Use GraphQL subscription to show progress of time-consuming operations

GraphQL is feature-rich query language designed to fit majority of needs of generic online applications. The 3 main types of operations in GraphQL are query, mutation and subscription. While queries and mutations are send in HTTP requests, subscriptions are running on WebSocket, which enables it to receive updates in real time. In this article, I would like to talk about using the subscription to report real-time results and/or progresses to time-consuming operations.

Measure per-letter dimension of text in JavaScript

TL;DR: Create a Range, set proper start and end points up to the text node with proper offset, then use Range.getBoundingClientRect() to get the dimensions.

As a part of the Lyricova Jukebox, we wanted to support inline karaoke swipe animation. With the time tags in the data, it is easy to figure out the time when the animation must reach a certain character. Then we need to figure out a way measure per character dimension for the animation to work.

How LyricsX keeps track of progress of media players

LyricsX is an open source software for macOS to download and display lyrics of current playing track on Music (previously iTunes), Spotify, Audirvana, Vox, Swinsian, or the Now Playing indicator in the OS. It gets time-tagged lyrics files from local storage or internet, and then display the lyrics in sync with the player.

As a crucial component of the development of Lyricova Jukebox, I have researched multiple implementations of real time lyrics display programs, and I found the mechanism behind LyricsX particularly interesting. Here in this article, I’d share with you how LyricsX tracking the player progress in a unique and resource-saving way.

Switch Galaxy Wearable Store Location using XPrivacyLua

Update 6 July 2020: Added alternative method using Riru Location Report Enabler.

Galaxy Wearable Store (GWS) is the app store for Galaxy wearable devices of Samsung. GWS is strongly region-dependent, just like other aspects of the device (you have to do some software hacking for a device purchased in one region to use Samsung Pay in another region). Being able to run with non-Samsung devices means that it cannot rely on the region-of-sale on the phone (and for some reason they didn’t choose to use the region of the device), GWS decided to use the region of your SIM card on the device to determine the store location.

Monitor Connected Devices to an ASUS Router Using Raspberry Pi

Title should have explained it all. A simple Python script to monitor if a certain device has connected to the router via Wi-Fi, and send notifications accordingly. You can use this script for whatever purpose you want1I used it to monitor whether my parent has left home when I am “seemingly asleep”. , though probably you might not be able to find one like most of others.

To use this script, you need SSH access to the router, something in your LAN that is always running (in my case, a Raspberry Pi), and the list of MAC addresses to monitor. In this example, I am using an Asus RT-AC1200GU as the router. Other brand or make might need a different command.

Read and Write Tags of Music Files with FFmpeg

In both my previous and recent projects, I have been working with tags (metadata) of music files. One of the reason being I am rather particular about having a nicely organised library with all tag data aligned to the same format. Until recently while I was seeking for a solution to read and write tags of (potentially) all music formats1I only have MP3, FLAC, AIFF and M4A in my library, so that’s kinda all for me., and I encountered FFmpeg, the Swiss Army Knife of media processing.

FFmpeg has always been my go-to solution for processing media programmatically or in batch, and I have recently found the way to write into the tags of music files using it. The way of doing so might be a little verbose as everything have to fit into the command line interface with other components.

Translate Text in Sphinx Templates and Configurations

Weeks ago when I was playing around with the docs of EFB and the Crowdin translation widget, I realized that the default theme for Sphinx — Alabaster isn’t really doing well in term of translation. It seems like the author isn’t really confident on that (or simply didn’t care since 4 years ago).

As the theme itself is open source, and Sphinx is flexible enough, couldn’t we just translate it ourselves? It turns out that things are not that complicated.