Zig - GTK4 Exploration

The original C repo

The Zig-implementation lives in youtube-tutorial.

Zig has the capability to translate C code to Zig code using a CLI tool via zig translate-c or in code with the built-in function @cImport().

Unfortunately Zig isn't capable of translating complex C code that heavily relies on macros like GTK4. Because of this, we aren't able to create custom widgets in a simple fashion.

The compromise I'm using is to create the boilerplate code in C while implementing the "heavy-lifting" methods in Zig.

Status

Zig data types carry extra information (like alignment) compared to C so it isn't trivial to use C pointer types directly in Zig. A lot of explicit casting has to take place, which in fairness happens in C as well, but the GTK4 macros masks out most of this noise.

That said, the idea is to convert as much C code to Zig while retaining sanity:

youtube-tutorial/1. The custom method (if we stick with the OOP metaphor) implementations are moved to demowidget.zig. These are all under an opaque type called DemoWidget exposing a canonical Zig function-calling scheme.
- demo_widget_init().
- demo_widget_dispose().
- demo_widget_finalize().
- demo_widget_class_init().
- A public "ziggified" version of demo_widget_new() to DemoWidget.new().
- Helper "ziggified" functions for internal use: DemoWidget.get_parent_class(), DemoWidget.get_button(), DemoWidget.set_button(). These are required because DemoWidget is an opaque type, and we can't access fields directly. The setter/getter implementation is on the C side in demowidget.c.
youtube-tutorial/2
youtube-tutorial/3
youtube-tutorial/4. At this point I determined that there is wayyyyyy too much hassle dealing with explicit casts that need to happen on almost every line of code so using GTK4 via translate-c is impractical. We should wait for some awesome people to create actual Zig bindings.
youtube-tutorial/5
youtube-tutorial/6

Conclusion

Although I learned a lot about Zig during this experiment I would not advise anyone to interoperate with C via translate-c directly when dealing with complex libraries like GTK4.

The only practical application for translate-c is for libraries that generate bindings really, anything more get too complex because of explicit casting needed at almost every line.

I'm keeping this repo around as a showcase.

Building

Go into any youtube-tutorial/* subfolder and execute zig build run to build and run the app.

Dependencies

libgtk-4-dev

Acknowledgements