Title: Using a game engine to write a graphical interface to the

	Title: Using a game engine to write a graphical interface to the
	OpenBSD package manager
	Author: Solène
	Date: 05 May 2022
	Tags: openbsd godot opensource
	Description: In this blog entry I'm explaining why I ended using a game
	engine to write a GUI program for OpenBSD and how well it turned.

	# Introduction

	I'm really trying hard to lower the barrier entry to OpenBSD, I realize
	most of my efforts are toward making OpenBSD easier.

	One thing I often mumbled about on OpenBSD was the lack of a user
	interface to browse packages and install them, there was a console
	program named pkg_mgr, but I never got it to work. Of course, I'm
	totally able to install packages using the command line, but I like to
	stroll looking for packages I wouldn't know about, a GUI is perfect for
	doing so, and is also useful for people less comfortable with the
	command line.

	So, today, I made a graphical user interface (GUI) using OpenBSD, using
	a game engine. Don't worry, all the packages operations are delegated
	to pkg_add and pkg_delete because they are doing they job fine.

	OpenBSD AppManager project website

	AppManager main menu
	AppManager giving a summary of changes

	# What is it doing?

	The purpose of this program is simple, display the list of available
	packages, highlight in yellow the one you have installed on your
	system, and let you select new packages to install or installed
	packages to remove.

	It features a search input instead of displaying a blunt list of a
	dozen of thousands of entries. The development was made on my Thinkpad
	T400 (core 2 duo), performance are excellent.

	One simple feature I'm proud of is the automatic classification of
	packages into three categories: GUI programs, terminal/console user
	interface programs and others. While this is not perfect because we
	don't have this metadata anywhere, I'm reusing the dependencies'
	information to guess in which category each package belongs, so far
	it's giving great results.

	# About the engine

	I rarely write GUI application because it's often very tedious and give
	poor results, so the ratio time/result is very bad. I've been playing
	with the Godot game engine for a week now, and I was astonished when
	I've been told the engine editor is done using the engine itself. As
	it was blazing fast and easy to make small games, I wondered if this
	would be suitable for a simple program like a package manager
	interface.

	First thing I checked was if it was supporting sqlite or json data
	natively without much work. This was important as the data used to
	query the package list is originally found in a sqlite database
	provided by the sqlports package, however the sqlite support was only
	available through 3rd party code while JSON was natively supported.
	When writing then simple script converting data from the sqlite
	database into a json, I took the opportunity to add the logic to
	determine if it's a GUI or a TUI (Terminal UI) and make the data format
	very easy to reuse.

	Finally, I got a proof of concept within 2h, it was able to install
	packages from a list. Then I added support for displaying already
	installed packages and then to delete packages. The polishing of the
	interfaces took the most time, but the whole project didn't take more
	than 8h which is unbelievable for me.

	# Conclusion

	From today, I'll seriously think about using Godot for writing GUI
	application, did I say it's cross platform? AppManager can be run on
	Linux or Windows (given you have pkg.json), except it will just fail at
	installing packages, but the whole UI works.

	Thinking about it, it could be easy to reuse it for another package
	manager.