Async?

[mharig]

import asyncio

from rich.tree import Tree

from textual.app import App
from textual.widgets import ScrollView

class MTree(App):
    async def on_load(self, event):
        await self.bind('q', 'quit', 'Quit app')


    async def on_mount(self, event):
        self.body = ScrollView(name='MTree')

        await self.view.dock(self.body)

        self.mbTree = Tree('root')
        self.mbTree.hide_root = True
        for c in ['a', 'b', 'c']:
            node = self.mbTree.add(c)
            await self.body.update(self.mbTree)
            await self.call_later(self.updateTree,node)

        


    async def updateTree(self, _node):
        await asyncio.sleep(2)
        _node.label = _node.label + ' R'
        await self.body.update(self.mbTree)


MTree.run(title='MTree')

The whole App get's displayed, after all updateTree calls are finished.
How do I get an update of the body in on_mount, and then successively change the labels later?
Or: How do I do an update without blocking, e.g. in a thread?

[mharig]

I found a more or less minimal solution, that does what I want:

import asyncio
from concurrent.futures import ThreadPoolExecutor
from rich.tree import Tree
from rich.panel import Panel

from textual.widget import Widget
from textual.app import App
from textual.widgets import ScrollView

from time import sleep

class MboxTree(Widget):

    def on_mount(self):
        self.mbTree = Tree('root')
        self.mbTree.hide_root = True
        self.nodes = []
        for c in ['a', 'b', 'c']:
            node = self.mbTree.add(c)
            self.nodes.append(node)

        self.panel = Panel(
                self.mbTree,
                title='Title',
                title_align='left'
        )
        self.refresh()
        self.executor = ThreadPoolExecutor(max_workers=3)
        self.updateTree()


    def getNewLabel(self, _node):
        sleep(2)
        _node.label = _node.label + ' R'
        self.refresh()


    def updateTree(self):
        loop = asyncio.get_event_loop()
        for node in self.nodes:
            loop.run_in_executor(self.executor, self.getNewLabel, node)


    def render(self) -> Panel:
        return self.panel



class MTree(App):
    async def on_load(self, event):
        await self.bind('q', 'quit', 'Quit app')


    async def on_mount(self, event):
        self.body = MboxTree()
        await self.view.dock(self.body)



MTree.run(title='MTree', log='minimal_tui.log')

Sorry for my misunderstanding of asyncio.

[fabge]

This was very helpful to me, thanks @mharig!