QPUIQ 0.4

"PUI" Python Declarative UI Framework

What is PUI

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

Slides for SciWork 2023

CPPUI: Experimental C++ Version

Installation

pip install QPUIQ

Get Started

Hello World

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

@PUIApp
def Example():
    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
  • SwiftUI style overlay ??
• Canvas
  • Rect
  • Arc
  • Image
  • ...
• Table
• Tree
• Dialog
• State with Pydantic support?