What is PUI

PUI is a declarative UI framework with two-way data binding. PUI doesn't do UI itself, it turns imperative UI libraries into declarative flavor with virtual DOM and aims to maintain interoperability.

Slides for SciWork 2023

Installation

pip install QPUIQ

Get Started

Hello World

# example/hello_world.py

from PUI.PySide6 import *

class Example(Application):
    def content(self):
        with Window(title="test", size=(320,240)):
            Label("Hello world")

root = Example()
root.run()

State & Data Binding

# example/generic_textfield.py
from PUI.PySide6 import *

data = State()
class Example(Application):
    def __init__(self):
        super().__init__()
        data.var = 0

    def content(self):
        with Window(title="blah"):
            with VBox():
                with HBox():
                    Button("-").click(self.on_minus)
                    Label(f"{data.var}")
                    Button("+").click(self.on_plus)

                TextField(data("var")) # binding

    def on_minus(self):
        data.var -= 1

    def on_plus(self):
        data.var += 1

root = Example()
root.run()

View Component

# example/bleak_list.py

....

@PUI # View Component
def DeviceView(device, advertising_data):
    Label(f"{device.address} {device.name} {advertising_data.rssi}")

class GUI(Application):
    def __init__(self, state):
        super().__init__()
        self.state = state

    def content(self):
        with Window(title="BLE List"):
            with VBox():
                Label(f"Found {len(self.state.scanned_devices)} devices")
                for device, advertising_data in self.state.scanned_devices:
                    DeviceView(device, advertising_data)

....

Layout & Styling

# example/pyside6_feedparser.py

...
with VBox():
    Label(title).qt(StyleSheet={"font-weight":"bold"}) # QT-specific

    with HBox():
        with Scroll():
            with VBox():
                for i,e in enumerate(entries):
                    Label(e.title).click(self.entry_selected, i)
                Spacer()

        with Scroll().layout(weight=1): # Generic Layout Parameter
            if 0 <= selected and selected < len(entries):
                (Text(entries[selected].description)
                    .layout(padding=10) # Generic Layout Parameter
                    .qt(StyleSheet={"background-color":"white", "color":"black"})) # QT-specific
...

Canvas

# example/generic_canvas.py

from PUI.PySide6 import *

data = State()
class Example(Application):
    def __init__(self):
        super().__init__()
        data.var = 50

    def content(self):
        with Window(title="blah", size=(640,480)):
            with VBox():
                Canvas(self.painter, data.var)
                with HBox():
                    Button("-").click(self.on_minus)
                    Label(f"{data.var}").layout(weight=1)
                    Button("+").click(self.on_plus)

    @staticmethod
    def painter(canvas, var):
        canvas.drawText(var, var/2, f"blah {var}")
        canvas.drawLine(var, var, var*2, var*3, color=0xFFFF00)

    def on_minus(self):
        data.var -= 1

    def on_plus(self):
        data.var += 1

root = Example()
root.run()

Cookbook

python -m cookbook PySide6 (requires pygments for syntax highlight)

python -m cookbook textual

python -m cookbook flet

python -m cookbook tkinter

Hot-Reload with Reloadium

Backends

Tier-1

• PySide6

Lower Priority

• tkinter
  • or https://github.com/rdbende/Sun-Valley-ttk-theme
• flet
• textual (Text Mode)
  • no canvas

Components

Reference

Hot Reload

Add these lines to your view file and run with reloadium

import reloadium

# reloadium: after_reload
def after_reload(actions):
    PUIView.reload()

TODO

• Toga
• [ISSUE] empty virtual node
• [ISSUE] textual layout sizing (cookbook scroll example)
• [ISSUE] flet layout sizing (cookbook scroll example)
• nested state trigger
  • set state in PUIView init
  • set state in setup() ?
• Tabs(tabposition)
• Lazy List
• StateObject decorator
• UI Flow
  • Navigation Stack
  • View Router
  • Model Window/Dialog
• Layout
  • ZBox
  • Grid
    • Row
    • Column
  • SwiftUI style overlay ??
• Canvas
  • Rect
  • Arc
  • Image
  • ...
• Table
• Tree
• Dialog
• State with Pydantic support?