Comment by 🦀 jeang3nie

=> Re: "Building native UI applications on Linux in the declarative/..." | In: u/ostov

I've seen a GTK binding on Racket that allows you to do everything without pain, but the problem is that the library is limited to primitive controls.

Is this not painful? I've seen this in other languages as well, where you have a cool idea for how to make it (gtk+) easier to work with, but all of the code for the bindings is hand written and never finished.

As for separating business logic from interface code, I have a program which draws a guitar fretboard for you. There are controls for scale length, nut and bridge width, number of frets etc. Whenever you twiddle a control it collects the values and calls into a separate library, which returns an svg which is used to update the preview. So all of the interesting stuff happens in the library, where I don't have to care about Gtk+ at all.

Eva smallweb browser is similar. All of the network protocols are in the "Bucky" library code. But as the program gets more complex it's harder to keep the interface code to a minimum and there are definitely places where I'm not happy with it.

=> 🦀 jeang3nie

2023-06-02 · 2 years ago

3 Later Comments ↓

=> 🚀 ostov [OP] · 2023-06-02 at 14:07:

To: @jeang3nie

The problem is in the interface code. I don't understand how to redraw the window interface when the given data changes.

This is critical for social applications where the interface is not static.

We usually have a State in which we store objects like blog posts. Then, when this state changes, it sends this state to the render function, where the interface is redrawn according to the state.

I'm a bit confused on how to organize this in GTK (Vala in particular).

=> 🦀 jeang3nie · 2023-06-02 at 14:34:

@ostov I see. There is no overall render function in Gtk+ as it isn't an immediate mode gui, but retained mode. Each widget has it's own internal state, and you have to update whatever widgets that you wish to change. There are tradeoffs with any method of working and this way has plenty of tradeoffs.

=> ☕️ Morgan · 2023-06-02 at 17:32:

Flutter works exactly as you describe; redraws are automatic from state. It's not JS, but then JS is not "native", although I was not clear if Flutter fits what you want there either. It can compile to binary code, it's native in that sense :) ... agreed about it not looking very desktop-like, I guess that may come later as desktop support is relatively recent.

Original Post

=> 🚀 ostov

Building native UI applications on Linux in the declarative/reactive way? — I like GTK+ visually. It's minimalistic and all applications look organically on one Gnome-based desktop. But when I decided to write an application myself for my favorite OS (Elementary), I went into a stupor. You can only write in Vala+GTK in HORRIBLE imperative style. After a long time programming in [Lisp Racket] and [JS], I can't go back to this. I can't imagine programming without lambdas and stateless...

=> 💬 8 comments · 2023-06-01 · 2 years ago · #coding #declarative #linux