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lgiquickstart

luci4 (luci4@undisclosed.example.com) — 2026-03-18T00:59:39+00:00

Getting Started with LGI (Lua GTK)

This tutorial covers everything you need to know to build your first GUI application using Lua and the GTK3 toolkit on Linux (I will be assuming Arch Linux, but any distro will work just fine). The focus will be on clean code architecture and understanding the core concepts that often confuse beginners.

Prerequisites

Before writing code, ensure the environment is set up correctly. Three main components are needed:

Lua: The programming language interpreter.
GTK3: The underlying C library that draws the windows and widgets (buttons, labels, etc.).
LGI: The Lua binding that allows your Lua code to talk to the GTK C library.

Luarocks (the Lua package manager) will be used for the Lua-specific libraries to ensure we have the most up-to-date version.

Installation

First, ensure you have the necessary system tools and the GTK3 library. Open your terminal:

sudo pacman -S vim gtk3 luarocks

Install the Lua bindings using Luarocks. This pulls down the LGI library which bridges Lua and GTK.

luarocks install lgi
luarocks install luafilesystem

The Mental Model: How GTK Works

Before typing code, it is crucial to understand how GTK (and therefore LGI) structures an application. If you skip this, the code will feel arbitrary.

Widgets

Everything is a “Widget”. A window is a widget. A button is a widget. A text label is a widget. You build an application by creating widgets and stacking them together.

Containers and Packing

A Window widget can only hold one child item. If you want a window with 5 buttons, you cannot simply “add” 5 buttons to the window. The window will reject them. Instead, you add a Container (like a Box) to the window, and then you “pack” your 5 buttons into that Box.

Visual Representation

Window
    Box (Container)
        Button 1
        Button 2
        Label

Properties as Tables

In traditional C programming, setting a button label looks like a function: gtk_button_set_label(btn, "Click Me"). In LGI Lua, we use a cleaner object-oriented style. Properties are treated like table fields:

btn.label = "Click Me"

First Application

We will build a simple “Greeter” application. It will have a text input field, a button, and a result label.

Project Setup

Create a directory for your project to keep things organized. We will use Vim to create and edit our main file.

mkdir lua_greeter
cd lua_greeter
vim main.lua

Writing the Code

Paste the following code in vim. Read the comments (lines starting with –) to understand what each part does.

-- 1. LOAD THE LIBRARY
local lgi = require("lgi")
local Gtk = lgi.require("Gtk", "3.0")
 
-- 2. INITIALIZE GTK
-- This function checks the system environment and prepares the GTK engine.
-- It must be called before creating any widgets.
Gtk.init()
 
-- 3. CREATE THE MAIN WINDOW
local window = Gtk.Window {
    title = "My First LGI App",
    default_width = 400,
    default_height = 300,
-- CONNECTING SIGNALS:
-- When the user clicks the 'X' button, the 'destroy' signal is emitted.
-- We connect this directly to Gtk.main_quit to stop the application loop.
-- Without this, the window would close, but the process would keep running in the background.
on_destroy = Gtk.main_quit
 
}
 
-- 4. CREATE CONTAINERS
-- Since a Window can only hold one item, we create a vertical Box.
-- This Box will stack our items top-to-bottom.
local vbox = Gtk.Box {
    orientation = "VERTICAL",
    spacing = 10,         -- 10 pixels of space between children
-- Margins create padding around the edges of the box inside the window
margin_top = 20,
margin_bottom = 20,
margin_start = 20,
margin_end = 20
 
}
 
-- 5. CREATE WIDGETS
local entry = Gtk.Entry {
    placeholder_text = "Type your name here..."
}
 
local btn = Gtk.Button {
    label = "Greet Me"
}
 
local resultLabel = Gtk.Label {
    label = "Result will appear here..."
}
 
-- 6. DEFINE LOGIC (SIGNAL HANDLERS)
-- We define what happens when the button is clicked.
-- 'on_clicked' is a special event listener built into Gtk.Button.
function btn:on_clicked()
    local name = entry.text -- Access the text property of the entry widget
if name == "" then
    resultLabel.label = "Please enter a name!"
else
    resultLabel.label = "Hello, " .. name .. "!"
end
 
end
 
-- 7. ASSEMBLE THE UI
-- We use pack_start to add widgets to our Box container.
-- Syntax: box:pack_start(widget, expand, fill, padding)
-- expand (false): Should this widget take up all extra vertical space? (No)
-- fill (false): If expanded, should the widget fill that space? (No)
-- padding (0): Extra pixels outside the widget.
 
vbox:pack_start(entry, false, false, 0)
vbox:pack_start(btn, false, false, 0)
 
-- For the label, we set expand to 'true'. It will take all remaining empty space.
vbox:pack_start(resultLabel, true, true, 0)
 
-- Finally, add the fully populated Box to the Window.
window:add(vbox)
 
-- 8. RUN THE APPLICATION
-- show_all() renders the window and all its children.
window:show_all()
 
-- Gtk.main() starts the Event Loop.
-- The program pauses here and waits for user actions (clicks, key presses).
-- It will only exit when Gtk.main_quit() is called.
Gtk.main()

Press Esc to exit Insert Mode, then type :wq and press Enter to save and quit Vim.

Running the Application

Back in the terminal, run your script with the Lua interpreter:

lua main.lua

You should see a native Linux window appear. Try typing your name and clicking the button.

Key Concepts Deep Dive

The Event Loop

You will notice that the script does not finish execution immediately. It hangs at the line Gtk.main(). This is intentional.

GUI applications are event-driven. They do not run linearly from start to finish; they wait. The Gtk.main() function creates a loop that constantly listens for events (mouse movements, clicks, system redraw requests). The program sleeps inside this loop until an event occurs.

Layout Management (Packing)

The pack_start function is the heart of GTK layout. It determines how widgets behave when you resize the window.

Expand (true/false): Does the widget grow if the window gets larger?
Fill (true/false): If the widget grows, does the content fill the new space, or does the widget just float in the center?

Example: If you set a Button to expand=true and fill=false, the button would stay its normal size but float in the middle of a large empty space when you maximize the window.

Finding Documentation

LGI documentation is sparse, but you can use the official GTK3 C documentation and “translate” it to Lua mentally.

C Syntax: gtk_button_new_with_label("Hello")

Lua Syntax: Gtk.Button { label = "Hello" }

C Syntax: gtk_window_set_title(win, "Title")

Lua Syntax: window.title = "Title"

Resource: Search for GTK3 Reference Manual online. It lists all widgets (Buttons, ComboBoxes, Scrollbars) and their properties, which apply directly to LGI.

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written: February 25 2026

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luci4 (luci4@undisclosed.example.com) — 2026-02-25T18:53:18+00:00

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dont_trust_apple

luci4 (luci4@undisclosed.example.com) — 2025-10-17T19:15:23+00:00

Apple Client Side Scanning, Data Control and Violation of Privacy

Do I trust Apple?

No, absolutely not! I don’t trust Apple for the same reasons I don’t trust other big tech corporations or any closed-source ecosystem.

If your trust comes from “they promised they’re not evil,” mine comes from documented behavior that says otherwise. Their reputation relies on marketing slogans like “we protect your privacy” while my skepticism is based on facts, history and hard evidence.

What’s Client Side Scanning?

“Client-side scanning” (CSS) refers to analyzing data, photos, messages, files, locally on your device before it’s encrypted or sent. The idea is that AI or machine learning models scan your content for illegal or harmful material (like Child Sexual Abuse Material, CSAM) without Apple or any third party ever needing to decrypt your data on their servers.

In theory, assuming we believe what Apple claims, this means your phone or computer runs a model comparing your content to a database of known illegal content hashes or patterns. If the model detects a match, it triggers an alert or sends metadata to Apple or relevant authorities for further action.

Apple’s client-side scanning system runs on certain chips:

A11 Bionic and later (iPhones from 2017 onward)

A12 and later

M1, M2, M3 chips (used in recent Macs and iPads)

Latest A17 Pro / M4 chips

This means this kind of scanning capability has been technically possible for years thanks to Apple’s Neural Engine and secure enclave hardware.

Why is Client Side Scanning Risky? What Doors Does It Open?

While client-side scanning is pitched as a privacy-preserving measure, there are major risks and concerns:

Expands the scope of surveillance on users’ private data

Even if scanning is done locally, the system must have access to all your content (photos, messages, files) in unencrypted form before encryption. This breaks the principle of true end-to-end encryption.

This creates a backdoor, not a traditional backdoor that Apple holds, but a built-in mechanism to scan all personal data on your device, which governments or other actors could exploit.

Potential for false positives and overreach

Machine learning models can make mistakes. Innocent content could be flagged as illegal, leading to unwarranted investigations or censorship.

Apple or third parties could expand the scanning scope beyond CSAM to politically sensitive content, activist messages, or even legal but “undesirable” material.

Governmental or authoritarian misuse

Governments with authoritarian tendencies could demand Apple or other companies expand scanning databases to include content critical of the government, religious minorities, journalists, or political activists.

Client-side scanning can become a tool for mass surveillance and suppression of dissent under the guise of security.

Increased risk of hacking or abuse

The scanning algorithms and databases themselves become a target for hackers. If malicious actors access these scanning components, they could 1) Reverse engineer or spoof the scanning process. 2) Introduce malicious hashes to flag innocent content, disrupt user privacy, or frame individuals.

Enables broad data collection and profiling

While Apple claims only metadata or alerts are sent if matches occur, client-side scanning creates a system where detailed knowledge about your data exists on your device. This could be leveraged to collect user behavior patterns or metadata, either by Apple or third parties.

Apple or “big tech” could use this data to profile users, refine targeted advertising, or even sell aggregated behavioral data to third parties, despite privacy promises.

How Could Big Tech Exploit Client Side Scanning?

Eroding End-to-End Encryption: client-side scanning introduces a “soft” backdoor that can be widened over time, allowing tech companies to access user content under the pretext of safety.

Expanding Surveillance Beyond CSAM: The scanning scope could gradually broaden from child abuse material to drug-related content, political opinions, or copyrighted content, increasing user data exposure.

Selling or Monetizing User Data: Although Apple says it doesn’t sell user data, the existence of detailed metadata or flagged content creates new rich datasets that could be monetized directly or indirectly by advertisers or government contracts.

Creating a Precedent for Other Companies: If Apple successfully normalizes client-side scanning, other big tech players might implement even more invasive scanning or data collection systems, accelerating privacy erosion industry-wide. Government Collaboration and Pressure: Governments can compel companies to add new categories to scanning databases or share flagged data under secret orders, sidestepping traditional privacy safeguards.

To summarize:

While client-side scanning may seem like a privacy-preserving way to combat illegal content, it fundamentally shifts control of your personal data from you to big tech and governments by:

Forcing devices to scan all private data locally,
Increasing surveillance capability and risk of abuse,
Weakening encryption and privacy protections,
Opening avenues for misuse, false accusations, and government overreach,
And enabling new forms of data collection, profiling, or monetization.

But Luci... I trust Apple! Their AD says "Privacy First!"

Here are some of the legal cases from 2025 involving Apple where it has been accused (or found) of violating user rights, privacy, consumer protection, misleading advertising etc.

Keep in mind that these are just the ones I found with a relatively quick search, since compiling a comprehensive list is beyond the scope of this post, and, importantly, this only covers the year 2025, the list would have been too long if I included additional years.

Key Cases & Legal Issues in 2025

Case / Action	Issue	Status / Outcome (as of 2025)
Siri Privacy Settlement (U.S.)	Class-action lawsuit alleging Siri was listening to users’ private conversations without their consent, including instances of accidental activation, sharing or using voice data, targeting ads etc. ([The Guardian][1])	Apple agreed to a $95 million settlement. ([The Guardian][1])
France Antitrust fine over App Tracking Transparency (ATT)	French regulator found that Apple abused its dominant position via ATT — specifically, that ATT’s implementation was “neither necessary nor proportionate,” hurting smaller publishers dependent on third-party tracking / advertising revenue. ([Reuters][2])	Apple was fined 150 million euros. ([Reuters][2])
Lawsuit by Authors over AI training using books	Authors claim Apple used copyrighted books without consent to train its AI systems (“OpenELM” etc.). Accusations include using pirated “shadow libraries”. ([CNBC][3])	Open, proposed class action. Seeking damages / injunctive relief. ([CNBC][3])
False advertising / delay of promised Siri / Apple Intelligence features (U.S. & Canada)	Apple marketed advanced Siri / “Apple Intelligence” features in iPhone 16 as available or imminent, but delayed their release. Plaintiffs allege this misled consumers, and that some bought devices under false expectations. ([MacRumors][4])	Lawsuits filed (class actions) in both countries. As of 2025 not resolved. ([MacRumors][4])
Developer lawsuit over external payment link injunction / App Store policy	Developers sued Apple over costs related to external payment links, anti-steering policies (i.e. policies that discourage or block linking outside the App Store), commissions etc., claiming Apple incurred revenues due to the restrictive policy, harming developers. ([MacRumors][5])	Lawsuit pending. Seeking restitution, etc. ([MacRumors][5])
Apple Books e-Books / Audiobooks availability lawsuit	Plaintiffs allege that when Apple loses licensing rights to certain digital books/audiobooks, Apple removes them entirely from the Books store, including revoking the ability to re-download even if the user “purchased” them. They say Apple misled customers into believing purchases were “perpetual.” ([MacRumors][6])	Class action filed, seeking up to US$5 billion in damages. ([MacRumors][6])
Canadian class action over Siri / conversation recordings	In Canada, class actions (e.g. Hammerco, Lex Group) have been filed alleging Apple recorded private conversations via Siri without consent, and possibly shared them with third parties. ([Hammerco][7])	Pending. ([Hammerco][7])

A couple of early cases worth mentioning:

Case	What Apple Did
2008 “Jansen case” (Watertown, NY)	Apple complied with the first court-ordered iPhone unlock. The company assisted in drafting the court order and bypassing a passcode. ([MacRumors][1])
Multiple early cases (2008-2014 era)	According to government filings and press reports, Apple “unlocked iPhones” or extracted some data from locked phones under court order during this period. ([CBS News][2])

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written: October 17 2025

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