export", "w") as f:
        f.write(str(message))
    controller.notify("file is export")

context = DisplayerContext(data_store, displayer, actions=Actions([("a", "Custom export", custom_export)]))
viewer = GViewer(context)

from gviewer import View, BaseDisplayer
class MyDisplayer(BaseDisplayer):
    def get_views(self):
        return [("view", self.view)]

    def view(self, message):
        return View([], actions=Actions([("a", "Custom export", self.custom_export)]))

    def custom_export(controller, message, *args, **kwargs):
        with open("export", "w") as f:
            f.write(str(message))
        controller.notify("file is export")