nicegui/nice_gui.py

#!/usr/bin/env python3
import traceback
import justpy as jp
from starlette.applications import Starlette
import uvicorn
import inspect
import time
import asyncio
from contextlib import contextmanager
from matplotlib import pyplot as plt
from utils import handle_exceptions, provide_arguments
import icecream

icecream.install()

wp = jp.WebPage(delete_flag=False, title='Nice GUI', favicon='favicon.png')
main = jp.Div(a=wp, classes='m-4 flex flex-col items-start gap-4')
main.add_page(wp)
jp.justpy(lambda: wp, start_server=False)

view_stack = [main]

class Element:

    def __init__(self, view: jp.HTMLBaseComponent):

        view_stack[-1].add(view)
        view.add_page(wp)
        self.view = view

    @property
    def text(self):
        return self.view.text

    @text.setter
    def text(self, text):
        self.view.text = text

    def set_text(self, text):
        self.view.text = text

    def __enter__(self):

        view_stack.append(self.view)

    def __exit__(self, *_):

        view_stack.pop()

class Plot(Element):

    def update(self, close=True):

        self.view.set_figure(plt.gcf())
        if close:
            plt.close()

class Ui(Starlette):

    def label(self, text=''):

        view = jp.Div(text=text)
        return Element(view)

    def button(self, text, on_click=None):

        view = jp.Button(text=text, classes='bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded')
        if on_click is not None:
            view.on('click', handle_exceptions(provide_arguments(on_click)))
        return Element(view)

    @contextmanager
    def plot(self, close=True):

        view = jp.Matplotlib()
        yield Plot(view)
        view.set_figure(plt.gcf())
        if close:
            plt.close()

    def row(self):

        view = jp.Div(classes='flex flex-row gap-4 items-start')
        return Element(view)

    def column(self):

        view = jp.Div(classes='flex flex-col gap-4 items-start')
        return Element(view)

    def card(self):

        view = jp.Div(classes='flex flex-col gap-4 items-start p-4 rounded shadow-lg')
        return Element(view)

    def timer(self, interval, callback, *, once=False):

        parent = view_stack[-1]

        async def timeout():

            await asyncio.sleep(interval)
            handle_exceptions(callback)()
            await main.update()

        async def loop():

            while True:
                try:
                    start = time.time()
                    handle_exceptions(callback)()
                    await main.update()
                    dt = time.time() - start
                    await asyncio.sleep(interval - dt)
                except:
                    traceback.print_exc()
                    await asyncio.sleep(interval)

        jp.run_task(timeout() if once else loop())

    def run(self):

        # NOTE: prevent reloader from restarting uvicorn
        if inspect.stack()[-2].filename.endswith('spawn.py'):
            return

        uvicorn.run('nice_gui:ui', host='0.0.0.0', port=80, lifespan='on', reload=True)

# NOTE: instantiate our own ui object with all capabilities of jp.app
ui = Ui()
ui.__dict__.update(jp.app.__dict__)