Edifice
Declarative GUI framework for Python and Qt
Edifice is a Python library declarative framework for application user
interfaces.
- Modern declarative UI paradigm from web development.
- 100% Python application development, no language inter-op.
- A native Qt desktop app instead of a bundled web browser.
- Fast iteration via hot-reloading.
Edifice uses PySide6
or PyQt6
as a backend. Edifice is like
React, but with
Python instead of JavaScript, and Qt Widgets instead of the HTML DOM.
If you have React experience, you’ll find Edifice easy to learn.
Edifice has function Components, Props, and Hooks just like React.
Getting Started
Why Edifice?
Declarative
Most existing GUI libraries in Python, such as Tkinter and Qt, operate imperatively.
To create a dynamic application using these libraries,
you must not only think about what widgets to display to the user,
but also how to issue the commands to modify the widgets.
With Edifice the developer
need only declare what is rendered,
not how the content is rendered.
User interactions update the application state, the state renders to a widget tree,
and Edifice modifies the existing widget tree to reflect the new state.
Edifice code looks like this:
number, set_number = use_state(0)
with VBoxView():
Button("Add 5", on_click=lambda event: set_number(number+5))
Label(str(number))
if number > 30 and number < 70:
Label("Number is mid")
The GUI displays
a button and a label with the current value of number
.
Clicking the button will add 5 to the number
.
If the number
is “mid” then another label will reveal that fact.
Edifice vs. Qt Quick
Qt Quick is Qt’s declarative GUI framework for Qt.
Qt Quick programs are written in Python + the
special QML language + JavaScript.
Edifice programs are written in Python.
Because Edifice programs are only Python, binding to the
UI is much more straightforward.
Edifice makes it easy to dynamically create, mutate, shuffle, and destroy sections of the UI.
Qt Quick assumes a much more static interface.
Qt Quick is like DOM + HTML + JavaScript, whereas Edifice is like React.
QML and HTML are both declarative UI languages but
they require imperative logic in another language for dynamism.
Edifice and React allow fully dynamic applications to be specified
declaratively in one language.
How it works
An Edifice component is a render function which declares the mapping from the state to UI.
The state of a component is divided into props and state.
props are passed to the component in the constructor,
whereas state is the component’s own internal state.
Changes to props or state will trigger a re-render of the component.
The old and new component trees will be compared to one another,
and a diffing algorithm will determine which components previously existed and which ones are new
(the algorithm behaves similarly to the React diffing algorithm).
Components that previously existed will maintain their state, whereas their props will be updated.
Finally, Edifice will issue the minimal update commands to update the UI.
Development Tools
Dynamic hot-reload
Dyanamic hot-reload is very useful for fine-tuning the presentation styles
of Elements deep within your application.
You can test if the margin should be 10px or 15px instantly without closing the app, reopening it, and waiting for everything to load.
Element Inspector
Similar to the Inspect Elements tool of a browser, the Element Inspector will
show you the tree of Elements in a running Edifice application, along with all of the props
and state of the Elements.
License
Edifice is MIT Licensed.
Edifice uses Qt under the hood, and both PyQt6 and PySide6 are supported. Note that PyQt6 is distributed with the GPL license while PySide6 is distributed
under the more flexible LGPL license.
See PyQt vs PySide Licensing.
Can I use PySide for commercial applications?
Yes, and you don't need to release your source code to customers. The LGPL only requires you to release any changes you make to PySide itself.
Version History / Change Log / Release Notes
See Release Notes
(source: versions.rst)
Contribution
Contributions are welcome; please send Pull Requests! See
DEVELOPMENT.md
for development notes.
When submitting a Pull Request, think about adding tests to tests and
adding a line to the Unreleased section of the
change log versions.rst.
Poetry Build System
The Poetry pyproject.toml
specifies the package dependecies.
Because Edifice supports PySide6 and PyQt6 at the same time, neither
are required by [tool.poetry.dependencies]
. Instead they are both
optional [tool.poetry.group.dev.dependencies]
. A project which depends
on Edifice should also depend on either PySide6
or
PySide6-Essentials
or PyQt6
.
The requirements.txt
is generated by
poetry export -f requirements.txt --output requirements.txt
To use the latest Edifice with a Poetry pyproject.toml
from Github
instead of PyPI, see
Poetry git dependencies,
for example:
[tool.poetry.dependencies]
python = ">=3.10,<3.11"
pyedifice = {git = "https://github.com/pyedifice/pyedifice.git"}
PySide6-Essentials = "6.6.2"